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Yao H, Zhang M, Wang D. The next decade of SET: from an oncoprotein to beyond. J Mol Cell Biol 2024; 16:mjad082. [PMID: 38157418 PMCID: PMC11267991 DOI: 10.1093/jmcb/mjad082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/22/2023] [Accepted: 12/24/2023] [Indexed: 01/03/2024] Open
Abstract
This year marks the fourth decade of research into the protein SET, which was discovered in 1992. SET was initially identified as an oncoprotein but later shown to be a multifaceted protein involved in regulating numerous biological processes under both physiological and pathophysiological conditions. SET dysfunction is closely associated with diseases, such as cancer and Alzheimer's disease. With the increasing understanding of how SET works and how it is regulated in cells, targeting aberrant SET has emerged as a potential strategy for disease intervention. In this review, we present a comprehensive overview of the advancements in SET studies, encompassing its biological functions, regulatory networks, clinical implications, and pharmacological inhibitors. Furthermore, we provide insights into the future prospects of SET research, with a particular emphasis on its promising potential in the realm of immune modulation.
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Affiliation(s)
- Han Yao
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
| | - Meng Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
| | - Donglai Wang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
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2
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Kim H, Takegahara N, Choi Y. PP2A-Mediated GSK3β Dephosphorylation Is Required for Protocadherin-7-Dependent Regulation of Small GTPase RhoA in Osteoclasts. Cells 2023; 12:1967. [PMID: 37566044 PMCID: PMC10417323 DOI: 10.3390/cells12151967] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/12/2023] Open
Abstract
Protocadherin-7 (Pcdh7) is a member of the non-clustered protocadherin δ1 subgroup of the cadherin superfamily. Pcdh7 has been revealed to control osteoclast differentiation by regulating Rho-family small GTPases, RhoA and Rac1, through its intracellular SET binding domain. However, the mechanisms by which small GTPases are regulated downstream of Pcdh7 remain unclear. Here, we demonstrate that protein phosphatase 2A (PP2A)-mediated dephosphorylation of Glycogen synthase kinase-3β (GSK3β) is required for Pcdh7-dependent activation of RhoA during osteoclast differentiation. Pcdh7-deficient (Pcdh7-/-) cells showed impaired PP2A activity, despite their normal expression of PP2A. GSK3β, whose activity is regulated by its inhibitory phosphorylation at Ser9, was dephosphorylated during osteoclast differentiation in a Pcdh7-dependent manner. Inhibition of protein phosphatase by okadaic acid reduced dephosphorylation of GSK3β in Pcdh7+/+ cells, while activation of PP2A by DT-061 rescued impaired dephosphorylation of GSK3β in Pcdh7-/- cells. Inhibition of GSK3β by AR-A014418 inhibited RANKL-induced RhoA activation and osteoclast differentiation in Pcdh7+/+ cells. On the other hand, DT-061 treatment rescued impaired RhoA activation and RANKL-induced osteoclast differentiation in Pcdh7-/- cells. Taken together, these results demonstrate that PP2A dephosphorylates GSK3β and thereby activates it in a Pcdh7-dependent manner, which is required for activation of small GTPase RhoA and proper osteoclast differentiation.
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Affiliation(s)
| | | | - Yongwon Choi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; (H.K.); (N.T.)
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3
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Di Mambro A, Esposito M. Thirty years of SET/TAF1β/I2PP2A: from the identification of the biological functions to its implications in cancer and Alzheimer's disease. Biosci Rep 2022; 42:BSR20221280. [PMID: 36345878 PMCID: PMC9679398 DOI: 10.1042/bsr20221280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 10/17/2022] [Accepted: 11/07/2022] [Indexed: 10/29/2023] Open
Abstract
The gene encoding for the protein SE translocation (SET) was identified for the first time 30 years ago as part of a chromosomal translocation in a patient affected by leukemia. Since then, accumulating evidence have linked overexpression of SET, aberrant SET splicing, and cellular localization to cancer progression and development of neurodegenerative tauopathies such as Alzheimer's disease. Molecular biology tools, such as targeted genetic deletion, and pharmacological approaches based on SET antagonist peptides, have contributed to unveil the molecular functions of SET and its implications in human pathogenesis. In this review, we provide an overview of the functions of SET as inhibitor of histone and non-histone protein acetylation and as a potent endogenous inhibitor of serine-threonine phosphatase PP2A. We discuss the role of SET in multiple cellular processes, including chromatin remodelling and gene transcription, DNA repair, oxidative stress, cell cycle, apoptosis cell migration and differentiation. We review the molecular mechanisms linking SET dysregulation to tumorigenesis and discuss how SET commits neurons to progressive cell death in Alzheimer's disease, highlighting the rationale of exploiting SET as a therapeutic target for cancer and neurodegenerative tauopathies.
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Affiliation(s)
- Antonella Di Mambro
- The Centre for Integrated Research in Life and Health Sciences, School of Health and Life Science, University of Roehampton, London, U.K
| | - Maria Teresa Esposito
- The Centre for Integrated Research in Life and Health Sciences, School of Health and Life Science, University of Roehampton, London, U.K
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4
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Protein Phosphatase 2A (PP2A) mutations in brain function, development, and neurologic disease. Biochem Soc Trans 2021; 49:1567-1588. [PMID: 34241636 DOI: 10.1042/bst20201313] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 12/15/2022]
Abstract
By removing Ser/Thr-specific phosphorylations in a multitude of protein substrates in diverse tissues, Protein Phosphatase type 2A (PP2A) enzymes play essential regulatory roles in cellular signalling and physiology, including in brain function and development. Here, we review current knowledge on PP2A gene mutations causally involved in neurodevelopmental disorders and intellectual disability, focusing on PPP2CA, PPP2R1A and PPP2R5D. We provide insights into the impact of these mutations on PP2A structure, substrate specificity and potential function in neurobiology and brain development.
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5
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Yao Y, Kang SS, Xia Y, Wang ZH, Liu X, Muller T, Sun YE, Ye K. A delta-secretase-truncated APP fragment activates CEBPB, mediating Alzheimer's disease pathologies. Brain 2021; 144:1833-1852. [PMID: 33880508 DOI: 10.1093/brain/awab062] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 11/13/2022] Open
Abstract
Amyloid-β precursor protein (APP) is sequentially cleaved by secretases and generates amyloid-β, the major components in senile plaques in Alzheimer's disease. APP is upregulated in human Alzheimer's disease brains. However, the molecular mechanism of how APP contributes to Alzheimer's disease pathogenesis remains incompletely understood. Here we show that truncated APP C586-695 fragment generated by δ-secretase directly binds to CCAAT/enhancer-binding protein beta (CEBPB), an inflammatory transcription factor, and enhances its transcriptional activity, escalating Alzheimer's disease-related gene expression and pathogenesis. The APP C586-695 fragment, but not full-length APP, strongly associates with CEBPB and elicits its nuclear translocation and augments the transcriptional activities on APP itself, MAPT (microtubule-associated protein tau), δ-secretase and inflammatory cytokine mRNA expression, finally triggering Alzheimer's disease pathology and cognitive disorder in a viral overexpression mouse model. Blockade of δ-secretase cleavage of APP by mutating the cleavage sites reduces its stimulatory effect on CEBPB, alleviating amyloid pathology and cognitive dysfunctions. Clearance of APP C586-695 from 5xFAD mice by antibody administration mitigates Alzheimer's disease pathologies and restores cognitive functions. Thus, in addition to the sequestration of amyloid-β, APP implicates in Alzheimer's disease pathology by activating CEBPB upon δ-secretase cleavage.
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Affiliation(s)
- Yinan Yao
- Tongji Hospital, Tongji University School of Medicine, Shanghai 20065, P.R. China.,Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yiyuan Xia
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Zhi-Hao Wang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Thorsten Muller
- Department of Molecular Biochemistry, Cell Signalling, Ruhr-University Bochum, 44801 Bochum, Germany.,Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich 80336, Germany
| | - Yi E Sun
- Tongji Hospital, Tongji University School of Medicine, Shanghai 20065, P.R. China.,Shanghai Institute of Stem Cell Research and Clinical Translation, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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Gnanaprakash M, Staniszewski A, Zhang H, Pitstick R, Kavanaugh MP, Arancio O, Nicholls RE. Leucine Carboxyl Methyltransferase 1 Overexpression Protects Against Cognitive and Electrophysiological Impairments in Tg2576 APP Transgenic Mice. J Alzheimers Dis 2021; 79:1813-1829. [PMID: 33459709 PMCID: PMC8203222 DOI: 10.3233/jad-200462] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background: The serine/threonine protein phosphatase, PP2A, is thought to play a central role in the molecular pathogenesis of Alzheimer’s disease (AD), and the activity and substrate specificity of PP2A is regulated, in part, through methylation and demethylation of its catalytic subunit. Previously, we found that transgenic overexpression of the PP2A methyltransferase, LCMT-1, or the PP2A methylesterase, PME-1, altered the sensitivity of mice to impairments caused by acute exposure to synthetic oligomeric amyloid-β (Aβ). Objective: Here we sought to test the possibility that these molecules also controlled sensitivity to impairments caused by chronically elevated levels of Aβ produced in vivo. Methods: To do this, we examined the effects of transgenic LCMT-1, or PME-1 overexpression on cognitive and electrophysiological impairments caused by chronic overexpression of mutant human APP in Tg2576 mice. Results: We found that LCMT-1 overexpression prevented impairments in short-term spatial memory and synaptic plasticity in Tg2576 mice, without altering APP expression or soluble Aβ levels. While the magnitude of the effects of PME-1 overexpression in Tg2576 mice was small and potentially confounded by the emergence of non-cognitive impairments, Tg2576 mice that overexpressed PME-1 showed a trend toward earlier onset and/or increased severity of cognitive and electrophysiological impairments. Conclusion: These data suggest that the PP2A methyltransferase, LCMT-1, and the PP2A methylesterase, PME-1, may participate in the molecular pathogenesis of AD by regulating sensitivity to the pathogenic effects of chronically elevated levels of Aβ.
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Affiliation(s)
- Madhumathi Gnanaprakash
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Agnieszka Staniszewski
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Hong Zhang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | | | | | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA
| | - Russell E Nicholls
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
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Salvadores N, Gerónimo-Olvera C, Court FA. Axonal Degeneration in AD: The Contribution of Aβ and Tau. Front Aging Neurosci 2020; 12:581767. [PMID: 33192476 PMCID: PMC7593241 DOI: 10.3389/fnagi.2020.581767] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/09/2020] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease (AD) represents the most common age-related neurodegenerative disorder, affecting around 35 million people worldwide. Despite enormous efforts dedicated to AD research over decades, there is still no cure for the disease. Misfolding and accumulation of Aβ and tau proteins in the brain constitute a defining signature of AD neuropathology, and mounting evidence has documented a link between aggregation of these proteins and neuronal dysfunction. In this context, progressive axonal degeneration has been associated with early stages of AD and linked to Aβ and tau accumulation. As the axonal degeneration mechanism has been starting to be unveiled, it constitutes a promising target for neuroprotection in AD. A comprehensive understanding of the mechanism of axonal destruction in neurodegenerative conditions is therefore critical for the development of new therapies aimed to prevent axonal loss before irreversible neuronal death occurs in AD. Here, we review current evidence of the involvement of Aβ and tau pathologies in the activation of signaling cascades that can promote axonal demise.
