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Bergeron M, Motter R, Tanaka P, Fauss D, Babcock M, Chiou SS, Nelson S, San Pablo F, Anderson JP. In vivo modulation of polo-like kinases supports a key role for PLK2 in Ser129 α-synuclein phosphorylation in mouse brain. Neuroscience 2013; 256:72-82. [PMID: 24128992 DOI: 10.1016/j.neuroscience.2013.09.061] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 11/29/2022]
Abstract
α-Synuclein is the major component of Lewy bodies. α-Synuclein phosphorylated at Ser 129 (Phospho-α-Syn) is the most common synuclein modification observed in Parkinson's disease pathology and transgenic animal models. Polo-like kinase 2 (PLK2) was previously proposed as an important kinase in α-synuclein phosphorylation at Ser129. To better understand the role of PLK2 in α-synuclein phosphorylation in vivo, we further evaluated the effect of PLK2 genetic knockdown and pharmacological inhibition on Phospho-α-Syn levels in different brain regions of PLK2 knockout (KO), heterozygous (Het) and wild-type (WT) mice. Whereas PLK2 knockdown had no effect on Total-α-synuclein brain levels, it resulted in a gene-dosage dependent, albeit incomplete, reduction of endogenous Phospho-α-Syn levels in all brain regions investigated. No compensatory induction of other α-synuclein kinases (PLK3, casein kinase-2, G-protein-coupled receptor kinase 5 (GRK5) and GRK6) was observed at the mRNA level in the PLK2 KO mouse brain. To determine whether increased activity of another PLK family member is responsible for the residual Phospho-α-Syn levels in the PLK2 KO mouse brain, the pan-PLK inhibitor BI 2536 was tested in PLK2 KO mice. Whereas BI 2536 reduced Phospho-α-Syn levels in WT mice, it did not further reduce the residual endogenous Phospho-α-Syn levels in PLK2 KO and Het mice, suggesting that a kinase other than PLK1-3 accounts for the remaining PLK inhibitor-resistant pool in the mouse brain. Moreover, PLK3 KO in mice had no effect on both Total- and Phospho-α-Syn brain levels. These results support a significant role for a PLK kinase in phosphorylating α-synuclein at Ser129 in the brain, and suggest that PLK2 is responsible for this activity under physiological conditions.
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Affiliation(s)
- M Bergeron
- Department of Pharmacological Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA.
| | - R Motter
- Department of Pharmacological Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - P Tanaka
- Department of Pharmacological Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - D Fauss
- Department of Pharmacological Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - M Babcock
- Department of Exploratory Research, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - S-S Chiou
- Department of Protein Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - S Nelson
- Department of Protein Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - F San Pablo
- Department of Pharmacological Sciences, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
| | - J P Anderson
- Department of Exploratory Research, Elan Pharmaceuticals, South San Francisco, CA 94080, USA
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2
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Aubele DL, Hom RK, Adler M, Galemmo RA, Bowers S, Truong AP, Pan H, Beroza P, Neitz RJ, Yao N, Lin M, Tonn G, Zhang H, Bova MP, Ren Z, Tam D, Ruslim L, Baker J, Diep L, Fitzgerald K, Hoffman J, Motter R, Fauss D, Tanaka P, Dappen M, Jagodzinski J, Chan W, Konradi AW, Latimer L, Zhu YL, Sham HL, Anderson JP, Bergeron M, Artis DR. Selective and brain-permeable polo-like kinase-2 (Plk-2) inhibitors that reduce α-synuclein phosphorylation in rat brain. ChemMedChem 2013; 8:1295-313. [PMID: 23794260 DOI: 10.1002/cmdc.201300166] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Indexed: 11/12/2022]
Abstract
Polo-like kinase-2 (Plk-2) has been implicated as the dominant kinase involved in the phosphorylation of α-synuclein in Lewy bodies, which are one of the hallmarks of Parkinson's disease neuropathology. Potent, selective, brain-penetrant inhibitors of Plk-2 were obtained from a structure-guided drug discovery approach driven by the first reported Plk-2-inhibitor complexes. The best of these compounds showed excellent isoform and kinome-wide selectivity, with physicochemical properties sufficient to interrogate the role of Plk-2 inhibition in vivo. One such compound significantly decreased phosphorylation of α-synuclein in rat brain upon oral administration and represents a useful probe for future studies of this therapeutic avenue toward the potential treatment of Parkinson's disease.
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Affiliation(s)
- Danielle L Aubele
- Molecular Discovery, Elan Pharmaceuticals, 180 Oyster Point Boulevard, South San Francisco, CA 94080, USA
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3
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Bowers S, Truong AP, Ye M, Aubele DL, Sealy JM, Neitz RJ, Hom RK, Chan W, Dappen MS, Galemmo RA, Konradi AW, Sham HL, Zhu YL, Beroza P, Tonn G, Zhang H, Hoffman J, Motter R, Fauss D, Tanaka P, Bova MP, Ren Z, Tam D, Ruslim L, Baker J, Pandya D, Diep L, Fitzgerald K, Artis DR, Anderson JP, Bergeron M. Design and synthesis of highly selective, orally active Polo-like kinase-2 (Plk-2) inhibitors. Bioorg Med Chem Lett 2013; 23:2743-9. [PMID: 23522834 DOI: 10.1016/j.bmcl.2013.02.065] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/06/2013] [Accepted: 02/13/2013] [Indexed: 12/13/2022]
Abstract
Polo-like kinase-2 (Plk-2) is a potential therapeutic target for Parkinson's disease and this Letter describes the SAR of a series of dihydropteridinone based Plk-2 inhibitors. By optimizing both the N-8 substituent and the biaryl region of the inhibitors we obtained single digit nanomolar compounds such as 37 with excellent selectivity for Plk-2 over Plk-1. When dosed orally in rats, compound 37 demonstrated a 41-45% reduction of pS129-α-synuclein levels in the cerebral cortex.
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Affiliation(s)
- Simeon Bowers
- Department of Chemical Sciences, Elan Pharmaceuticals, 180 Oyster Point Boulevard, South San Francisco, CA 94080, USA.
