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Varma C, Luo E, Bostrom G, Bathini P, Berdnik D, Wyss‐Coray T, Zhao T, Dong X, Ervin FR, Beierschmitt A, Palmour RM, Lemere CA. Plasma and CSF biomarkers of aging and cognitive decline in Caribbean vervets. Alzheimers Dement 2024; 20:5460-5480. [PMID: 38946666 PMCID: PMC11350037 DOI: 10.1002/alz.14038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 07/02/2024]
Abstract
INTRODUCTION Vervets are non-human primates that share high genetic homology with humans and develop amyloid beta (Aβ) pathology with aging. We expand current knowledge by examining Aβ pathology, aging, cognition, and biomarker proteomics. METHODS Amyloid immunoreactivity in the frontal cortex and temporal cortex/hippocampal regions from archived vervet brain samples ranging from young adulthood to old age was quantified. We also obtained cognitive scores, plasma samples, and cerebrospinal fluid (CSF) samples in additional animals. Plasma and CSF proteins were quantified with platforms utilizing human antibodies. RESULTS We found age-related increases in Aβ deposition in both brain regions. Bioinformatic analyses assessed associations between biomarkers and age, sex, cognition, and CSF Aβ levels, revealing changes in proteins related to immune-related inflammation, metabolism, and cellular processes. DISCUSSION Vervets are an effective model of aging and early-stage Alzheimer's disease, and we provide translational biomarker data that both align with previous results in humans and provide a basis for future investigations. HIGHLIGHTS We found changes in immune and metabolic plasma biomarkers associated with age and cognition. Cerebrospinal fluid (CSF) biomarkers revealed changes in cell signaling indicative of adaptative processes. TNFRSF19 (TROY) and Artemin co-localize with Alzheimer's disease pathology. Vervets are a relevant model for translational studies of early-stage Alzheimer's disease.
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Affiliation(s)
- Curran Varma
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
| | - Eva Luo
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
| | - Gustaf Bostrom
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Department of Public Health and Caring SciencesGeriatrics, Uppsala UniversityUppsalaSweden
- Centre for Clinical ResearchUppsala UniversityVästmanland County HospitalVästeråsSweden
| | - Praveen Bathini
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
| | - Daniela Berdnik
- Department of Neurology and Neurological SciencesStanford University School of MedicineStanfordCaliforniaUSA
| | - Tony Wyss‐Coray
- Department of Neurology and Neurological SciencesStanford University School of MedicineStanfordCaliforniaUSA
| | - Tingting Zhao
- Department of Medical OncologyDana‐Farber Cancer InstituteBostonMassachusettsUSA
| | - Xianjun Dong
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
- Genomics and Bioinformatics HubBrigham and Women's HospitalBostonMassachusettsUSA
| | - Frank R. Ervin
- Behavioral Sciences FoundationSaint Kitts, Eastern CaribbeanMontrealCanada
- Faculty of Medicine and Health SciencesMcGill UniversityMontrealCanada
| | - Amy Beierschmitt
- Behavioral Sciences FoundationSaint Kitts, Eastern CaribbeanMontrealCanada
- Department of Biomedical SciencesRoss University School of Veterinary MedicineSt KittsUK
| | - Roberta M. Palmour
- Behavioral Sciences FoundationSaint Kitts, Eastern CaribbeanMontrealCanada
- Faculty of Medicine and Health SciencesMcGill UniversityMontrealCanada
| | - Cynthia A. Lemere
- Department of NeurologyAnn Romney Center for Neurologic DiseasesBrigham and Women's HospitalBostonMassachusettsUSA
- Department of NeurologyHarvard Medical SchoolBostonMassachusettsUSA
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Ait-Bouziad N, Chiki A, Limorenko G, Xiao S, Eliezer D, Lashuel HA. Phosphorylation of the overlooked tyrosine 310 regulates the structure, aggregation, and microtubule- and lipid-binding properties of Tau. J Biol Chem 2020; 295:7905-7922. [PMID: 32341125 PMCID: PMC7278352 DOI: 10.1074/jbc.ra119.012517] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/22/2020] [Indexed: 01/15/2023] Open
Abstract
The microtubule-associated protein Tau is implicated in the pathogenesis of several neurodegenerative disorders, including Alzheimer's disease. Increasing evidence suggests that post-translational modifications play critical roles in regulating Tau's normal functions and its pathogenic properties in tauopathies. Very little is known about how phosphorylation of tyrosine residues influences the structure, aggregation, and microtubule- and lipid-binding properties of Tau. Here, we sought to determine the relative contributions of phosphorylation of one or several of the five tyrosine residues in Tau (Tyr-18, -29, -197, -310, and -394) to the regulation of its biophysical, aggregation, and functional properties. We used a combination of site-specific mutagenesis and in vitro phosphorylation by c-Abl kinase to generate Tau species phosphorylated at all five tyrosine residues, all tyrosine residues except Tyr-310 or Tyr-394 (pTau-Y310F and pTau-Y394F, respectively) and Tau phosphorylated only at Tyr-310 or Tyr-394 (4F/pTyr-310 or 4F/pTyr-394). We observed that phosphorylation of all five tyrosine residues, multiple N-terminal tyrosine residues (Tyr-18, -29, and -197), or specific phosphorylation only at residue Tyr-310 abolishes Tau aggregation and inhibits its microtubule- and lipid-binding properties. NMR experiments indicated that these effects are mediated by a local decrease in β-sheet propensity of Tau's PHF6 domain. Our findings underscore Tyr-310 phosphorylation has a unique role in the regulation of Tau aggregation, microtubule, and lipid interactions. These results also highlight the importance of conducting further studies to elucidate the role of Tyr-310 in the regulation of Tau's normal functions and pathogenic properties.
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Affiliation(s)
- Nadine Ait-Bouziad
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Anass Chiki
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Galina Limorenko
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Shifeng Xiao
- Shenzhen Key Laboratory of Marine Biotechnology and Ecology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
- Department of Biochemistry and Program in Structural Biology, Weill Cornell Medical College, New York, New York
| | - David Eliezer
- Department of Biochemistry and Program in Structural Biology, Weill Cornell Medical College, New York, New York
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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3
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Alam J, Sharma L. Potential Enzymatic Targets in Alzheimer's: A Comprehensive Review. Curr Drug Targets 2020; 20:316-339. [PMID: 30124150 DOI: 10.2174/1389450119666180820104723] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/23/2018] [Accepted: 08/15/2018] [Indexed: 12/13/2022]
Abstract
Alzheimer's, a degenerative cause of the brain cells, is called as a progressive neurodegenerative disease and appears to have a heterogeneous etiology with main emphasis on amyloid-cascade and hyperphosphorylated tau-cascade hypotheses, that are directly linked with macromolecules called enzymes such as β- & γ-secretases, colinesterases, transglutaminases, and glycogen synthase kinase (GSK-3), cyclin-dependent kinase (cdk-5), microtubule affinity-regulating kinase (MARK). The catalytic activity of the above enzymes is the result of cognitive deficits, memory impairment and synaptic dysfunction and loss, and ultimately neuronal death. However, some other enzymes also lead to these dysfunctional events when reduced to their normal activities and levels in the brain, such as α- secretase, protein kinase C, phosphatases etc; metabolized to neurotransmitters, enzymes like monoamine oxidase (MAO), catechol-O-methyltransferase (COMT) etc. or these abnormalities can occur when enzymes act by other mechanisms such as phosphodiesterase reduces brain nucleotides (cGMP and cAMP) levels, phospholipase A2: PLA2 is associated with reactive oxygen species (ROS) production etc. On therapeutic fronts, several significant clinical trials are underway by targeting different enzymes for development of new therapeutics to treat Alzheimer's, such as inhibitors for β-secretase, GSK-3, MAO, phosphodiesterase, PLA2, cholinesterases etc, modulators of α- & γ-secretase activities and activators for protein kinase C, sirtuins etc. The last decades have perceived an increasing focus on findings and search for new putative and novel enzymatic targets for Alzheimer's. Here, we review the functions, pathological roles, and worth of almost all the Alzheimer's associated enzymes that address to therapeutic strategies and preventive approaches for treatment of Alzheimer's.