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Affiliation(s)
- Natalia Salvadores
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Fondap Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Cristian Gerónimo-Olvera
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Fondap Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Felipe A Court
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Fondap Geroscience Center for Brain Health and Metabolism, Santiago, Chile.,Buck Institute for Research on Aging, Novato, CA, United States
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8
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Protein Biomarkers for the Diagnosis of Alzheimer's Disease at Different Stages of Neurodegeneration. Int J Mol Sci 2020; 21:ijms21186749. [PMID: 32942527 PMCID: PMC7554800 DOI: 10.3390/ijms21186749] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/08/2020] [Accepted: 09/11/2020] [Indexed: 12/24/2022] Open
Abstract
Mainly obtained from familial Alzheimer’s disease patients’ data, we know that some features of the neurodegenerative start several years before the appearance of clinical symptoms. In this brief review, we comment on some molecular and cellular markers appearing at different stages of the disease, before or once the clinical symptoms are evident. These markers are present in biological fluids or could be identified by image techniques. The combined use of molecular and cellular markers will be of interest to determine the development of the different phases of the disease.
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9
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Reduced Expression of the PP2A Methylesterase, PME-1, or the PP2A Methyltransferase, LCMT-1, Alters Sensitivity to Beta-Amyloid-Induced Cognitive and Electrophysiological Impairments in Mice. J Neurosci 2020; 40:4596-4608. [PMID: 32341098 DOI: 10.1523/jneurosci.2983-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/27/2020] [Accepted: 04/17/2020] [Indexed: 12/16/2022] Open
Abstract
Beta-amyloid (Aβ) is thought to play a critical role in Alzheimer's disease (AD), and application of soluble oligomeric forms of Aβ produces AD-like impairments in cognition and synaptic plasticity in experimental systems. We found previously that transgenic overexpression of the PP2A methylesterase, PME-1, or the PP2A methyltransferase, LCMT-1, altered the sensitivity of mice to Aβ-induced impairments, suggesting that PME-1 inhibition may be an effective approach for preventing or treating these impairments. To explore this possibility, we examined the behavioral and electrophysiological effects of acutely applied synthetic Aβ oligomers in male and female mice heterozygous for either a PME-1 KO or an LCMT-1 gene-trap mutation. We found that heterozygous PME-1 KO mice were resistant to Aβ-induced impairments in cognition and synaptic plasticity, whereas LCMT-1 gene-trap mice showed increased sensitivity to Aβ-induced impairments. The heterozygous PME-1 KO mice produced normal levels of endogenous Aβ and exhibited normal electrophysiological responses to picomolar concentrations of Aβ, suggesting that reduced PME-1 expression in these animals protects against Aβ-induced impairments without impacting normal physiological Aβ functions. Together, these data provide additional support for roles for PME-1 and LCMT-1 in regulating sensitivity to Aβ-induced impairments, and suggest that inhibition of PME-1 may constitute a viable therapeutic approach for selectively protecting against the pathologic actions of Aβ in AD.SIGNIFICANCE STATEMENT Elevated levels of β-amyloid (Aβ) in the brain are thought to contribute to the cognitive impairments observed in Alzheimer's disease patients. Here we show that genetically reducing endogenous levels of the PP2A methylesterase, PME-1, prevents the cognitive and electrophysiological impairments caused by acute exposure to pathologic concentrations of Aβ without impairing normal physiological Aβ function or endogenous Aβ production. Conversely, reducing endogenous levels of the PP2A methyltransferase, LCMT-1, increases sensitivity to Aβ-induced impairments. These data offer additional insights into the molecular factors that control sensitivity to Aβ-induced impairments, and suggest that inhibiting PME-1 may constitute a viable therapeutic avenue for preventing Aβ-related impairments in Alzheimer's disease.
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Li X, Run X, Wei Z, Zeng K, Liang Z, Huang F, Ke D, Wang Q, Wang JZ, Liu R, Zhang B, Wang X. Intranasal Insulin Prevents Anesthesia-induced Cognitive Impairments in Aged Mice. Curr Alzheimer Res 2020; 16:8-18. [PMID: 30381076 DOI: 10.2174/1567205015666181031145045] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/16/2018] [Accepted: 10/15/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Preclinical and clinical evidence suggests that elderly individuals are at increased risk of cognitive decline after general anesthesia. General anesthesia is also believed to be a risk factor for Postoperative Cognitive Dysfunction (POCD) and Alzheimer's Disease (AD). Intranasal administration of insulin, which delivers the drug directly into the brain, improves memory and cognition in both animal studies and small clinical trials. However, how insulin treatment improves cognitive function is poorly understood. METHODS Aged mice were pretreated with intranasal insulin or saline before anesthesia. Propofol was added intraperitoneally to the mice from 7th day of insulin/saline treatment, and general anesthesia was induced and maintained for 2 hours/day for 5 consecutive days. Mice were evaluated at 26th day when the mice were continued on insulin or saline administration for another 15 days. RESULTS We found that intranasal insulin treatment prevented anesthesia-induced cognitive impairments, as measured by novel object recognition test and contextual-dependent fear conditioning test. Insulin treatment also increased the expression level of Post-synaptic Density Protein 95 (PSD95), as well as upregulated Microtubule-associated Protein-2 (MAP-2) in the dentate gyrus of the hippocampus. Furthermore, we found that insulin treatment restored insulin signaling disturbed by anesthesia via activating PI3K/PDK1/AKT pathway, and attenuated anesthesia-induced hyperphosphorylation of tau at multiple AD-associated sites. We found the attenuation of tau hyperphosphorylation occurred by increasing the level of GSK3β phosphorylated at Ser9, which leads to inactivation of GSK-3β. CONCLUSION Intranasal insulin administration might be a promising therapy to prevent anesthesiainduced cognitive deficit in elderly individuals.
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Affiliation(s)
- Xing Li
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoqin Run
- Department of Vascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhen Wei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Kuan Zeng
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhihou Liang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Huang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Dan Ke
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Qun Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
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11
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Wei Z, Mahaman YAR, Zhu F, Wu M, Xia Y, Zeng K, Yang Y, Liu R, Wang JZ, Shu X, Wang X. GSK-3β and ERK1/2 incongruously act in tau hyperphosphorylation in SPS-induced PTSD rats. Aging (Albany NY) 2019; 11:7978-7995. [PMID: 31548435 PMCID: PMC6782009 DOI: 10.18632/aging.102303] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/15/2019] [Indexed: 01/20/2023]
Abstract
Post-traumatic stress disorder (PTSD) manifests in neurocognitive deficits in association with increased tau deposition, which mainly consist of phosphorylated tau in Alzheimer disease (AD) brain. However, the exact mechanism of PTSD inducing tau hyperphosphorylation remains unclear and therefore no effective treatment options are currently available. We here show that employing single prolonged stress (SPS), as a consensus PTSD model, induced a typical anxiety and abnormal hyperphosphorylation of tau at Ser202/Thr205 (AT8) and Ser404 but not at Ser199 and Ser396 in the hippocampus compared to the control rats. Furthermore, there was a decrease in the level of inactivated phosphorylated GSK-3β at Ser9, an increase in the level of activated phosphorylated GSK-3β at Thr216 and an obvious decrease in the level of activated phosphorylated ERK1/2, but no alterations in CaMKII and PP2A in hippocampus of SPS rats. On the other hand, the levels of both phosphorylated AKT and total SGK1, stress- and GSK-3β/ERK1/2-related proteins, were down-regulated. Interestingly, Overexpression of SGK1 increased the level of phosphorylated ERK1/2 and led to tau hyperphosphorylation at Ser199 and Ser396. These findings suggest that SPS exposure results in differential tau phosphorylation at different sites probably due to incongruous action between AKT-related GSK-3β activation and SGK1-related ERK1/2 inactivation, suggesting a link between SPS-induced PTSD and AD-associated tau pathogenic mechanisms.
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Affiliation(s)
- Zhen Wei
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yacoubou Abdoul Razak Mahaman
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University, Shenzhen 518001, Guangdong Province, China
| | - Feiqi Zhu
- Cognitive Impairment Ward of Neurology Department, The Third Affiliated Hospital of Shenzhen University, Shenzhen 518001, Guangdong Province, China
| | - Mengjuan Wu
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Yiyuan Xia
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Kuan Zeng
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ying Yang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Rong Liu
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Xiji Shu
- Department of Pathology and Pathophysiology, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Xiaochuan Wang
- Department of Pathophysiology, School of Basic Medicine, Key Laboratory of Education Ministry of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
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12
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Zhang L, Chen C, Mak MSH, Lu J, Wu Z, Chen Q, Han Y, Li Y, Pi R. Advance of sporadic Alzheimer's disease animal models. Med Res Rev 2019; 40:431-458. [DOI: 10.1002/med.21624] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 05/21/2019] [Accepted: 06/27/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Lili Zhang
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
| | - Chen Chen
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
| | - Marvin SH Mak
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese MedicineThe Hong Kong Polytechnic University, Hung Hom Hong Kong
| | - Junfeng Lu
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
| | - Zeqing Wu
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
| | - Qiuhe Chen
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
| | - Yifan Han
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese MedicineThe Hong Kong Polytechnic University, Hung Hom Hong Kong
- International Joint Laboratory<SYSU‐PolyU HK>of Novel Anti‐Dementia Drugs of GuangzhouGuangzhou China
- State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation)The Hong Kong Polytechnic University Shenzhen Research InstituteShenzhen China
| | - Yuefeng Li
- Guangdong Landau Biotechnology Co LtdGuangzhou China
| | - Rongbiao Pi
- School of Pharmaceutical SciencesSun Yat‐Sen UniversityGuangzhou China
- International Joint Laboratory<SYSU‐PolyU HK>of Novel Anti‐Dementia Drugs of GuangzhouGuangzhou China
- National and Local United Engineering Lab of Druggability and New Drugs EvaluationSun Yat‐Sen UniversityGuangzhou China
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of MedicineSun Yat‐Sen UniversityGuangzhou China
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13
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Basurto-Islas G, Gu JH, Tung YC, Liu F, Iqbal K. Mechanism of Tau Hyperphosphorylation Involving Lysosomal Enzyme Asparagine Endopeptidase in a Mouse Model of Brain Ischemia. J Alzheimers Dis 2019; 63:821-833. [PMID: 29689717 DOI: 10.3233/jad-170715] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dementias including Alzheimer's disease (AD) are multifactorial disorders that involve several different etiopathogenic mechanisms. Cerebral ischemia has been suspected in the altered regulation of protein kinases and phosphatases that leads to hyperphosphorylation of tau and further neurofibrillary pathology, a key hallmark of AD and related neurodegenerative diseases. However, the deregulation of these enzymes and their relationship with ischemia and AD remain unclear. Previously, we reported a mechanism by which the lysosomal enzyme asparagine endopeptidase (AEP) is associated with brain acidosis and AD. In this study, we subjected mice to middle cerebral artery occlusion and found that compared with wild type mice, the ischemia-induced brain injury and motor deficit in AEP-knockout mice are reduced, probably because ischemia activates AEP. AEP cleaves inhibitor 2 of protein phosphatase 2A (I2PP2A), which translocates from the neuronal nucleus to the cytoplasm and produces hyperphosphorylation of tau through inhibition of PP2A. These findings suggest a possible mechanism of tau pathology associated with ischemia.
