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Yue W, Deng X, Wang Z, Jiang M, Hu R, Duan Y, Wang Q, Cui J, Fang Y. Inhibition of the MEK/ERK pathway suppresses immune overactivation and mitigates TDP-43 toxicity in a Drosophila model of ALS. Immun Ageing 2023; 20:27. [PMID: 37340309 DOI: 10.1186/s12979-023-00354-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 06/08/2023] [Indexed: 06/22/2023]
Abstract
TDP-43 is an important DNA/RNA-binding protein that is associated with age-related neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD); however, its pathomechanism is not fully understood. In a transgenic RNAi screen using Drosophila as a model, we uncovered that knockdown (KD) of Dsor1 (the Drosophila MAPK kinase dMEK) suppressed TDP-43 toxicity without altering TDP-43 phosphorylation or protein levels. Further investigation revealed that the Dsor1 downstream gene rl (dERK) was abnormally upregulated in TDP-43 flies, and neuronal overexpression of dERK induced profound upregulation of antimicrobial peptides (AMPs). We also detected a robust immune overactivation in TDP-43 flies, which could be suppressed by downregulation of the MEK/ERK pathway in TDP-43 fly neurons. Furthermore, neuronal KD of abnormally increased AMPs improved the motor function of TDP-43 flies. On the other hand, neuronal KD of Dnr1, a negative regulator of the Drosophila immune deficiency (IMD) pathway, activated the innate immunity and boosted AMP expression independent of the regulation by the MEK/ERK pathway, which diminished the mitigating effect of RNAi-dMEK on TDP-43 toxicity. Finally, we showed that an FDA-approved MEK inhibitor trametinib markedly suppressed immune overactivation, alleviated motor deficits and prolonged the lifespan of TDP-43 flies, but did not exhibit a lifespan-extending effect in Alzheimer disease (AD) or spinocerebellar ataxia type 3 (SCA3) fly models. Together, our findings suggest an important role of abnormal elevation of the MEK/ERK signaling and innate immunity in TDP-43 pathogenesis and propose trametinib as a potential therapeutic agent for ALS and other TDP-43-related diseases.
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Affiliation(s)
- Wenkai Yue
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xue Deng
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhao Wang
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Mingsheng Jiang
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rirong Hu
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yongjia Duan
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiangqiang Wang
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Jihong Cui
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Yanshan Fang
- Interdisciplinary Research Center On Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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MEK1/2 inhibition rescues neurodegeneration by TFEB-mediated activation of autophagic lysosomal function in a model of Alzheimer's Disease. Mol Psychiatry 2022; 27:4770-4780. [PMID: 35948663 PMCID: PMC9734062 DOI: 10.1038/s41380-022-01713-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/10/2022] [Accepted: 07/15/2022] [Indexed: 12/14/2022]
Abstract
Alzheimer's Disease (AD) is a progressive neurodegenerative disorder, which is characterized by cognitive deficit due to synaptic loss and neuronal death. Extracellular amyloid β plaques are one of the pathological hallmarks of AD. The autophagic lysosomal pathway is the essential mechanism to maintain cellular homeostasis by driving clearance of protein aggregates and is dysfunctional in AD. Here, we showed that inhibiting MEK/ERK signaling using a clinically available MEK1/2 inhibitor, trametinib (GSK1120212, SNR1611), induces the protection of neurons through autophagic lysosomal activation mediated by transcription factor EB (TFEB) in a model of AD. Orally administered trametinib recovered impaired neural structures, cognitive functions, and hippocampal long-term potentiation (LTP) in 5XFAD mice. Trametinib also reduced Aβ deposition via induction of autophagic lysosomal activation. RNA-sequencing analysis revealed upregulation of autophagic lysosomal genes by trametinib administration. In addition, trametinib inhibited TFEB phosphorylation at Ser142 and promoted its nuclear translocation, which in turn induced autophagic lysosomal related genes, indicating that trametinib activates the autophagic lysosomal process through TFEB activation. From these observations, we concluded that MEK inhibition provides neuronal protection from the Aβ burden by increasing autophagic lysosomal activity. Thus, MEK inhibition may be an effective therapeutic strategy for AD.