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Affiliation(s)
- Jahangir Alam
- School of Pharmaceutical Sciences, Shoolini University, Solan, H.P., Pin 173229, India
| | - Lalit Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, H.P., Pin 173229, India
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Untargeted Metabolomics and Steroid Signatures in Urine of Male Pattern Baldness Patients after Finasteride Treatment for a Year. Metabolites 2020; 10:metabo10040131. [PMID: 32235609 PMCID: PMC7241081 DOI: 10.3390/metabo10040131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 01/25/2023] Open
Abstract
Male pattern baldness (MPB) has been associated with dihydrotestosterone (DHT) expression. Finasteride treats MPB by inhibiting 5-alpha reductase and blocking DHT production. In this study, we aimed to identify metabolic differences in urinary metabolomics profiles between MPB patients after a one-year treatment with finasteride and healthy controls. Untargeted and targeted metabolomics profiling was performed using liquid chromatography-mass spectrometry (LC-MS). We hypothesized that there would be changes in overall metabolite concentrations, especially steroids, in the urine of hair loss patients treated with finasteride and normal subjects. Untargeted analysis indicated differences in steroid hormone biosynthesis. Therefore, we conducted targeted profiling for steroid hormone biosynthesis to identify potential biomarkers, especially androgens and estrogens. Our study confirmed the differences in the concentration of urinary androgens and estrogens between healthy controls and MPB patients. Moreover, the effect of finasteride was confirmed by the DHT/T ratio in urine samples of MPB patients. Our metabolomics approach provided insight into the physiological alterations in MPB patients who have been treated with finasteride for a year and provided evidence for the association of finasteride and estrogen levels. Through a targeted approach, our results suggest that urinary estrogens must be studied in relation to MPB and post-finasteride syndrome.
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Li Z, Xiong Z, Manor LC, Cao H, Li T. Integrative computational evaluation of genetic markers for Alzheimer's disease. Saudi J Biol Sci 2018; 25:996-1002. [PMID: 30108454 PMCID: PMC6088103 DOI: 10.1016/j.sjbs.2018.05.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 02/05/2023] Open
Abstract
Recent studies have reported hundreds of genes linked to Alzheimer’s Disease (AD). However, many of these candidate genes may be not identified in different studies when analyses were replicated. Moreover, results could be controversial. Here, we proposed a computational workflow to curate and evaluate AD related genes. The method integrates large scale literature knowledge data and gene expression data that were acquired from postmortem human brain regions (AD case/control: 31/32 and 22/8). Pathway Enrichment, Sub-Network Enrichment, and Gene-Gene Interaction analysis were conducted to study the pathogenic profile of the candidate genes, with 4 metrics proposed and validated for each gene. By using our approach, a scalable AD genetic database was developed, including AD related genes, pathways, diseases and info of supporting references. The AD case/control classification supported the effectiveness of the 4 proposed metrics, which successfully identified 21 well-studied AD genes (i.g. TGFB1, CTNNB1, APP, IL1B, PSEN1, PTGS2, IL6, VEGFA, SOD1, AKT1, CDK5, TNF, GSK3B, TP53, CCL2, BDNF, NGF, IGF1, SIRT1, AGER and TLR) and highlighted one recently reported AD gene (i.g. ITGB1). The computational biology approach and the AD database developed in this study provide a valuable resource which may facilitate the understanding of the AD genetic profile.
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Affiliation(s)
- Zhe Li
- The Mental Health Center and the Psychiatric Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China.,The Mental Rehabilitation Center, Karamay Municipal People's Hospital, Karamay, Xinjiang 830054, China
| | - ZhenZhen Xiong
- School of Nursing, Chengdu Medical College, Chengdu, Sichuan 610083, China
| | - Lydia C Manor
- Department of Bioinformatics, American Informatics Consultant LLC, Rockville, MD 20852, USA
| | - Hongbao Cao
- Unit on Statistical Genomics, National Institute of Mental Health, NIH, Bethesda 20892, USA.,Department of Genomics Research, R&D Solutions, Elsevier Inc., Rockville, MD 20852, USA
| | - Tao Li
- The Mental Health Center and the Psychiatric Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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Poulsen ET, Iannuzzi F, Rasmussen HF, Maier TJ, Enghild JJ, Jørgensen AL, Matrone C. An Aberrant Phosphorylation of Amyloid Precursor Protein Tyrosine Regulates Its Trafficking and the Binding to the Clathrin Endocytic Complex in Neural Stem Cells of Alzheimer's Disease Patients. Front Mol Neurosci 2017; 10:59. [PMID: 28360834 PMCID: PMC5350151 DOI: 10.3389/fnmol.2017.00059] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/21/2017] [Indexed: 11/15/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and is likely caused by defective amyloid precursor protein (APP) trafficking and processing in neurons leading to amyloid plaques containing the amyloid-β (Aβ) APP peptide byproducts. Understanding how APP is targeted to selected destinations inside neurons and identifying the mechanisms responsible for the generation of Aβ are thus the keys for the advancement of new therapies. We previously developed a mouse model with a mutation at tyrosine (Tyr) 682 in the C-terminus of APP. This residue is needed for APP to bind to the coating protein Clathrin and to the Clathrin adaptor protein AP2 as well as for the correct APP trafficking and sorting in neurons. By extending these findings to humans, we found that APP binding to Clathrin is decreased in neural stem cells from AD sufferers. Increased APP Tyr phosphorylation alters APP trafficking in AD neurons and it is associated to Fyn Tyr kinase activation. We show that compounds affecting Tyr kinase activity and counteracting defects in AD neurons can control APP location and compartmentalization. APP Tyr phosphorylation is thus a potential therapeutic target for AD.
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Affiliation(s)
- Ebbe T. Poulsen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark
| | | | | | - Thorsten J. Maier
- Institute of Biomedicine, Aarhus UniversityAarhus, Denmark
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Goethe UniversityFrankfurt, Germany
| | - Jan J. Enghild
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark
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Computational identification and analysis of neurodegenerative disease associated protein kinases in hominid genomes. Genes Dis 2016; 3:228-237. [PMID: 30258892 PMCID: PMC6147167 DOI: 10.1016/j.gendis.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/15/2016] [Indexed: 01/18/2023] Open
Abstract
Protein kinases play an important role in the incidence of neurodegenerative diseases. However their incidence in non-human primates is found to be very low. Small differences among the genomes might influence the disease susceptibilities. The present study deals with finding the genetic differences of protein kinases in humans and their three closest evolutionary partners chimpanzee, gorilla and orangutan for three neurodegenerative diseases namely, Alzheimer's, Parkinson's and Huntington's diseases. In total 47 human protein kinases associated with three neurodegenerative diseases and their orthologs from other three non-human primates were identified and analyzed for any possible susceptibility factors in humans. Multiple sequence alignment and pairwise sequence alignment revealed that, 18 human protein kinases including DYRK1A, RPS6KB1, and GRK6 contained significant indels and substitutions. Further phosphorylation site analysis revealed that eight kinases including MARK2 and LTK contained sites of phosphorylation exclusive to human genomes which could be particular candidates in determining disease susceptibility between human and non-human primates. Final pathway analysis of these eight kinases and their targets revealed that these kinases could have long range consequences in important signaling pathways which are associated with neurodegenerative diseases.