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Affiliation(s)
- Gustavo Basurto-Islas
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.,Division of Science and Engineering of University of Guanajuato, Campus Leon, Leon, Guanajuato, Mexico
| | - Jin-Hua Gu
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education of China, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
| | - Yunn Chyn Tung
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Fei Liu
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
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14
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Zhang Y, Zhang J, Wang E, Qian W, Fan Y, Feng Y, Yin H, Li Y, Wang Y, Yuan T. Microcystin-Leucine-Arginine Induces Tau Pathology Through Bα Degradation via Protein Phosphatase 2A Demethylation and Associated Glycogen Synthase Kinase-3β Phosphorylation. Toxicol Sci 2019; 162:475-487. [PMID: 29228318 DOI: 10.1093/toxsci/kfx271] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Microcystin-leucine-arginine (MC-LR) has been implicated as a potential environmental factor in Alzheimer's disease because of its potent inhibition of protein phosphatase 2A (PP2A) activity, but experimental evidence to support its detailed neurotoxic effects and their underlying mechanisms has been lacking. The present study investigated the role of PP2A catalytic subunit (PP2Ac) demethylation and its link with glycogen synthase kinase-3β (GSK)-3β in tau hyperphosphorylation induced by MC-LR. The results showed that MC-LR treatment significantly increased demethylation of PP2Ac, with a concomitant increase in GSK-3β phosphorylation at Ser9 resulting in elevated tau hyperphosphorylation at PP2A-favorable sites in SH-SY5Y cells and rat hippocampus. Coimmunoprecipitation experiments showed that MC-LR treatment dissociated PP2Ac from Bα, making it incompetent in binding tau, thus causing tau hyperphosphorylation. Moreover, we found that inhibition of PP2A resulted in an increase in phosphorylation of GSK-3β at Ser9 and a decrease in GSK-3β activity, which further promoted demethylation of PP2Ac induced by MC-LR. These findings suggest a scenario in which MC-LR-mediated demethylation of PP2Ac is associated with GSK-3β phosphorylation at Ser9 and contributes to dissociation of Bα from PP2Ac, which would result in Bα degradation and disruption of PP2A/Bα-tau interactions, thus promoting tau hyperphosphorylation and paired helical filaments-tau accumulation and, consequently, axonal degeneration and cell death.
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Affiliation(s)
- Yali Zhang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Jiahui Zhang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Enhao Wang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Wei Qian
- Department of Biochemistry and Molecular Biology, School of Medicine.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education and Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jangsu 226001, China
| | - Yan Fan
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Ying Feng
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Haimeng Yin
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Yang Li
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Yuning Wang
- Department of Biochemistry and Molecular Biology, School of Medicine
| | - Tianli Yuan
- Department of Biochemistry and Molecular Biology, School of Medicine
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15
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Rao SS, Adlard PA. Untangling Tau and Iron: Exploring the Interaction Between Iron and Tau in Neurodegeneration. Front Mol Neurosci 2018; 11:276. [PMID: 30174587 PMCID: PMC6108061 DOI: 10.3389/fnmol.2018.00276] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 07/20/2018] [Indexed: 11/16/2022] Open
Abstract
There is an emerging link between the accumulation of iron in the brain and abnormal tau pathology in a number of neurodegenerative disorders, such as Alzheimer’s disease (AD). Studies have demonstrated that iron can regulate tau phosphorylation by inducing the activity of multiple kinases that promote tau hyperphosphorylation and potentially also by impacting protein phosphatase 2A activity. Iron is also reported to induce the aggregation of hyperphosphorylated tau, possibly through a direct interaction via a putative iron binding motif in the tau protein, facilitating the formation of neurofibrillary tangles (NFTs). Furthermore, in human studies high levels of iron have been reported to co-localize with tau in NFT-bearing neurons. These data, together with our own work showing that tau has a role in mediating cellular iron efflux, provide evidence supporting a critical tau:iron interaction that may impact both the symptomatic presentation and the progression of disease. Importantly, this may also have relevance for therapeutic directions, and indeed, the use of iron chelators such as deferiprone and deferoxamine have been reported to alleviate the phenotypes, reduce phosphorylated tau levels and stabilize iron regulation in various animal models. As these compounds are also moving towards clinical translation, then it is imperative that we understand the intersection between iron and tau in neurodegeneration. In this article, we provide an overview of the key pathological and biochemical interactions between tau and iron. We also review the role of iron and tau in disease pathology and the potential of metal-based therapies for tauopathies.
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Affiliation(s)
- Shalini S Rao
- Division of Mental Health, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - Paul Anthony Adlard
- Division of Mental Health, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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16
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Borin M, Saraceno C, Catania M, Lorenzetto E, Pontelli V, Paterlini A, Fostinelli S, Avesani A, Di Fede G, Zanusso G, Benussi L, Binetti G, Zorzan S, Ghidoni R, Buffelli M, Bolognin S. Rac1 activation links tau hyperphosphorylation and Aβ dysmetabolism in Alzheimer's disease. Acta Neuropathol Commun 2018; 6:61. [PMID: 30005699 PMCID: PMC6045891 DOI: 10.1186/s40478-018-0567-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022] Open
Abstract
One of the earliest pathological features characterizing Alzheimer’s disease (AD) is the loss of dendritic spines. Among the many factors potentially mediating this loss of neuronal connectivity, the contribution of Rho-GTPases is of particular interest. This family of proteins has been known for years as a key regulator of actin cytoskeleton remodeling. More recent insights have indicated how its complex signaling might be triggered also in pathological conditions. Here, we showed that the Rho-GTPase family member Rac1 levels decreased in the frontal cortex of AD patients compared to non-demented controls. Also, Rac1 increased in plasma samples of AD patients with Mini-Mental State Examination < 18 compared to age-matched non demented controls. The use of different constitutively active peptides allowed us to investigate in vitro Rac1 specific signaling. Its activation increased the processing of amyloid precursor protein and induced the translocation of SET from the nucleus to the cytoplasm, resulting in tau hyperphosphorylation at residue pT181. Notably, Rac1 was abnormally activated in the hippocampus of 6-week-old 3xTg-AD mice. However, the total protein levels decreased at 7-months. A rescue strategy based on the intranasal administration of Rac1 active peptide at 6.5 months prevented dendritic spine loss. This data suggests the intriguing possibility of a dual role of Rac1 according to the different stages of the pathology. In an initial stage, Rac1 deregulation might represent a triggering co-factor due to the direct effect on Aβ and tau. However, at a later stage of the pathology, it might represent a potential therapeutic target due to the beneficial effect on spine dynamics.
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17
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Luo HB, Shang N, Xie WZ, Wen DJ, Qu M, Huang S, Fan SS, Chen W, Mou NQ, Liu XY, Chen Q, Xie FF, Li JX. Trillium tschonoskii maxim extract attenuates abnormal Tau phosphorylation. Neural Regen Res 2018; 13:915-922. [PMID: 29863023 PMCID: PMC5998638 DOI: 10.4103/1673-5374.232487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer’s disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to promote memory. However, scientific understanding of its mechanism of action is limited. This report studied the potential neuroprotective effects of Trillium tschonoskii maxim extract against homocysteine-induced cognitive deficits. Rats were intravenously injected with homocysteine (400 μg/kg) for 14 days to induce a model of Alzheimer’s disease. These rats were then intragastrically treated with Trillium tschonoskii maxim extract (0.125 or 0.25 g/kg) for 7 consecutive days. Open field test and Morris water maze test were conducted to measure spontaneous activity and learning and memory abilities. Western blot assay was used to detect the levels of Tau protein and other factors involved in Tau phosphorylation in the hippocampus. Immunohistochemical staining was used to examine Tau protein in the hippocampus. Golgi staining was applied to measure hippocampal dendritic spines. Our results demonstrated that homocysteine produced learning and memory deficits and increased levels of Tau phosphorylation, and diminished the activity of catalytic protein phosphatase 2A. The total number of hippocampal dendritic spines was also decreased. Trillium tschonoskii maxim extract treatment reversed the homocysteine-induced changes. The above results suggest that Trillium tschonoskii maxim extract can lessen homocysteine-induced abnormal Tau phosphorylation and improve cognitive deterioration such as that present in Alzheimer’s disease.
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Affiliation(s)
- Hong-Bin Luo
- Hubei Key Laboratory of Biological Resource Protection and Utilization; Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Nan Shang
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Wen-Zhi Xie
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - De-Jian Wen
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Min Qu
- Hubei Provincial Key Laboratory for Applied Toxicology, Hubei Provincial Center for Disease Control and Prevention, Wuhan, Hubei Province, China
| | - Sheng Huang
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Sha-Sha Fan
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Wei Chen
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Nan-Qiao Mou
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Xiang-Yu Liu
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Qin Chen
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Feng-Feng Xie
- Medical College, Hubei University for Nationalities; Institute of Neurological and Psychiatric Comorbidity, Hubei University for Nationalities, Enshi, Hubei Province, China
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
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18
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Protein phosphatase 2ACα gene knock-out results in cortical atrophy through activating hippo cascade in neuronal progenitor cells. Int J Biochem Cell Biol 2018; 95:53-62. [DOI: 10.1016/j.biocel.2017.12.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 12/02/2017] [Accepted: 12/19/2017] [Indexed: 12/12/2022]
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19
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Hu W, Tung YC, Zhang Y, Liu F, Iqbal K. Involvement of Activation of Asparaginyl Endopeptidase in Tau Hyperphosphorylation in Repetitive Mild Traumatic Brain Injury. J Alzheimers Dis 2018; 64:709-722. [PMID: 29889065 PMCID: PMC6087458 DOI: 10.3233/jad-180177] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2018] [Indexed: 12/13/2022]
Abstract
Traumatic brain injury (TBI) is an established risk factor for the development of neurodegeneration and dementia late in life. Repetitive mild TBI (r-mTBI) is directly associated with chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disorder characterized by focal perivascular to widespread Alzheimer-type neurofibrillary pathology of hyperphosphorylated tau. Studies in animal models have shown hyperphosphorylation of tau after TBI. However, the molecular mechanisms by which TBI leads to tau pathology are not understood. In this study, we employed western blots and immunohistochemistry to test, in triple-transgenic mouse model of Alzheimer's disease (3xTg-AD), the effect of r-mTBI on tau hyperphosphorylation and activation of asparaginyl endopeptidase (AEP), a cysteine proteinase which is known to be involved in tau hyperphosphorylation. We found that the level of active AEP was increased and correlated with the level of tau hyperphosphorylation following r-mTBI, and that fimbria showed increased immunoreactivity to phospho-tau. In addition, inhibitor 2 of protein phosphatase 2A (I2PP2A) was translocated from neuronal nucleus to the cytoplasm and colocalized with hyperphosphorylated tau. These data suggest the involvement of AEP-I2PP2A-PP2A-ptau pathway in tau pathology in TBI.
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Affiliation(s)
- Wen Hu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
- Key Laboratory for Neuroregeneration of Ministry of Education and Co-innovation Center for Neuroregeneration of Jiangsu Province, Nantong University, Nantong, Jiangsu, P.R. China
| | - Yunn Chyn Tung
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Yanchong Zhang
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
- Key Laboratory for Neuroregeneration of Ministry of Education and Co-innovation Center for Neuroregeneration of Jiangsu Province, Nantong University, Nantong, Jiangsu, P.R. China
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
- Key Laboratory for Neuroregeneration of Ministry of Education and Co-innovation Center for Neuroregeneration of Jiangsu Province, Nantong University, Nantong, Jiangsu, P.R. China
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
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20
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Asam K, Staniszewski A, Zhang H, Melideo SL, Mazzeo A, Voronkov M, Huber KL, Pérez E, Stock M, Stock JB, Arancio O, Nicholls RE. Eicosanoyl-5-hydroxytryptamide (EHT) prevents Alzheimer's disease-related cognitive and electrophysiological impairments in mice exposed to elevated concentrations of oligomeric beta-amyloid. PLoS One 2017; 12:e0189413. [PMID: 29253878 PMCID: PMC5734769 DOI: 10.1371/journal.pone.0189413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 11/24/2017] [Indexed: 02/04/2023] Open
Abstract
Soluble forms of oligomeric beta-amyloid (Aβ) are thought to play a central role in Alzheimer's disease (AD). Transgenic manipulation of methylation of the serine/threonine protein phosphatase, PP2A, was recently shown to alter the sensitivity of mice to AD-related impairments resulting from acute exposure to elevated levels of Aβ. In addition, eicosanoyl-5-hydroxytryptamide (EHT), a naturally occurring component from coffee beans that modulates PP2A methylation, was shown to confer therapeutic benefits in rodent models of AD and Parkinson's disease. Here, we tested the hypothesis that EHT protects animals from the pathological effects of exposure to elevated levels of soluble oligomeric Aβ. We treated mice with EHT-containing food at two different doses and assessed the sensitivity of these animals to Aβ-induced behavioral and electrophysiological impairments. We found that EHT administration protected animals from Aβ-induced cognitive impairments in both a radial-arm water maze and contextual fear conditioning task. We also found that both chronic and acute EHT administration prevented Aβ-induced impairments in long-term potentiation. These data add to the accumulating evidence suggesting that interventions with pharmacological agents, such as EHT, that target PP2A activity may be therapeutically beneficial for AD and other neurological conditions.