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4
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Fauss D, Motter R, Dofiles L, Rodrigues MAV, You M, Diep L, Yang Y, Seto P, Tanaka K, Baker J, Bergeron M. Development of an enzyme-linked immunosorbent assay (ELISA) to measure the level of tyrosine hydroxylase protein in brain tissue from Parkinson's disease models. J Neurosci Methods 2013; 215:245-57. [DOI: 10.1016/j.jneumeth.2013.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/15/2013] [Accepted: 03/18/2013] [Indexed: 01/06/2023]
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5
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Garofalo AW, Adler M, Aubele DL, Brigham EF, Chian D, Franzini M, Goldbach E, Kwong GT, Motter R, Probst GD, Quinn KP, Ruslim L, Sham HL, Tam D, Tanaka P, Truong AP, Ye XM, Ren Z. Discovery of 4-alkylamino-7-aryl-3-cyanoquinoline LRRK2 kinase inhibitors. Bioorg Med Chem Lett 2013; 23:1974-7. [DOI: 10.1016/j.bmcl.2013.02.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/02/2013] [Accepted: 02/07/2013] [Indexed: 10/27/2022]
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Motter R, Veinbergs I, Cremers T, Van der Hart M, Yu L, Kooijker H, Flik G, Freije R, Brendza R, Tanaka P. P1‐029: A comparison of conventional versus push‐pull microdialysis for the detection of amyloid β in the mouse brain. Alzheimers Dement 2011. [DOI: 10.1016/j.jalz.2011.05.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | | | | | - Lisa Yu
- Brains On‐LineSouth San FranciscoCalifornia
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Shapiro RI, Plavina T, Schlain BR, Pepinsky RB, Garber EA, Jarpe M, Hochman PS, Wehner NG, Bard F, Motter R, Yednock TA, Taylor FR. Development and validation of immunoassays to quantify the half-antibody exchange of an IgG4 antibody, natalizumab (Tysabri®) with endogenous IgG4. J Pharm Biomed Anal 2011; 55:168-75. [PMID: 21300512 DOI: 10.1016/j.jpba.2011.01.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 12/30/2010] [Accepted: 01/11/2011] [Indexed: 11/25/2022]
Abstract
Natalizumab is a humanized IgG4 monoclonal antibody which binds human α4 integrin and is approved for treatment of multiple sclerosis and Crohn's disease. Assessment of the in vivo disposition of natalizumab presents a unique assay development challenge due to the ability of human IgG4 antibodies to undergo half-antibody exchange in vivo. Such exchange generates IgG4 molecules of mixed specificity comprising a natalizumab heavy-light chain pair coupled to an IgG4 heavy-light chain pair of unknown specificity. Since exchanged and non-exchanged species cannot be quantified independently using a single enzyme linked immunosorbent assay (ELISA), a novel quantitation strategy was developed employing two ELISAs: one measuring total natalizumab including both intact and exchanged molecules, and the second measuring only intact natalizumab. The presence and amount of exchanged natalizumab in serum is calculated by the difference in values obtained in the two assays. To evaluate assay performance, a control reagent was created from natalizumab and an irrelevant humanized monoclonal IgG4 antibody. Subsequent validation demonstrated that both assays are specific, accurate, and precise within the working ranges of the assays (1.5-10μg/mL for total and 0.5-12μg/mL for intact natalizumab assays). The mean accuracy, intra- and inter-assay precision for both assays were 82-113%, ≤9% and ≤20%, respectively. Additionally, the limits of detection of intact and exchanged natalizumab were established using statistical methods. The utility of the two-assay strategy was confirmed by analyzing samples from a pharmacokinetic study in rats using different variants of natalizumab administered along with another human IgG4 antibody as an exchange partner.
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Basi GS, Hemphill S, Brigham EF, Liao A, Aubele DL, Baker J, Barbour R, Bova M, Chen XH, Dappen MS, Eichenbaum T, Goldbach E, Hawkinson J, Lawler-Herbold R, Hu K, Hui T, Jagodzinski JJ, Keim PS, Kholodenko D, Latimer LH, Lee M, Marugg J, Mattson MN, McCauley S, Miller JL, Motter R, Mutter L, Neitzel ML, Ni H, Nguyen L, Quinn K, Ruslim L, Semko CM, Shapiro P, Smith J, Soriano F, Szoke B, Tanaka K, Tang P, Tucker JA, Ye XM, Yu M, Wu J, Xu YZ, Garofalo AW, Sauer JM, Konradi AW, Ness D, Shopp G, Pleiss MA, Freedman SB, Schenk D. Amyloid precursor protein selective gamma-secretase inhibitors for treatment of Alzheimer's disease. Alzheimers Res Ther 2010; 2:36. [PMID: 21190552 PMCID: PMC3031881 DOI: 10.1186/alzrt60] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 12/16/2010] [Accepted: 12/29/2010] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Inhibition of gamma-secretase presents a direct target for lowering Aβ production in the brain as a therapy for Alzheimer's disease (AD). However, gamma-secretase is known to process multiple substrates in addition to amyloid precursor protein (APP), most notably Notch, which has limited clinical development of inhibitors targeting this enzyme. It has been postulated that APP substrate selective inhibitors of gamma-secretase would be preferable to non-selective inhibitors from a safety perspective for AD therapy. METHODS In vitro assays monitoring inhibitor potencies at APP γ-site cleavage (equivalent to Aβ40), and Notch ε-site cleavage, in conjunction with a single cell assay to simultaneously monitor selectivity for inhibition of Aβ production vs. Notch signaling were developed to discover APP selective gamma-secretase inhibitors. In vivo efficacy for acute reduction of brain Aβ was determined in the PDAPP transgene model of AD, as well as in wild-type FVB strain mice. In vivo selectivity was determined following seven days x twice per day (b.i.d.) treatment with 15 mg/kg/dose to 1,000 mg/kg/dose ELN475516, and monitoring brain Aβ reduction vs. Notch signaling endpoints in periphery. RESULTS The APP selective gamma-secretase inhibitors ELN318463 and ELN475516 reported here behave as classic gamma-secretase inhibitors, demonstrate 75- to 120-fold selectivity for inhibiting Aβ production compared with Notch signaling in cells, and displace an active site directed inhibitor at very high concentrations only in the presence of substrate. ELN318463 demonstrated discordant efficacy for reduction of brain Aβ in the PDAPP compared with wild-type FVB, not observed with ELN475516. Improved in vivo safety of ELN475516 was demonstrated in the 7d repeat dose study in wild-type mice, where a 33% reduction of brain Aβ was observed in mice terminated three hours post last dose at the lowest dose of inhibitor tested. No overt in-life or post-mortem indications of systemic toxicity, nor RNA and histological end-points indicative of toxicity attributable to inhibition of Notch signaling were observed at any dose tested. CONCLUSIONS The discordant in vivo activity of ELN318463 suggests that the potency of gamma-secretase inhibitors in AD transgenic mice should be corroborated in wild-type mice. The discovery of ELN475516 demonstrates that it is possible to develop APP selective gamma-secretase inhibitors with potential for treatment for AD.
