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Chen Y, Strickland MR, Soranno A, Holtzman DM. Apolipoprotein E: Structural Insights and Links to Alzheimer Disease Pathogenesis. Neuron 2020; 109:205-221. [PMID: 33176118 DOI: 10.1016/j.neuron.2020.10.008] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 01/02/2023]
Abstract
Apolipoprotein E (ApoE) is of great interest due to its role as a cholesterol/lipid transporter in the central nervous system (CNS) and as the most influential genetic risk factor for Alzheimer disease (AD). Work over the last four decades has given us important insights into the structure of ApoE and how this might impact the neuropathology and pathogenesis of AD. In this review, we highlight the history and progress in the structural and molecular understanding of ApoE and discuss how these studies on ApoE have illuminated the physiology of ApoE, receptor binding, and interaction with amyloid-β (Aβ). We also identify future areas of study needed to advance our understanding of how ApoE influences neurodegeneration.
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Affiliation(s)
- Yun Chen
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA; Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA; The Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, USA; Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
| | - Michael R Strickland
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA; Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, USA; Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA; The Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, USA
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, St. Louis, MO, USA; Center for Science & Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO, USA
| | - David M Holtzman
- Department of Neurology, Washington University in St. Louis, St. Louis, MO, USA; Center for Science & Engineering of Living Systems, Washington University in St. Louis, St. Louis, MO, USA; Knight Alzheimer's Disease Research Center, Washington University in St. Louis, St. Louis, MO, USA.
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2
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A Comparative Study on 5hmC Targeting Regulation of Neurons in AD Mice by Several Natural Compounds. BIOMED RESEARCH INTERNATIONAL 2020; 2020:5016706. [PMID: 32802849 PMCID: PMC7426765 DOI: 10.1155/2020/5016706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/27/2020] [Accepted: 06/29/2020] [Indexed: 11/25/2022]
Abstract
A series of studies have confirmed that DNA methylation disorder (5mC/5hmC) is closely related to the occurrence and development of some diseases, such as Alzheimer's disease (AD). This study aims at discovering natural compounds that could adjust and control 5-hydroxymethylcytosine (5hmC) levels and improve Alzheimer's disease (AD) neuronal status. Cordycepin and cordycepic acid were selected as research materials, with resveratrol as positive control. The results of Dot Blot indicated that cordycepin, cordycepic acid, and resveratrol significantly increased the expression level of 5hmC. Combined with qPCR results, it was revealed that cordycepin increased the expression of ten-eleven translocation (TETs) mRNA compared with the abovementioned cordycepic acid and resveratrol. Besides, cordycepin dramatically reduced the transcription level of Apolipoprotein E (ApoE), suggesting that cordycepin might hinder the formation of NFTs (neurofibrillary tangles) and the accumulation of amyloid β-protein (Aβ) in the brain by reducing the expression of ApoE, resulting in affecting the progression of AD. Meanwhile, the immunofluorescence (IF) staining results demonstrated that the percentage of differentiation of SHSY-5Y cells reasonably increased after the treatment of cordycepin and cordycepic acid. Simultaneously, the length of axons and the number of dendritic branches in mouse primary neurons were substantially increased by cordycepin. The screening results illustrated that cordycepin had a positive influence on the level of 5hmC and the morphology of neurons, and most of the effects were better compared to the positive control (resveratrol). It indicated that cordycepin delayed the progression of neurodegenerative diseases such as AD. However, the specific mechanism of action still needs to be further investigated. Our research provided a foundation for further discussion about the influence of cordycepin on AD and a new idea for the pathological study of related diseases.
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Sakata N, Hoshii Y, Nakamura T, Kiyama M, Arai H, Omoto M, Morimatsu M, Ishihara T. Colocalization of Apolipoprotein AI in Various Kinds of Systemic Amyloidosis. J Histochem Cytochem 2016; 53:237-42. [PMID: 15684336 DOI: 10.1369/jhc.4a6387.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Apolipoprotein AI (apoAI), a major component of high-density lipoproteins, is one of the major amyloid fibril proteins and a minor constituent of the senile plaques observed in Alzheimer's disease. We examined colocalization of apoAI in various kinds of systemic amyloidosis in this study. Forty-three of 48 formalin-fixed paraffin-embedded heart specimens with various forms of systemic amyloidosis reacted immunohistochemically with anti-human apoAI antibody. ApoAI was also detected in water-extracted amyloid material by immunoblotting. In addition, we observed colocalization of apoAI and murine amyloid A (AA) amyloidosis in human apoAI transgenic mice. This is the first report of colocalization of apoAI with amyloid deposits in various forms of human systemic amyloidosis and murine AA amyloidosis in human apoAI transgenic mice. ApoAI may not always be a major component of amyloid fibrils, even when it is present in systemic amyloid deposits.
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Affiliation(s)
- Naohiro Sakata
- Department of Clinical Neuroscience, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
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4
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Tai LM, Mehra S, Shete V, Estus S, Rebeck GW, Bu G, LaDu MJ. Soluble apoE/Aβ complex: mechanism and therapeutic target for APOE4-induced AD risk. Mol Neurodegener 2014; 9:2. [PMID: 24386905 PMCID: PMC3897976 DOI: 10.1186/1750-1326-9-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/27/2013] [Indexed: 01/14/2023] Open
Abstract
The APOE4 allele of apolipoprotein E (apoE) is the greatest genetic risk factor for Alzheimer's disease (AD) compared to APOE2 and APOE3. Amyloid-β (Aβ), particularly in a soluble oligomeric form (oAβ), is considered a proximal cause of neurodegeneration in AD. Emerging data indicate that levels of soluble oAβ are increased with APOE4, providing a potential mechanism of APOE4-induced AD risk. However, the pathway(s) by which apoE4 may increase oAβ levels are unclear and the subject of continued inquiry. In this editorial review, we present the hypothesis that apoE isoform-specific interactions with Aβ, namely apoE/Aβ complex, modulate Aβ levels. Specifically, we propose that compared to apoE3, apoE4-containing lipoproteins are less lipidated, leading to less stable apoE4/Aβ complexes, resulting in reduced apoE4/Aβ levels and increased accumulation, particularly of oAβ. Evidence that support or counter this argument, as well as the therapeutic significance of this pathway to neurodegeneration, are discussed.
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Affiliation(s)
- Leon M Tai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., M/C 512, Chicago, IL 60612, USA
| | - Shipra Mehra
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., M/C 512, Chicago, IL 60612, USA
| | - Varsha Shete
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., M/C 512, Chicago, IL 60612, USA
| | - Steve Estus
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - G William Rebeck
- Department of Neuroscience, Georgetown University, Washington, DC 20057, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., M/C 512, Chicago, IL 60612, USA
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Rembach A, Ryan TM, Roberts BR, Doecke JD, Wilson WJ, Watt AD, Barnham KJ, Masters CL. Progress towards a consensus on biomarkers for Alzheimer’s disease: a review of peripheral analytes. Biomark Med 2013; 7:641-62. [DOI: 10.2217/bmm.13.59] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of dementia in the elderly population and attempts to develop therapies have been unsuccessful because there is no means to target an effective therapeutic window. CNS biomarkers are insightful but impractical for high-throughput population-based screening. Therefore, a peripheral, blood-based biomarker for AD would significantly improve early diagnosis, potentially enable presymptomatic detection and facilitate effective targeting of disease-modifying treatments. The various constituents of blood, including plasma, platelets and cellular fractions, are now being systematically explored as a pool of putative peripheral biomarkers for AD. In this review we cover some less known peripheral biomarkers and highlight the latest developments for their clinical application.