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Affiliation(s)
- Kesava Asam
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Agnieszka Staniszewski
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Hong Zhang
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Scott L. Melideo
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Adolfo Mazzeo
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
| | - Michael Voronkov
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Kristen L. Huber
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Eduardo Pérez
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Maxwell Stock
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Jeffry B. Stock
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Signum Biosciences, 133 Wall Street, Princeton, New Jersey, United States of America
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
- Department of Medicine, Columbia University, New York, NY, United States of America
| | - Russell E. Nicholls
- Department of Pathology and Cell Biology, Columbia University, New York, NY, United States of America
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, United States of America
- * E-mail:
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21
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Bao J, Mahaman YAR, Liu R, Wang JZ, Zhang Z, Zhang B, Wang X. Sex Differences in the Cognitive and Hippocampal Effects of Streptozotocin in an Animal Model of Sporadic AD. Front Aging Neurosci 2017; 9:347. [PMID: 29163130 PMCID: PMC5671606 DOI: 10.3389/fnagi.2017.00347] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/16/2017] [Indexed: 01/07/2023] Open
Abstract
More than 95% of Alzheimer's disease (AD) belongs to sporadic AD (sAD), and related animal models are the important research tools for investigating the pathogenesis and developing new drugs for sAD. An intracerebroventricular infusion of streptozotocin (ICV-STZ) is commonly employed to generate sporadic AD animal model. Moreover, the potential impact of sex on brain function is now emphasized in the field of AD. However, whether sex differences exist in AD animal models remains unknown. Here we reported that ICV-STZ remarkably resulted in learning and memory impairment in the Sprague-Dawley male rats, but not in the female rats. We also found tau hyperphosphorylation, an increase of Aβ40/42 as well as increase in both GSK-3β and BACE1 activities, while a loss of dendritic and synaptic plasticity was observed in the male STZ rats. However, STZ did not induce above alterations in the female rats. Furthermore, estradiol levels of serum and hippocampus of female rats were much higher than that of male rats. In conclusion, sex differences exist in this sporadic AD animal model (Sprague-Dawley rats induced by STZ), and this should be considered in future AD research.
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Affiliation(s)
- Jian Bao
- Key Laboratory of Ministry of Education of China for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yacoubou A R Mahaman
- Key Laboratory of Ministry of Education of China for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rong Liu
- Key Laboratory of Ministry of Education of China for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Key Laboratory of Ministry of Education of China for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Zhiguo Zhang
- School of Medicine and Health Management, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Xiaochuan Wang
- Key Laboratory of Ministry of Education of China for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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22
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Panza F, Solfrizzi V, Seripa D, Imbimbo BP, Lozupone M, Santamato A, Tortelli R, Galizia I, Prete C, Daniele A, Pilotto A, Greco A, Logroscino G. Tau-based therapeutics for Alzheimer's disease: active and passive immunotherapy. Immunotherapy 2017; 8:1119-34. [PMID: 27485083 DOI: 10.2217/imt-2016-0019] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Pharmacological manipulation of tau protein in Alzheimer's disease included microtubule-stabilizing agents, tau protein kinase inhibitors, tau aggregation inhibitors, active and passive immunotherapies and, more recently, inhibitors of tau acetylation. Animal studies have shown that both active and passive approaches can remove tau pathology and, in some cases, improve cognitive function. Two active vaccines targeting either nonphosphorylated (AAD-vac1) and phosphorylated tau (ACI-35) have entered Phase I testing. Notwithstanding, the recent discontinuation of the monoclonal antibody RG7345 for Alzheimer's disease, two other antitau antibodies, BMS-986168 and C2N-8E12, are also currently in Phase I testing for progressive supranuclear palsy. After the recent impressive results in animal studies obtained by salsalate, the dimer of salicylic acid, inhibitors of tau acetylation are being actively pursued.
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Affiliation(s)
- Francesco Panza
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, & Sense Organs, University of Bari Aldo Moro, Bari, Italy.,Department of Clinical Research in Neurology, University of Bari Aldo Moro, 'Pia Fondazione Cardinale G. Panico,' Tricase, Lecce, Italy.,Geriatric Unit & Laboratory of Gerontology & Geriatrics, Department of Medical Sciences, IRCCS 'Casa Sollievo della Sofferenza,' San Giovanni Rotondo, Foggia, Italy
| | - Vincenzo Solfrizzi
- Geriatric Medicine-Memory Unit & Rare Disease Centre, University of Bari Aldo Moro, Bari, Italy
| | - Davide Seripa
- Geriatric Unit & Laboratory of Gerontology & Geriatrics, Department of Medical Sciences, IRCCS 'Casa Sollievo della Sofferenza,' San Giovanni Rotondo, Foggia, Italy
| | - Bruno P Imbimbo
- Research & Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Madia Lozupone
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, & Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Andrea Santamato
- Physical Medicine & Rehabilitation Section, 'OORR' Hospital, University of Foggia, Foggia, Italy
| | - Rosanna Tortelli
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, & Sense Organs, University of Bari Aldo Moro, Bari, Italy.,Department of Clinical Research in Neurology, University of Bari Aldo Moro, 'Pia Fondazione Cardinale G. Panico,' Tricase, Lecce, Italy
| | - Ilaria Galizia
- Psychiatric Unit, Department of Basic Medicine, Neuroscience, & Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Camilla Prete
- Department of OrthoGeriatrics, Rehabilitation & Stabilization, Frailty Area, E.O. Galliera NR-HS Hospital, Genova, Italy
| | - Antonio Daniele
- Institute of Neurology, Catholic University of Sacred Heart, Rome, Italy
| | - Alberto Pilotto
- Department of OrthoGeriatrics, Rehabilitation & Stabilization, Frailty Area, E.O. Galliera NR-HS Hospital, Genova, Italy
| | - Antonio Greco
- Geriatric Unit & Laboratory of Gerontology & Geriatrics, Department of Medical Sciences, IRCCS 'Casa Sollievo della Sofferenza,' San Giovanni Rotondo, Foggia, Italy
| | - Giancarlo Logroscino
- Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, & Sense Organs, University of Bari Aldo Moro, Bari, Italy.,Department of Clinical Research in Neurology, University of Bari Aldo Moro, 'Pia Fondazione Cardinale G. Panico,' Tricase, Lecce, Italy.,Institute of Neurology, Catholic University of Sacred Heart, Rome, Italy
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23
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Seripa D, Solfrizzi V, Imbimbo BP, Daniele A, Santamato A, Lozupone M, Zuliani G, Greco A, Logroscino G, Panza F. Tau-directed approaches for the treatment of Alzheimer's disease: focus on leuco-methylthioninium. Expert Rev Neurother 2016; 16:259-77. [PMID: 26822031 DOI: 10.1586/14737175.2016.1140039] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Small molecular weight compounds able to inhibit formation of tau oligomers and fibrils have already been tested for Alzheimer's disease (AD) treatment. The most advanced tau aggregation inhibitor (TAI) is methylthioninium (MT), a drug existing in equilibrium between a reduced (leuco-methylthioninium) and oxidized form (MT(+)). MT chloride (also known as methylene blue) was investigated in a 24-week Phase II study in 321 mild-to-moderate AD patients at the doses of 69, 138, and 228 mg/day. This trial failed to show significant positive effects of MT in the overall patient population. The dose of 138 mg/day showed potential benefits on cognitive performance of moderately affected patients and cerebral blood flow in mildly affected patients. A follow-up compound (TRx0237) claimed to be more bioavailable and less toxic than MT, is now being developed. Phase III clinical trials on this novel TAI in AD and in the behavioral variant of frontotemporal dementia are underway.
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Affiliation(s)
- Davide Seripa
- a Geriatric Unit & Laboratory of Gerontology and Geriatrics, Department of Medical Sciences , IRCCS 'Casa Sollievo della Sofferenza' , San Giovanni Rotondo , Foggia , Italy
| | - Vincenzo Solfrizzi
- b Geriatric Medicine-Memory Unit and Rare Disease Centre , University of Bari Aldo Moro , Bari , Italy
| | - Bruno P Imbimbo
- c Research & Development Department , Chiesi Farmaceutici , Parma , Italy
| | - Antonio Daniele
- d Institute of Neurology , Catholic University of Sacred Heart , Rome , Italy
| | - Andrea Santamato
- e Physical Medicine and Rehabilitation Section, 'OORR' Hospital , University of Foggia , Foggia , Italy
| | - Madia Lozupone
- f Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs , University of Bari Aldo Moro , Bari , Italy
| | - Giovanni Zuliani
- g Department of Medical Science, Section of Internal and Cardiopulmonary Medicine , University of Ferrara
| | - Antonio Greco
- a Geriatric Unit & Laboratory of Gerontology and Geriatrics, Department of Medical Sciences , IRCCS 'Casa Sollievo della Sofferenza' , San Giovanni Rotondo , Foggia , Italy
| | - Giancarlo Logroscino
- f Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs , University of Bari Aldo Moro , Bari , Italy.,h Department of Clinical Research in Neurology , University of Bari Aldo Moro, 'Pia Fondazione Cardinale G. Panico' , Tricase , Lecce , Italy
| | - Francesco Panza
- a Geriatric Unit & Laboratory of Gerontology and Geriatrics, Department of Medical Sciences , IRCCS 'Casa Sollievo della Sofferenza' , San Giovanni Rotondo , Foggia , Italy.,f Neurodegenerative Disease Unit, Department of Basic Medicine, Neuroscience, and Sense Organs , University of Bari Aldo Moro , Bari , Italy.,h Department of Clinical Research in Neurology , University of Bari Aldo Moro, 'Pia Fondazione Cardinale G. Panico' , Tricase , Lecce , Italy
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24
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Qi C, Bao J, Wang J, Zhu H, Xue Y, Wang X, Li H, Sun W, Gao W, Lai Y, Chen JG, Zhang Y. Asperterpenes A and B, two unprecedented meroterpenoids from Aspergillus terreus with BACE1 inhibitory activities. Chem Sci 2016; 7:6563-6572. [PMID: 28042460 PMCID: PMC5131395 DOI: 10.1039/c6sc02464e] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 06/25/2016] [Indexed: 11/21/2022] Open
Abstract
Asperterpenes A (1) and B (2), two 3,5-dimethylorsellinic acid-based meroterpenoids that contain a unique β-oriented Me-21 with an unprecedented 1,2,5-trimethyl-4,9-dioxobicyclo[3.3.1]non-2-ene-3-carboxylic acid moiety, were obtained from Aspergillus terreus in very limited amounts of 3.6 mg and 1.8 mg, respectively. The absolute structure of 1 was determined using X-ray diffraction. Because of the low yield of 1, a comprehensive characterization of the BACE1 inhibitory activities of 1 was completed via molecular biological, cell and animal studies guided by in silico target confirmation (ISTC). ISTC assays suggested that compounds 1 and 2 might be BACE1 inhibitors. In cell-based tests, asperterpenes A and B, as natural products, exhibited promising inhibitory activities against BACE1, with IC50 values of 78 and 59 nM, respectively. LY2811376 (the positive control), one of the most potent clinical BACE1 inhibitors, has shown an IC50 value of 260 nM. In vivo, compound 1 exhibited activity similar to that of LY2811376 against Alzheimer's disease (AD) in 3xTg AD mice. Taken together, these findings demonstrate that asperterpene A, which contains a novel carbon skeleton, is the first terpenoid to exhibit effective BACE1 inhibitory activity. Moreover, 1 represents a potential lead compound and a versatile scaffold for the development of drugs for the treatment of AD.