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8
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Crutcher KA, Anderton BH, Barger SW, Ohm TG, Snow AD. Cellular and molecular pathology in alzheimer's disease. Hippocampus 2013. [DOI: 10.1002/hipo.1993.4500030730] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Keith A. Crutcher
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A
| | | | - Steven W. Barger
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington, Kentucky, U.S.A
| | - Thomas G. Ohm
- Zentrum der Morphologie, J. W. Goethe‐Universität, Frankfurt, Germany
| | - Alan D. Snow
- Department of Neuropathology, University of Washington, Seattle, Washington, U.S.A
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9
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Köhler C, Dinekov M, Götz J. Active glycogen synthase kinase-3 and tau pathology-related tyrosine phosphorylation in pR5 human tau transgenic mice. Neurobiol Aging 2013; 34:1369-79. [DOI: 10.1016/j.neurobiolaging.2012.11.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 10/05/2012] [Accepted: 11/22/2012] [Indexed: 02/08/2023]
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10
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Reyes JF, Reynolds MR, Horowitz PM, Fu Y, Guillozet-Bongaarts AL, Berry R, Binder LI. A possible link between astrocyte activation and tau nitration in Alzheimer's disease. Neurobiol Dis 2008; 31:198-208. [PMID: 18562203 DOI: 10.1016/j.nbd.2008.04.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 03/28/2008] [Accepted: 04/17/2008] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) pathology has been characterized, in part, by the self-assembly of the tau molecule into neurofibrillary tangles (NFT). While different post-translational modifications have been identified that accelerate tau aggregation, nitration at tyrosine residues prevents or slows tau filament formation in vitro. Of the five tyrosine residues within the molecule, nitration at the first tyrosine residue (Tyr 18) results in a profound inhibition of filament self-assembly. To determine whether nitration at Tyr 18 occurs in AD pathology, monoclonal antibodies were raised against a synthetic tau peptide nitrated at Tyr 18. A clone, termed Tau-nY18, reacts specifically with tau proteins nitrated at Tyr 18 and fails to cross-react with other nitrated tyrosine residues spanning the length of the molecule or with other proteins known to be nitrated in neurodegenerative diseases. In situ, Tau-nY18 sparsely labels the neuronal pathological hallmarks of the disease, including NFT and dystrophic neurites. Surprisingly however, Tau-nY18 robustly labels nitrated tau within activated, GFAP positive astrocytes intimately associated with amyloid plaques. Furthermore, this antibody detects nitrated tau in soluble preparations from both severe AD brains (Braak stage V, VI) and age-matched controls. Collectively, these findings suggest that nitration at Tyr 18 may be linked to astrocyte activation, an early event associated with amyloid plaque formation.
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Affiliation(s)
- Juan F Reyes
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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11
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Sharma VM, Litersky JM, Bhaskar K, Lee G. Tau impacts on growth-factor-stimulated actin remodeling. J Cell Sci 2007; 120:748-57. [PMID: 17284520 DOI: 10.1242/jcs.03378] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The microtubule-associated protein tau interacts with the SH3 domain of non-receptor Src family protein tyrosine kinases. A potential consequence of the SH3 interaction is the upregulation of tyrosine kinase activity. Here we investigated the activation of Src or Fyn by tau, both in vitro and in vivo. Tau increased the kinase activity in in vitro assays and in transfected COS7 cells. In platelet-derived growth factor (PDGF)-stimulated fibroblasts, tau appeared to prime Src for activation following PDGF stimulation, as reflected by changes in Src-mediated actin rearrangements. In addition, while fibroblasts normally recovered actin stress fibers by 5-7 hours after PDGF stimulation, tau-expressing cells showed sustained actin breakdown. Microtubule association by tau was not required for the observed changes in actin morphology. Inhibition of Src kinases or a mutant deficient in Src interaction reduced the effects, implicating Src family protein tyrosine kinases as a mediator of the effects of tau on actin rearrangements. Our results provide evidence that the interaction of tau with Src upregulates tyrosine kinase activity and that this interaction allows tau to impact on growth-factor-induced actin remodeling.
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Affiliation(s)
- Vandana M Sharma
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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12
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Lee G, Thangavel R, Sharma VM, Litersky JM, Bhaskar K, Fang SM, Do LH, Andreadis A, Van Hoesen G, Ksiezak-Reding H. Phosphorylation of tau by fyn: implications for Alzheimer's disease. J Neurosci 2004; 24:2304-12. [PMID: 14999081 PMCID: PMC6730442 DOI: 10.1523/jneurosci.4162-03.2004] [Citation(s) in RCA: 299] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The abnormal phosphorylation of tau protein on serines and threonines is a hallmark characteristic of the neurofibrillary tangles of Alzheimer's disease (AD). The discovery that tau could be phosphorylated on tyrosine and evidence that Abeta signal transduction involved tyrosine phosphorylation led us to question whether tyrosine phosphorylation of tau occurred during the neurodegenerative process. In this study we determined that human tau tyr18 was phosphorylated by the src family tyrosine kinase fyn. By developing both polyclonal and monoclonal probes specific for phospho-tyr18, we found that the phosphorylation of tau at tyr18 occurred at early developmental stages in mouse but was absent in the adult. Our phosphospecific probes also revealed that paired helical filament preparations exhibited phospho-tyr18 reactivity that was sensitive to phosphotyrosine-specific protein phosphatase treatment. Moreover, immunocytochemical studies indicated that tyrosine phosphorylated tau was present in the neurofibrillary tangles in AD brain. However, the staining pattern excluded neuropil threads and dystrophic neurites indicating that tyrosine phosphorylated tau was distributed in AD brain in a manner dissimilar from other abnormally phosphorylated tau. We also found evidence suggesting that differentially phosphorylated tau existed within degenerating neurons. Our data add new support for a role for fyn in the neurodegenerative process.
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Affiliation(s)
- Gloria Lee
- Department of Internal Medicine, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242, USA.
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Chromy BA, Lambert MP, Klein WL. Increased Protein Tyrosine Phosphorylation in Apoptotic Neural Cell Death Due to Microtubule Perturbations. Neurotox Res 2000; 2:357-372. [PMID: 25242875 DOI: 10.1007/bf03033343] [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] [Indexed: 10/20/2022]
Abstract
The microtubule-perturbing drugs colchicine and taxol have been found to induce apoptosis in a CNS neuronal cell line. Apoptosis in drug-treated rat B103 neuroblastoma cells was evident in characteristic morphological changes, internucleosomal DNA fragmentation, and loss of nuclear content. Since colchicine and taxol have opposite actions on microtubule integrity, disruption of the active turnover of the microtubule network appears to be a crucial step for apoptosis to occur. It has been suggested that the basis for apoptosis by these drugs derives from their known block of the cell cycle at G2/M, but this does not appear the sole reason as both colchicine and taxol were able to evoke high levels of apoptosis in cells differentiated by Bt2cAMP or serum withdrawal. Further tests of cellular consequences of microtubule perturbation revealed a specific impact on signal transduction involving protein tyrosine phosphorylation. Immunoprecipitation with antibodies against tyrosine phosphorylated proteins showed a striking increase in the phosphorylation of a Triton-insoluble ~90 kDa protein, roughly concurrent with the onset of internucleosomal DNA fragmentation. Cycloheximide and genistein significantly reduced cell death and blocked appearance of the ~90 kDa tyrosine phosphorylated protein. Data suggest the hypothesis that signal transduction leading to apoptosis can be triggered by anomalous microtubule turnover and that the mechanism involves tyrosine phosphorylation of a ~90 kDa Triton-resistant protein.