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Affiliation(s)
- Alan Rembach
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia.
| | - Tim M Ryan
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia
| | - Blaine R Roberts
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia
| | - James D Doecke
- The Australian e-Health Research Centre, Herston, Queensland, 4029, Australia
- CSIRO Preventative Health National Research Flagship, North Ryde, New South Wales, 2113, Australia
| | - William J Wilson
- CSIRO Preventative Health National Research Flagship, North Ryde, New South Wales, 2113, Australia
| | - Andrew D Watt
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia
| | - Kevin J Barnham
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia
| | - Colin L Masters
- The Mental Health Research Institute, The University of Melbourne, Kenneth Myer Building, 30 Royal Parade, Parkville, Victoria, 3010, Australia
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Mass spectrometry quantification revealed accumulation of C-terminal fragment of apolipoprotein E in the Alzheimer's frontal cortex. PLoS One 2013; 8:e61498. [PMID: 23593485 PMCID: PMC3623866 DOI: 10.1371/journal.pone.0061498] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 03/10/2013] [Indexed: 11/19/2022] Open
Abstract
Polymorphic variation in the apolipoprotein E (apoE) gene is the major genetic susceptibility factor for late-onset Alzheimer's disease (AD) and likely contributes to neuropathology through various pathways. It is also recognized that apoE undergoes proteolytic cleavage in the brain and the resultant apoE fragments likely have a variety of bioactive properties that regulate neuronal signaling and may promote neurodegeneration. ApoE fragmentation in the human brain has been intensively studied using different immunochemical methods, but has never been analyzed in a quantitative manner to establish preferably accumulated fragments. Here we report quantification using multiple reaction monitoring mass spectrometry (MRM MS) with 15N-labeled full-length apoE4 as an internal standard. Measurements were performed on frontal cortex from control and severe AD donors. Our data point to a preferable accumulation of C-terminal apoE fragment in the insoluble fraction of tissue homogenate in the severe AD group versus the control group. Further insight into the biological consequences of this accumulation may lead to a better understanding of the basic mechanism of AD pathology.
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Teoh CL, Griffin MDW, Howlett GJ. Apolipoproteins and amyloid fibril formation in atherosclerosis. Protein Cell 2011; 2:116-27. [PMID: 21400045 DOI: 10.1007/s13238-011-1013-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 01/29/2011] [Indexed: 10/18/2022] Open
Abstract
Amyloid fibrils arise from the aggregation of misfolded proteins into highly-ordered structures. The accumulation of these fibrils along with some non-fibrillar constituents within amyloid plaques is associated with the pathogenesis of several human degenerative diseases. A number of plasma apolipoproteins, including apolipoprotein (apo) A-I, apoA-II, apoC-II and apoE are implicated in amyloid formation or influence amyloid formation by other proteins. We review present knowledge of amyloid formation by apolipoproteins in disease, with particular focus on atherosclerosis. Further insights into the molecular mechanisms underlying their amyloidogenic propensity are obtained from in vitro studies which describe factors affecting apolipoprotein amyloid fibril formation and interactions. Additionally, we outline the evidence that amyloid fibril formation by apolipoproteins might play a role in the development and progression of atherosclerosis, and highlight possible molecular mechanisms that could contribute to the pathogenesis of this disease.
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Affiliation(s)
- Chai Lean Teoh
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia
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Elliott DA, Tsoi K, Holinkova S, Chan SL, Kim WS, Halliday GM, Rye KA, Garner B. Isoform-specific proteolysis of apolipoprotein-E in the brain. Neurobiol Aging 2009; 32:257-71. [PMID: 19278755 DOI: 10.1016/j.neurobiolaging.2009.02.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 02/01/2009] [Accepted: 02/03/2009] [Indexed: 11/19/2022]
Abstract
Apolipoprotein-E (apoE) plays important roles in neurobiology and the apoE4 isoform increases risk for Alzheimer's disease (AD). ApoE peptides are biologically active and may be produced in the brain. It is unclear if apoE proteolysis is dependent on isoform or AD status and this was addressed here. Hippocampus, frontal cortex, occipital lobe and cerebellum samples were homogenized into fractions that were soluble in Tris-buffered saline (TBS), Triton X-100 or guanidine hydrochloride and analysed for apoE fragmentation by Western blotting. Approximately 20% of apoE3 was detected as fragments and this was predominantly as a 25 kDa peptide in TBS-soluble fractions. The concentration of TBS-soluble apoE fragments was two- to three-fold higher in apoE3 compared to apoE4 subjects. This difference was observed in all areas of the brain examined and was not related to AD status. Cathepsin-D treatment generated apoE fragments that were very similar to those detected in brain, however, no apoE isoform-specific differences in susceptibility to cathepsin-D proteolysis were detected. This indicates that proteolytic processing of apoE to form soluble fragments in the human brain is dependent on apoE isoform but not AD status.
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Affiliation(s)
- David A Elliott
- Prince of Wales Medical Research Institute, Randwick, NSW 2031, Australia
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Frangione B, Castaño EM, Wisniewski T, Ghiso J, Prelli F, Vidal R. Apolipoprotein E and amyloidogenesis. CIBA FOUNDATION SYMPOSIUM 2007; 199:132-41; discussion 141-5. [PMID: 8915608 DOI: 10.1002/9780470514924.ch9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Alzheimer's amyloid beta-protein (A beta) is a modified, pathogenic form of a constitutive host protein, soluble amyloid beta-protein (sA beta). Both are conformational isomers encoded by the gene for the beta-amyloid precursor protein (APP), located on chromosome 21. sA beta and A beta have identical sequence but are thought to differ in their secondary structure and physicochemical properties, hence they are conformational isomers. sA beta is easily degraded, while A beta is particularly resistant. A beta has a high beta-pleated sheet content, while sA beta is thought to be more random-coil and/or alpha-helical. A beta, unlike sA beta, adopts an amyloidogenic conformation, forms aggregates and gives rise to fibrils. Most early-onset forms of Alzheimer's disease (AD) have been linked to mutations of the presenilin 1, presenilin 2 or APP genes, located on chromosomes 14, 1 and 21, respectively. Their relationship to amyloidogenesis is being investigated. On the other hand, the major risk factor for the most common form, sporadic and familial late-onset AD, is the presence of the apoE epsilon 4 allele. Recent studies have shown that a 10 kDa C-terminal fragment of apoE is complexed to A beta in neuritic plaques and that apoE isoforms can modulate amyloid formation in vitro. Moreover, thrombin cleavage of apoE generates a similar C-terminal fragment that can form amyloid-like fibrils. Thus neuritic plaques may contain both A beta and apoE amyloid fibrils. AD can be neuropathologically defined by the presence of several interacting proteins that can adopt an amyloidogenic conformation. This has led us to hypothesize that in AD, amyloidosis may be reactive rather than causative.
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Affiliation(s)
- B Frangione
- Department of Pathology, New York University Medical Center, NY 10016, USA
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Ritland JS, Utheim TP, Utheim OA, Espeseth T, Lydersen S, Semb SO, Rootwelt H, Elsås T. Effects of APOE and CHRNA4 genotypes on retinal nerve fibre layer thickness at the optic disc and on risk for developing exfoliation syndrome. ACTA ACUST UNITED AC 2007; 85:257-61. [PMID: 17488453 DOI: 10.1111/j.1600-0420.2006.00824.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE To investigate whether CHRNA4 and APOE genotypes influence retinal nerve fibre layer (RNFL) thickness at the optic disc, intraocular pressure (IOP) and the development of exfoliation syndrome (XFS). METHODS A sample of 88 healthy adults (aged 50-75 years) genotyped for polymorphisms of APOE and CHRNA4 underwent an eye examination including slit-lamp examination and fundus photography, as well as measurements of visual acuity, refraction, IOP and RNFL thickness at the optic disc by optical coherence tomography. The Fisher-Boschloo unconditional full multinomial test and two sample t-tests were used in the statistical analyses. RESULTS There was no correlation between CHRNA4 and APOE genotypes and average RNFL thickness at the optic disc in the two eyes. Mean IOP in the eyes of APOE2 carriers was 13.18 mmHg, whereas that in the eyes of non-APOE2 carriers, at 14.82 mmHg, was significantly higher (p = 0.014). Exfoliation syndrome was found in one or both eyes in 15 persons. The presence of XFS was less likely in CC carriers of the CHRNA4 gene than in TT and TC carriers (p = 0.049). CONCLUSIONS We found no significant difference in RNFL thickness at the optic disc in the different genotype carriers of the APOE and CHRNA4 genes, and thereby no evidence for increased loss of ganglion cells in the retina as an effect of these genes. APOE2 carriers had significantly lower IOP than non-APOE2 carriers. However, both values are within the normal range and RNFL thickness measurements at the optic disc showed no difference between these two groups. In our study population, CC carriers of the CHRNA4 gene were less likely to develop XFS.