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Affiliation(s)
- Changxing Qi
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Jian Bao
- School of Basic Medicine , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Jianping Wang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Hucheng Zhu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Yongbo Xue
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Xiaochuan Wang
- School of Basic Medicine , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Hua Li
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Weiguang Sun
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Weixi Gao
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Yongji Lai
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
| | - Jian-Guo Chen
- School of Basic Medicine , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China
| | - Yonghui Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation , School of Pharmacy , Tongji Medical College , Huazhong University of Science and Technology , Wuhan 430030 , China .
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25
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Increases of SET level and translocation are correlated with tau hyperphosphorylation at ser202/thr205 in CA1 of Ts65Dn mice. Neurobiol Aging 2016; 46:43-8. [DOI: 10.1016/j.neurobiolaging.2016.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 05/18/2016] [Accepted: 06/14/2016] [Indexed: 01/28/2023]
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26
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Knockdown of microRNA-195 contributes to protein phosphatase-2A inactivation in rats with chronic brain hypoperfusion. Neurobiol Aging 2016; 45:76-87. [DOI: 10.1016/j.neurobiolaging.2016.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/25/2016] [Accepted: 05/10/2016] [Indexed: 12/26/2022]
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27
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Abstract
SET is elevated and mislocalized in the neuronal cytoplasm in brains of Alzheimer's disease (AD) and Down syndrome (DS) patients. Cytoplasm SET leads to inhibition of protein phosphatase 2A and is involved in the tau pathology. However, the regulation of SET gene expression remains elusive. In the present study, we cloned a 1399-bp segment of the 5' flanking region of the human SET gene and identified that the transcription start site (TSS) of SET transcript 1 is located at 123 bp upstream of the translation start site ATG in exon 1. Sequence analysis reveals several putative regulatory elements including NFkB, Sp1, and HSE. Luciferase assay and electrophoretic mobility shift assay (EMSA) identified a functional cis-acting NFkB-responsive element in the SET gene promoter. Overexpression and activation of NFkB upregulate transcription of SET isoform 1 but not isoform 2, indicating that the expression of these two isoforms is differentially regulated. The results demonstrate that NFkB plays an important role in regulation of the human SET gene expression. Our findings suggest that oxidative stress and inflammatory responses could result in abnormal SET gene expression, contributing to the tauopathy in AD pathogenesis.
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28
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Zhang Z, Xie M, Ye K. Asparagine endopeptidase is an innovative therapeutic target for neurodegenerative diseases. Expert Opin Ther Targets 2016; 20:1237-45. [PMID: 27115710 DOI: 10.1080/14728222.2016.1182990] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Asparagine endopeptidase (AEP) is a pH-dependent endolysosomal cysteine protease that cleaves its substrates after asparagine residues. Our most recent study identifies that it possesses the delta-secretase activity, and that it is implicated in numerous neurological diseases such as Alzheimer's disease (AD) and stroke. Accumulating evidence supports that the inhibition of AEP exhibits beneficial effects for treating these devastating diseases. AREAS COVERED Based on recent evidence, it is clear that AEP cleaves its substrate, such as amyloid precursor protein (APP), tau and SET, and plays a critical role in neuronal cell death in various neurodegenerative diseases and stroke. In this article, the basic biology of AEP, its knockout phenotypes in mouse models, its substrates in neurodegenerative diseases, and its small peptidyl inhibitors and prodrugs are discussed. In addition, we discuss the potential of AEP as a novel therapeutic target for neurodegenerative diseases. EXPERT OPINION AEP plays a unique role in numerous biological processes, depending on both pH and context. Most striking is our most recent finding; that AEP is activated in an age-dependent manner and simultaneously cleaves both APP and tau, thereby unifying both major pathological events in AD. Thus, AEP acts as an innovative trigger for neurodegenerative diseases. Inhibition of AEP will provide a disease-modifying treatment for neurodegenerative diseases including AD.
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Affiliation(s)
- Zhentao Zhang
- a Department of Neurology , Renmin Hospital of Wuhan University , Wuhan , China.,b Department of Pathology and Laboratory Medicine , Emory University School of Medicine , Atlanta , GA , USA
| | - Manling Xie
- b Department of Pathology and Laboratory Medicine , Emory University School of Medicine , Atlanta , GA , USA
| | - Keqiang Ye
- b Department of Pathology and Laboratory Medicine , Emory University School of Medicine , Atlanta , GA , USA
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29
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Huang Y, Wu Z, Zhou B. Behind the curtain of tauopathy: a show of multiple players orchestrating tau toxicity. Cell Mol Life Sci 2016; 73:1-21. [PMID: 26403791 PMCID: PMC11108533 DOI: 10.1007/s00018-015-2042-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 07/22/2015] [Accepted: 09/08/2015] [Indexed: 12/24/2022]
Abstract
tau, a microtubule-associated protein, directly binds with microtubules to dynamically regulate the organization of cellular cytoskeletons, and is especially abundant in neurons of the central nervous system. Under disease conditions such as Pick's disease, progressive supranuclear palsy, frontotemporal dementia, parkinsonism linked to chromosome 17 and Alzheimer's disease, tau proteins can self-assemble to paired helical filaments progressing to neurofibrillary tangles. In these diseases, collectively referred to as "tauopathies", alterations of diverse tau modifications including phosphorylation, metal ion binding, glycosylation, as well as structural changes of tau proteins have all been observed, indicating the complexity and variability of factors in the regulation of tau toxicity. Here, we review our current knowledge and hypotheses from relevant studies on tau toxicity, emphasizing the roles of phosphorylations, metal ions, folding and clearance control underlining tau etiology and their regulations. A summary of clinical efforts and associated findings of drug candidates under development is also presented. It is hoped that a more comprehensive understanding of tau regulation will provide us with a better blueprint of tau networking in neuronal cells and offer hints for the design of more efficient strategies to tackle tau-related diseases in the future.
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Affiliation(s)
- Yunpeng Huang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhihao Wu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Bing Zhou
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Beijing Institute for Brain Disorders, Beijing, China.
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30
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Wang X, Blanchard J, Grundke-Iqbal I, Iqbal K. Memantine Attenuates Alzheimer's Disease-Like Pathology and Cognitive Impairment. PLoS One 2015; 10:e0145441. [PMID: 26697860 PMCID: PMC4689401 DOI: 10.1371/journal.pone.0145441] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/03/2015] [Indexed: 12/02/2022] Open
Abstract
Deficiency of protein phosphatase-2A is a key event in Alzheimer’s disease. An endogenous inhibitor of protein phosphatase-2A, inhibitor-1, I1PP2A, which inhibits the phosphatase activity by interacting with its catalytic subunit protein phosphatase-2Ac, is known to be upregulated in Alzheimer’s disease brain. In the present study, we overexpressed I1PP2A by intracerebroventricular injection with adeno-associated virus vector-1-I1PP2A in Wistar rats. The I1PP2A rats showed a decrease in brain protein phosphatase-2A activity, abnormal hyperphosphorylation of tau, neurodegeneration, an increase in the level of activated glycogen synthase kinase-3beta, enhanced expression of intraneuronal amyloid-beta and spatial reference memory deficit; littermates treated identically but with vector only, i.e., adeno-associated virus vector-1-enhanced GFP, served as a control. Treatment with memantine, a noncompetitive NMDA receptor antagonist which is an approved drug for treatment of Alzheimer’s disease, rescued protein phosphatase-2A activity by decreasing its demethylation at Leu309 selectively and attenuated Alzheimer’s disease-like pathology and cognitive impairment in adeno-associated virus vector-1-I1PP2A rats. These findings provide new clues into the possible mechanism of the beneficial therapeutic effect of memantine in Alzheimer’s disease patients.
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Affiliation(s)
- Xiaochuan Wang
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
- Department of Pathophysiology, Key Laboratory of Neurological Disease of National Education Ministry, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Julie Blanchard
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Inge Grundke-Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
| | - Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America
- * E-mail:
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31
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Sun LH, Ban T, Liu CD, Chen QX, Wang X, Yan ML, Hu XL, Su XL, Bao YN, Sun LL, Zhao LJ, Pei SC, Jiang XM, Zong DK, Ai J. Activation of Cdk5/p25 and tau phosphorylation following chronic brain hypoperfusion in rats involves microRNA-195 down-regulation. J Neurochem 2015; 134:1139-51. [PMID: 26118667 DOI: 10.1111/jnc.13212] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 11/27/2022]
Abstract
Chronic brain hypoperfusion (CBH) is a common clinical feature of Alzheimer's disease and vascular dementia, but the underlying molecular mechanism is unclear. Our previous study reported that the down-regulation of microRNA-195 (miR-195) promotes amyloidogenesis via regulation of amyloid precursor protein and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) expression at the post-transcriptional level in CBH rats with bilateral common carotid artery occlusion (2VO). CBH owing to unilateral common carotid artery occlusion (UCCAO) increases tau phosphorylation levels at multiple phosphorylation sites in the brain, but the molecular mechanism is poorly understood. The purpose of this study was to investigate whether miR-195 could both deregulate amyloid metabolism and indirectly deregulate tau phosphorylation in CBH. We observed that 2VO leads to tau hyperphosphorylation at Ser202/Thr205, Ser262, Thr231, and Ser422 and to the conversion from cyclin-dependent kinase 5 (Cdk5)/p35 to Cdk5/p25 in rat hippocampi. Endogenous miR-195 was knocked down using over-expression of its antisense molecule (pre-AMO-miR-195) via a lentivirus (lenti-pre-AMO-miR-195); this knockdown increased the tau phosphorylation at Ser202/Thr205, Ser262, Thr231, Ser422, and the Cdk5/p25 activation, but over-expression of miR-195 using lenti-pre-miR-195 decreased the tau phosphorylation and Cdk5/p25 activation. Further in vitro studies demonstrated that miR-195 over-expression prevented tau hyperphosphorylation and Cdk5/p35 activity, which were increased by miR-195 inhibition. A dual luciferase reporter assay showed that miR-195 bound to the Cdk5r1 gene, which encodes p35 protein, in the 3'UTR and inhibited p35 expression. We concluded that tau hyperphosphorylation involves the down-regulation of miR-195, which is mediated by Cdk5/p25 activation in 2VO rats. Our findings demonstrated that down-regulation of miR-195 led to increased vulnerability via the regulation of multiple targets. Schematic diagram of miR-195 mediated Aβ aggregation and tau hyperphosphorylation in chronic brain hypoperfusion (CBH). First, CBH results in the elevation of nuclear factor-κB (NF-κB), which binds with the promoter sequences of miR-195 and negatively regulates the expression of miR-195. Second, down-regulated miR-195 induces up-regulation of APP and BACE1 and leads to an increase in Aβ levels. Third, some of the elevated Aβ then enter the intracellular space and activate calpain, which promotes the conversion of Cdk5/p35 to Cdk5/p25 and catalyzes the degradation of IκB; IκB is an inhibitor of NF-κB, which activates NF-κB. Cdk5/p25 directly phosphorylates Tau. Fourth, down-regulated miR-195 induces an up-regulation of p35, which provides the active substrates of p25. Our findings demonstrated that the down-regulation of miR-195 plays a key role in the increased vulnerability to dementia via the regulation of multiple targets following CBH.