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Lin L, Jadoon SS, Liu SZ, Zhang RY, Li F, Zhang MY, Ai-Hua T, You QY, Wang P. Tanshinone IIA Ameliorates Spatial Learning and Memory Deficits by Inhibiting the Activity of ERK and GSK-3β. J Geriatr Psychiatry Neurol 2019; 32:152-163. [PMID: 30885037 DOI: 10.1177/0891988719837373] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Alzheimer disease (AD) is the most common type of dementia which is becoming a primary problem in the present society, but it lacks effective treatment methods and means of AD. Tanshinone IIA (Tan IIA) has been reported to have neuroprotective effects to restrain the Aβ25-35-mediated apoptosis. However, few studies try to understand how Aβ1-42 affects hyperphosphorylation of tau and how Tan IIA regulates this process at the molecular level. METHODS Fifty male Sprague-Dawley rats were randomly divided into 5 groups and infused through the lateral ventricle with Aβ1-42 except the control group. Then the rats were treated with Tan IIA through intragastric administration for 4 weeks. After the ability of learning and memory being measured, histomorphological examination and Western blot were used to detect the possible mechanism in the AD-associated model rats. RESULTS We observed that Aβ1-42 infusion could induce spatial learning and memory deficits in rats. Simultaneously, Aβ1-42 also could reduce the neuron in cornu ammonis 1 and dentate gyrus of hippocampus, as well as increase the levels of cleaved caspase 3, hyperphosphorylated tau at the sites Ser396, Ser404, and Thr205 with enhancing staining of black granules in brain. We also found that Aβ1-42 could increase the activity of extracellular signal-regulated protein kinase (ERK) and glycogen synthase kinase-3β (GSK-3β). Meanwhile, these phenomena could be ameliorated when Tan IIA was used. CONCLUSION We concluded that Tan IIA might have neuroprotective effect and improving learning and memory ability to be a viable candidate in AD therapy with mechanisms involving the ERK and GSK-3β signal pathway.
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Affiliation(s)
- Li Lin
- 1 Cell Molecular Biology Laboratory of Basic Medical College, Hubei University of Chinese Medicine, Wuhan, China.,2 Hubei Research Institute of Geriatrics, Collaborative Innovation Center of Hubei Province, Hubei University of Chinese Medicine, Wuhan, China
| | - Sarmad Sheraz Jadoon
- 1 Cell Molecular Biology Laboratory of Basic Medical College, Hubei University of Chinese Medicine, Wuhan, China.,3 Department of Pharmacology, College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China
| | - Shang-Zhi Liu
- 1 Cell Molecular Biology Laboratory of Basic Medical College, Hubei University of Chinese Medicine, Wuhan, China
| | - Ru-Yi Zhang
- 3 Department of Pharmacology, College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China
| | - Fan Li
- 3 Department of Pharmacology, College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China
| | - Mei-Ya Zhang
- 3 Department of Pharmacology, College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China
| | - Tan Ai-Hua
- 1 Cell Molecular Biology Laboratory of Basic Medical College, Hubei University of Chinese Medicine, Wuhan, China.,2 Hubei Research Institute of Geriatrics, Collaborative Innovation Center of Hubei Province, Hubei University of Chinese Medicine, Wuhan, China
| | - Qiu-Yun You
- 3 Department of Pharmacology, College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China
| | - Ping Wang
- 2 Hubei Research Institute of Geriatrics, Collaborative Innovation Center of Hubei Province, Hubei University of Chinese Medicine, Wuhan, China
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Lennarz S, Alich TC, Kelly T, Blind M, Beck H, Mayer G. Selective Aptamer-Based Control of Intraneuronal Signaling. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201409597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sabine Lennarz
- Life and Medical Sciences Institute; University of Bonn; Gerhard-Domagk-Str. 1 Bonn Germany
| | - Therese Christine Alich
- Laboratory of Experimental Epileptology and Cognition Research; Department of Epileptology; Sigmund-Freud Str. 25 Bonn Germany
| | - Tony Kelly
- Laboratory of Experimental Epileptology and Cognition Research; Department of Epileptology; Sigmund-Freud Str. 25 Bonn Germany
| | - Michael Blind