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Su KL, Wen TH, Chou CY, Chang GG, Liu GY, Hung HC. Structural variation manipulates the differential oxidative susceptibility and conformational stability of apolipoprotein E isoforms. Proteins 2007; 68:363-74. [PMID: 17410580 DOI: 10.1002/prot.21443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A growing amount of evidence implicates the involvement of apolipoprotein E (apoE) in the development of late-onset and sporadic forms of Alzheimer's disease (AD). It is now generally believed that the epsilon4 allele is associated with AD and the oxidative stress is more pronounced in AD. However, only limited data are available on apoE isoform-specificity and its relationship to both the oxidative susceptibility and conformational stability of apoE. In this article, we use site-directed mutagenesis to investigate the structural role of amino acid residue 112, which is the only differing residue between apoE3 and E4. We examine the structural variation manipulating the oxidative susceptibility and conformational stability of apolipoprotein E isoforms. Arg112 in apoE4 was changed to Ala and Glu. Previous research has reported that apoE4 is more susceptible to free radicals than apoE3. In protein oxidation experiments, apoE4-R112A becomes more resistant to free radicals to the same extent as apoE3. In contrast, apoE4-R112E becomes the most susceptible protein to free radicals among all the apoE proteins. We also examine the conformational stability and the quaternary structural change by fluorescence spectroscopy and analytical ultracentrifugation, respectively. ApoE3 and E4 show apparent three- and two-state unfolding patterns, respectively. ApoE4-R112A, similar to apoE3, demonstrates a biphasic denaturation with an intermediate that appears. The denaturation curve for apoE4-R112E, however, also displays a biphasic profile but with a slight shoulder at approximately 1.5M GdmCl, implying that an unstable intermediate existed in the denaturation equilibrium. The size distribution of apoE isoforms display similar patterns. ApoE4-R112E, however, has a greater tendency to dissociate from high-molecular-weight species to tetramers. These experimental data suggest that the amino acid residue 112 governs the differences in salt-bridges between these two isoforms and thus has a significant impact on the free radical susceptibility and structural variation of the apoE isoforms.
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Affiliation(s)
- Kuo-Liang Su
- Department of Life Sciences, National Chung-Hsing University, Taichung, Taiwan, Republic of China
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Mhatre M, Hensley K, Nguyen A, Grammas P. Chronic thrombin exposure results in an increase in apolipoprotein-E levels. J Neurosci Res 2006; 84:444-9. [PMID: 16683250 PMCID: PMC1865107 DOI: 10.1002/jnr.20887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Studies have shown that individuals with both a history of traumatic brain injury and inheritance of apolipoprotein E-4 (ApoE4) allele are associated with a poor neurologic outcome and an increased risk for Alzheimer's disease. We assessed the hypothesis that thrombin released during brain injury causes an increase in apolipoprotein-E levels and such increase in the levels of apolipoprotein-E4 isoform may have amyloidogenic effects. Rats received either thrombin (100 nm, 0.25 microl/hr, 28 days) or vehicle via intracerebroventricular (i.c.v.) infusion. Thrombin treatment increased apolipoprotein-E levels in hippocampus as compared to vehicle treatment (P < 0.001). Infusion of human apolipoprotein-E4 (0.6 ng/hr, i.c.v., 56 days) into rats resulted in beta-amyloid deposition and increased the number of GFAP-positive astrocytes. ApoE4 infusion also resulted in significant spatial memory deficits. These findings suggest that thrombin released during brain injury may contribute to an increase in apolipoprotein-E levels. Such increase in Apolipoprotein-E4 isoform facilitates beta-amyloid deposition and cognitive deficits.
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Affiliation(s)
- Molina Mhatre
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, 73104, USA.
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Yamamoto S, Hasegawa K, Yamaguchi I, Goto Y, Gejyo F, Naiki H. Kinetic analysis of the polymerization and depolymerization of β2-microglobulin-related amyloid fibrils in vitro. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1753:34-43. [PMID: 16084781 DOI: 10.1016/j.bbapap.2005.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Accepted: 07/12/2005] [Indexed: 11/16/2022]
Abstract
beta(2)-Microglobulin-related (Abeta(2)M) amyloidosis is a serious complication in patients on long-term dialysis, and partial unfolding of beta(2)-microglobulin (beta(2)-m) is believed to be prerequisite to its assembly into Abeta(2)M amyloid fibrils. Many kinds of amyloid-associated molecules (e.g., apolipoprotein E (apoE), glycosaminoglycans (GAGs), proteoglycans (PGs)) may contribute to the development of Abeta(2)M amyloidosis. The formation of Abeta(2)M amyloid fibrils in vitro was first observed at low pH (2.0-3.0). Very recently, low concentrations of 2,2,2-trifluoroethanol (TFE) and the sub-micellar concentration of sodium dodecyl sulfate, a model for anionic phospholipids, have been reported to cause the extension of Abeta(2)M amyloid fibrils at a neutral pH, inducing partial unfolding of beta(2)-m and stabilization of the fibrils. Moreover, apoE, GAGs and PGs were found to stabilize Abeta(2)M amyloid fibrils at a neutral pH, forming a stable complex with the fibrils. Some GAGs, especially heparin enhanced the fibril extension in the presence of TFE at a neutral pH. Some PGs, especially biglycan also induced the polymerization of acid-denatured beta(2)-m. These findings are consistent with the hypothesis that in vivo, specific molecules that affect the conformation and stability of beta(2)-m and amyloid fibrils will have significant effects on the deposition of Abeta(2)M amyloid fibrils.
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Affiliation(s)
- Suguru Yamamoto
- Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Science, Niigata 951-8510, Japan
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14
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Yilmaz A, Tamer L, Ateş NA, Camdeviren H, Değirmenci U. Effects of apolipoprotein E genotypes on the development of exfoliation syndrome. Exp Eye Res 2005; 80:871-5. [PMID: 15939044 DOI: 10.1016/j.exer.2004.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Revised: 12/22/2004] [Accepted: 12/31/2004] [Indexed: 01/24/2023]
Abstract
Apolipoprotein E (apo E) is directly involved in the amyloid deposition and fibril formation and is present in many cerebral and systemic amyloidoses immunologically. It is encoded by a polymorphic gene and it has three common alleles-epsilon2, epsilon3, and epsilon4. Exfoliation syndrome (XFS) is characterized by the deposition throughout the body of focal fibrillogranular aggregates in which there have been some reports of amyloid or amyloid-like features. We evaluated the possible association between apo E polymorphism and the occurrence of XFS. Using High Pure PCR Template Preparation Kits, genomic DNAs were extracted from whole blood and apo E polymorphisms were determined by using Lightcycler-Apo E Mutation Detection Kits in 76 patients with XFS and 74 controls. The E2/E2, E2/E3 and E2/E4 genotypes (OR 29.9, 95% CI 3.1-293.7; OR 56.1, 95% CI 12.5-252.7; OR 43.9, 95% CI 7.4-257.6, respectively) and the in2 allele are found to have an increased risk of developing XFS (p=0.0001); whereas the in3 allele was found to be protective (p=0.0001). Apo E polymorphism and the presence of in2 allele are seem to be significantly associated with the development of XFS.
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Affiliation(s)
- Ayça Yilmaz
- Ophthalmology Department, Mersin University Faculty of Medicine, 33079 Mersin, Turkey.
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15
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Raftery M, Campbell R, Glaros EN, Rye KA, Halliday GM, Jessup W, Garner B. Phosphorylation of Apolipoprotein-E at an Atypical Protein Kinase CK2 PSD/E Site in Vitro†. Biochemistry 2005; 44:7346-53. [PMID: 15882073 DOI: 10.1021/bi0504052] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Apolipoprotein-E (apoE) plays an important role in neuronal lipid transport and is thought to stabilize microtubules by preventing tau hyperphosphorylation. ApoE is also associated with insoluble amyloid detected in Alzheimer disease brain lesions. The apoE C-terminal shares several physicochemical features with alpha-synuclein, another neuronal apolipoprotein-like protein. Alpha-synuclein is phosphorylated by protein kinase CK2 (CK2) at an atypical PSD/E motif in vivo and in vitro. We identified a similar PSD/E motif in apoE and therefore investigated its potential phosphorylation by CK2 in vitro. When a [(32)P]-labeling approach was used, CK2 readily phosphorylated purified human apoE as well as recombinant forms of human apoE3 and apoE4. Using liquid chromatography mass spectrometry techniques, we mapped the major apoE CK2 phosphorylation site to Ser296 within the apoE PSD/E motif. We also found that apoE potently activated CK2 as demonstrated by increased CK2beta subunit autophosphorylation and by increased phosphorylation of tau when the latter was added to the kinase reaction mixtures. Other proteins such as apolipoprotein A-I and albumin did not effectively activate CK2. The phosphorylation of apoE by CK2 as well as the activation of CK2 by apoE may be relevant in vivo where apoE, CK2, and tau are co-localized with additional CK2 targets on neuronal microtubules.