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Affiliation(s)
- Guriqbal S Basi
- Elan Pharmaceuticals, Inc, 180 Oyster Point Blvd, S, San Francisco, CA 94080, USA.
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9
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Brigham E, Quinn K, Motter R, Hoffman W, Goldbach E, Kholodenko D, Kwong G, Willits C, Probst G, Gunther J, Adams E, Sauer JM, Kinney G, Ness D. P3‐322: Effects of single and multiple dose oral administration of ELND006, a novel APP‐selective gamma‐secretase inhibitor, on amyloid‐β concentrations in the brain and CSF of cynomolgus monkeys. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.1823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Kevin Quinn
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Ruth Motter
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | | | - Grace Kwong
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | - Gary Probst
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | | | - Gene Kinney
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Daniel Ness
- Elan PharmaceuticalsSouth San Francisco CA USA
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10
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Schroeter S, Brigham E, Motter R, Nishioka C, Guido T, Khan K, Kholodenko D, Tanaka P, Soriano F, Quinn K, Goldbach E, Games D, Ness D. P3‐321: APP‐selective gamma secretase inhibitor ELND006 effects on brain parenchymal and vascular amyloid beta in the PDAPP mouse model of Alzheimer's disease. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.1822] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Ruth Motter
- Elan Pharmaceuticals,South San Francisco CA USA
| | | | - Terry Guido
- Elan Pharmaceuticals,South San Francisco CA USA
| | - Karen Khan
- Elan Pharmaceuticals,South San Francisco CA USA
| | | | | | | | - Kevin Quinn
- Elan Pharmaceuticals,South San Francisco CA USA
| | | | - Dora Games
- Elan Pharmaceuticals,South San Francisco CA USA
| | - Daniel Ness
- Elan Pharmaceuticals,South San Francisco CA USA
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11
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Brigham E, Quinn K, Kwong G, Willits C, Goldbach E, Motter R, Lee M, Hu K, Wallace W, Kholodenko D, Tang-Tanaka P, Ni H, Hemphill S, Chen XH, Eichenbaum T, Ruslim L, Nguyen L, Santiago P, Liao A, Bova M, Probst G, Dappen M, Jagodzinski J, Basi G, Ness D. P3‐320: Pharmacokinetic and pharmacodynamic investigation of ELND006, a novel APP‐selective gamma‐secretase inhibitor, on amyloid‐β concentrations in the brain, CSF and plasma of multiple nonclinical species following oral administration. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.1821] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Kevin Quinn
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Grace Kwong
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | - Ruth Motter
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Michael Lee
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Kang Hu
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | | | - Huifang Ni
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | | | - Lany Ruslim
- Elan PharmaceuticalsSouth San Francisco CA USA
| | - Lan Nguyen
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | - Anna Liao
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | - Gary Probst
- Elan PharmaceuticalsSouth San Francisco CA USA
| | | | | | | | - Daniel Ness
- Elan PharmaceuticalsSouth San Francisco CA USA
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12
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Inglis KJ, Chereau D, Brigham EF, Chiou SS, Schöbel S, Frigon NL, Yu M, Caccavello RJ, Nelson S, Motter R, Wright S, Chian D, Santiago P, Soriano F, Ramos C, Powell K, Goldstein JM, Babcock M, Yednock T, Bard F, Basi GS, Sham H, Chilcote TJ, McConlogue L, Griswold-Prenner I, Anderson JP. Polo-like kinase 2 (PLK2) phosphorylates alpha-synuclein at serine 129 in central nervous system. J Biol Chem 2008; 284:2598-2602. [PMID: 19004816 PMCID: PMC2631975 DOI: 10.1074/jbc.c800206200] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several neurological diseases, including Parkinson disease and dementia with Lewy bodies, are characterized by the accumulation of alpha-synuclein phosphorylated at Ser-129 (p-Ser-129). The kinase or kinases responsible for this phosphorylation have been the subject of intense investigation. Here we submit evidence that polo-like kinase 2 (PLK2, also known as serum-inducible kinase or SNK) is a principle contributor to alpha-synuclein phosphorylation at Ser-129 in neurons. PLK2 directly phosphorylates alpha-synuclein at Ser-129 in an in vitro biochemical assay. Inhibitors of PLK kinases inhibited alpha-synuclein phosphorylation both in primary cortical cell cultures and in mouse brain in vivo. Finally, specific knockdown of PLK2 expression by transduction with short hairpin RNA constructs or by knock-out of the plk2 gene reduced p-Ser-129 levels. These results indicate that PLK2 plays a critical role in alpha-synuclein phosphorylation in central nervous system.
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Affiliation(s)
- Kelly J Inglis
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - David Chereau
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | - San-San Chiou
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | | | - Mei Yu
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | - Seth Nelson
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Ruth Motter
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Sarah Wright
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - David Chian
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | - Ferdie Soriano
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Carla Ramos
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Kyle Powell
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | | | - Ted Yednock
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | | | - Hing Sham
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | | | | | - John P Anderson
- Elan Pharmaceuticals, South San Francisco, California 94080.
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Seubert P, Barbour R, Khan K, Motter R, Tang P, Kholodenko D, Kling K, Schenk D, Johnson-Wood K, Schroeter S, Gill D, Jacobsen JS, Pangalos M, Basi G, Games D. Antibody Capture of Soluble Aβ Does Not Reduce Cortical Aβ Amyloidosis in the PDAPP Mouse. NEURODEGENER DIS 2008; 5:65-71. [DOI: 10.1159/000112834] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 06/14/2007] [Indexed: 11/19/2022] Open
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McConlogue L, Buttini M, Anderson JP, Brigham EF, Chen KS, Freedman SB, Games D, Johnson-Wood K, Lee M, Zeller M, Liu W, Motter R, Sinha S. Partial reduction of BACE1 has dramatic effects on Alzheimer plaque and synaptic pathology in APP Transgenic Mice. J Biol Chem 2007; 282:26326-34. [PMID: 17616527 DOI: 10.1074/jbc.m611687200] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The aspartyl protease beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) initiates processing of amyloid precursor protein (APP) into amyloid beta (Abeta) peptide, the major component of Alzheimer disease (AD) plaques. To determine the role that BACE1 plays in the development of Abeta-driven AD-like pathology, we have crossed PDAPP mice, a transgenic mouse model of AD overexpressing human mutated APP, onto mice with either a homozygous or heterozygous BACE1 gene knockout. Analysis of PDAPP/BACE(-/-) mice demonstrated that BACE1 is absolutely required for both Abeta generation and the development of age-associated plaque pathology. Furthermore, synaptic deficits, a neurodegenerative pathology characteristic of AD, were also reversed in the bigenic mice. To determine the extent of BACE1 reduction required to significantly inhibit pathology, PDAPP mice having a heterozygous BACE1 gene knock-out were evaluated for Abeta generation and for the development of pathology. Although the 50% reduction in BACE1 enzyme levels caused only a 12% decrease in Abeta levels in young mice, it nonetheless resulted in a dramatic reduction in Abeta plaques, neuritic burden, and synaptic deficits in older mice. Quantitative analyses indicate that brain Abeta levels in young APP transgenic mice are not the sole determinant for the changes in plaque pathology mediated by reduced BACE1. These observations demonstrate that partial reductions of BACE1 enzyme activity and concomitant Abeta levels lead to dramatic inhibition of Abeta-driven AD-like pathology, making BACE1 an excellent target for therapeutic intervention in AD.