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Affiliation(s)
- Brett A Chromy
- Dept. of Ncurobiology and Physiology, Northwestern University, Evanston, IL 60208
| | - Mary P Lambert
- Dept. of Ncurobiology and Physiology, Northwestern University, Evanston, IL 60208
| | - William L Klein
- Dept. of Ncurobiology and Physiology, Northwestern University, Evanston, IL 60208
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Bryan-Sisneros AA, Fraser SP, Suh YH, Djamgoz MB. Toxic effect of the beta-amyloid precursor protein C-terminus fragment and Na+/Ca2+ gradients. Neuroreport 2000; 11:3357-60. [PMID: 11059902 DOI: 10.1097/00001756-200010200-00019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
There is evidence to suggest that certain metabolic fragments of the beta-amyloid precursor protein (betaAPP) containing the whole of the beta-amyloid (Abeta) sequence are toxic to cells. We showed previously that the 105-amino acid C-terminal peptide (CT105) fragment, incorporating Abeta, is particularly toxic to Xenopus oocytes as well as to mammalian neurons. Here, we investigated the contributions of Na+ and Ca2+ gradients to intracellular CT105-induced toxicity in oocytes, monitored by measuring the membrane resting potential. The concentration gradients of Na+ and Ca2+ were manipulated to determine the involvement of the trans-membrane concentration gradients of these ions in the mode of action of CT105. The results suggested that Na+ influx and intracellular events are mainly responsible for the observed CT105-induced toxicity.
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Affiliation(s)
- A A Bryan-Sisneros
- Imperial College of Science, Technology and Medicine, Department of Biology, London, UK
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15
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Battaini F, Pascale A, Lucchi L, Pasinetti GM, Govoni S. Protein kinase C anchoring deficit in postmortem brains of Alzheimer's disease patients. Exp Neurol 1999; 159:559-64. [PMID: 10506528 DOI: 10.1006/exnr.1999.7151] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein kinase C (PKC) has been implicated in the pathophysiology of Alzheimer's disease (AD). The levels of particular isoforms and the activation of PKC are reduced in postmortem brain cortex of AD subjects. Receptors for activated C kinase (RACK) are a family of proteins involved in anchoring activated PKCs to relevant subcellular compartments. Recent evidence has indicated that the impaired activation (translocation) of PKC in the aging brain is associated with a deficit in RACK1, the most well-characterized member of this family. The present study was conducted to determine whether alterations in RACK1 occurred in cortical areas where an impaired translocation of PKC has been demonstrated in AD. Here we report the presence of RACK1 immunoreactivity in human brain frontal cortex for the first time and demonstrate a decrease in RACK1 content in cytosol and membrane extracts in AD when compared with non-AD controls. By comparison, the levels of the RACK1-related PKCbetaII were not modified in the same membrane extracts. These observations add a new perspective in understanding the disease-associated defective PKC signal transduction and indicate that a decrease in an anchoring protein for PKC is an additional determinant of this deficit.
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Affiliation(s)
- F Battaini
- Department of Neurosciences, University of Roma Tor Vergata, Rome, Italy
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Girault JA, Costa A, Derkinderen P, Studler JM, Toutant M. FAK and PYK2/CAKbeta in the nervous system: a link between neuronal activity, plasticity and survival? Trends Neurosci 1999; 22:257-63. [PMID: 10354603 DOI: 10.1016/s0166-2236(98)01358-7] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A major aim of neurobiology today is to improve understanding of the signaling pathways that couple rapid events, such as the action potential and neurotransmitter release, to long-lasting changes in synaptic strength and increased neuronal survival. These adaptations involve interactions of neurons with other cells and with the extracellular matrix. They use, in part, the same molecular machinery that controls adhesion, motility or survival in non-neuronal cells. This machinery includes two homologous non-receptor tyrosine kinases, FAK and PYK2/CAKbeta, and the associated SRC-family tyrosine kinases. Specific brain isoforms of FAK with distinct properties are regulated by neurotransmitters, whereas PYK2/CAKbeta is highly sensitive to depolarization. The multiplicity of the pathways that can be activated by these tyrosine kinases indicates their importance in signal transduction in the adult brain.
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Affiliation(s)
- J A Girault
- INSERM U114, Collège de France, 75005 Paris, France
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17
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Mahadev K, Vemuri MC. Effect of pre- and postnatal ethanol exposure on protein tyrosine kinase activity and its endogenous substrates in rat cerebral cortex. Alcohol 1999; 17:223-9. [PMID: 10231170 DOI: 10.1016/s0741-8329(98)00052-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The rat brain contains high levels of tyrosine-specific protein kinases (PTKs) that specifically phosphorylate the tyrosine-containing synthetic peptide poly(Glu4Tyr1). Using this peptide as a substrate, we have measured the protein tyrosine kinase activity in membrane and cytosolic fractions from the cerebral cortices of pre- and postnatal ethanol-exposed rats at time intervals of 8, 30, and 90 days. During the course of development of the cerebral cortex, PTK activity decreased both in the membrane and cytosolic fractions from 8 and 90 days of age. Maximum activity was associated at the age of 8 days and gradually declined in the later ages (30 and 90 days) of postnatal development. However, PTK activity in the ethanol exposed rat cerebral cortex was further decreased when compared to controls in all the ages of postnatal development in membrane as well as in cytosolic fractions. In the presence of vanadate, a specific inhibitor of protein tyrosine phosphatases (PTPs), the PTK activity increased, indicating that the balance between protein tyrosine kinase and protein tyrosine phosphatase might be lost during ethanol exposure. In addition, when using an antibody specific for phosphotyrosine, endogenous substrates for protein tyrosine kinases were identified on an immunoblot of membrane and cytosolic fractions from the ethanol-exposed rat cerebral cortex. The immunoblot showed several phosphotyrosine-containing proteins with molecular weights of 114, 70, 36, 34, 32, 20, and 14 kDa that were present in the cerebral cortex. However, higher levels of immunoreactivity of these proteins were found in the ethanol-exposed membrane fractions when compared to control fractions-particularly at the age of 30 and 90 days. Two phosphotyrosine proteins with molecular weights of 38 and 40 kDa showed decreased immunoreactivity at the age of 90 days in the cytosolic fraction of an ethanol-exposed rat's cerebral cortex. The differences in tyrosine-specific protein kinase activity and in phosphotyrosine-containing proteins observed during pre- and postnatal ethanol exposure may reflect specific functional defects in the cerebral cortex which could possibly underlie the mechanism contributing to fetal alcohol syndrome (FAS).
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Affiliation(s)
- K Mahadev
- School of Life Sciences, University of Hyderabad, India
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18
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Shimohama S, Sasaki Y, Fujimoto S, Kamiya S, Taniguchi T, Takenawa T, Kimura J. Phospholipase C isozymes in the human brain and their changes in Alzheimer's disease. Neuroscience 1998; 82:999-1007. [PMID: 9466424 DOI: 10.1016/s0306-4522(97)00342-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phosphoinositide-specific phospholipase C is a key enzyme in signal transduction. We have previously demonstrated that an isozyme of phospholipase C, phospholipase C-delta1, accumulates aberrantly in the brains of patients with Alzheimer's disease. In the present study, we examined the property of phospholipase C isozymes in human brains using the methods of chromatofocusing and gel filtration chromatography, and investigated their changes in Alzheimer's disease brains. The chromatofocusing profile of human brain phospholipase C activity on a Mono P HR column demonstrated that phospholipase C-gamma1, exhibiting an isoelectric point value of 5.2, and phospholipase C-delta1, exhibiting isoelectric point values of 5.2 and 4.6, are partly overlapped in their elution. In contrast, the elution profiles of control and Alzheimer's disease brain phospholipase C on Superdex 200 pg column gel filtration chromatography indicated that phospholipase C-gamma1 and phospholipase C-delta1 can be separated with the elution position having a molecular weight of about 240,000 and 140,000, respectively, in the human brain. Using this gel filtration chromatography it was revealed that the phospholipase C-gamma1 activity was significantly decreased and the phospholipase C-delta1 activity was significantly increased in Alzheimer's disease brains compared with controls. These results suggest that the phospholipase C isozymes are differentially involved in Alzheimer's disease.