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Affiliation(s)
- Mark Raftery
- Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney NSW 2052, Australia
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16
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Bergström J, Murphy CL, Weiss DT, Solomon A, Sletten K, Hellman U, Westermark P. Two different types of amyloid deposits--apolipoprotein A-IV and transthyretin--in a patient with systemic amyloidosis. J Transl Med 2004; 84:981-8. [PMID: 15146166 DOI: 10.1038/labinvest.3700124] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Certain forms of systemic amyloidosis have been associated with the pathologic deposition as fibrils of three different apolipoprotein-related proteins--apolipoprotein A-I, apolipoprotein A-II, and serum amyloid A. We have previously reported (Bergström et al, Biochem Biophys Res Commun 2001;285:903-908) that amyloid fibrils extracted from the heart of an elderly male with senile systemic amyloidosis contained, in addition to wild-type transthyretin-related molecules, an N-terminal fragment of yet a fourth apolipoprotein--apolipoprotein A-IV (apoA-IV). We now provide the results of our studies that have established the complete amino-acid sequence of this approximately 70-residue component and, additionally, have shown this protein to be the product of an unmutated apoA-IV gene. Notably, the apoA-IV and transthyretin fibrils were not codeposited but, rather, had anatomically distinct patterns of distribution within the heart and other organs, as evidenced immunohistochemically, by variation in the ultra structural morphology and by differences in the intensity of Congo red birefringence. These findings provide the first conclusive evidence that two separate forms of amyloid, each derived from a wild-type amyloidogenic precursor protein, were present in a patient with systemic amyloidosis.
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Affiliation(s)
- Joakim Bergström
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
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17
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Saito H, Dhanasekaran P, Nguyen D, Baldwin F, Weisgraber KH, Wehrli S, Phillips MC, Lund-Katz S. Characterization of the heparin binding sites in human apolipoprotein E. J Biol Chem 2003; 278:14782-7. [PMID: 12588864 DOI: 10.1074/jbc.m213207200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein (apo) E mediates lipoprotein remnant clearance via interaction with cell-surface heparan sulfate proteoglycans. Both the 22-kDa N-terminal domain and 10-kDa C-terminal domain of apoE contain a heparin binding site; the N-terminal site overlaps with the low density lipoprotein receptor binding region and the C-terminal site is undefined. To understand the molecular details of the apoE-heparin interaction, we defined the microenvironments of all 12 lysine residues in intact apoE3 and examined their relative contributions to heparin binding. Nuclear magnetic resonance measurements showed that, in apoE3-dimyristoyl phosphatidylcholine discs, Lys-143 and -146 in the N-terminal domain and Lys-233 in the C-terminal domain have unusually low pK(a) values, indicating high positive electrostatic potential around these residues. Binding experiments using heparin-Sepharose gel demonstrated that the lipid-free 10-kDa fragment interacted strongly with heparin and a point mutation K233Q largely abolished the binding, indicating that Lys-233 is involved in heparin binding and that an unusually basic lysine microenvironment is critical for the interaction with heparin. With lipidated apoE3, it is confirmed that the Lys-233 site is completely masked and the N-terminal site mediates heparin binding. In addition, mutations of the two heparin binding sites in intact apoE3 demonstrated the dominant role of the N-terminal site in the heparin binding of apoE even in the lipid-free state. These results suggest that apoE interacts predominately with cell-surface heparan sulfate proteoglycans through the N-terminal binding site. However, Lys-233 may be involved in the binding of apoE to certain cell-surface sites, such as the protein core of biglycan.
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Affiliation(s)
- Hiroyuki Saito
- Joseph Stokes, Jr. Research Institute, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4318, USA
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18
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Burns MP, Noble WJ, Olm V, Gaynor K, Casey E, LaFrancois J, Wang L, Duff K. Co-localization of cholesterol, apolipoprotein E and fibrillar Abeta in amyloid plaques. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 110:119-25. [PMID: 12573540 DOI: 10.1016/s0169-328x(02)00647-2] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent evidence strongly suggests a role for cholesterol and apolipoprotein E in the etiology of Alzheimer's disease. We have demonstrated the co-localization of cholesterol and apolipoprotein E with beta-amyloid immunoreactivity and thioflavin S immunofluorescence in AD type plaques of a transgenic mouse model. Cholesterol and apolipoprotein E co-localized to the core of thioflavin S-positive (fibrillar) plaques, but not thioflavin S-negative (diffuse) plaques from an early age. By 18 months of age, there was extensive coverage of fibrillar plaques immunopositive for apolipoprotein E and cholesterol oxidase. These findings support evidence that cholesterol and apolipoprotein E are involved in fibrillar plaque formation or maintenance, and suggest that cholesterol may impact amyloid formation extracellularly, as well as through an intracellular effect.
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Affiliation(s)
- Mark P Burns
- Center for Dementia Research, Nathan S. Kline Institute, 140 Old Orangeburg Rd, Orangeburg, NY 10962, USA.
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19
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Takahashi N, Hasegawa K, Yamaguchi I, Okada H, Ueda T, Gejyo F, Naiki H. Establishment of a first-order kinetic model of light chain-associated amyloid fibril extension in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1601:110-20. [PMID: 12429509 DOI: 10.1016/s1570-9639(02)00435-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Light chain-associated (AL) amyloidosis is a common and fatal systemic amyloidosis. AL amyloid fibrils (fAL) are composed of intact or fragmental monoclonal light chains (AL proteins). To elucidate the molecular mechanisms of fAL formation from AL proteins, we purified fAL and AL proteins from the amyloid-deposited organs of five AL amyloidosis patients. By electron microscopy and fluorometric thioflavin T method, we observed optimal fibril extension at pH 2.0-3.5 for the fibrils obtained from four patients, while at pH 7.5-8.0 for those obtained from one patient. Fragmental AL proteins were more efficient in the extension reaction than intact AL proteins. The fibrils obtained from all five patients showed clear fibril extension electron microscopically at pH 7.5. The extension of the fibrils obtained from all five patients could be explained by a first-order kinetic model, i.e., fibril extension proceeds via the consecutive association of AL proteins onto the ends of existing fibrils. Fibril extension was accelerated by dermatan sulfate proteoglycan, and inhibited by apolipoprotein E, alpha1-microglobulin, fibronectin, and an antioxidant nordihydroguaiaretic acid. These findings contribute to our understanding of the molecular mechanism underlying the pathogenesis of AL amyloidosis, and will be useful for developing a therapeutic strategy against the disease.
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Affiliation(s)
- Naoki Takahashi
- Department of Pathology, Fukui Medical University, 23-3 Shimoaizuki, Matsuoka, Fukui 910-1193, Japan
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Bergström J, Murphy C, Eulitz M, Weiss DT, Westermark GT, Solomon A, Westermark P. Codeposition of apolipoprotein A-IV and transthyretin in senile systemic (ATTR) amyloidosis. Biochem Biophys Res Commun 2001; 285:903-8. [PMID: 11467836 DOI: 10.1006/bbrc.2001.5260] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein material was extracted from amyloid-rich sections of formalin-fixed and paraffin-embedded heart tissue from an individual with senile systemic amyloidosis, known to contain wild-type transthyretin as major amyloid fibril protein. Amino acid sequence analysis of tryptic peptides of this material revealed in addition to transthyretin sequences, also amino acid sequence corresponding to an N-terminal fragment of apolipoprotein A-IV. In immunohistochemistry, an antiserum to a synthetic apolipoprotein A-IV peptide labeled amyloid specifically. This peptide formed spontaneously amyloid-like fibrils in vitro and enhanced fibril formation from wild-type transthyretin. We conclude that several apolipoproteins, including apolipoprotein A-IV, may be important minor amyloid constituents, promoting fibril formation.
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Affiliation(s)
- J Bergström
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
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21
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Yamaguchi I, Hasegawa K, Takahashi N, Gejyo F, Naiki H. Apolipoprotein E inhibits the depolymerization of beta 2-microglobulin-related amyloid fibrils at a neutral pH. Biochemistry 2001; 40:8499-507. [PMID: 11456487 DOI: 10.1021/bi0027128] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
beta 2-Microglobulin-related (A beta 2M) amyloidosis is a common and serious complication in patients on long-term hemodialysis, and beta 2-microglobulin (beta 2-m) is a major structural component of A beta 2M amyloid fibrils. Fluorescence spectroscopic analysis with thioflavin T and electron microscopic study revealed that A beta 2M amyloid fibrils readily depolymerize into monomeric beta 2-m at a neutral to basic pH. Circular dichroism analysis revealed that soon after the initiation of the depolymerization reaction at pH 7.5, the characteristic spectrum of beta 2-m in A beta 2M amyloid fibrils changes to resemble that of monomeric beta 2-m at pH 7.5. Apolipoprotein E (apoE), a representative amyloid-associated protein, formed a stable complex with A beta 2M amyloid fibrils and inhibited the depolymerization of A beta 2M amyloid fibrils dose-dependently in a range of 0--10 microM. These results showed that apoE could enhance the deposition of amyloid fibrils in vivo, possibly by binding directly to the surface of the fibrils and stabilizing the conformation of beta 2-m in the fibrils.