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Affiliation(s)
- Lisa McConlogue
- Department of Biology, Elan Pharmaceuticals, South San Francisco, California 94080, USA.
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15
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Chen G, Chen KS, Kobayashi D, Barbour R, Motter R, Games D, Martin SJ, Morris RGM. Active beta-amyloid immunization restores spatial learning in PDAPP mice displaying very low levels of beta-amyloid. J Neurosci 2007; 27:2654-62. [PMID: 17344403 PMCID: PMC6672499 DOI: 10.1523/jneurosci.3710-06.2007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The behavioral and biochemical impact of active immunization against human beta-amyloid (Abeta) was assessed using male transgenic (Tg) mice overexpressing a human mutant amyloid precursor protein (heterozygous PDAPP mice) and littermate controls. Administration of aggregated Abeta42 occurred at monthly intervals from 7 months ("prevention") or 11 months ("reversal"), followed by double-blind behavioral training at 16 months on a cued task, then serial spatial learning in a water maze. Using a 2 x 2 design, with Abeta42 adjuvanted with MPL-AF (adjuvant formulation of monophosphoryl lipid A) or MPL-AF alone, PDAPP mice were impaired compared with non-Tg littermates on two separate measures of serial spatial learning. Immunization caused no overall rescue of learning but limited the accumulation of total Abeta and Abeta42 levels in cortex and hippocampus by up to 60%. In immunized PDAPP mice, significant negative correlations were observed between hippocampal and cortical Abeta levels and learning capacity, particularly in the prevention study, and correlations between learning capacity and antibody titer. Moreover, a subset of PDAPP mice with very low Abeta levels (hippocampal Abeta levels of <6000 ng/g or cortical Abeta levels of <1000 ng/g) was indistinguishable from non-Tg controls. Mice in the prevention study were also rescued from cognitive impairment more effectively than those in the reversal study. The combination of variability in antibody response and differential levels of Abeta accumulation across the population of immunized PDAPP mice may be responsible for success in cognitive protection with only a subset of these animals, but the similarity to the findings of certain human vaccination trials is noteworthy.
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Affiliation(s)
- Guiquan Chen
- Laboratory for Cognitive Neuroscience, Centre for Cognitive and Neural Systems, Edinburgh EH8 9JZ, United Kingdom, and
| | - Karen S. Chen
- Elan Pharmaceuticals, South San Francisco, California 94080
| | | | - Robin Barbour
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Ruth Motter
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Dora Games
- Elan Pharmaceuticals, South San Francisco, California 94080
| | - Stephen J. Martin
- Laboratory for Cognitive Neuroscience, Centre for Cognitive and Neural Systems, Edinburgh EH8 9JZ, United Kingdom, and
| | - Richard G. M. Morris
- Laboratory for Cognitive Neuroscience, Centre for Cognitive and Neural Systems, Edinburgh EH8 9JZ, United Kingdom, and
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Slemmon JR, Painter CL, Nadanaciva S, Catana F, Cook A, Motter R, Seubert P. Distribution of Abeta peptide in whole blood. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 846:24-31. [PMID: 16939717 DOI: 10.1016/j.jchromb.2006.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 07/17/2006] [Accepted: 08/06/2006] [Indexed: 11/18/2022]
Abstract
The measurement of amyloid beta peptides (Abeta) in blood and plasma is expected to be a useful biomarker as potential therapeutics designed to lower Abeta peptide enter clinical trials. Many reports have suggested that Abeta could bind to substances in blood that may influence the recovery of Abeta peptide in plasma, its detection by conventional ELISAs or the actual turnover and half-life of the peptide in blood. In this study we describe a process for analyzing total Abeta in whole blood and plasma using denaturing solid-phase extraction followed by reverse-phase HPLC linked to ELISA. Comparison of total Abeta peptide levels in whole blood and plasma from the same bleed showed that most of the Abeta peptide is captured in the plasma if the samples are first denatured. In contrast, plasma that was assayed without denaturation could show greater than 70% reduction in apparent total Abeta peptide. This suggested that there was a pool of Abeta peptide in non-denatured plasma that is occluded from detection by ELISA, perhaps by binding to plasma proteins.
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Affiliation(s)
- J Randall Slemmon
- Genomics and Biotechnology, Pfizer Global Research and Development, Skokie, IL 60077, USA.
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17
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Buttini M, Masliah E, Barbour R, Grajeda H, Motter R, Johnson-Wood K, Khan K, Seubert P, Freedman S, Schenk D, Games D. Beta-amyloid immunotherapy prevents synaptic degeneration in a mouse model of Alzheimer's disease. J Neurosci 2005; 25:9096-101. [PMID: 16207868 PMCID: PMC6725749 DOI: 10.1523/jneurosci.1697-05.2005] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Alzheimer's disease neuropathology is characterized by key features that include the deposition of the amyloid beta peptide (Abeta) into plaques, the formation of neurofibrillary tangles, and the loss of neurons and synapses in specific brain regions. The loss of synapses, and particularly the associated presynaptic vesicle protein synaptophysin in the hippocampus and association cortices, has been widely reported to be one of the most robust correlates of Alzheimer's disease-associated cognitive decline. The beta-amyloid hypothesis supports the idea that Abeta is the cause of these pathologies. However, the hypothesis is still controversial, in part because the direct role of Abeta in synaptic degeneration awaits confirmation. In this study, we show that Abeta reduction by active or passive Abeta immunization protects against the progressive loss of synaptophysin in the hippocampal molecular layer and frontal neocortex of a transgenic mouse model of Alzheimer's disease. These results, substantiated by quantitative electron microscopic analysis of synaptic densities, strongly support a direct causative role of Abeta in the synaptic degeneration seen in Alzheimer's disease and strengthen the potential of Abeta immunotherapy as a treatment approach for this disease.