- Life and Medical Sciences Institute; University of Bonn; Gerhard-Domagk-Str. 1 Bonn Germany
| | - Heinz Beck
- Laboratory of Experimental Epileptology and Cognition Research; Department of Epileptology; Sigmund-Freud Str. 25 Bonn Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen in der Helmholtz Gemeinschaft
| | - Günter Mayer
- Life and Medical Sciences Institute; University of Bonn; Gerhard-Domagk-Str. 1 Bonn Germany
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5
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Lennarz S, Alich TC, Kelly T, Blind M, Beck H, Mayer G. Selective aptamer-based control of intraneuronal signaling. Angew Chem Int Ed Engl 2015; 54:5369-73. [PMID: 25754968 PMCID: PMC5324602 DOI: 10.1002/anie.201409597] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/29/2015] [Indexed: 11/11/2022]
Abstract
Cellular behavior is orchestrated by the complex interactions of a myriad of intracellular signal transduction pathways. To understand and investigate the role of individual components in such signaling networks, the availability of specific inhibitors is of paramount importance. We report the generation and validation of a novel variant of an RNA aptamer that selectively inhibits the mitogen-activated kinase pathway in neurons. We demonstrate that the aptamer retains function under intracellular conditions and that application of the aptamer through the patch-clamp pipette efficiently inhibits mitogen-activated kinase-dependent synaptic plasticity. This approach introduces synthetic aptamers as generic tools, readily applicable to inhibit different components of intraneuronal signaling networks with utmost specificity.
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Affiliation(s)
- Sabine Lennarz
- Life and Medical Sciences Institute, University of Bonn, Gerhard-Domagk-Str. 1, Bonn (Germany)
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Oeckl P, Steinacker P, Feneberg E, Otto M. Cerebrospinal fluid proteomics and protein biomarkers in frontotemporal lobar degeneration: Current status and future perspectives. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:757-68. [PMID: 25526887 DOI: 10.1016/j.bbapap.2014.12.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/18/2014] [Accepted: 12/11/2014] [Indexed: 12/13/2022]
Abstract
Frontotemporal lobar degeneration (FTLD) comprises a spectrum of rare neurodegenerative diseases with an estimated prevalence of 15-22 cases per 100,000 persons including the behavioral variant of frontotemporal dementia (bvFTD), progressive non-fluent aphasia (PNFA), semantic dementia (SD), FTD with motor neuron disease (FTD-MND), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). The pathogenesis of the diseases is still unclear and clinical diagnosis of FTLD is hampered by overlapping symptoms within the FTLD subtypes and with other neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Intracellular protein aggregates in the brain are a major hallmark of FTLD and implicate alterations in protein metabolism or function in the disease's pathogenesis. Cerebrospinal fluid (CSF) which surrounds the brain can be used to study changes in neurodegenerative diseases and to identify disease-related mechanisms or neurochemical biomarkers for diagnosis. In the present review, we will give an overview of the current literature on proteomic studies in CSF of FTLD patients. Reports of targeted and unbiased proteomic approaches are included and the results are discussed in regard of their informative value about disease pathology and the suitability to be used as diagnostic biomarkers. Finally, we will give some future perspectives on CSF proteomics and a list of candidate biomarkers which might be interesting for validation in further studies. This article is part of a Special Issue entitled: Neuroproteomics: Applications in neuroscience and neurology.
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Affiliation(s)
- Patrick Oeckl
- Department of Neurology, Ulm University Hospital, Oberer Eselsberg 45, 89081 Ulm, Germany.
| | - Petra Steinacker
- Department of Neurology, Ulm University Hospital, Oberer Eselsberg 45, 89081 Ulm, Germany.
| | - Emily Feneberg
- Department of Neurology, Ulm University Hospital, Oberer Eselsberg 45, 89081 Ulm, Germany.
| | - Markus Otto
- Department of Neurology, Ulm University Hospital, Oberer Eselsberg 45, 89081 Ulm, Germany.