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Affiliation(s)
- I Yamaguchi
- Department of Pathology, Fukui Medical University, Fukui 910-1193, Japan
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22
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Yamauchi K, Tozuka M, Hidaka H, Nakabayashi T, Sugano M, Kondo Y, Nakagawara A, Katsuyama T. Effect of apolipoprotein AII on the interaction of apolipoprotein E with beta-amyloid: some apo(E-AII) complexes inhibit the internalization of beta-amyloid in cultures of neuroblastoma cells. J Neurosci Res 2000; 62:608-14. [PMID: 11070505 DOI: 10.1002/1097-4547(20001115)62:4<608::aid-jnr16>3.0.co;2-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Apolipoprotein (apo) E and its polymorphism are linked to the pathogenesis of late-onset and sporadic Alzheimer's disease (AD). ApoE facilitates the deposition and fibrillogenesis of beta-amyloid (Abeta), and may participate in Abeta clearance. We recently found that apo(E-AII) complex binds to Abeta much more strongly than does monomeric apoE. Here, we investigated the effect of apoAII on the interaction between apoE and Abeta. Addition of apoAII to apoE monomers increased the binding of apoE2 and apoE3 to Abeta(1-42), presumably following the formation of apo(E3-AII), apo(E2-AII), and apo(AII-E2-AII) complexes. This increased binding was not seen in the case of apoE4. When neuroblastoma cells were cultured in media containing Abeta(1-42) and a mixture of apoE3 and apoAII, intracellular Abeta was significantly reduced and cell viability was maintained at a higher level than in cells cultured without apoAII. ApoE2 itself seemed to act as an inhibitor of the endocytosis of Abeta, and we did not observe a significant effect of apoAII on the movement of Abeta in apoE2-containing medium. However, cell viability could be maintained at a higher level (as with apoE3) by adding apoAII to apoE2, despite the reduced viability of cells incubated without apoAII. In medium containing apoE4, both the amount of Abeta accumulated into cells and the cell viability were unchanged by the presence of apoAII in the medium. In addition, apoE4 itself was toxic, as previously suggested. These findings demonstrate that the type of apo(E-AII) complex present could underlie the isoform-specific role of apoE in the pathogenesis of AD.
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Affiliation(s)
- K Yamauchi
- Central Clinical Laboratories, Shinshu University Hospital, Asahi, Matsumoto, Japan
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23
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Cazeneuve C, Ajrapetyan H, Papin S, Roudot-Thoraval F, Geneviève D, Mndjoyan E, Papazian M, Sarkisian A, Babloyan A, Boissier B, Duquesnoy P, Kouyoumdjian JC, Girodon-Boulandet E, Grateau G, Sarkisian T, Amselem S. Identification of MEFV-independent modifying genetic factors for familial Mediterranean fever. Am J Hum Genet 2000; 67:1136-43. [PMID: 11017802 PMCID: PMC1288556 DOI: 10.1016/s0002-9297(07)62944-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2000] [Accepted: 09/06/2000] [Indexed: 11/27/2022] Open
Abstract
Familial Mediterranean fever (FMF) is a recessively inherited disorder predisposing to renal amyloidosis and associated with mutations in MEFV, a gene encoding a protein of unknown function. Differences in clinical expression have been attributed to MEFV-allelic heterogeneity, with the M694V/M694V genotype associated with a high prevalence of renal amyloidosis. However, the variable risk for patients with identical MEFV mutations to develop this severe complication, prevented by lifelong administration of colchicine, strongly suggests a role for other genetic and/or environmental factors. To overcome the well-known difficulties in the identification of modifying genetic factors, we investigated a relatively homogeneous population sample consisting of 137 Armenian patients with FMF from 127 independent families living in Armenia. We selected the SAA1, SAA2, and APOE genes-encoding serum amyloid proteins and apolipoprotein E, respectively-as well as the patients' sex, as candidate modifiers for renal amyloidosis. A stepwise logistic-regression analysis showed that the SAA1alpha/alpha genotype was associated with a sevenfold increased risk for renal amyloidosis, compared with other SAA1 genotypes (odds ratio [OR] 6. 9; 95% confidence interval [CI] 2.5-19.0). This association, which was present whatever the MEFV genotype, was extremely marked in patients homozygous for M694V (11/11). The risk for male patients of developing renal amyloidosis was fourfold higher than that for female patients (OR=4.0; 95% CI=1.5-10.8). This association, particularly marked in patients who were not homozygous for M694V (34.0% vs. 11.6%), was independent of SAA1-allelic variations. Polymorphisms in the SAA2 or APOE gene did not appear to influence susceptibility to renal amyloidosis. Overall, these data, which provide new insights into the pathophysiology of FMF, demonstrate that susceptibility to renal amyloidosis in this Mendelian disorder is influenced by at least two MEFV-independent factors of genetic origin-SAA1 and sex-that act independently of each other.
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Affiliation(s)
- Cécile Cazeneuve
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Hasmik Ajrapetyan
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Stéphanie Papin
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Françoise Roudot-Thoraval
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - David Geneviève
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Elizaveta Mndjoyan
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Marina Papazian
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Ashot Sarkisian
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Ara Babloyan
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Brigitte Boissier
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Philippe Duquesnoy
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Jean-Claude Kouyoumdjian
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Emmanuelle Girodon-Boulandet
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Gilles Grateau
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Tamara Sarkisian
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
| | - Serge Amselem
- Service de Biochimie et de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (Unité 468), and Service de Santé Publique, Hôpital Henri-Mondor, Créteil; Service de Médecine Interne, Hôpital de l'Hôtel-Dieu, Paris; and Center of Medical Genetics, National Academy of Sciences, and "Arabkir” Medical Center, Yerevan, Armenia
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24
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Cazeneuve C, Ajrapetyan H, Papin S, Roudot‐Thoraval F, Genevieve D, Mndjoyan E, Papazian M, Sarkisian A, Babloyan A, Boissier B, Duquesnoy P, Kouyoumdjian J, Girodon‐Boulandet E, Grateau G, Sarkisian T, Amselem S. Identification ofMEFV‐Independent Modifying Genetic Factors for Familial Mediterranean Fever. Am J Hum Genet 2000. [DOI: 10.1086/321196] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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25
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Abstract
Amyloid beta-protein (Abeta), the major component of plaques in Alzheimer's disease, is a small hydrophobic protein that is carried on apolipoprotein E (ApoE)- and ApoJ-containing lipoprotein particles in plasma and cerebrospinal fluid (CSF). Microglia, the scavenger cells of the CNS, take up and degrade Abeta via lipoprotein receptors including scavenger receptors A and B, and possibly via other receptors. Lipoproteins, ApoE, and ApoJ influence the uptake and degradation of Abeta in vitro and in vivo. Differences in ApoE-E4, -E3, and -E2 isoforms with respect to Abeta binding to lipoproteins and delivery to cells, including microglia, may contribute to the increased risk of Alzheimer's disease for people with an APOE4 genotype and to risk reduction with APOE2.
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Affiliation(s)
- G M Cole
- Sepulveda VA Medical Center, Sepulveda, California 91343, USA.