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Affiliation(s)
- S Shimohama
- Department of Neurology, Faculty of Medicine, Kyoto University, Sakyoku, Japan
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19
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Abstract
Amyloid precursor protein (APP) is known to have neurotrophic effects but little information is available on the signaling pathways activated by APP. Since neurotrophic factors activate tyrosine phosphorylation signaling pathway in general, we investigated whether or not APP activates tyrosine phosphorylation pathway. Alpha-secretase derived APP (sAPP alpha) increased the number of neurites per cell and enhanced tyrosine phosphorylation levels on distinct 125 and 200 kDa protein bands. The APP3 19-335 17-mer peptide, which has been reported to be responsible for the neurotrophic effect of sAPP alpha [Jin, L.-W., Ninomiya, H., Roch, J.-M., Schubert, D., Masliah, E., Otero, D.A.C. and Saitoh, T., J. Neurosci., 14 (1994) 5461-5470], increased neurite extension as well as tyrosine phosphorylation on 125 and 200 kDa proteins in a similar manner to sAPP alpha. Both effects were blocked by an antagonist peptide to 17-mer ERMSQ (APP329-333). These results indicate that the 17-mer domain of APP induces tyrosine phosphorylation on distinct proteins under the condition that induces neurite extension.
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Affiliation(s)
- I Mook-Jung
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla 92093-0624, USA.
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20
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Liguri G, Cecchi C, Latorraca S, Pieri A, Sorbi S, Degl'Innocenti D, Ramponi G. Alteration of acylphosphatase levels in familial Alzheimer's disease fibroblasts with presenilin gene mutations. Neurosci Lett 1996; 210:153-6. [PMID: 8805118 DOI: 10.1016/0304-3940(96)12696-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Acylphosphatase (AcPase), an enzyme that modulates the activity of Ca(2+)-ATPase by hydrolysing its phosphorylated moiety, has been found to be significantly higher in cultured skin fibroblasts from donors affected by early onset familial Alzheimer's disease (EOFAD) with PS-1 and PS-2 gene mutations. Of the two known isoenzymes of acylphosphatase, only the erythrocyte one accounts for the total increase in activity. No relevant alteration was observed in phosphotyrosine phosphatase activity (PTPase), in Ca(2+)-ATPase and Na+, K(+)-ATPase activities of the same cells as compared to age-matched controls. This finding could suggest a possible explanation for the calcium-dependent biochemical alterations previously described in Alzheimer's disease fibroblasts.
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Affiliation(s)
- G Liguri
- Department of Biochemical Sciences, University of Florence, Italy
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21
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Jin LW, Masliah E, Iimoto D, Deteresa R, Mallory M, Sundsmo M, Mori N, Sobel A, Saitoh T. Neurofibrillary tangle-associated alteration of stathmin in Alzheimer's disease. Neurobiol Aging 1996; 17:331-41. [PMID: 8725893 DOI: 10.1016/0197-4580(96)00021-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Stathmin (p19), a 19-kDa cytosolic phosphorotein, plays a key role in converting extracellular signals into intracellular biochemical changes. Antibodies and cDNA specific for stathmin were used to study its levels and localization in normal and Alzheimer's disease (AD) brain tissue. The stathmin protein concentration was reduced in AD neocortex as assessed by Western blotting, whereas the concentration of its mRNA detected by both in situ hybridization and slot blot were increased in AD. The alteration of the stathmin protein concentration was negatively correlated with neurofibrillary tangle numbers but not with plaque numbers. Immunoreactivity was evenly localized to the cytoplasm of neurons in control cortical sections, whereas in AD it was preferentially localized to some of the neurofibrillary tangle-bearing neurons. Numbers of stathmin-positive neurons were inversely correlated with tangle numbers but not with plaque numbers in the frontal cortex of AD patients.
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Affiliation(s)
- L W Jin
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla 92093, USA
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22
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Shimohama S, Fujimoto S, Chachin M, Taniguchi T, Perry G, Whitehouse PJ, Kimura J. Alterations of low molecular weight acid phosphatase protein level in Alzheimer's disease. Brain Res 1995; 699:125-9. [PMID: 8616601 DOI: 10.1016/0006-8993(95)00995-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have previously reported that the activity of low molecular weight (LMW) acid phosphatase, which can remove tyrosine-linked phosphates of epidermal growth factor receptor, was significantly decreased in Alzheimer brains. In the present study, a specific antibody was prepared to analyze the protein level of this enzyme. Western blot analysis indicated that the level of LMW acid phosphatase protein was significantly reduced, whereas the activity of LMW acid phosphatase per enzyme molecule was not changed in Alzheimer brains. These results suggest that the reduction of LMW acid phosphatase activity in Alzheimer brains is due to its decreased protein level in Alzheimer's disease.
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Affiliation(s)
- S Shimohama
- Department of Neurology, Faculty of Medicine, Kyoto University, Japan
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23
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Luo YQ, Hirashima N, Li YH, Alkon DL, Sunderland T, Etcheberrigaray R, Wolozin B. Physiological levels of beta-amyloid increase tyrosine phosphorylation and cytosolic calcium. Brain Res 1995; 681:65-74. [PMID: 7552293 DOI: 10.1016/0006-8993(95)00282-u] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The a beta peptide is a neurotoxic peptide that accumulates in the brains of Alzheimer patients, but is also present in body fluids at subnanomolar levels. The potential effects of these low levels of a beta are unclear. We now show that one such action is to increase tyrosine phosphorylation in PC12 cells and olfactory neuroblasts. Application of a beta 25-35 or a beta 1-40 induces a dose-dependent increase in the tyrosine phosphorylation in both whole cells and in vitro. The increase in tyrosine phosphorylation is both rapid and sensitive, being stimulated by picomolar doses of a beta and occurring within 1 min of application. Calcium imaging experiments provide further support for the role of tyrosine phosphorylation in the action of a beta. While a beta does not alter calcium metabolism under basal conditions, the addition of a beta induces a rapid increase in cytoplasmic calcium in olfactory neuroblasts that have been treated with the tyrosine phosphatase inhibitor, sodium orthovanadate or in PC12 cells treated with nerve growth factor. These responses could be blocked by the tyrosine kinase inhibitor, herbimycin. These calcium responses displayed an obligate requirement for the presence of matrix proteins. The identification of a rapid, sensitive assay for the action of a beta may facilitate investigations of its mechanism of action.
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Affiliation(s)
- Y Q Luo
- Section on Geriatric Psychiatry, NIMH, Bethesda, MD 20892-1264, USA
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24
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Slack BE, Breu J, Petryniak MA, Srivastava K, Wurtman RJ. Tyrosine phosphorylation-dependent stimulation of amyloid precursor protein secretion by the m3 muscarinic acetylcholine receptor. J Biol Chem 1995; 270:8337-44. [PMID: 7713942 DOI: 10.1074/jbc.270.14.8337] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Stimulation of m1 and m3 muscarinic acetylcholine receptors, which are coupled to phosphoinositide hydrolysis and protein kinase C activation, has been shown to increase the release of soluble amyloid precursor protein derivatives (APPs). The effect is mimicked by phorbol esters, which directly activate protein kinase C. Using human embryonic kidney cells expressing individual muscarinic receptor subtypes, we found that stimulation of APPs release by the muscarinic agonist carbachol was only partially reduced by a specific inhibitor of protein kinase C (the bisindolylmaleimide GF 109203X), while the response to phorbol 12-myristate 13-acetate (PMA) was abolished. The increase in APPs release elicited by carbachol and PMA was accompanied by elevated tyrosine phosphorylation of several proteins and reduced by tyrosine kinase inhibitors; GF 109203X significantly reduced the stimulation of tyrosine phosphorylation by carbachol and PMA. Inhibition of protein tyrosine phosphatases by vanadyl hydroperoxide markedly increased cellular tyrosine phosphorylation and enhanced APPs release as effectively as PMA and carbachol. Direct phosphorylation of amyloid precursor protein on tyrosine residues following treatment with carbachol, PMA, or vanadyl hydroperoxide was not observed. The results implicate both tyrosine phosphorylation and protein kinase C-dependent mechanisms in the regulation of APPs release by G protein-coupled receptors, and suggest that carbachol and PMA increase APPs release from human embryonic kidney cells expressing m3 muscarinic receptors via partially divergent pathways that converge at a tyrosine phosphorylation-dependent step.