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Menard C, Bastianetto S, Quirion R. Neuroprotective effects of resveratrol and epigallocatechin gallate polyphenols are mediated by the activation of protein kinase C gamma. Front Cell Neurosci 2013; 7:281. [PMID: 24421757 PMCID: PMC3872731 DOI: 10.3389/fncel.2013.00281] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/15/2013] [Indexed: 01/08/2023] Open
Abstract
Polyphenols such as epigallocatechin gallate (EGCG) and resveratrol have received a great deal of attention because they may contribute to the purported neuroprotective action of the regular consumption of green tea and red wine. Many studies, including those published by our group, suggest that this protective action includes their abilities to prevent the neurotoxic effects of beta-amyloid, a protein whose accumulation likely plays a pivotal role in Alzheimer's disease. Moreover, the scavenging activities of polyphenols on reactive oxygen species and their inhibitory action of cyclooxygenase likely explain, at least in part, their antioxidant and anti-inflammatory activities. Besides these well-documented properties, the modulatory action of these polyphenols on intracellular signaling pathways related to cell death/survival (e.g., protein kinase C, PKC) has yet to be investigated in detail. Using rat hippocampal neuronal cells, we aimed to investigate here the effects of EGCG and resveratrol on cell death induced by GF 109203X, a selective inhibitor of PKC. The MTT/resazurin and spectrin assays indicated that EGCG and resveratrol protected against GF 109203X-induced cell death and cytoskeleton degeneration, with a maximal effect at 1 and 3 μM, respectively. Moreover, immunofluorescence data revealed that cells treated with these polyphenols increased PKC gamma (γ) activation and promoted neuronal interconnections. Finally, we found that the protective effects of both polyphenols on the cytoskeleton and synaptic plasticity were mediated by the PKCγ subunit. Taken together, the results suggest that PKC, and more specifically its γ subunit, plays a critical role in the protective action of EGCG and resveratrol on neuronal integrity.
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Affiliation(s)
- Caroline Menard
- Laboratory of Neuroendocrinology of Aging, Centre Hospitalier de l'Université de Montréal Research Center Montreal, QC, Canada ; Department of Medicine, University of Montreal Montreal, QC, Canada ; Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Department of Psychiatry, McGill University Montreal, QC, Canada
| | - Stéphane Bastianetto
- Douglas Mental Health University Institute, McGill University Montreal, QC, Canada
| | - Rémi Quirion
- Douglas Mental Health University Institute, McGill University Montreal, QC, Canada ; Department of Psychiatry, McGill University Montreal, QC, Canada
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Cestari V, Rossi-Arnaud C, Saraulli D, Costanzi M. The MAP(K) of fear: from memory consolidation to memory extinction. Brain Res Bull 2013; 105:8-16. [PMID: 24080449 DOI: 10.1016/j.brainresbull.2013.09.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/20/2013] [Accepted: 09/21/2013] [Indexed: 11/25/2022]
Abstract
The highly conserved mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling cascade is involved in several intracellular processes ranging from cell differentiation to proliferation, as well as in synaptic plasticity. In the last two decades, the role of MAPK/ERK in long-term memory formation in mammals, particularly in fear-related memories, has been extensively investigated. In this review we describe knowledge advancement on the role of MAPK/ERK in orchestrating the intracellular processes that lead to the consolidation, reconsolidation and extinction of fear memories. In doing so, we report studies in which the specific role of MAP/ERK in switching from memory formation to memory erasure has been suggested. The possibility to target MAPK/ERK in developing and/or refining pharmacological approaches to treat psychiatric disorders in which fear regulation is defective has also been envisaged.