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26
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Klezovitch O, Formato M, Cherchi GM, Weisgraber KH, Scanu AM. Structural determinants in the C-terminal domain of apolipoprotein E mediating binding to the protein core of human aortic biglycan. J Biol Chem 2000; 275:18913-8. [PMID: 10751422 DOI: 10.1074/jbc.m909644199] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein (apo) E-containing high density lipoprotein particles were reported to interact in vitro with the proteoglycan biglycan (Bg), but the direct participation of apoE in this binding was not defined. To this end, we examined the in vitro binding of apoE complexed with dimyristoylphosphatidylcholine (DMPC) to human aortic Bg before and after glycosaminoglycan (GAG) depletion. In a solid-phase assay, apoE.DMPC bound to Bg and GAG-depleted protein core in a similar manner, suggesting a protein-protein mode of interaction. The binding was decreased in the presence of 1 m NaCl and was partially inhibited by either positively (0.2 m lysine, arginine) or negatively charged (0.2 m aspartic, glutamic) amino acids. A recombinant apoE fragment representing the C-terminal 10-kDa domain, complexed with DMPC, bound as efficiently as full-length apoE, whereas the N-terminal 22-kDa domain was inactive. Similar results were obtained with a gel mobility shift assay. Competition studies using a series of recombinant truncated apoEs showed that the charged segment in the C-terminal domain between residues 223 and 230 was involved in the binding. Overall, our results demonstrate that the C-terminal domain contains elements critical for the binding of apoE to the Bg protein core and that this binding is ionic in nature and independent of GAGs.
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Affiliation(s)
- O Klezovitch
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
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27
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Abstract
Current assumptions and conclusions in several active areas of amyloid research are examined to see how consistent the data from chosen in vitro and in vivo model systems are with clinical and anatomic observations. These areas include the assembly of amyloid-like fibrils in vitro, the nucleation phenomenon, amyloid fibril structure in vivo and in vitro, common structural components of the amyloids, and the regression of tissue amyloid and proteolysis of amyloid proteins. Divergences and congruencies are highlighted, which in turn suggests caution in the interpretation of present data, greater collaboration and communication among investigators, and, additional areas and techniques for investigation.
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Affiliation(s)
- R Kisilevsky
- Department of Pathology, Queen's University, The Syl and Molly Apps Research Center, Kingston General Hospital, Ontario, Kingston, K7L 3N6, Canada
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Mullins RF, Russell SR, Anderson DH, Hageman GS. Drusen associated with aging and age‐related macular degeneration contain proteins common to extracellular deposits associated with atherosclerosis, elastosis, amyloidosis, and dense deposit disease. FASEB J 2000. [DOI: 10.1096/fasebj.14.7.835] [Citation(s) in RCA: 610] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Robert F. Mullins
- Department of Ophthalmology and Visual Sciences, The University of IowaThe University of Iowa Center for Macular DegenerationIowa City Iowa 52242 USA
| | - Stephen R. Russell
- Department of Ophthalmology and Visual Sciences, The University of IowaThe University of Iowa Center for Macular DegenerationIowa City Iowa 52242 USA
| | - Don H. Anderson
- Center for the Study of Macular DegenerationNeuroscience Research Institute, University of CaliforniaSanta Barbara California 93106 USA
| | - Gregory S. Hageman
- Department of Ophthalmology and Visual Sciences, The University of IowaThe University of Iowa Center for Macular DegenerationIowa City Iowa 52242 USA
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Shuvaev VV, Siest G. Heparin specifically inhibits binding of apolipoprotein E to amyloid beta-peptide. Neurosci Lett 2000; 280:131-4. [PMID: 10686395 DOI: 10.1016/s0304-3940(00)00764-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Apolipoprotein E (apoE) binds to non-fibrillar amyloid beta-peptide with high affinity. We find here that heparin specifically inhibits apoE-amyloid beta-peptide (1-40) interaction. Low molecular weight heparins reduce the affinity of this interaction 3-fold as it was estimated by surface plasmon resonance. The binding is not affected by high salt concentration, which prevents heparin-induced changes of apoE conformation. We propose that rigid protein conformation, induced by high affinity heparin binding to apoE, is unfavorable for its interaction to amyloid beta-peptide. Using thioflavin T assay, we find that heparin promotes fibrillogenesis of amyloid beta-peptide whereas apoE abolishes this effect. The data suggests that the relationship between apoE and glycosaminoglycans may be important for amyloid beta-peptide fibril formation.
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Affiliation(s)
- V V Shuvaev
- Centre de Médicament, Université Henri Poincaré Nancy I, 30, rue Lionnois, 54000, Nancy, France
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Jolivalt C, Leininger-Muller B, Bertrand P, Herber R, Christen Y, Siest G. Differential oxidation of apolipoprotein E isoforms and interaction with phospholipids. Free Radic Biol Med 2000; 28:129-40. [PMID: 10656299 DOI: 10.1016/s0891-5849(99)00232-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Accumulation of oxidized proteins has been demonstrated in the brain of patients suffering from Alzheimer's disease (AD). Among the proteins found in cerebral amyloid deposits, apolipoprotein (apo) E is a polymorphic protein which one specific isoform, apo E4, has been widely associated with AD. Apo E may be linked with AD by its isoform-specific interaction with lipids or other proteins in amyloid plaques. Using the myeloperoxidase oxidative system, we report that oxidation of the three recombinant apo E isoforms is differential (as estimated using immunoblot and high-performance liquid chromatography analysis), with apo E4 being more susceptible than apo E3, which in turn is much more susceptible than apo E2. In addition, susceptibility to thrombin proteolysis is reduced when apo E is oxidized, and oxidation of apo E decreases its incorporation into phospholipid discs by approximately 50%. Oxidation of apo E may contribute to inefficient lipid recycling in the brain, particularly regarding apo E4 and E3. Our results link and strengthen both the E4 allele linkage with AD and the role of protein oxidation in AD. The cerebral mechanisms underlying apo E oxidation and/or myeloperoxidase functions in vivo remain to be assessed.
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Affiliation(s)
- C Jolivalt
- Centre du Médicament, UPRES, Faculté de Pharmacie, Université Henri Poincaré Nancy 1, France
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31
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Abstract
INTRODUCTION Recent data in amyloid research have shed light on the amyloid substance and have broadened our knowledge on the mechanism of amyloid deposition. CURRENT KNOWLEDGE AND KEY POINTS Despite uniform physical properties relating to the presence of beta-pleates, amyloid deposits are chemically heterogeneous and have different origins; additional types will probably be described in the future. Immunohistochemical techniques using specific antisera for each of the major protein present in fibrils could help greatly to subclassify these disorders. In most circumstances, a circulating precursor protein may result from overproduction of either intact or aberrant molecule, a reduction in its degradation or excretion, or genetic abnormalities associated with variant proteins. The cleavage of protein precursor molecules of the protein component of amyloid fibrils characterizes amyloidogenesis, though it is not necessary for some amyloidosis forms. This review summarizes advances in the understanding of the nature of amyloid substances, the mechanism of amyloid deposition and the principal pathogenic hypothesis. FUTURE PROSPECTS AND PROJECTS SAP component is common in all amyloidosis and may be the target for future therapy.
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Affiliation(s)
- H Lebrazi
- Laboratoire de biochimie, faculté des sciences Ben M'sik, Casablanca, Maroc
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Yamauchi K, Tozuka M, Nakabayashi T, Sugano M, Hidaka H, Kondo Y, Katsuyama T. Higher avidity binding of apolipoprotein (E-AII) complex than of apolipoprotein E monomer to ?-amyloid. J Neurosci Res 1999. [DOI: 10.1002/(sici)1097-4547(19991015)58:2<301::aid-jnr10>3.0.co;2-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yamauchi K, Tozuka M, Nakabayashi T, Sugano M, Hidaka H, Kondo Y, Katsuyama T. Apolipoprotein E in Cerebrospinal Fluid: Relation to Phenotype and Plasma Apolipoprotein E Concentrations. Clin Chem 1999. [DOI: 10.1093/clinchem/45.4.497] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AbstractBackground: Apolipoprotein (apo) E may be related to the development of Alzheimer disease, but data on apoE in cerebrospinal fluid (CSF) are limited. The aim of the present study was to measure apoE in CSF and relate its concentrations to apoE phenotype and CSF lipids.Methods: We adapted an assay for CSF apoE sensitivity using an ELISA. It allowed us to measure CSF apoE with sufficient reproducibility and precision.Results: The within- and between-run CVs were <7%, and the detection limit was 0.025 mg/L. No cross-reaction was found for other apolipoproteins. No significant differences related to sex or apoE phenotype were observed in the CSF apoE concentration. The mean CSF apoE concentration was significantly higher in the 0–5 year group (n = 6; 18.47 ± 1.14 mg/L, mean ± SD) than in the >5 year group (n = 34; 8.82 ± 3.31 mg/L). The mean concentrations of total cholesterol (TC) and phospholipid (PL) in CSF were 2.68 ± 2.16 and 6.50 ± 2.84 mg/L (n = 52), respectively. Although no significant differences in TC or PL in the CSF were found with respect to sex or age, the concentrations in subjects with the apoE phenotype E4/E3 were significantly lower than in those with E3/E3 and E3/E2. The concentrations of apoE, TC, and PL in CSF did not correlate with those in plasma. The time-related fluctuations in CSF apoE were independent of those in total protein and IgG. CSF apoE was significantly correlated with TC and PL concentrations in the CSF, but not with the number of cells in the CSF.Conclusions: These findings support the idea that apoE and lipids are unable to cross the blood-brain barrier and that their concentrations in CSF may reflect production in central nervous tissue.