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Affiliation(s)
- Manuel Buttini
- Elan Pharmaceuticals, South San Francisco, California 94080, USA.
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18
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Bard F, Barbour R, Cannon C, Carretto R, Fox M, Games D, Guido T, Hoenow K, Hu K, Johnson-Wood K, Khan K, Kholodenko D, Lee C, Lee M, Motter R, Nguyen M, Reed A, Schenk D, Tang P, Vasquez N, Seubert P, Yednock T. Epitope and isotype specificities of antibodies to beta -amyloid peptide for protection against Alzheimer's disease-like neuropathology. Proc Natl Acad Sci U S A 2003; 100:2023-8. [PMID: 12566568 PMCID: PMC149952 DOI: 10.1073/pnas.0436286100] [Citation(s) in RCA: 311] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transgenic PDAPP mice, which express a disease-linked isoform of the human amyloid precursor protein, exhibit CNS pathology that is similar to Alzheimer's disease. In an age-dependent fashion, the mice develop plaques containing beta-amyloid peptide (Abeta) and exhibit neuronal dystrophy and synaptic loss. It has been shown in previous studies that pathology can be prevented and even reversed by immunization of the mice with the Abeta peptide. Similar protection could be achieved by passive administration of some but not all monoclonal antibodies against Abeta. In the current studies we sought to define the optimal antibody response for reducing neuropathology. Immune sera with reactivity against different Abeta epitopes and monoclonal antibodies with different isotypes were examined for efficacy both ex vivo and in vivo. The studies showed that: (i) of the purified or elicited antibodies tested, only antibodies against the N-terminal regions of Abeta were able to invoke plaque clearance; (ii) plaque binding correlated with a clearance response and neuronal protection, whereas the ability of antibodies to capture soluble Abeta was not necessarily correlated with efficacy; (iii) the isotype of the antibody dramatically influenced the degree of plaque clearance and neuronal protection; (iv) high affinity of the antibody for Fc receptors on microglial cells seemed more important than high affinity for Abeta itself; and (v) complement activation was not required for plaque clearance. These results indicate that antibody Fc-mediated plaque clearance is a highly efficient and effective process for protection against neuropathology in an animal model of Alzheimer's disease.
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Affiliation(s)
- Frédérique Bard
- Elan Pharmaceuticals, 800 Gateway Boulevard, South San Francisco, CA 94080, USA.
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19
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Brayden DJ, Templeton L, McClean S, Barbour R, Huang J, Nguyen M, Ahern D, Motter R, Johnson-Wood K, Vasquez N, Schenk D, Seubert P. Encapsulation in biodegradable microparticles enhances serum antibody response to parenterally-delivered beta-amyloid in mice. Vaccine 2001; 19:4185-93. [PMID: 11457544 DOI: 10.1016/s0264-410x(01)00162-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Poly(lactide-co-glycolide) (PLG) microspheres were tested as a parenteral delivery system for human beta-amyloid (1-42) (Abeta), a potential immunotherapeutic undergoing assessment in Phase 1 studies for Alzheimer's disease (AD). Abeta was successfully encapsulated in PLG microspheres of average sizes of 3 or 15 microm diameter. Swiss Webster (SW) mice were injected by the sub-cutaneous (s.c.) or intra-peritoneal (i.p.) routes with 3-33 microg Abeta. Abeta-PLG microparticles (3 microm) induced dose-dependent antibody responses, which were maximal at 33 microg Abeta, while Abeta in phosphate-buffered saline (PBS) produced weak antibody responses at the same doses by both routes. Significantly increased antibody responses were seen for both small and large particle formulations given by the i.p. route in comparison to the s.c route. It was previously reported that passive immunisation with Abeta-specific antibodies cleared amyloid plaques in a mouse model of AD (Bard F, Cannon C, Barbour R, et al. Peripherally administered antibodies against amyloid beta-peptide enter the nervous system and reduce pathology in a mouse model of Alzheimer disease. Nature Med 2000;6:916-19), an indication that induction of serum antibody is a prerequisite for efficacy.
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Affiliation(s)
- D J Brayden
- Elan Biotechnology Research, Biotechnology Building, Trinity College, 2, Dublin, Ireland.
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20
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Roberds SL, Anderson J, Basi G, Bienkowski MJ, Branstetter DG, Chen KS, Freedman SB, Frigon NL, Games D, Hu K, Johnson-Wood K, Kappenman KE, Kawabe TT, Kola I, Kuehn R, Lee M, Liu W, Motter R, Nichols NF, Power M, Robertson DW, Schenk D, Schoor M, Shopp GM, Shuck ME, Sinha S, Svensson KA, Tatsuno G, Tintrup H, Wijsman J, Wright S, McConlogue L. BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics. Hum Mol Genet 2001; 10:1317-24. [PMID: 11406613 DOI: 10.1093/hmg/10.12.1317] [Citation(s) in RCA: 527] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major components of plaque, beta-amyloid peptides (Abetas), are produced from amyloid precursor protein (APP) by the activity of beta- and gamma-secretases. beta-secretase activity cleaves APP to define the N-terminus of the Abeta1-x peptides and, therefore, has been a long- sought therapeutic target for treatment of AD. The gene encoding a beta-secretase for beta-site APP cleaving enzyme (BACE) was identified recently. However, it was not known whether BACE was the primary beta-secretase in mammalian brain nor whether inhibition of beta-secretase might have effects in mammals that would preclude its utility as a therapeutic target. In the work described herein, we generated two lines of BACE knockout mice and characterized them for pathology, beta-secretase activity and Abeta production. These mice appeared to develop normally and showed no consistent phenotypic differences from their wild-type littermates, including overall normal tissue morphology and brain histochemistry, normal blood and urine chemistries, normal blood-cell composition, and no overt behavioral and neuromuscular effects. Brain and primary cortical cultures from BACE knockout mice showed no detectable beta-secretase activity, and primary cortical cultures from BACE knockout mice produced much less Abeta from APP. The findings that BACE is the primary beta-secretase activity in brain and that loss of beta-secretase activity produces no profound phenotypic defects with a concomitant reduction in beta-amyloid peptide clearly indicate that BACE is an excellent therapeutic target for treatment of AD.
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Affiliation(s)
- S L Roberds
- Department of Genomics, Pharmacia Corp., 301 Henrietta Street, Kalamazoo, MI 49007, USA.