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Affiliation(s)
- Li-Hua Sun
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Tao Ban
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Cheng-Di Liu
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Qing-Xin Chen
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xu Wang
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Mei-Ling Yan
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xue-Ling Hu
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xiao-Lin Su
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Ya-Nan Bao
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Lin-Lin Sun
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Lin-Jing Zhao
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Shuang-Chao Pei
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Xue-Mei Jiang
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - De-Kang Zong
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
| | - Jing Ai
- Department of Pharmacology (the State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, China
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Trakhtenberg EF, Morkin MI, Patel KH, Fernandez SG, Sang A, Shaw P, Liu X, Wang Y, Mlacker GM, Gao H, Velmeshev D, Dombrowski SM, Vitek MP, Goldberg JL. The N-terminal Set-β Protein Isoform Induces Neuronal Death. J Biol Chem 2015; 290:13417-26. [PMID: 25833944 DOI: 10.1074/jbc.m114.633883] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/06/2022] Open
Abstract
Set-β protein plays different roles in neurons, but the diversity of Set-β neuronal isoforms and their functions have not been characterized. The expression and subcellular localization of Set-β are altered in Alzheimer disease, cleavage of Set-β leads to neuronal death after stroke, and the full-length Set-β regulates retinal ganglion cell (RGC) and hippocampal neuron axon growth and regeneration in a subcellular localization-dependent manner. Here we used various biochemical approaches to investigate Set-β isoforms and their role in the CNS, using the same type of neurons, RGCs, across studies. We found multiple alternatively spliced isoforms expressed from the Set locus in purified RGCs. Set transcripts containing the Set-β-specific exon were the most highly expressed isoforms. We also identified a novel, alternatively spliced Set-β transcript lacking the nuclear localization signal and demonstrated that the full-length (∼39-kDa) Set-β is localized predominantly in the nucleus, whereas a shorter (∼25-kDa) Set-β isoform is localized predominantly in the cytoplasm. Finally, we show that an N-terminal Set-β cleavage product can induce neuronal death.
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Affiliation(s)
- Ephraim F Trakhtenberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Melina I Morkin
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Karan H Patel
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | | | - Alan Sang
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Peter Shaw
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Xiongfei Liu
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Yan Wang
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Gregory M Mlacker
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Han Gao
- From the Neuroscience Program and
| | - Dmitry Velmeshev
- Molecular and Cellular Pharmacology Program,University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Susan M Dombrowski
- Genomatix Software, Ann Arbor, Michigan 48108, the Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan 48201
| | - Michael P Vitek
- Oncotide Pharmaceuticals Inc., Durham, North Carolina 27709, and the Department of Neurology, Duke University Medical Center, Durham, North Carolina 27708
| | - Jeffrey L Goldberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093,
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33
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Medina M, Avila J. Further understanding of tau phosphorylation: implications for therapy. Expert Rev Neurother 2015; 15:115-22. [PMID: 25555397 DOI: 10.1586/14737175.2015.1000864] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tau is a brain microtubule-associated protein that regulates microtubule structure and function. Prominent tau neurofibrillary pathology is a common feature in a number of neurodegenerative disorders collectively referred to as tauopathies, the most common of which is Alzheimer's disease. Beyond its classical role as a microtubule-associated protein, recent advances in our understanding of tau cellular functions have unveiled novel important tau cellular functions that may also play a pivotal role in pathogenesis and render novel targets for therapeutic intervention. Regulation of tau behavior and function under physiological and pathological conditions is mainly achieved through post-translational modifications, especially phosphorylation, which has significant implications for the development of novel therapeutic approaches in a number of neurodegenerative disorders.
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Affiliation(s)
- Miguel Medina
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, 28041-Madrid, Spain
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34
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Qu N, Zhou XY, Han L, Wang L, Xu JX, Zhang T, Chu J, Chen Q, Wang JZ, Zhang Q, Tian Q. Combination of PPT with LiCl Treatment Prevented Bilateral Ovariectomy-Induced Hippocampal-Dependent Cognition Deficit in Rats. Mol Neurobiol 2014; 53:894-904. [DOI: 10.1007/s12035-014-9050-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/02/2014] [Indexed: 12/17/2022]
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35
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Networks of protein kinases and phosphatases in the individual phases of contextual fear conditioning in the C57BL/6J mouse. Behav Brain Res 2014; 280:45-50. [PMID: 25461266 DOI: 10.1016/j.bbr.2014.11.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 11/08/2014] [Accepted: 11/12/2014] [Indexed: 01/05/2023]
Abstract
Although protein kinases and phosphatases have been reported to be involved in fear memory, information about these signalling molecules in the individual phases of contextual fear conditioning (cFC) is limited. C57BL/6J mice were tested in cFC, sacrificed and hippocampi were used for screening of approximately 800 protein kinases and phosphatases by protein microarrays with subsequent Western blot confirmation of threefold higher or lower hippocampal levels as compared to foot shock controls. Immunoblotting of the protein kinases and phosphatases screened out was carried out by Western blotting. A network of protein kinases and phosphatases was generated (STRING 9.1). Animals learned the task in the paradigm and protein kinase and phosphatase levels were determined in the individual phases acquisition, consolidation and retrieval and compared to foot shock controls. Protein kinases discoidin containing receptor 2 (DDR2), mitogen activated protein kinase kinase kinase 7 (TAK1), protein phosphatases dual specificity protein phosphatase (PTEN) and protein phosphatase 2a (PP2A) were modulated in the individual phases of cFC. Phosphatidyl-inositol-3,4,5-triphosphate 3-phosphatase and phosphatidylinositol-3 kinase (PI3K) that is interacting with PTEN were modulated as well. Freezing time was correlating with PP2A levels in the retrieval phase of cFC. The abovementioned protein kinases, phosphatases and inositol-signalling enzymes were not reported so far in cFC and the results are relevant for interpretation of previous and design of future studies in cFC or fear memory. Protein phosphatase PP2A was, however, the only signalling compound tested that was directly linked to retrieval in the cFC.
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Arif M, Wei J, Zhang Q, Liu F, Basurto-Islas G, Grundke-Iqbal I, Iqbal K. Cytoplasmic retention of protein phosphatase 2A inhibitor 2 (I2PP2A) induces Alzheimer-like abnormal hyperphosphorylation of Tau. J Biol Chem 2014; 289:27677-91. [PMID: 25128526 PMCID: PMC4183805 DOI: 10.1074/jbc.m114.565358] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 08/11/2014] [Indexed: 12/22/2022] Open
Abstract
Abnormal hyperphosphorylation of Tau leads to the formation of neurofibrillary tangles, a hallmark of Alzheimer disease (AD), and related tauopathies. The phosphorylation of Tau is regulated by protein phosphatase 2A (PP2A), which in turn is modulated by endogenous inhibitor 2 (I2 (PP2A)). In AD brain, I2 (PP2A) is translocated from neuronal nucleus to cytoplasm, where it inhibits PP2A activity and promotes abnormal phosphorylation of Tau. Here we describe the identification of a potential nuclear localization signal (NLS) in the C-terminal region of I2 (PP2A) containing a conserved basic motif, (179)RKR(181), which is sufficient for directing its nuclear localization. The current study further presents an inducible cell model (Tet-Off system) of AD-type abnormal hyperphosphorylation of Tau by expressing I2 (PP2A) in which the NLS was inactivated by (179)RKR(181) → AAA along with (168)KR(169) → AA mutations. In this model, the mutant NLS (mNLS)-I2 (PP2A) (I2 (PP2A)AA-AAA) was retained in the cell cytoplasm, where it physically interacted with PP2A and inhibited its activity. Inhibition of PP2A was associated with the abnormal hyperphosphorylation of Tau, which resulted in microtubule network instability and neurite outgrowth impairment. Expression of mNLS-I2 (PP2A) activated CAMKII and GSK-3β, which are Tau kinases regulated by PP2A. The immunoprecipitation experiments showed the direct interaction of I2 (PP2A) with PP2A and GSK-3β but not with CAMKII. Thus, the cell model provides insights into the nature of the potential NLS and the mechanistic relationship between I2 (PP2A)-induced inhibition of PP2A and hyperphosphorylation of Tau that can be utilized to develop drugs preventing Tau pathology.
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Affiliation(s)
- Mohammad Arif
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Jianshe Wei
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Qi Zhang
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Fei Liu
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Gustavo Basurto-Islas
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Inge Grundke-Iqbal
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
| | - Khalid Iqbal
- From the Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314
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Lashine YA, Salah S, Aboelenein HR, Abdelaziz AI. Correcting the expression of miRNA-155 represses PP2Ac and enhances the release of IL-2 in PBMCs of juvenile SLE patients. Lupus 2014; 24:240-7. [DOI: 10.1177/0961203314552117] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
MicroRNA-155 is involved in immune cell, differentiation, maturation and function. MiR-155 showed variable dysregulated expression in autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) patients. MiR-155 was previously confirmed to directly target CAMP response element binding protein (CREB), which was previously identified as a positive regulator of protein phosphatase 2A (PP2A). PP2A is a key negative regulator of interleukin-2, which is an important immune modulator and was previously shown to be decreased in SLE. In this study we aimed at investigating the regulation of PP2A by miR-155 and hence its role in juvenile SLE disease pathogenesis. MiR-155 showed significant downregulation in PBMCs from juvenile SLE and juvenile familial Mediterranean fever (FMF) and significant upregulation in PBMCs from juvenile idiopathic arthritis (JIA) patients. In SLE, miR-155 expression was negatively correlated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score and proteinuria and was positively correlated with white blood cell (WBC) count. The mRNA of the catalytic subunit of PP2A (PP2Ac) showed significant upregulation in PBMCs from SLE and FMF but not in JIA patients. Additionally, the relative expression of PP2Ac mRNA was positively correlated with SLEDAI score. Forced expression of miR-155 led to decreased relative expression of PP2Ac mRNA and increased IL-2 release in cultured-stimulated PBMCs. This study suggests for the first time the possible role of an miR-155-PP2Ac loop in regulating IL-2 release and identifies miR-155 as a potential therapeutic target in juvenile SLE disease through relieving IL-2 from the inhibitory role of PP2A.
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Affiliation(s)
- Y A Lashine
- The Molecular Pathology Research Group, the German University in Cairo, Cairo, Egypt
| | - S Salah
- Abou el Reesh Pediatric Hospital, Kasr Al Aini, Cairo University, Cairo, Egypt
| | - H R Aboelenein
- The Molecular Pathology Research Group, the German University in Cairo, Cairo, Egypt
| | - A I Abdelaziz
- The Molecular Pathology Research Group, the German University in Cairo, Cairo, Egypt
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Cytoplasmic SET induces tau hyperphosphorylation through a decrease of methylated phosphatase 2A. BMC Neurosci 2014; 15:82. [PMID: 24981783 PMCID: PMC4086270 DOI: 10.1186/1471-2202-15-82] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/25/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The neuronal cytoplasmic localization of SET, an inhibitor of the phosphatase 2A (PP2A), results in tau hyperphosphorylation in the brains of Alzheimer patients through mechanisms that are still not well defined. RESULTS We used primary neurons and mouse brain slices to show that SET is translocated to the cytoplasm in a manner independent of both its cleavage and over-expression. The localization of SET in the cytoplasm, either by the translocation of endogenous SET or by internalization of the recombinant full-length SET protein, induced tau hyperphosphorylation. Cytoplasmic recombinant full-length SET in mouse brain slices induced a decrease of PP2A activity through a decrease of methylated PP2A levels. The levels of methylated PP2A were negatively correlated with tau hyperphosphorylation at Ser-202 but not with the abnormal phosphorylation of tau at Ser-422. CONCLUSIONS The presence of full-length SET in the neuronal cytoplasm is sufficient to impair PP2A methylation and activity, leading to tau hyperphosphorylation. In addition, our data suggest that tau hyperphosphorylation is regulated by different mechanisms at distinct sites. The translocation of SET to the neuronal cytoplasm, the low activity of PP2A, and tau hyperphosphorylation are associated in the brains of Alzheimer patients. Our data show a link between the translocation of SET in the cytoplasm and the decrease of methylated PP2A levels leading to a decrease of PP2A activity and tau hyperphosphorylation. This chain of events may contribute to the pathogenesis of Alzheimer disease.