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Affiliation(s)
- Kazuyoshi Yamauchi
- Central Clinical Laboratories, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Minoru Tozuka
- Central Clinical Laboratories, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Tetsuo Nakabayashi
- Central Clinical Laboratories, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Mitsutoshi Sugano
- Central Clinical Laboratories, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Hiroya Hidaka
- Central Clinical Laboratories, Shinshu University Hospital, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Yoshiyuki Kondo
- Department of Functional Polymer Science, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokita, Ueda 386-0018, Japan
| | - Tsutomu Katsuyama
- Department of Laboratory Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
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Pillot T, Goethals M, Najib J, Labeur C, Lins L, Chambaz J, Brasseur R, Vandekerckhove J, Rosseneu M. Beta-amyloid peptide interacts specifically with the carboxy-terminal domain of human apolipoprotein E: relevance to Alzheimer's disease. J Neurochem 1999; 72:230-7. [PMID: 9886074 DOI: 10.1046/j.1471-4159.1999.0720230.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Growing evidence indicates the involvement of apolipoprotein E (apoE) in the development of late-onset and sporadic forms of Alzheimer's disease, although its exact role remains unclear. We previously demonstrated that beta-amyloid peptide (Abeta) displays membrane-destabilizing properties and that only apoE2 and E3 isoforms inhibit these properties. In this study, we clearly demonstrate that the carboxy-terminal lipid-binding domain of apoE (e.g., residues 200-299) is responsible for the Abeta-binding activity of apoE and that this interaction involves pairs of apoE amphipathic alpha-helices. We further demonstrate that Abeta is able to inhibit the association of the C-terminal domain of apoE with lipids due to the formation of Abeta/apoE complexes resistant to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. On the contrary, the amino-terminal receptor-binding domain of apoE (e.g., residues 129-169) is not able to form stable complexes with Abeta. These data extend our understanding of human apoE-dependent binding of Abeta by involving the C-terminal domain of apoE in the efficient formation of apoE/Abeta complex.
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Affiliation(s)
- T Pillot
- Laboratory for Lipoprotein Chemistry, University of Gent, Belgium
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35
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Application of polyacrylamide slab gel electrophoresis to the analysis and small-scale purification of amyloid proteins. Anal Chim Acta 1998. [DOI: 10.1016/s0003-2670(98)00336-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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36
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Stable complexes involving acetylcholinesterase and amyloid-beta peptide change the biochemical properties of the enzyme and increase the neurotoxicity of Alzheimer's fibrils. J Neurosci 1998. [PMID: 9547230 DOI: 10.1523/jneurosci.18-09-03213.1998] [Citation(s) in RCA: 215] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Brain acetylcholinesterase (AChE) forms stable complexes with amyloid-beta peptide (Abeta) during its assembly into filaments, in agreement with its colocalization with the Abeta deposits of Alzheimer's brain. The association of the enzyme with nascent Abeta aggregates occurs as early as after 30 min of incubation. Analysis of the catalytic activity of the AChE incorporated into these complexes shows an anomalous behavior reminiscent of the AChE associated with senile plaques, which includes a resistance to low pH, high substrate concentrations, and lower sensitivity to AChE inhibitors. Furthermore, the toxicity of the AChE-amyloid complexes is higher than that of the Abeta aggregates alone. Thus, in addition to its possible role as a heterogeneous nucleator during amyloid formation, AChE, by forming such stable complexes, may increase the neurotoxicity of Abeta fibrils and thus may determine the selective neuronal loss observed in Alzheimer's brain.
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Abstract
The genetic associations with the pathological features of AD are diverse: A rapidly growing number of mutations in presenilin 1 and 2 on chromosomes 14 and 1, respectively, are found in many early-onset FAD patients (Lendon et al., 1997). In addition, beta PP mutations are found in a small percentage of early-onset FAD kindreds. The apoE4 allele on chromosome 19 is associated with the presence of the most common form of AD, sporadic AD (Wisniewski & Frangione, 1992; Namba et al., 1991). However, it is clear that other proteins are also involved in the pathogenesis of AD, since some early-onset FAD kindreds do not have linkage to PS1, PS2, apoE, or beta PP, while at least 50% of late-onset AD is unrelated to apoE. Other proteins which have been implicated in the formation of senile plaques, but so far are not known to have any genetic linkage to AD, include proteoglycans (Snow et al., 1987), apoA1 (Wisniewski et al., 1995a), alpha 1-antichymotrypsin (Abraham et al., 1988), HB-GAM (Wisniewski et al., 1996a), complement components (McGeer & Rogers, 1992), acetylcholinesterase (Friede, 1965), and NAC (Ueda et al., 1993). Which of these proteins will be the most important for the etiology of the most common form of AD, late-onset sporadic AD, remains an open question. Three of the genes which are now known to be linked to AD, including PS1, beta PP, and apoE, have been established immunohistochemically and biochemically to be components of senile plaques (see Fig. 1). This raises at least two possibilities: either each of these proteins is part of one pathway with A beta-related amyloid formation as a final causative pathogenic event or amyloid deposition in AD is a reactive process related to dysfunction of a number of different CNS proteins. Whether or not amyloid formation is directly causative in the pathogenesis of AD, current data suggest that new therapeutic approaches which may inhibit the aggregation and/or the conformational change of sA beta to A beta fibrils (Soto et al., 1996) have the greatest likelihood to make a significant impact on controlling amyloid accumulation in AD.
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Affiliation(s)
- T Wisniewski
- Department of Neurology, New York University Medical Center, New York 10016, USA.
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38
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Plastic neuronal remodeling is impaired in patients with Alzheimer's disease carrying apolipoprotein epsilon 4 allele. J Neurosci 1997. [PMID: 8987775 DOI: 10.1523/jneurosci.17-02-00516.1997] [Citation(s) in RCA: 208] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A relationship between the apolipoprotein E (apoE) genotype and the risk to develop Alzheimer's disease has been established recently. Apolipoprotein synthesis is implicated in developmental processes and in neuronal repair of the adult nervous system. In the present study, we investigated the influence of the apolipoprotein polymorphism on the severity of neuronal degeneration and the extent of plastic dendritic remodeling in Alzheimer's disease. Changes in length and arborization of dendrites of Golgi-impregnated neurons in the basal nucleus of Meynert, locus coeruleus, raphe magnus nucleus, medial amygdaloid nucleus, pedunculopontine tegmental nucleus, and substantia nigra were analyzed after three-dimensional reconstruction. Patients with either one or two apoE epsilon 4 alleles not only showed a more severe degeneration in all areas investigated than in patients lacking the apoE 4 allele but also revealed significantly less plastic dendritic changes. ApoE epsilon 4 allele copy number, furthermore, had a significant effect on the pattern of dendritic arborization. Moreover, the relationship between the intensity of dendritic growth and both the extent of neuronal degeneration and the stage of the disease seen in patients lacking the apoE epsilon 4 allele was very weak in the presence of one epsilon 4 allele and completely lost in patients homozygous for the epsilon 4 allele. The results provide direct evidence that neuronal reorganization is affected severely in patients with Alzheimer's disease carrying the apoE epsilon 4 allele. This impairment of neuronal repair might lead to a more rapid functional decompensation, thereby contributing to an earlier onset and more rapid progression of the disease.
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39
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Elliott-Bryant R, Cathcart ES. Apolipoprotein E and apolipoprotein A-1 knock-out mice readily develop amyloid A protein amyloidosis. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1997; 85:104-8. [PMID: 9325076 DOI: 10.1006/clin.1997.4397] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Studies have identified apolipoprotein E (apoE) ubiquitously in biochemically distinct amyloid deposits including amyloid A protein (AA) in secondary amyloidosis and amyloid beta protein (A beta) amyloid in Alzheimer's disease (AD). Apolipoprotein A-1 (apoA-1) has been identified in cortical plaques derived from the tissues of patients with AD. To determine if apoE is essential for and apoA-1 may be a factor in AA-amyloidogenesis we investigated induction of secondary amyloidosis in mutant C57BL/6J mice that lack either apoE or apoA-1. Induction of secondary amyloidosis in nonmutant C57BL/6J mice that are AA amyloid-susceptible were the AA positive control. Discreet deposits of AA amyloid were detected in the perifollicular regions of spleens derived from mutant and nonmutant strains. The findings clearly demonstrate that generation of AA fibrils can occur independently of apoE and ApoA-1 expression.