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Affiliation(s)
- B E Slack
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139, USA
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25
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Zhang L. The role of protein kinase C in inducing Alzheimer's A68 protein expression in the culture of human neuroblastoma cells. Neurosci Lett 1994; 181:95-7. [PMID: 7898780 DOI: 10.1016/0304-3940(94)90568-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
By using the monoclonal antibody Alz50, we studied the role of protein kinase C (PKC) in inducing A68 protein expression in a human neuronal cell line. Both phorbol 12-myristate 13-acetate and H7 strongly induced A68 protein, while HA1004 and calphoslin C had no effect. The results suggest that the inhibitor and activator of PKC induce A68 protein expression by different mechanisms.
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Affiliation(s)
- L Zhang
- Lab. of Clinical Science, NIMH/NIH, Baltimore, MD 21224
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26
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Simonian NA, Elvhage T, Czernik AJ, Greengard P, Hyman BT. Calcium/calmodulin-dependent protein kinase II immunostaining is preserved in Alzheimer's disease hippocampal neurons. Brain Res 1994; 657:294-9. [PMID: 7820630 DOI: 10.1016/0006-8993(94)90979-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Alterations in protein phosphorylation may be important in the pathogenesis of Alzheimer's disease and recent observations suggest that a subset of protein kinase pathways may be selectively altered. Calcium/calmodulin-dependent protein kinase II CaM kinase II) is the most abundant protein kinase in the brain and is believed to play an important role in the regulation of synaptic transmission, long-term potentiation and other forms of neuronal plasticity. We have now evaluated brains of individuals with Alzheimer's disease for changes in the distribution and density of immunoreactivity for the alpha subunit of CaM kinase II. CaM kinase II immunoreactivity was found in cytoarchitectural areas and neurons vulnerable to the formation of neurofibrillary angles and senile plaques. Over 80% of neurons bearing neurofibrillary tangles expressed CaM kinase II. Loss of CaM kinase II immunoreactivity was found in CA1, commensurate with neuronal loss in this area. Remaining CA1 neurons, however, had preserved CaM kinase II immunoreactivity. Preservation in the distribution and density of CaM kinase II immunoreactivity was observed in other hippocampal regions and in a multimodal association area, area 20. These results suggest CaM kinase II expression in the Alzheimer's disease brain is unaltered despite marked neuropathological changes.
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Affiliation(s)
- N A Simonian
- Massachusetts General Hospital, Harvard Medical School, Boston 02114
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27
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Vig PJ, Desaiah D, Joshi P, Subramony SH, Fratkin JD, Currier RD. Decreased insulin-like growth factor I-mediated protein tyrosine phosphorylation in human olivopontocerebellar atrophy and lurcher mutant mouse. J Neurol Sci 1994; 124:38-44. [PMID: 7931420 DOI: 10.1016/0022-510x(94)90008-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We examined insulin-like growth factor I (IGF-I)-dependent phosphorylation and protein tyrosine kinase (PTK) activity in cerebellar cortex of normal humans, patients with olivopontocerebellar atrophy (OPCA) ("C" kindred) and in lurcher mutant mouse, a suggested animal model for OPCA. PTK activity and IGF-I-dependent protein tyrosine phosphorylation was significantly reduced in cerebellar cortex of human OPCA patients as compared to the normal controls. Immunoblot analysis also demonstrated a decrease in cerebellar 80 kDa phosphotyrosine protein in these patients. By autoradiography, IGF-I receptors were localized in the molecular layer of 30-day-old control and lurcher mutant mice cerebella. However, the lurcher mutant mice showed a decrease in [125I]-IGF-I binding in the molecular layer as compared to the littermate controls. The IGF-I receptor autophosphorylation was also markedly reduced in 15-day- and 22-day-old lurcher cerebella. These results suggest that the process of cerebellar degeneration in human OPCA and lurcher mutant mouse may be associated with altered IGF-I receptor binding and protein tyrosine phosphorylation.
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Affiliation(s)
- P J Vig
- Department of Neurology, University of Mississippi Medical Center, Jackson 39216
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28
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Bothmer J, Jolles J. Phosphoinositide metabolism, aging and Alzheimer's disease. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1225:111-24. [PMID: 8280779 DOI: 10.1016/0925-4439(94)90068-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J Bothmer
- Department of Neuropsychology and Psychobiology, University of Limburg, Maastricht, The Netherlands
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29
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Pettegrew JW, Panchalingam K, Klunk WE, McClure RJ, Muenz LR. Alterations of cerebral metabolism in probable Alzheimer's disease: a preliminary study. Neurobiol Aging 1994; 15:117-32. [PMID: 8159258 DOI: 10.1016/0197-4580(94)90152-x] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Previous in vitro and in vivo 31P MRS studies of Alzheimer's disease patients have revealed alterations in membrane phospholipid metabolism and PET studies have shown alterations in glucose and oxidative metabolism. This study of probable Alzheimer's disease patients demonstrates severity dependent alterations in measures of both high-energy phosphate and membrane phospholipid metabolism. Mildly demented Alzheimer's patients compared to the controls, have increases in the levels of phosphomonoesters, decreases in the levels of phosphocreatine and probably adenosine diphosphate, and an increased oxidative metabolic rate. As the dementia worsens, the levels of phosphocreatine and adenosine diphosphate increase, the levels of phosphomonoesters decrease, and the oxidative metabolic rate decreases. The phosphomonoester findings replicate previous findings and provide a new dimension to the molecular pathology of Alzheimer's disease, implicating basic defects in membrane metabolism. The changes in oxidative metabolic rate suggest the AD brain is under energetic stress. The changes in energy metabolites with increasing dementia could be a consequence of nerve terminal degeneration and are consistent with previous PET findings. 31P MRS provides new diagnostic and metabolic insights into this disease and would be a noninvasive method to follow the progression of the disease and the metabolic response to therapeutic interventions.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry, University of Pittsburgh, School of Medicine, PA 15213
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30
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Hu BR, Yang YB, Wieloch T. Depression of neuronal protein synthesis initiation by protein tyrosine kinase inhibitors. J Neurochem 1993; 61:1789-94. [PMID: 8228995 DOI: 10.1111/j.1471-4159.1993.tb09817.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Growth factors stimulate cellular protein synthesis, but the intracellular signaling mechanisms that regulate initiation of mRNA translation in neurons have not been clarified. A rate-limiting step in the initiation of protein synthesis is the formation of the ternary complex among GTP, eukaryotic initiation factor 2 (eIF-2), and the initiator tRNA. Here we report that genistein, a specific tyrosine kinase inhibitor, decreases tyrosine kinase activity and the content of phosphotyrosine proteins in cultured primary cortical neurons. Genistein inhibits protein synthesis by > 80% in a dose-dependent manner (10-80 micrograms/ml) and concurrently decreases ternary complex formation by 60%. At the doses investigated, genistein depresses tyrosine kinase activity and concomitantly stimulates PKC activity. We propose that a protein tyrosine kinase participates in the initiation of protein synthesis in neurons, by affecting the activity of eIF-2 directly or through a protein kinase cascade.