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Affiliation(s)
- Vincenzo Cestari
- Institute of Cellular Biology and Neurobiology, National Research Council and Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143 Rome, Italy; Department of Psychology and "Daniel Bovet" Center, Sapienza University of Rome, via dei Marsi 78, 00185 Rome, Italy.
| | - Clelia Rossi-Arnaud
- Department of Psychology, Sapienza University of Rome, via dei Marsi 78, 00185 Rome, Italy
| | - Daniele Saraulli
- Institute of Cellular Biology and Neurobiology, National Research Council and Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143 Rome, Italy; Department of Psychology, Sapienza University of Rome, via dei Marsi 78, 00185 Rome, Italy
| | - Marco Costanzi
- Institute of Cellular Biology and Neurobiology, National Research Council and Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143 Rome, Italy; Department of Human Sciences, LUMSA University, p.zza delle Vaschette 101, 00193 Rome, Italy
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9
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Bibl M, Esselmann H, Wiltfang J. Neurochemical biomarkers in Alzheimer's disease and related disorders. Ther Adv Neurol Disord 2012; 5:335-48. [PMID: 23139704 PMCID: PMC3487531 DOI: 10.1177/1756285612455367] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Neurochemical biomarkers for diagnosing dementias are currently under intensive investigation and the field is rapidly expanding. The main protagonists and the best defined among them are cerebrospinal fluid levels of Aβ42, tau and its phosphorylated forms (p-tau). In addition, novel cerebrospinal fluid biomarkers are emerging and their multiparametric assessment seems most promising for increasing the accuracy in neurochemical dementia diagnostics. The combined assessment of Aβ42 and p-tau has recently shown value for diagnosing prodromal states of Alzheimer's dementia, that is, mild cognitive impairment. Disease-specific biomarkers for other degenerative dementias are still missing, but some progress has recently been made. As lumbar puncture is an additional burden for the patient, blood-based neurochemical biomarkers are definitely warranted and promising new discoveries have been made in this direction. These diagnostic developments have implicit therapeutic consequences and give rise to new requirements for future neurochemical dementia diagnostics.
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Affiliation(s)
- Mirko Bibl
- Department of Psychiatry, Psychotherapy and Addiction Medicine, Kliniken Essen-Mitte; University of Duisburg-Essen, Essen, Germany
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Spitzer P, Schieb H, Kamrowski-Kruck H, Otto M, Chiasserini D, Parnetti L, Herukka SK, Schuchhardt J, Wiltfang J, Klafki HW. Evidence for Elevated Cerebrospinal Fluid ERK1/2 Levels in Alzheimer Dementia. Int J Alzheimers Dis 2011; 2011:739847. [PMID: 22145083 PMCID: PMC3227514 DOI: 10.4061/2011/739847] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 08/31/2011] [Indexed: 11/22/2022] Open
Abstract
Cerebrospinal fluid (CSF) samples from 33 patients with Alzheimer dementia (AD), 21 patients with mild cognitive impairment who converted to AD during followup (MCI-AD), 25 patients with stable mild cognitive impairment (MCI-stable), and 16 nondemented subjects (ND) were analyzed with a chemiluminescence immunoassay to assess the levels of the mitogen-activated protein kinase ERK1/2 (extracellular signal-regulated kinase 1/2). The results were evaluated in relation to total Tau (tTau), phosphorylated Tau (pTau), and beta-amyloid 42 peptide (Aβ42). CSF-ERK1/2 was significantly increased in the AD group as compared to stable MCI patients and the ND group. Western blot analysis of a pooled cerebrospinal fluid sample revealed that both isoforms, ERK1 and ERK2, and low amounts of doubly phosphorylated ERK2 were detectable. As a predictive diagnostic AD biomarker, CSF-ERK1/2 was inferior to tTau, pTau, and Aβ42.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Laboratory for Molecular Neurobiology, LVR-Klinikum Essen, University of Duisburg-Essen, Virchowstraße 174, 45147 Essen, Germany
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11
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Abstract
The concentration of amyloid-β (Aβ) within the brain extracellular space is one determinant of whether the peptide will aggregate into toxic species that are important in Alzheimer's disease (AD) pathogenesis. Some types of synaptic activity can regulate Aβ levels. Here we demonstrate two distinct mechanisms that are simultaneously activated by NMDA receptors and regulate brain interstitial fluid (ISF) Aβ levels in opposite directions in the living mouse. Depending on the dose of NMDA administered locally to the brain, ISF Aβ levels either increase or decrease. Low doses of NMDA increase action potentials and synaptic transmission which leads to an elevation in synaptic Aβ generation. In contrast, high doses of NMDA activate signaling pathways that lead to ERK (extracellular-regulated kinase) activation, which reduces processing of APP into Aβ. This depression in Aβ via APP processing occurs despite dramatically elevated synaptic activity. Both of these synaptic mechanisms are simultaneously active, with the balance between them determining whether ISF Aβ levels will increase or decrease. NMDA receptor antagonists increase ISF Aβ levels, suggesting that basal activity at these receptors normally suppresses Aβ levels in vivo. This has implications for understanding normal Aβ metabolism as well as AD pathogenesis.