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Affiliation(s)
- R Elliott-Bryant
- Edith Nourse Rogers Memorial Veterans Administration Medical Center, Bedford, Massachusetts 01750, USA
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40
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Alvarez A, Opazo C, Alarcón R, Garrido J, Inestrosa NC. Acetylcholinesterase promotes the aggregation of amyloid-beta-peptide fragments by forming a complex with the growing fibrils. J Mol Biol 1997; 272:348-61. [PMID: 9325095 DOI: 10.1006/jmbi.1997.1245] [Citation(s) in RCA: 219] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Acetylcholinesterase (AChE), an enzyme involved in the hydrolysis of the neurotransmitter acetylcholine, consistently colocalizes with the amyloid deposits characteristic of Alzheimer's disease and may contribute to the generation of amyloid proteins and/or physically affect fibril assembly. In order to identify the structural domains of the amyloid-beta-peptide (Abeta) involved in the aggregation induced by AChE, we have studied the effect of this cholinergic enzyme on Abeta peptide fragments of different sizes. AChE enhanced the aggregation of the Abeta(12-28) and Abeta(25-35) peptides but not of the Abeta(1-16) fragment. The inductive effect of AChE on the aggregation of Abeta(12-28) was abolished by the presence of either Abeta(1-16) or Abeta(9-21). The effect of the enzyme was also analysed using two different mutant fragments, possessing a low and the other a high capacity for fibrillogenesis. The fragments used were Abeta(12-28)Val18-->Ala and Abeta(12-28)Glu22-->Gln, respectively. AChE was able to promote the aggregation of these fragments in a very specific way and both mutant peptides were able to form amyloid fibrils, as revealed by negative staining under the electron microscope. Binding assays indicated that AChE was bound to Abeta(12-28), as well as to the Abeta(1-16) peptide. AChE was seen to form strong complexes with the Abeta(12-28) fibrils as such complexes stained positively for both thioflavine-T and AChE activity, were resistant to high ionic strength treatment, and were partially sensitive to detergents, suggesting that hydrophobic interactions may play a role in the stabilization of the AChE-Abeta complex. Our results suggest that such amyloid-AChE complexes are formed when AChE interacts with the growing amyloid fibrils and accelerates the assembly of Abeta peptides. This is consistent with the fact that AChE is known to be present within Abeta deposits including the pre-amyloid diffuse and mature senile plaques found in Alzheimer's brain.
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Affiliation(s)
- A Alvarez
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Aizawa Y, Fukatsu R, Takamaru Y, Tsuzuki K, Chiba H, Kobayashi K, Fujii N, Takahata N. Amino-terminus truncated apolipoprotein E is the major species in amyloid deposits in Alzheimer's disease-affected brains: a possible role for apolipoprotein E in Alzheimer's disease. Brain Res 1997; 768:208-14. [PMID: 9369317 DOI: 10.1016/s0006-8993(97)00640-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Amyloid deposits in Alzheimer's disease (AD) are composed of amyloid beta protein (A beta) and many other components called amyloid-associated proteins. Apolipoprotein E (apoE) is one of the most important amyloid-associated proteins. The role apoE plays in AD, however, is yet to be determined. In this study, we present the biochemical and histochemical nature of apoE in AD-affected brains using four monoclonal antibodies (mAbs) against apoE and newly established antibodies against the amino-terminal (anti-apoE-N), and carboxyl-terminal regions (anti-apoE-C) of apoE. Competitive ELISA and Western-blot analysis combined with thrombolytic digestion of apoE indicated that our four mAbs recognized at least two different epitopes within a 22-kDa amino-terminal domain of apoE. Using these mAbs and an anti-A beta mAb, double immunostaining showed that the majority of amyloid deposits were stained by both anti-apoE and anti-A beta mAbs, but the minority of them were detected only by either anti-apoE or anti-A beta mAbs. Differences in staining properties between anti-apoE-N and anti-apoE-C were that anti-apoE-C recognized both amyloid deposits and astrocytes similar to anti-apoE mAbs, but anti-apoE-N strongly stained only astrocytes. Preliminary semi-quantitative determinations of apoE in CSF and brain homogenate showed that the amount of apoE increased in AD and Creutzfeldt-Jakob disease brains compared to normal samples. Our immunological data, using antibodies specific for the amino and carboxyl termini of apoE, suggest that apoE may, in some circumstances, initiate plaque formation, and that apoE in amyloid deposits has at least part of its amino termini cleaved out.
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Affiliation(s)
- Y Aizawa
- Department of Neuropsychiatry, Sapporo Medical University School of Medicine, Japan
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Rocken C, Paris D, Steusloff K, Saeger W. Investigation of the Presence of Apotipoprotein E, G lycosaminoglycans, Basement Membrane Proteins, and Protease inhibitors in Senile interstitial Amyloid of the Pituitary. Endocr Pathol 1997; 8:205-214. [PMID: 12114724 DOI: 10.1007/bf02738787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The aim of our study was to test whether local- or organ-limited interstitial amyloid of the pituitary is associated with the presence of glycosaminoglycans, basement membrane proteins, protease inhibitors, and apolipoprotein E (apo E), as previously observed in other amyloid syndromes. Serial sections from amyloidotic and nonamyloidotic autopsy pituitaries of patients age 85 yr and over were stained with Congo red, Alcian blue, and, applying immunohistochemistry, with antibodies directed against fibronectin, collagen IV, laminin, apo E, a(1)-antitrypsin and a(1)-antichymotrypsin. Interstitial amyloid was deposited in the immediate vicinity of capillaries and around the acini of the anterior lobe. Glycosaminoglycans were found in capillaries and around the acini of both nonamyloidotic and amyloidotic glands and they were also related spatially to amyloid deposits. Immunostaining of nonamyloidotic and amyloidotic glands demonstrated the presence of fibronectin, collagen IV, and laminin, which was related to basement membranes (fibronectin, collagen IV, and laminin), interstitium, and serum (fibronectin only). In amyloidotic glands, each basement membrane protein presented with an additional spatial relationship to amyloid deposits. Apo E was found in amyloidotic cases only within the amyloid deposits. The results are consistent with the presence of glycosaminoglycans, basement membrane proteins, and apo E in local interstitial amyloid deposits of the pituitary, as previously described in other amyloid syndromes, such as inflammatory related AA-amyloidosis or AB-amyloidosis related to Alzheimer's disease.
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43
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Kwon YJ, Tsai J, Relkin NR. NIA/AIzA Conference on apolipoprotein E genotyping in Alzheimer's disease. Bibliography. Ann N Y Acad Sci 1996; 802:177-224. [PMID: 9012315 DOI: 10.1111/j.1749-6632.1996.tb32609.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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44
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Golabek AA, Soto C, Vogel T, Wisniewski T. The interaction between apolipoprotein E and Alzheimer's amyloid beta-peptide is dependent on beta-peptide conformation. J Biol Chem 1996; 271:10602-6. [PMID: 8631862 DOI: 10.1074/jbc.271.18.10602] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
An important feature of Alzheimer's disease (AD) is the cerebral deposition of amyloid. The main component of the amyloid is a 39-44-amino acid residue protein called amyloid beta (A beta), which also exists as a normal protein in biological fluids, known as soluble A beta. A major risk factor for late-onset AD is the inheritance of the apolipoprotein (apo) E4 isotype of apoE. How apoE is involved in the pathogenesis of AD is unclear; however, evidence exists for a direct apoE/A beta interaction. We and others have shown that apoE copurifies with A beta from AD amyloid plaques and that under certain in vitro conditions apoE promotes a beta-sheet structure in A beta peptides. Currently we document the high affinity binding of A beta peptides to both human recombinant apoE3 and -E4 with a KD of 20 nM. This interaction is greatly influenced by the conformational state of the A beta peptide used. Furthermore, we show that the fibril modulating effect of apoE is also influenced by the initial secondary structure of the A beta peptide. The preferential binding of apoE to A beta peptides with a beta-sheet conformation can in part explain the copurification of A beta and apoE from AD amyloid plaques.
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Affiliation(s)
- A A Golabek
- Department of Neurology, New York University Medical Center, New York 10016, USA
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