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21
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Bard F, Cannon C, Barbour R, Burke RL, Games D, Grajeda H, Guido T, Hu K, Huang J, Johnson-Wood K, Khan K, Kholodenko D, Lee M, Lieberburg I, Motter R, Nguyen M, Soriano F, Vasquez N, Weiss K, Welch B, Seubert P, Schenk D, Yednock T. Peripherally administered antibodies against amyloid beta-peptide enter the central nervous system and reduce pathology in a mouse model of Alzheimer disease. Nat Med 2000; 6:916-9. [PMID: 10932230 DOI: 10.1038/78682] [Citation(s) in RCA: 1458] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
One hallmark of Alzheimer disease is the accumulation of amyloid beta-peptide in the brain and its deposition as plaques. Mice transgenic for an amyloid beta precursor protein (APP) mini-gene driven by a platelet-derived (PD) growth factor promoter (PDAPP mice), which overexpress one of the disease-linked mutant forms of the human amyloid precursor protein, show many of the pathological features of Alzheimer disease, including extensive deposition of extracellular amyloid plaques, astrocytosis and neuritic dystrophy. Active immunization of PDAPP mice with human amyloid beta-peptide reduces plaque burden and its associated pathologies. Several hypotheses have been proposed regarding the mechanism of this response. Here we report that peripheral administration of antibodies against amyloid beta-peptide, was sufficient to reduce amyloid burden. Despite their relatively modest serum levels, the passively administered antibodies were able to enter the central nervous system, decorate plaques and induce clearance of preexisting amyloid. When examined in an ex vivo assay with sections of PDAPP or Alzheimer disease brain tissue, antibodies against amyloid beta-peptide triggered microglial cells to clear plaques through Fc receptor-mediated phagocytosis and subsequent peptide degradation. These results indicate that antibodies can cross the blood-brain barrier to act directly in the central nervous system and should be considered as a therapeutic approach for the treatment of Alzheimer disease and other neurological disorders.
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Affiliation(s)
- F Bard
- Elan Pharmaceuticals, 800 Gateway Boulevard, South San Francisco, California 94080, USA.
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22
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Sunderland T, Wolozin B, Galasko D, Levy J, Dukoff R, Bahro M, Lasser R, Motter R, Lehtimäki T, Seubert P. Longitudinal stability of CSF tau levels in Alzheimer patients. Biol Psychiatry 1999; 46:750-5. [PMID: 10494442 DOI: 10.1016/s0006-3223(99)00143-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Antemortem levels of tau in the cerebrospinal fluid (CSF) of Alzheimer's disease (AD) patients have repeatedly been demonstrated to be elevated when compared to controls. Although CSF tau has been reported to be elevated even in very mild AD, it is unknown how tau levels change during the course of the disease. METHODS We have followed 29 mild-to-moderately affected AD subjects over 2 years with repeated CSF taps. Clinical measures of dementia severity (Clinical Dementia Rating Scale, Global Deterioration Scale and Mini-Mental Status Examination) were obtained at the start and conclusion of the observation period, and CSF tau was measured with a standard enzyme-linked immunoabsorbent assay (ELISA) using two monoclonal antibodies. RESULTS Despite significant changes in the clinical measures consistent with progression of the disease, no significant overall change in CSF tau levels (548 +/- 355 vs. 557 +/- 275 pg/mL, NS) was observed. None of the clinical variables was significantly correlated with either baseline measures of CSF tau or delta CSF tau (last-first). Similarly, CSF tau at baseline and changes over time were not significantly related to Apolipoprotein E (APO E) phenotype. CONCLUSIONS These data suggest that CSF tau levels are stable over extended periods of time in a group of mild-to-moderately demented AD subjects and that CSF tau levels do not predict the severity or rate of progression of AD, at least not during the middle stages of the illness.
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Affiliation(s)
- T Sunderland
- Geriatric Psychiatry Branch, National Institute of Mental Health, NIH, Bethesda, MD 20892-1275, USA
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23
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Schenk D, Barbour R, Dunn W, Gordon G, Grajeda H, Guido T, Hu K, Huang J, Johnson-Wood K, Khan K, Kholodenko D, Lee M, Liao Z, Lieberburg I, Motter R, Mutter L, Soriano F, Shopp G, Vasquez N, Vandevert C, Walker S, Wogulis M, Yednock T, Games D, Seubert P. Immunization with amyloid-beta attenuates Alzheimer-disease-like pathology in the PDAPP mouse. Nature 1999; 400:173-7. [PMID: 10408445 DOI: 10.1038/22124] [Citation(s) in RCA: 2201] [Impact Index Per Article: 88.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Amyloid-beta peptide (Abeta) seems to have a central role in the neuropathology of Alzheimer's disease (AD). Familial forms of the disease have been linked to mutations in the amyloid precursor protein (APP) and the presenilin genes. Disease-linked mutations in these genes result in increased production of the 42-amino-acid form of the peptide (Abeta42), which is the predominant form found in the amyloid plaques of Alzheimer's disease. The PDAPP transgenic mouse, which overexpresses mutant human APP (in which the amino acid at position 717 is phenylalanine instead of the normal valine), progressively develops many of the neuropathological hallmarks of Alzheimer's disease in an age- and brain-region-dependent manner. In the present study, transgenic animals were immunized with Abeta42, either before the onset of AD-type neuropathologies (at 6 weeks of age) or at an older age (11 months), when amyloid-beta deposition and several of the subsequent neuropathological changes were well established. We report that immunization of the young animals essentially prevented the development of beta-amyloid-plaque formation, neuritic dystrophy and astrogliosis. Treatment of the older animals also markedly reduced the extent and progression of these AD-like neuropathologies. Our results raise the possibility that immunization with amyloid-beta may be effective in preventing and treating Alzheimer's disease.
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Affiliation(s)
- D Schenk
- Elan Pharmaceuticals, South San Francisco, California 94080, USA.
