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ImmunoPET Directed to the Brain: A New Tool for Preclinical and Clinical Neuroscience. Biomolecules 2023; 13:biom13010164. [PMID: 36671549 PMCID: PMC9855881 DOI: 10.3390/biom13010164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/14/2023] Open
Abstract
Immuno-positron emission tomography (immunoPET) is a non-invasive in vivo imaging method based on tracking and quantifying radiolabeled monoclonal antibodies (mAbs) and other related molecules, such as antibody fragments, nanobodies, or affibodies. However, the success of immunoPET in neuroimaging is limited because intact antibodies cannot penetrate the blood-brain barrier (BBB). In neuro-oncology, immunoPET has been successfully applied to brain tumors because of the compromised BBB. Different strategies, such as changes in antibody properties, use of physiological mechanisms in the BBB, or induced changes to BBB permeability, have been developed to deliver antibodies to the brain. These approaches have recently started to be applied in preclinical central nervous system PET studies. Therefore, immunoPET could be a new approach for developing more specific PET probes directed to different brain targets.
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2
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Dodiya HB, Lutz HL, Weigle IQ, Patel P, Michalkiewicz J, Roman-Santiago CJ, Zhang CM, Liang Y, Srinath A, Zhang X, Xia J, Olszewski M, Zhang X, Schipma MJ, Chang EB, Tanzi RE, Gilbert JA, Sisodia SS. Gut microbiota-driven brain Aβ amyloidosis in mice requires microglia. J Exp Med 2022; 219:e20200895. [PMID: 34854884 PMCID: PMC8647415 DOI: 10.1084/jem.20200895] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/16/2021] [Accepted: 10/14/2021] [Indexed: 12/25/2022] Open
Abstract
We previously demonstrated that lifelong antibiotic (ABX) perturbations of the gut microbiome in male APPPS1-21 mice lead to reductions in amyloid β (Aβ) plaque pathology and altered phenotypes of plaque-associated microglia. Here, we show that a short, 7-d treatment of preweaned male mice with high-dose ABX is associated with reductions of Aβ amyloidosis, plaque-localized microglia morphologies, and Aβ-associated degenerative changes at 9 wk of age in male mice only. More importantly, fecal microbiota transplantation (FMT) from transgenic (Tg) or WT male donors into ABX-treated male mice completely restored Aβ amyloidosis, plaque-localized microglia morphologies, and Aβ-associated degenerative changes. Transcriptomic studies revealed significant differences between vehicle versus ABX-treated male mice and FMT from Tg mice into ABX-treated mice largely restored the transcriptome profiles to that of the Tg donor animals. Finally, colony-stimulating factor 1 receptor (CSF1R) inhibitor-mediated depletion of microglia in ABX-treated male mice failed to reduce cerebral Aβ amyloidosis. Thus, microglia play a critical role in driving gut microbiome-mediated alterations of cerebral Aβ deposition.
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Affiliation(s)
- Hemraj B. Dodiya
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Holly L. Lutz
- Department of Pediatrics and Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA
| | - Ian Q. Weigle
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Priyam Patel
- Center for Genetic Medicine, Northwestern University, Chicago, IL
| | | | | | | | - Yingxia Liang
- Department of Neurology, Harvard Medical School, Boston, MA
| | - Abhinav Srinath
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Xulun Zhang
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Jessica Xia
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Monica Olszewski
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | - Xiaoqiong Zhang
- Department of Neurobiology, The University of Chicago, Chicago, IL
| | | | - Eugene B. Chang
- Department of Digestive Diseases, The University of Chicago, Chicago, IL
| | | | - Jack A. Gilbert
- Department of Pediatrics and Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA
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3
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Reyes-Ruiz JM, Nakajima R, Baghallab I, Goldschmidt L, Sosna J, Mai Ho PN, Kumosani T, Felgner PL, Glabe C. An "epitomic" analysis of the specificity of conformation-dependent, anti-Aß amyloid monoclonal antibodies. J Biol Chem 2021; 296:100168. [PMID: 33298522 PMCID: PMC7949048 DOI: 10.1074/jbc.ra120.015501] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/21/2022] Open
Abstract