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Basurto-Islas G, Blanchard J, Tung YC, Fernandez JR, Voronkov M, Stock M, Zhang S, Stock JB, Iqbal K. Therapeutic benefits of a component of coffee in a rat model of Alzheimer's disease. Neurobiol Aging 2014; 35:2701-2712. [PMID: 25034344 DOI: 10.1016/j.neurobiolaging.2014.06.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/29/2014] [Accepted: 06/10/2014] [Indexed: 10/25/2022]
Abstract
A minor component of coffee unrelated to caffeine, eicosanoyl-5-hydroxytryptamide (EHT), provides protection in a rat model for Alzheimer's disease (AD). In this model, viral expression of the phosphoprotein phosphatase 2A (PP2A) endogenous inhibitor, the I2(PP2A), or SET protein in the brains of rats leads to several characteristic features of AD including cognitive impairment, tau hyperphosphorylation, and elevated levels of cytoplasmic amyloid-β protein. Dietary supplementation with EHT for 6-12 months resulted in substantial amelioration of all these defects. The beneficial effects of EHT could be associated with its ability to increase PP2A activity by inhibiting the demethylation of its catalytic subunit PP2Ac. These findings raise the possibility that EHT may make a substantial contribution to the apparent neuroprotective benefits associated with coffee consumption as evidenced by numerous epidemiologic studies indicating that coffee drinkers have substantially lowered risk of developing AD.
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Affiliation(s)
- Gustavo Basurto-Islas
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Julie Blanchard
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Yunn Chyn Tung
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Jose R Fernandez
- Signum Biosciences Inc, 133 Wall Street, Princeton, NJ 08540, USA
| | - Michael Voronkov
- Signum Biosciences Inc, 133 Wall Street, Princeton, NJ 08540, USA
| | - Maxwell Stock
- Signum Biosciences Inc, 133 Wall Street, Princeton, NJ 08540, USA
| | - Sherry Zhang
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Jeffry B Stock
- Signum Biosciences Inc, 133 Wall Street, Princeton, NJ 08540, USA; Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.
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Upregulation of SET expression by BACE1 and its implications in Down syndrome. Mol Neurobiol 2014; 51:781-90. [PMID: 24935721 DOI: 10.1007/s12035-014-8782-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/09/2014] [Indexed: 01/18/2023]
Abstract
Down syndrome (DS) is one of the most common genetic diseases. Patients with DS display growth delay and intellectual disabilities and develop Alzheimer's disease (AD) neuropathology after middle age, including neuritic plaques and neurofibrillary tangles. Beta-site amyloid β precursor protein (APP) cleaving enzyme 1 (BACE1), essential for Aβ production and neuritic plaque formation, is elevated in DS patients. However, its homolog, β-site APP cleaving enzyme 2 (BACE2), functions as θ-secretase and plays a differential role in plaque formation. In this study, by using Two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (2D SDS-PAGE) and LC-MS/MS proteomic profiling analysis, we found that the SET oncogene protein (SET) expression was associated with BACE1 but not BACE2. SET protein was increased in BACE1 overexpressing cells and was markedly reduced in the BACE1 knockout mice. We found that the overexpression of BACE1 or SET significantly inhibited cell proliferation. Moreover, knockdown of SET in BACE1 overexpression cells significantly rescued BACE1-induced cell growth suppression. Furthermore, both BACE1 and SET protein levels were increased in Down syndrome patients. It suggests that BACE1 overexpression-induced SET upregulation may contribute to growth delay and cognitive impairment in DS patients. Our work provides a new insight that BACE1 overexpression not only promotes neuritic plaque formation but may also potentiate neurodegeneration mediated by SET elevation in Alzheimer-associated dementia in DS.
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Zhang Y, Ma RH, Li XC, Zhang JY, Shi HR, Wei W, Luo DJ, Wang Q, Wang JZ, Liu GP. Silencing [Formula: see text] Rescues Tau Pathologies and Memory Deficits through Rescuing PP2A and Inhibiting GSK-3β Signaling in Human Tau Transgenic Mice. Front Aging Neurosci 2014; 6:123. [PMID: 24987368 PMCID: PMC4060416 DOI: 10.3389/fnagi.2014.00123] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 05/27/2014] [Indexed: 01/12/2023] Open
Abstract
Increase of inhibitor-2 of protein phosphatase-2A [Formula: see text] is associated with protein phosphatase-2A (PP2A) inhibition and tau hyperphosphorylation in Alzheimer's disease (AD). Down-regulating [Formula: see text] attenuated amyloidogenesis and improved the cognitive functions in transgenic mice expressing amyloid precursor protein (tg2576). Here, we found that silencing [Formula: see text] by hippocampal infusion of [Formula: see text] down-regulated [Formula: see text] (~45%) with reduction of tau phosphorylation/accumulation, improvement of memory deficits, and dendritic plasticity in 12-month-old human tau transgenic mice. Silencing [Formula: see text] not only restored PP2A activity but also inhibited glycogen synthase kinase-3β (GSK-3β) with a significant activation of protein kinase A (PKA) and Akt. In HEK293/tau and N2a/tau cells, silencing [Formula: see text] by [Formula: see text] also significantly reduced tau hyperphosphorylation with restoration of PP2A activity and inhibition of GSK-3β, demonstrated by the decreased GSK-3β total protein and mRNA levels, and the increased inhibitory phosphorylation of GSK-3β at serine-9. Furthermore, activation of PKA but not Akt mediated the inhibition of GSK-3β by [Formula: see text] silencing. We conclude that targeting [Formula: see text] can improve tau pathologies and memory deficits in human tau transgenic mice, and activation of PKA contributes to GSK-3β inhibition induced by silencing [Formula: see text]in vitro, suggesting that [Formula: see text] is a promising multiple target of AD.
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Affiliation(s)
- Yao Zhang
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Endocrinology, Liyuan Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Rong-Hong Ma
- Department of Laboratory Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xia-Chun Li
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia-Yu Zhang
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hai-Rong Shi
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Wei
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Jinan University, Guangzhou, China
| | - Dan-Ju Luo
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qun Wang
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gong-Ping Liu
- Key Laboratory of Neurological Disease of Chinese Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Sontag JM, Sontag E. Protein phosphatase 2A dysfunction in Alzheimer's disease. Front Mol Neurosci 2014; 7:16. [PMID: 24653673 PMCID: PMC3949405 DOI: 10.3389/fnmol.2014.00016] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/22/2014] [Indexed: 01/26/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a large family of enzymes that account for the majority of brain Ser/Thr phosphatase activity. While PP2A enzymes collectively modulate most cellular processes, sophisticated regulatory mechanisms are ultimately responsible for ensuring isoform-specific substrate specificity. Of particular interest to the Alzheimer’s disease (AD) field, alterations in PP2A regulators and PP2A catalytic activity, subunit expression, methylation and/or phosphorylation, have been reported in AD-affected brain regions. “PP2A” dysfunction has been linked to tau hyperphosphorylation, amyloidogenesis and synaptic deficits that are pathological hallmarks of this neurodegenerative disorder. Deregulation of PP2A enzymes also affects the activity of many Ser/Thr protein kinases implicated in AD. This review will more specifically discuss the role of the PP2A/Bα holoenzyme and PP2A methylation in AD pathogenesis. The PP2A/Bα isoform binds to tau and is the primary tau phosphatase. Its deregulation correlates with increased tau phosphorylation in vivo and in AD. Disruption of PP2A/Bα-tau protein interactions likely contribute to tau deregulation in AD. Significantly, alterations in one-carbon metabolism that impair PP2A methylation are associated with increased risk for sporadic AD, and enhanced AD-like pathology in animal models. Experimental studies have linked deregulation of PP2A methylation with down-regulation of PP2A/Bα, enhanced phosphorylation of tau and amyloid precursor protein, tau mislocalization, microtubule destabilization and neuritic defects. While it remains unclear what are the primary events that underlie “PP2A” dysfunction in AD, deregulation of PP2A enzymes definitely affects key players in the pathogenic process. As such, there is growing interest in developing PP2A-centric therapies for AD, but this may be a daunting task without a better understanding of the regulation and function of specific PP2A enzymes.
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Affiliation(s)
- Jean-Marie Sontag
- Faculty of Health and Medicine, School of Biomedical Sciences and Pharmacy, The University of Newcastle Callaghan, NSW, Australia
| | - Estelle Sontag
- Faculty of Health and Medicine, School of Biomedical Sciences and Pharmacy, The University of Newcastle Callaghan, NSW, Australia
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Wang X, Blanchard J, Grundke-Iqbal I, Wegiel J, Deng HX, Siddique T, Iqbal K. Alzheimer disease and amyotrophic lateral sclerosis: an etiopathogenic connection. Acta Neuropathol 2014; 127:243-56. [PMID: 24136402 DOI: 10.1007/s00401-013-1175-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 08/29/2013] [Indexed: 12/12/2022]
Abstract
The etiopathogenesis of neither the sporadic form of Alzheimer disease (AD) nor of amyotrophic lateral sclerosis (ALS) is well understood. The activity of protein phosphatase-2A (PP2A), which regulates the phosphorylation of tau and neurofilaments, is negatively regulated by the myeloid leukemia-associated protein SET, also known as inhibitor-2 of PP2A, I2(PP2A). In AD brain, PP2A activity is compromised, probably because I2(PP2A) is overexpressed and is selectively cleaved at asparagine 175 into an N-terminal fragment, I2NTF, and a C-terminal fragment, I2CTF, and both fragments inhibit PP2A. Here, we analyzed the spinal cords from ALS and control cases for I2(PP2A) cleavage and PP2A activity. As observed in AD brain, we found a selective increase in the cleavage of I2(PP2A) into I2NTF and I2CTF and inhibition of the activity and not the expression of PP2A in the spinal cords of ALS cases. To test the hypothesis that both AD and ALS could be triggered by I2CTF, a cleavage product of I2(PP2A), we transduced by intracerebroventricular injections newborn rats with adeno-associated virus serotype 1 (AAV1) containing human I2CTF. AAV1-I2CTF produced reference memory impairment and tau pathology, and intraneuronal accumulation of Aβ by 5-8 months, and motor deficit and hyperphosphorylation and proliferation of neurofilaments, tau and TDP-43 pathologies, degeneration and loss of motor neurons and axons in the spinal cord by 10-14 months in rats. These findings suggest a previously undiscovered etiopathogenic relationship between sporadic forms of AD and ALS that is linked to I2(PP2A) and the potential of I2(PP2A)-based therapeutics for these diseases.
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Affiliation(s)
- Xiaochuan Wang
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research, In Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY, 10314-6399, USA
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New perspectives on the role of tau in Alzheimer's disease. Implications for therapy. Biochem Pharmacol 2014; 88:540-7. [PMID: 24462919 DOI: 10.1016/j.bcp.2014.01.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/10/2014] [Accepted: 01/14/2014] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) and related dementias constitute a major public health issue due to an increasingly aged population as a consequence of generally improved medical care and demographic changes. Current drug treatment of AD, the most prevalent dementia, with cholinesterase inhibitors or NMDA antagonists have demonstrated very modest, symptomatic efficacy, leaving an unmet medical need for new, more effective therapies. While drug development efforts in the last two decades have primarily focused on the amyloid cascade hypothesis, so far with disappointing results, tau-based strategies have received little attention until recently despite that the presence of extensive tau pathology is central to the disease. The discovery of mutations within the tau gene that cause fronto-temporal dementia demonstrated that tau dysfunction, in the absence of amyloid pathology, was sufficient to cause neuronal loss and clinical dementia. Abnormal levels and hyperphosphorylation of tau protein have been reported to be the underlying cause of a group of neurodegenerative disorders collectively known as 'tauopathies'. The detrimental consequence is the loss of affinity between this protein and the microtubules, increased production of fibrillary aggregates and the accumulation of insoluble intracellular neurofibrillary tangles. However, it has become clear in recent years that tau is not only a microtubule interacting protein, but rather has additional roles in cellular processes. This review focuses on emerging therapeutic strategies aimed at treating the underlying causes of the tau pathology in tauopathies and AD, including some novel approaches on the verge of providing new treatment paradigms within the coming years.