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24
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Chen KS, Masliah E, Grajeda H, Guido T, Huang J, Khan K, Motter R, Soriano F, Games D. Neurodegenerative Alzheimer-like pathology in PDAPP 717V-->F transgenic mice. Prog Brain Res 1999; 117:327-34. [PMID: 9932418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
In summary, PDAPP mice overexpressing a mutation associated with some cases of familial early-onset AD express several of the major pathological hallmarks associated with AD. Amyloid plaques in PDAPP mice appear quite similar to A beta deposits in AD as shown by a variety of different antibodies and stains, and are of both the diffuse and compacted varieties. Additionally, a subset of these amyloid plaques appear to be neuritic plaques. Neurodegenerative changes, including the loss of synaptic and dendritic proteins, abnormal phosphorylation of cytoskeletal elements, subcellular degenerative changes, and the deposition of lysosomal and acute phase proteins has also been seen in PDAPP mouse brains. Reactive astrocytosis and microgliosis have also been observed in association with the amyloid plaques in the PDAPP mice. No neurofibrillary tangles or paired helical filaments have been found in the mice to date. It remains unknown whether mice are capable of generating these in a manner comparable to AD in less than two years. Extensive behavioral analyses are currently being performed in these mice, and preliminary results indicate that the PDAPP mice are significantly impaired on a variety of different learning and memory tests. In conclusion, the PDAPP mouse model doesn't display all the pathological hallmarks of AD, but it does display most of them in a robust manner that increases with age and gene dosage. Therefore, this transgenic model provides evidence that alterations in APP processing and A beta production can result in AD-like neuropathology, can contribute to a mechanistic understanding of AD (since examination of AD brains yields a static view, and we are unable to view the development of various pathological changes), as well as providing an useful animal model for the testing of various therapeutic interventions directed towards specific aspects of the neurodegenerative process.
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Affiliation(s)
- K S Chen
- Athena Neurosciences, South San Francisco, California 94080, USA. amyloid!
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25
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Ellis RJ, Seubert P, Motter R, Galasko D, Deutsch R, Heaton RK, Heyes MP, McCutchan JA, Atkinson JH, Grant I. Cerebrospinal fluid tau protein is not elevated in HIV-associated neurologic disease in humans. HIV Neurobehavioral Research Center Group (HNRC). Neurosci Lett 1998; 254:1-4. [PMID: 9780077 DOI: 10.1016/s0304-3940(98)00549-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We measured the concentrations of the neuron-specific protein, tau, in the cerebrospinal fluid (CSF) of 32 neurologically characterized HIV-infected (HIVpos) subjects and nine matched seronegative (HIVneg) controls using a sensitive ELISA assay. Of 32 HIVpos subjects, nine had HIV-associated neurocognitive disorders, and nine had clinically diagnosed peripheral neuropathies. CSF tau levels in subjects with HIV-associated neurocognitive disorders were similar to those in HIVneg subjects (185 +/- 83 vs. 223 +/- 106 pg/ml; P = 57). CSF tau levels in HIVpos subjects with peripheral neuropathies did not differ from those without neuropathies (320 +/- 190 vs. 251 +/- 185; P = 23). In summary, CSF tau levels were not elevated in patients with HIV-associated neurologic disease.
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Affiliation(s)
- R J Ellis
- Department of Neurosciences, University of California, San Diego, USA.
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26
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Galasko D, Chang L, Motter R, Clark CM, Kaye J, Knopman D, Thomas R, Kholodenko D, Schenk D, Lieberburg I, Miller B, Green R, Basherad R, Kertiles L, Boss MA, Seubert P. High cerebrospinal fluid tau and low amyloid beta42 levels in the clinical diagnosis of Alzheimer disease and relation to apolipoprotein E genotype. Arch Neurol 1998; 55:937-45. [PMID: 9678311 DOI: 10.1001/archneur.55.7.937] [Citation(s) in RCA: 275] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To evaluate cerebrospinal fluid (CSF) levels of amyloid beta protein ending at amino acid 42 (Abeta42) and tau as markers for Alzheimer disease (AD) and to determine whether clinical variables influence these levels. DESIGN Cohort study. SETTING Six academic research centers with expertise in dementia. SUBJECTS Eighty-two patients with probable AD, including 24 with very mild dementia (Mini-Mental State Examination score >23/30) (AD group); 60 cognitively normal elderly control subjects (NC group); and 74 subjects with neurological disorders, including dementia (ND group). MAIN OUTCOME MEASURES Levels of Abeta42 and tau were compared among AD, NC, and ND groups. Relationships of age, sex, Mini-Mental State Examination score, and apolipoprotein E (Apo E) genotype with these levels were examined using multiple linear regression. Classification tree models were developed to optimize distinguishing AD from NC groups. RESULTS Levels of Abeta42 were significantly lower, and levels of tau were significantly higher, in the AD group than in the NC or ND group. In the AD group, Abeta42 level was inversely associated with Apo E epsilon4 allele dose and weakly related to Mini-Mental State Examination score; tau level was associated with male sex and 1 Apo E epsilon4 allele. Classification tree analysis, comparing the AD and NC subjects, was 90% sensitive and 80% specific. With specificity set at greater than 90%, the tree was 77% sensitive for AD. This tree classified 26 of 74 members of the ND group as having AD. They had diagnoses difficult to distinguish from AD clinically and a high Apo E epsilon4 allele frequency. Markers in CSF were used to correctly classify 12 of 13 patients who later underwent autopsy, including 1 with AD not diagnosed clinically. CONCLUSIONS Levels of CSF Abeta42 decrease and levels of CSF tau increase in AD. Apolipoprotein E epsilon4 had a dose-dependent relationship with CSF levels of Abeta42, but not tau. Other covariates influenced CSF markers minimally. Combined analysis of CSF Abeta42 and tau levels discriminated patients with AD, including patients with mild dementia, from the NC group, supporting use of these proteins to identify AD and to distinguish early AD from aging. In subjects in the ND group with an AD CSF profile, autopsy follow-up will be required to decide whether CSF results are false positive, or whether AD is a primary or concomitant cause of dementia.
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Affiliation(s)
- D Galasko
- Department of Neurosciences, University of California, San Diego, San Diego Veterans Affairs Medical Center, USA
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27
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Galasko D, Clark C, Chang L, Miller B, Green RC, Motter R, Seubert P. Assessment of CSF levels of tau protein in mildly demented patients with Alzheimer's disease. Neurology 1997; 48:632-5. [PMID: 9065538 DOI: 10.1212/wnl.48.3.632] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
CSF levels of tau protein are increased in many patients with Alzheimer's disease (AD). Studies disagree on whether the increase is found in moderate or severe AD to a greater extent than in mild AD, and in two reports there was an inverse correlation between tau levels and cognitive scores. To readdress this question, we measured CSF tau in a group of mildly impaired patients with AD (Mini-Mental State Examination [MMSE] scores > or =20/30) and compared their tau levels with those in age-comparable normal and neurologic controls. We found that the mean level of CSF tau was significantly increased in the AD group compared with the controls, and 29 of 36 patients with AD had levels that exceeded a cutoff determined in a previous study. CSF tau levels did not correlate with MMSE scores. These findings and those of previous studies show that elevated CSF tau levels are found in most patients with AD, occur early in the course of dementia, and may be useful in supporting the diagnosis of AD.