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Affiliation(s)
- B R Hu
- Laboratory for Experimental Brain Research, University of Lund, Lund Hospital, Sweden
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31
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Vener AV, Aksenova MV, Burbaeva GS. Drastic reduction of the zinc- and magnesium-stimulated protein tyrosine kinase activities in Alzheimer's disease hippocampus. FEBS Lett 1993; 328:6-8. [PMID: 7688325 DOI: 10.1016/0014-5793(93)80953-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Tyrosine phosphorylation of proteins from postmortem hippocampi of five Alzheimer's disease and five control cases have been compared. It was found that addition of Zn2+ or Mg2+ to membrane fractions of control hippocampi caused the phosphorylation of 32-, 40-, 55-, 60-, 80- and 100-kDa proteins or 43-, 55-, 60- and 90-KdA proteins, respectively. The phosphorylation of all these proteins is shown to be drastically reduced in Alzheimer's disease hippocampi. Vanadate, an inhibitor of protein tyrosine phosphatases, had no influence on the level of protein phosphorylation. Western blot analysis did not reveal any differences in the anti-phosphotyrosine immunoreactive membrane proteins from Alzheimer's disease and control hippocampi. Tyrosine kinase activity of immunoprecipitated p60c-src from Alzheimer's disease and control hippocampi were the same. In conclusion, the Zn(2+)- and Mg(2+)-stimulated tyrosine kinase activities, distinct from activity of p60c-src, are decreased in Alzheimer's disease hippocampus.
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Affiliation(s)
- A V Vener
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation
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32
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Huang H, Gibson G. Altered beta-adrenergic receptor-stimulated cAMP formation in cultured skin fibroblasts from Alzheimer donors. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)82377-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Kataoka H, Nakai K, Katagiri Y, Makita M. Analysis of free and bound O-phosphoamino acids in urine by gas chromatography with flame photometric detection. Biomed Chromatogr 1993; 7:184-8. [PMID: 7693088 DOI: 10.1002/bmc.1130070403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A selective and sensitive method has been developed for the analysis of free and bound forms of O-phosphoamino acids, such as O-phosphoserine, O-phosphothreonine and O-phosphotyrosine, in urine samples by gas chromatography (GC). For free O-phosphoamino acid analysis, the urine sample was extracted with trichloroacetic acid and run through an ion exchange column. For total (free plus bound) O-phosphoamino acid analysis, the urine sample was hydrolysed in acid and base in order to release the O-phosphoamino acid from peptides or proteins. O-Phosphoamino acids in these prepared samples were converted into their N-isobutoxycarbonyl trimethyl ester derivatives and then measured by GC with flame photometric detection (FPD-GC). The calibration curve was linear in the range of 10-500 ng for each O-phosphoamino acid, and the detection limits were 30-80 pg as injection amounts. O-Phosphoamino acids in the urine samples could be selectively determined by the FPD-GC method without any influence from coexisting substances. The recoveries of O-phosphoamino acids added to urines and urine hydrolysates were 90-98% and relative standard deviations were 1.5-8.0%. By using this method, we investigated an age dependence of O-phosphoamino acid excretion in normal subjects.
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Affiliation(s)
- H Kataoka
- Faculty of Pharmaceutical Sciences, Okayama University, Japan
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34
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Shimohama S, Fujimoto S, Taniguchi T, Kameyama M, Kimura J. Reduction of low-molecular-weight acid phosphatase activity in Alzheimer brains. Ann Neurol 1993; 33:616-21. [PMID: 8498842 DOI: 10.1002/ana.410330610] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Recent studies in Alzheimer brains have shown aberrant protein phosphorylation, suggesting an alteration in protein kinases and/or phosphoprotein phosphatases. In the present study, the activity of acid phosphatase was investigated in samples prepared from postmortem normal human and Alzheimer brains. p-Nitrophenyl phosphate, a nonprotein phosphoester, was used as a substrate for acid phosphatase. The separation profile on Sephadex G-100 gel filtration chromatography revealed that two major forms of high-molecular-weight and low-molecular-weight acid phosphatase were present in the crude extracts of both rat and human brains. Another class of zinc ion (Zn2+)-dependent acid p-nitrophenyl phosphatase was also detected in rat and human brains. In Alzheimer brains, the low-molecular-weight acid phosphatase activity was significantly decreased compared to that in control brains; however, the high-molecular-weight and Zn(2+)-dependent acid phosphatase activity in control and Alzheimer brains was not different. These results suggest that reduced activity of the low-molecular-weight acid phosphatase, which possesses phosphotyrosine protein phosphatase activity, might be linked to aberrant protein tyrosine phosphorylation found in Alzheimer brains.
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Affiliation(s)
- S Shimohama
- Department of Neurology, Faculty of Medicine, Kyoto University, Japan
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35
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Kataoka H, Nakai K, Makita M. Identification of O-phosphoamino acids in urine hydrolysate by gas chromatography-mass spectrometry. JOURNAL OF CHROMATOGRAPHY 1993; 615:136-141. [PMID: 7688003 DOI: 10.1016/0378-4347(93)80299-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The occurrence of O-phosphoserine (P-Ser), O-phosphothreonine (P-Thr) and O-phosphotyrosine (P-Tyr) in the hydrolysate of human urine was demonstrated. Urine samples were separated into non-adsorbed and adsorbed fractions by DEAE-cellulose column chromatography. After acid and base hydrolyses of these fractions, the O-phosphoamino acids in the hydrolysates were converted into their N-isobutoxycarbonyl methyl ester derivatives and identified by gas chromatography-mass spectrometry. By gas chromatography with flame photometric detection, the urinary contents of P-Ser, P-Thr and P-Tyr were estimated to be 945 +/- 3, 109 +/- 3 and 2.9 +/- 0.2 ng/ml, respectively.
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Affiliation(s)
- H Kataoka
- Faculty of Pharmaceutical Sciences, Okayama University, Japan
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Huston JP, Hasenöhrl RU, Boix F, Gerhardt P, Schwarting RK. Sequence-specific effects of neurokinin substance P on memory, reinforcement, and brain dopamine activity. Psychopharmacology (Berl) 1993; 112:147-62. [PMID: 7532865 DOI: 10.1007/bf02244906] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
There is ample evidence that the neurokinin substance P (SP) can have neurotrophic as well as memory-promoting effects. This paper outlines a recent series of experiments dealing with the effects of SP and its N- and C-terminal fragments on memory, reinforcement, and brain monoamine metabolism. It was shown that SP, when applied peripherally (IP), promotes memory (inhibitory avoidance learning) and is reinforcing (place preference task) at the same dose of 37 nmol/kg. Most important, however, is the finding that these effects seemed to be encoded by different SP sequences, since the N-terminal SP1-7 (185 nmol/kg) enhanced memory, whereas C-terminal hepta- and hexapeptide sequences of SP proved to be reinforcing in a dose equimolar to SP. These differential behavioral effects were paralleled by selective and site-specific changes in dopamine (DA) activity, as both SP and its C-, but not N-terminus, increased extracellular DA in the nucleus accumbens (NAc), but not in the neostriatum. The neurochemical changes lasted at least 2 h after injection. These results show that the reinforcing action of peripheral administered SP may be mediated by its C-terminal sequence, and that this effect could be related to DA activity in the NAc. Direct application of SP (0.74 pmol) into the region of the nucleus basalis magnocellularis (NBM) was also memory-promoting and reinforcing, and again, these effects were differentially produced by the N-terminus and C-terminus, supporting the proposed structure-activity relationship for SP's effects on memory and reinfrocement. These results may provide a hypothetical link between the memory-modulating and reinforcing effects of SP and the impairment in associative functioning accompanying certain neurodegenerative processes.