Antibodies against Aß amyloid are indispensable research tools and potential therapeutics for Alzheimer's disease. They display several unusual properties, such as specificity for aggregated forms of the peptide, the ability to distinguish polymorphic aggregate structures, and the ability to recognize generic aggregation-related epitopes formed by unrelated amyloid sequences. Understanding the mechanisms underlying these unusual properties and the structures of their corresponding epitopes is crucial for the understanding why antibodies display different therapeutic activities and for the development of more effective therapeutic agents. Here we employed a novel "epitomic" approach to map the fine structure of the epitopes of 28 monoclonal antibodies against amyloid-beta using immunoselection of random sequences from a phage display library, deep sequencing, and pattern analysis to define the critical sequence elements recognized by the antibodies. Although most of the antibodies map to major linear epitopes in the amino terminal 1 to 14 residues of Aß, the antibodies display differences in the target sequence residues that are critical for binding and in their individual preferences for nontarget residues, indicating that the antibodies bind to alternative conformations of the sequence by different mechanisms. Epitomic analysis also identifies discontinuous, nonoverlapping sequence Aß segments that may constitute the conformational epitopes that underlie the aggregation specificity of antibodies. Aggregation-specific antibodies recognize sequences that display a significantly higher predicted propensity for forming amyloid than antibodies that recognize the monomer, indicating that the ability of random sequences to aggregate into amyloid is a critical element of their binding mechanism.
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Affiliation(s)
- Jorge Mauricio Reyes-Ruiz
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA
| | - Rie Nakajima
- Department of Physiology and Biophysics, Vaccine Research and Development Center, University of California Irvine, Irvine, California, USA
| | - Ibtisam Baghallab
- Biochemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Luki Goldschmidt
- Department of Biochemistry, Institute for Protein Design, University of Washington, Seattle, Washington, USA
| | - Justyna Sosna
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA
| | - Phuong Nguyen Mai Ho
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA
| | - Taha Kumosani
- Biochemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Philip L Felgner
- Department of Physiology and Biophysics, Vaccine Research and Development Center, University of California Irvine, Irvine, California, USA
| | - Charles Glabe
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, USA.
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Natarajan A. Copper-64-immunoPET imaging: bench to bedside. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF RADIOPHARMACEUTICAL CHEMISTRY AND BIOLOGY 2020; 64:356-363. [PMID: 33045821 DOI: 10.23736/s1824-4785.20.03310-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Positron emission tomography (PET) is a growing non-invasive diagnostic and molecular imaging tool in nuclear medicine, that is used to identify several diseases including cancer. The immunoPET probe is made up of monoclonal antibodies (mAbs) or its fragments or similar molecules that tagged with positron radioisotopes (68Ga, 64Cu, 89Zr) bound together by a bifunctional chelator (BFC). This probe is designed to identify a specific disease. Currently, several immunoPET probes are being developed for preclinical as well as for clinical applications. These studies are showing promising results, both in preclinical and patients, using mostly 64Cu, 89Zr isotopes. This review elucidates the 64Cu based immunoPET applications, their pipelines and the emerging scope of this technique within the nuclear medicine and molecular imaging clinics from bench to bedside. Recently, immunoPET research have sharply increased especially after a big surge in approval of oncology antibodies by the FDA for immune checkpoint-blockade cancer immunotherapies. Currently, preclinical to clinical translations of immunoPET has several challenges, including designing probes, choice of radioisotopes, selection of stable BFC, and size of antibody and its tracer kinetics. All these obstacles will be addressed eventually by improving PET scanner sensitivity, designing appropriate size of imaging probe, and combining immunoPET with specific targeting antibodies. These improvements should contribute to the immunoPET becoming more applicable in clinics, which, in turn, will provide critical information for correct patient selection, for right dosing, and for the right time/staging of treatment.