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Mossello E, Ballini E, Mello AM, Tarantini F, Simoni D, Baldasseroni S, Marchionni N. Biomarkers of Alzheimer's disease: from central nervous system to periphery? Int J Alzheimers Dis 2010; 2011:342980. [PMID: 21197431 PMCID: PMC3010633 DOI: 10.4061/2011/342980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/15/2010] [Indexed: 11/20/2022] Open
Abstract
Alzheimer's Disease (AD) is the most frequent form of dementia and represents one of the main causes of disability among older subjects. Up to now, the diagnosis of AD has been made according to clinical criteria. However, the use of such criteria does not allow an early diagnosis, as pathological alterations may be apparent many years before the clear-cut clinical picture. An early diagnosis is even more valuable to develop new treatments, potentially interfering with the pathogenetic process. During the last decade, several neuroimaging and cerebrospinal fluid (CSF) parameters have been introduced to allow an early and accurate detection of AD patients, and, recently, they have been included among research criteria for AD diagnosis. However, their use in clinical practice suffers from limitations both in accuracy and availability. The increasing amount of knowledge about peripheral biomarkers will possibly allow the future identification of reliable and easily available diagnostic tests.
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Affiliation(s)
- Enrico Mossello
- Unit of Gerontology and Geriatric Medicine, Department of Critical Care Medcine and Surgery, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
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13
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Spitzer P, Klafki HW, Blennow K, Buée L, Esselmann H, Herruka SK, Jimenez C, Klivenyi P, Lewczuk P, Maler JM, Markus K, Meyer HE, Morris C, Müller T, Otto M, Parnetti L, Soininen H, Schraen S, Teunissen C, Vecsei L, Zetterberg H, Wiltfang J. cNEUPRO: Novel Biomarkers for Neurodegenerative Diseases. Int J Alzheimers Dis 2010; 2010. [PMID: 20886057 PMCID: PMC2945639 DOI: 10.4061/2010/548145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 07/05/2010] [Indexed: 12/04/2022] Open
Abstract
“clinical NEUroPROteomics of neurodegenerative diseases” (cNEUPRO) is a Specific Targeted Research Project (STREP) within the sixth framework program of the European Commission dedicated to the search for novel biomarker candidates for Alzheimer's disease and other neurodegenerative diseases. The ultimate goal of cNEUPRO is to identify one or more valid biomarker(s) in blood and CSF applicable to support the early and differential diagnosis of dementia disorders. The consortium covers all steps required for the discovery of novel biomarker candidates such as acquisition of high quality CSF and blood samples from relevant patient groups and controls, analysis of body fluids by various methods, and finally assay development and assay validation. Here we report the standardized procedures for diagnosis and preanalytical sample-handling within the project, as well as the status of the ongoing research activities and some first results.
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Affiliation(s)
- Philipp Spitzer
- Laboratory for Molecular Neurobiology, Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, LVR-Klinikum Essen, Virchowstraße 174, 45147 Essen, Germany
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