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Affiliation(s)
- J P Huston
- Institute of Physiological Psychology I, Heinrich-Heine-University of Düsseldorf, Germany
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Lower EE, Franco RS, Miller MA, Martelo OJ. Enzymatic and immunohistochemical evaluation of tyrosine phosphorylation in breast cancer specimens. Breast Cancer Res Treat 1993; 26:217-24. [PMID: 7504533 DOI: 10.1007/bf00665799] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Using a synthetic peptide substrate, tyrosine protein kinase (TPK) activity was measured in 21 tumors from patients with histologically confirmed breast cancer and in five normal breast tissues from patients undergoing reduction mammoplasty. In 20 of 21 cancer specimens, tumor was available to assess phosphotyrosine (PT) immunohistochemically. Breast cancer specimens possessed significantly more TPK activity than normal breast tissues (Cancer = 43.9 +/- 3.1 pm/mg protein/min, [Mean +/- S.E.M.]; Normal = 3.4 +/- 0.9, p < 0.001). TPK activity was higher in the clinically more aggressive infiltrating ductal cancers compared to the less aggressive intraductal cancers (Infiltrating = 55.9 +/- 5.8; Intraductal = 17.2 +/- 3.4, p < 0.01). TPK activity in tumors with both infiltrating and intraductal histology was intermediate (34.0 +/- 7.2). Significant correlation existed between membrane TPK enzymatic activity and PT expression by immunohistochemistry. There was no relationship between estrogen or progesterone receptor status and TPK activity or PT; however, TPK activity from node negative breast cancer tissue was significantly less than from node positive specimens (p < 0.01). We conclude that breast cancer specimens possess elevated amounts of TPK which correlate with PT expression, and that increased tyrosine phosphorylation appears to correlate with the biologic aggressiveness of the malignant tumor.
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Affiliation(s)
- E E Lower
- Department of Internal Medicine, University of Cincinnati College of Medicine, Ohio
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Saitoh T, Masliah E, Baum L, Sundsmo M, Flanagan L, Vikramkumar R, Kay MM. Degradation of proteins in the membrane-cytoskeleton complex in Alzheimer's disease. Might amyloidogenic APP processing be just the tip of the iceberg? Ann N Y Acad Sci 1992; 674:180-92. [PMID: 1288363 DOI: 10.1111/j.1749-6632.1992.tb27487.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- T Saitoh
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla 92093-0624
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Gerhardt P, Hasenöhrl RU, Huston JP. Enhanced learning produced by injection of neurokinin substance P into the region of the nucleus basalis magnocellularis: mediation by the N-terminal sequence. Exp Neurol 1992; 118:302-8. [PMID: 1284861 DOI: 10.1016/0014-4886(92)90187-u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of unilateral injection of the neurokinin substance P (SP) and of certain N- or C-terminal SP-fragments into the region of the nucleus basalis magnocellularis (NBM) on inhibitory avoidance learning was investigated. Rats with chronically implanted cannulae were tested on a one-trial uphill avoidance task. Immediately after the training trial, rats were injected with 0.74 pmol SP or equimolar dosed SP(1-7), DIME-C7, or SP(7-11). Control groups included vehicle-injected rats and a group given an injection of SP(1-7) 5-h after the trial. When tested 24 h later, rats treated with SP or SP(1-7), but not with DIME-C7 or SP(7-11), exhibited longer step-up latencies than vehicle-treated controls. The retention latencies for rats in the SP(1-7) 5-h delay group did not differ from those of vehicle-injected animals, ruling out proactive effects of SP(1-7) on performance. The results show that SP facilitates retention of an inhibitory avoidance response when injected into the NBM. Furthermore, the amino acid sequence that encodes this effect may be located in the N-terminal part of the SP-molecule.
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Affiliation(s)
- P Gerhardt
- Institute of Physiological Psychology I, University of Düsseldorf, Federal Republic of Germany
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Abstract
Phosphatidylinositol (PI) kinase and PI phosphate (PIP) kinase activities were measured in postmortem samples of brain tissue from patients with Alzheimer's disease and nondemented control subjects. A membrane-free cytosolic fraction from four neocortical locations, with exogenous inositol lipids as the substrate, was used. Tissue from patients with Alzheimer's disease was characterized by reduced PIP formation; the reduction was 50% in prefrontal cortex, temporal cortex, and parietal cortex and 40% in precentral gyrus. In contrast, no alterations were found in PI bisphosphate formation in these four neocortical locations. The specific changes in PI kinase but not PIP kinase activity suggest that the findings may have functional relevance to the involvement of brain membrane processes in Alzheimer's disease.
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Affiliation(s)
- J Jolles
- Department of Neuropsychology and Psychobiology, University of Limburg, Maastricht, The Netherlands
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Lehmann HD. The puzzle of Alzheimer's disease (AD). Med Hypotheses 1992; 38:5-10. [PMID: 1614358 DOI: 10.1016/0306-9877(92)90152-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A compromised defensive system of brain cells against aluminium, together with local defects in glucose metabolism, causes AD. Lack of citrate is a driving force and free cis-aconitate or glutamate are potential carriers, which enable the exotoxin to cross lipid membranes. Only a few aluminium ions replace magnesium in key positions. They block the reversibility of phosphorylation reactions, which are important for short term memory: sensitization of the insulin receptor and protein phosphorylations. Due to disturbed phosphorylation of the cytoskeleton, protein synthesis runs out of balance. Efforts to restore the disturbed reactions result in AD specific deposits. Aluminium ions are the common cause for the induction of AD pathogenesis in patients with genetic defects, with mechanical brain lesions or with minor infarcts, as well as with changes in the relation between numbers of neurons and neuron nursing glia cells due to age.
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Affiliation(s)
- H D Lehmann
- NMI Naturwissenschaftliches und Medizinisches Institut, Universität Tübingen, Reutlingen, Germany
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Masliah E, Mallory M, Hansen L, Alford M, Albright T, Terry R, Shapiro P, Sundsmo M, Saitoh T. Immunoreactivity of CD45, a protein phosphotyrosine phosphatase, in Alzheimer's disease. Acta Neuropathol 1991; 83:12-20. [PMID: 1838850 DOI: 10.1007/bf00294425] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Both protein kinases and phosphoprotein phosphatases are important components of signal transduction systems in cells. Recent studies in Alzheimer's disease (AD) have shown abnormal protein phosphorylation in the cortex suggesting an alteration in these enzymes. In the present study, an antibody against CD45 was used to analyze the status of this protein phosphotyrosine phosphatase in AD. We studied and quantified the immunohistochemical and immunochemical distribution of this integral membrane protein in control and AD brain. We found that anti-CD45 immunostained the great majority of microglia, both resting and activated. These cells were Ricinus communis agglutinin I positive and glial fibrillary acidic protein and neurofilament negative. The AD frontal cortex showed a 35% (P less than 0.01) increase in the number of anti-CD45 immunoreactive microglia as compared with controls. These results were consistent with the immunoblot quantification of CD45 immunoreactivity following native gel electrophoresis. In AD, 30% of the CD45-immunostained microglia were clustered in the neuritic plaques (about six per plaque) while the remaining 70% were scattered in the neuropil. The AD hippocampus showed an increase in CD45-immunoreactive microglia in the molecular layer of the dentate gyrus. At the ultrastructural level, CD45 immunoreactivity was localized exclusively to the plasma membrane of the microglia. The presence of the anti-CD45 immunoreactivity in microglia suggests the possibility that they may require the presence of CD45 as a cell surface receptor which may regulate cell function through modulation of intracellular signaling.
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Affiliation(s)
- E Masliah
- University of California, San Diego, School of Medicine, Department of Neurosciences, La Jolla 92093-0624
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