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Affiliation(s)
- D Galasko
- Department of Neurosciences, University of California, San Diego, USA
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28
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Johnson-Wood K, Lee M, Motter R, Hu K, Gordon G, Barbour R, Khan K, Gordon M, Tan H, Games D, Lieberburg I, Schenk D, Seubert P, McConlogue L. Amyloid precursor protein processing and A beta42 deposition in a transgenic mouse model of Alzheimer disease. Proc Natl Acad Sci U S A 1997; 94:1550-5. [PMID: 9037091 PMCID: PMC19829 DOI: 10.1073/pnas.94.4.1550] [Citation(s) in RCA: 523] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The PDAPP transgenic mouse, which overexpresses human amyloid precursor protein (APP717V-->F), has been shown to develop much of the pathology associated with Alzheimer disease. In this report, levels of APP and its amyloidogenic metabolites were measured in brain regions of transgenic mice between 4 and 18 months of age. While absolute levels of APP expression likely contribute to the rate of amyloid beta-peptide (Abeta) deposition, regionally specific factors also seem important, as homozygotic mice express APP levels in pathologically unaffected regions in excess of that measured in certain amyloid plaque-prone regions of heterozygotic mice. Regional levels of APP and APP-beta were nearly constant at all ages, while A beta levels dramatically and predictably increased in brain regions undergoing histochemically confirmed amyloidosis, most notably in the cortex and hippocampus. In hippocampus, A beta concentrations increase 17-fold between the ages of 4 and 8 months, and by 18 months of age are over 500-fold that at 4 months, reaching an average level in excess of 20 nmol of A beta per g of tissue. A beta1-42 constitutes the vast majority of the depositing A beta species. The similarities observed between the PDAPP mouse and human Alzheimer disease with regard to A beta42 deposition occurring in a temporally and regionally specific fashion further validate the use of the model in understanding processes related to the disease.
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Affiliation(s)
- K Johnson-Wood
- Athena Neurosciences, Inc., South San Francisco, CA 94080, USA
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29
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Johnson GV, Seubert P, Cox TM, Motter R, Brown JP, Galasko D. The tau protein in human cerebrospinal fluid in Alzheimer's disease consists of proteolytically derived fragments. J Neurochem 1997; 68:430-3. [PMID: 8978756 DOI: 10.1046/j.1471-4159.1997.68010430.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Previous studies have shown that the levels of the microtubule-associated protein tau in the CSF of patients with Alzheimer's disease (AD) are elevated compared with age-matched controls. In spite of these findings, the nature of tau in CSF has not been well documented. In the present study, tau was immunoprecipitated from CSF of patients with AD or acute stroke, as well as normal elderly controls, followed by immunoblot analysis. In all cases, CSF tau consisted primarily of a band migrating at 26-28 kDa. In AD and stroke patients, several smaller tau fragments were also detected. No intact tau was detected in any of the CSF samples examined. Further immunoprecipitation studies showed that the majority of the tau fragments contained the amino terminus of the molecule. Treatment of CSF tau with alkaline phosphatase did not alter the electrophoretic properties of the fragments. These studies clearly demonstrate that CSF tau is truncated rather than intact.
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Affiliation(s)
- G V Johnson
- Department of Psychiatry, University of Alabama at Birmingham, USA
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Citron M, Westaway D, Xia W, Carlson G, Diehl T, Levesque G, Johnson-Wood K, Lee M, Seubert P, Davis A, Kholodenko D, Motter R, Sherrington R, Perry B, Yao H, Strome R, Lieberburg I, Rommens J, Kim S, Schenk D, Fraser P, St George Hyslop P, Selkoe DJ. Mutant presenilins of Alzheimer's disease increase production of 42-residue amyloid beta-protein in both transfected cells and transgenic mice. Nat Med 1997; 3:67-72. [PMID: 8986743 DOI: 10.1038/nm0197-67] [Citation(s) in RCA: 892] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The mechanism by which mutations in the presenilin (PS) genes cause the most aggressive form of early-onset Alzheimer's disease (AD) is unknown, but fibroblasts from mutation carriers secrete increased levels of the amyloidogenic A beta 42 peptide, the main component of AD plaques. We established transfected cell and transgenic mouse models that coexpress human PS and amyloid beta-protein precursor (APP) genes and analyzed quantitatively the effects of PS expression on APP processing. In both models, expression of wild-type PS genes did not alter APP levels, alpha- and beta-secretase activity and A beta production. In the transfected cells, PS1 and PS2 mutations caused a highly significant increase in A beta 42 secretion in all mutant clones. Likewise, mutant but not wildtype PS1 transgenic mice showed significant overproduction of A beta 42 in the brain, and this effect was detectable as early as 2-4 months of age. Different PS mutations had differential effects on A beta generation. The extent of A beta 42 increase did not correlate with presenilin expression levels. Our data demonstrate that the presenilin mutations cause a dominant gain of function and may induce AD by enhancing A beta 42 production, thus promoting cerebral beta-amyloidosis.
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Affiliation(s)
- M Citron
- Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Affiliation(s)
- D Schenk
- Athena Neurosciences, South San Francisco, California 94080, USA
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Motter R, Vigo-Pelfrey C, Kholodenko D, Barbour R, Johnson-Wood K, Galasko D, Chang L, Miller B, Clark C, Green R. Reduction of beta-amyloid peptide42 in the cerebrospinal fluid of patients with Alzheimer's disease. Ann Neurol 1995; 38:643-8. [PMID: 7574461 DOI: 10.1002/ana.410380413] [Citation(s) in RCA: 451] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this clinical study the cerebrospinal fluid (CSF) level of a novel form of the beta-amyloid peptide (A beta) extending to position 42 (A beta 42) was determined in patients with Alzheimer's disease (AD) as well as controls. In addition to measurement of CSF A beta 42 levels, total A beta peptides, microtubule-associated protein tau, and apolipoprotein E (ApoE) genotype were also assessed. It is interesting that CSF A beta 42 levels were found to be significantly lower in AD patients relative to controls, whereas total A beta levels were not. A beta 42 has recently been shown to preferentially deposit in the brain tissue of patients with AD, suggesting that diminished clearance may account for its reduction in CSF. As previously reported, tau levels were increased in AD patients; however, neither A beta 42 nor tau levels were apparently influenced by the ApoE genotype.
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Affiliation(s)
- R Motter
- Athena Neurosciences, Inc, South San Francisco, CA 94080, USA
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