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Iqbal K, Liu F, Gong CX. Alzheimer disease therapeutics: focus on the disease and not just plaques and tangles. Biochem Pharmacol 2014; 88:631-9. [PMID: 24418409 DOI: 10.1016/j.bcp.2014.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 12/26/2013] [Accepted: 01/02/2014] [Indexed: 12/13/2022]
Abstract
The bulk of AD research during the last 25 years has been Aβ-centric based on a strong faith in the Amyloid Cascade Hypothesis which is not supported by the data on humans. To date, Aβ-based therapeutic clinical trials on sporadic cases of AD have been negative. Although most likely the major reason for the failure is that Aβ is not an effective therapeutic target for sporadic AD, initiation of the treatment at mild to moderate stages of the disease is blamed as too late to be effective. Clinical trials on presymptomatic familial AD cases have been initiated with the logic that Aβ is a trigger of the disease and hence initiation of the Aβ immunotherapies several years before any clinical symptoms would be effective. There is an urgent need to explore targets other than Aβ. There is now increasing interest in inhibiting tau pathology, which does have a far more compelling rationale than Aβ. AD is multifactorial and over 99% of the cases are the sporadic form of the disease. Understanding of the various etiopathogenic mechanisms of sporadic AD and generation of the disease-relevant animal models are required to develop rational therapeutic targets and therapies. Treatment of AD will require both inhibition of neurodegeneration and regeneration of the brain.
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Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA.
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
| | - Cheng-Xin Gong
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314, USA
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Iqbal K, Gong CX, Liu F. Microtubule-associated protein tau as a therapeutic target in Alzheimer's disease. Expert Opin Ther Targets 2014; 18:307-18. [PMID: 24387228 DOI: 10.1517/14728222.2014.870156] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Alzheimer's disease (AD) is a major public health problem in modern society and as yet, other than a few symptomatic drugs, there is no disease-modifying treatment for this disease available. AREAS COVERED Neurofibrillary pathology, which is made up from abnormally hyperphosphorylated microtubule-associated protein tau, is both a hallmark and key lesion of AD and related tauopathies. The density of neurofibrillary pathology in the cerebral cortex correlates with the degree of dementia. Both experimental and transgenic animal studies have consistently shown that abnormal hyperphosphorylation of tau causes cognitive impairment. Abnormal hyperphosphorylation of tau converts it from a microtubule assembly-promoting to a microtubule-disrupting protein and promotes its self-assembly into paired helical filaments. To date, the bulk of studies have shown that abnormal hyperphosphorylation is the key gain of toxic function step though some cell culture and transgenic mouse studies have also reported that aggregated tau can lead to neurodegeneration. In this article, we have reviewed data from our lab and that from PubMed search on the molecular mechanism of tau pathology and the potential of tau as a therapeutic target for AD and related disorders. EXPERT OPINION In our opinion, inhibition of abnormal hyperphosphorylation of tau is the most rational therapeutic target. Therapeutic approaches include restoration of the activity of protein phosphatase-2A, which is the major regulator of tau phosphorylation and the activity of which is compromised in AD brain, inhibition of one or more tau protein kinases which include GSK-3β, cyclin-dependent protein kinase-5, dual-specificity tyrosine phosphorylated-regulated kinase 1A, Ca(2+)/calmodulin-activated protein kinase II and casein kinase I, enhancement of O-GlcNAcylation of tau, and tau immunization.
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Affiliation(s)
- Khalid Iqbal
- New York State Institute for Basic Research in Developmental Disabilities, Department of Neurochemistry, Inge Grundke-Iqbal Research Floor , 1050 Forest Hill Road, Staten Island, NY 10314 , USA +1 718 494 5259 ;
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King MK, Pardo M, Cheng Y, Downey K, Jope RS, Beurel E. Glycogen synthase kinase-3 inhibitors: Rescuers of cognitive impairments. Pharmacol Ther 2014; 141:1-12. [PMID: 23916593 PMCID: PMC3867580 DOI: 10.1016/j.pharmthera.2013.07.010] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/18/2013] [Indexed: 01/02/2023]
Abstract
Impairment of cognitive processes is a devastating outcome of many diseases, injuries, and drugs affecting the central nervous system (CNS). Most often, very little can be done by available therapeutic interventions to improve cognitive functions. Here we review evidence that inhibition of glycogen synthase kinase-3 (GSK3) ameliorates cognitive deficits in a wide variety of animal models of CNS diseases, including Alzheimer's disease, Fragile X syndrome, Down syndrome, Parkinson's disease, spinocerebellar ataxia type 1, traumatic brain injury, and others. GSK3 inhibitors also improve cognition following impairments caused by therapeutic interventions, such as cranial irradiation for brain tumors. These findings demonstrate that GSK3 inhibitors are able to ameliorate cognitive impairments caused by a diverse array of diseases, injury, and treatments. The improvements in impaired cognition instilled by administration of GSK3 inhibitors appear to involve a variety of different mechanisms, such as supporting long-term potentiation and diminishing long-term depression, promotion of neurogenesis, reduction of inflammation, and increasing a number of neuroprotective mechanisms. The potential for GSK3 inhibitors to repair cognitive deficits associated with many conditions warrants further investigation of their potential for therapeutic interventions, particularly considering the current dearth of treatments available to reduce loss of cognitive functions.
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Affiliation(s)
- Margaret K King
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Marta Pardo
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Yuyan Cheng
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Kimberlee Downey
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Richard S Jope
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Eléonore Beurel
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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Facchinetti P, Dorard E, Contremoulins V, Gaillard MC, Déglon N, Sazdovitch V, Guihenneuc-Jouyaux C, Brouillet E, Duyckaerts C, Allinquant B. SET translocation is associated with increase in caspase cleaved amyloid precursor protein in CA1 of Alzheimer and Down syndrome patients. Neurobiol Aging 2013; 35:958-68. [PMID: 24262202 DOI: 10.1016/j.neurobiolaging.2013.08.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/26/2013] [Accepted: 08/31/2013] [Indexed: 11/30/2022]
Abstract
Caspase cleaved amyloid precursor protein (APPcc) and SET are increased and mislocalized in the neuronal cytoplasm in Alzheimer Disease (AD) brains. Translocated SET to the cytoplasm can induce tau hyperphosphorylation. To elucidate the putative relationships between mislocalized APPcc and SET, we studied their level and distribution in the hippocampus of 5 controls, 3 Down syndrome and 10 Alzheimer patients. In Down syndrome and Alzheimer patients, APPcc and SET levels were increased in CA1 and the frequency of both localizations in the neuronal cytoplasm was high in CA1, and low in CA4. As the increase of APPcc is already present at early stages of AD, we overexpressed APPcc in CA1 and the dentate gyrus neurons of adult mice with a lentiviral construct. APPcc overexpression in CA1 and not in the dentate gyrus induced endogenous SET translocation and tau hyperphosphorylation. These data suggest that increase in APPcc in CA1 neurons could be an early event leading to the translocation of SET and the progression of AD through tau hyperphosphorylation.
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Affiliation(s)
- Patricia Facchinetti
- INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Emilie Dorard
- INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Vincent Contremoulins
- ImagoSeine, Institut Jacques Monod, UMR 7592, CNRS and Université Paris Diderot, Paris, France
| | | | | | - Véronique Sazdovitch
- Laboratoire de Neuropathologie Escourolle, Hôpital de la Salpêtrière, AP-HP, and Centre de Recherche de l'ICM (UPMC, INSERM UMR S 975, CNRS UMR 7225), Paris, France
| | - Chantal Guihenneuc-Jouyaux
- EA 4064, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | | | - Charles Duyckaerts
- Laboratoire de Neuropathologie Escourolle, Hôpital de la Salpêtrière, AP-HP, and Centre de Recherche de l'ICM (UPMC, INSERM UMR S 975, CNRS UMR 7225), Paris, France
| | - Bernadette Allinquant
- INSERM UMR 894, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France.
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Iqbal K, Gong CX, Liu F. Hyperphosphorylation-induced tau oligomers. Front Neurol 2013; 4:112. [PMID: 23966973 PMCID: PMC3744035 DOI: 10.3389/fneur.2013.00112] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/23/2013] [Indexed: 11/13/2022] Open
Abstract
In normal adult brain the microtubule associated protein (MAP) tau contains 2-3 phosphates per mol of the protein and at this level of phosphorylation it is a soluble cytosolic protein. The normal brain tau interacts with tubulin and promotes its assembly into microtubules and stabilizes these fibrils. In Alzheimer disease (AD) brain tau is three to fourfold hyperphosphorylated. The abnormally hyperphosphorylated tau binds to normal tau instead of the tubulin and this binding leads to the formation of tau oligomers. The tau oligomers can be sedimented at 200,000 × g whereas the normal tau under these conditions remains in the supernatant. The abnormally hyperphosphorylated tau is capable of sequestering not only normal tau but also MAP MAP1 and MAP2 and causing disruption of the microtubule network promoted by these proteins. Unlike Aβ and prion protein (PrP) oligomers, tau oligomerization in AD and related tauopathies is hyperphosphorylation-dependent; in vitro dephosphorylation of AD P-tau with protein phosphatase 2A (PP2A) inhibits and rehyperphosphorylation of the PP2A-AD P-tau with more than one combination of tau protein kinases promotes its oligomerization. In physiological assembly conditions the AD P-tau readily self-assembles into paired helical filaments. Missense tau mutations found in frontotemporal dementia apparently lead to tau oligomerization and neurofibrillary pathology by promoting its abnormal hyperphosphorylation. Dysregulation of the alternative splicing of tau that alters the 1:1 ratio of the 3-repeat: 4-repeat taus such as in Down syndrome, Pick disease, and progressive supranuclear palsy leads to the abnormal hyperphosphorylation of tau.
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Affiliation(s)
- Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities , Staten Island, NY , USA
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Silencing PP2A inhibitor by lenti-shRNA interference ameliorates neuropathologies and memory deficits in tg2576 mice. Mol Ther 2013; 21:2247-57. [PMID: 23922015 DOI: 10.1038/mt.2013.189] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 07/31/2013] [Indexed: 01/10/2023] Open
Abstract
Deficits of protein phosphatase-2A (PP2A) play a crucial role in tau hyperphosphorylation, amyloid overproduction, and synaptic suppression of Alzheimer's disease (AD), in which PP2A is inactivated by the endogenously increased inhibitory protein, namely inhibitor-2 of PP2A (I2(PP2A)). Therefore, in vivo silencing I2(PP2A) may rescue PP2A and mitigate AD neurodegeneration. By infusion of lentivirus-shRNA targeting I2(PP2A) (LV-siI2(PP2A)) into hippocampus and frontal cortex of 11-month-old tg2576 mice, we demonstrated that expression of LV-siI2(PP2A) decreased remarkably the elevated I2(PP2A) in both mRNA and protein levels. Simultaneously, the PP2A activity was restored with the mechanisms involving reduction of the inhibitory binding of I2(PP2A) to PP2A catalytic subunit (PP2AC), repression of the inhibitory Leu309-demethylation and elevation of PP2AC. Silencing I2(PP2A) induced a long-lasting attenuation of amyloidogenesis in tg2576 mice with inhibition of amyloid precursor protein hyperphosphorylation and β-secretase activity, whereas simultaneous inhibition of PP2A abolished the antiamyloidogenic effects of I2(PP2A) silencing. Finally, silencing I2(PP2A) could improve learning and memory of tg2576 mice with preservation of several memory-associated components. Our data reveal that targeting I2(PP2A) can efficiently rescue Aβ toxicities and improve the memory deficits in tg2576 mice, suggesting that I2(PP2A) could be a promising target for potential AD therapies.
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