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5
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Focused ultrasound for opening blood-brain barrier and drug delivery monitored with positron emission tomography. J Control Release 2020; 324:303-316. [DOI: 10.1016/j.jconrel.2020.05.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022]
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Engineered antibodies: new possibilities for brain PET? Eur J Nucl Med Mol Imaging 2019; 46:2848-2858. [PMID: 31342134 PMCID: PMC6879437 DOI: 10.1007/s00259-019-04426-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/03/2019] [Indexed: 12/18/2022]
Abstract
Almost 50 million people worldwide are affected by Alzheimer’s disease (AD), the most common neurodegenerative disorder. Development of disease-modifying therapies would benefit from reliable, non-invasive positron emission tomography (PET) biomarkers for early diagnosis, monitoring of disease progression, and assessment of therapeutic effects. Traditionally, PET ligands have been based on small molecules that, with the right properties, can penetrate the blood–brain barrier (BBB) and visualize targets in the brain. Recently a new class of PET ligands based on antibodies have emerged, mainly in applications related to cancer. While antibodies have advantages such as high specificity and affinity, their passage across the BBB is limited. Thus, to be used as brain PET ligands, antibodies need to be modified for active transport into the brain. Here, we review the development of radioligands based on antibodies for visualization of intrabrain targets. We focus on antibodies modified into a bispecific format, with the capacity to undergo transferrin receptor 1 (TfR1)-mediated transcytosis to enter the brain and access pathological proteins, e.g. amyloid-beta. A number of such antibody ligands have been developed, displaying differences in brain uptake, pharmacokinetics, and ability to bind and visualize the target in the brain of transgenic mice. Potential pathological changes related to neurodegeneration, e.g. misfolded proteins and neuroinflammation, are suggested as future targets for this novel type of radioligand. Challenges are also discussed, such as the temporal match of radionuclide half-life with the ligand’s pharmacokinetic profile and translation to human use. In conclusion, brain PET imaging using bispecific antibodies, modified for receptor-mediated transcytosis across the BBB, is a promising method for specifically visualizing molecules in the brain that are difficult to target with traditional small molecule ligands.
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Ahmedova A, Todorov B, Burdzhiev N, Goze C. Copper radiopharmaceuticals for theranostic applications. Eur J Med Chem 2018; 157:1406-1425. [DOI: 10.1016/j.ejmech.2018.08.051] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/15/2018] [Accepted: 08/18/2018] [Indexed: 12/12/2022]
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8
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Amyloid β-targeted metal complexes for potential applications in Alzheimer's disease. Future Med Chem 2018; 10:679-701. [DOI: 10.4155/fmc-2017-0248] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is currently an incurable neurodegenerative disorder that affects millions of people around the world. The aggregation of amyloid-β peptides (Aβ), one of the primary pathological hallmarks of AD, plays a key role in the AD pathogenesis. In this regard, Aβ aggregates have been considered as both biomarkers and drug targets for the diagnosis and therapy of AD. Various Aβ-targeted metal complexes have exhibited promising potential as anti-AD agents due to their fascinating physicochemical properties over the past two decades. This review classifies the complexes into three groups based on their potential applications in AD including therapy, diagnosis and theranosis. The recent representative examples are highlighted in terms of design rationale, working mechanism and potential applications.
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Mouse models of neurodegenerative disease: preclinical imaging and neurovascular component. Brain Imaging Behav 2017; 12:1160-1196. [PMID: 29075922 DOI: 10.1007/s11682-017-9770-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurodegenerative diseases represent great challenges for basic science and clinical medicine because of their prevalence, pathologies, lack of mechanism-based treatments, and impacts on individuals. Translational research might contribute to the study of neurodegenerative diseases. The mouse has become a key model for studying disease mechanisms that might recapitulate in part some aspects of the corresponding human diseases. Neurodegenerative disorders are very complicated and multifactorial. This has to be taken in account when testing drugs. Most of the drugs screening in mice are very difficult to be interpretated and often useless. Mouse models could be condiderated a 'pathway models', rather than as models for the whole complicated construct that makes a human disease. Non-invasive in vivo imaging in mice has gained increasing interest in preclinical research in the last years thanks to the availability of high-resolution single-photon emission computed tomography (SPECT), positron emission tomography (PET), high field Magnetic resonance, Optical Imaging scanners and of highly specific contrast agents. Behavioral test are useful tool to characterize different animal models of neurodegenerative pathology. Furthermore, many authors have observed vascular pathological features associated to the different neurodegenerative disorders. Aim of this review is to focus on the different existing animal models of neurodegenerative disorders, describe behavioral tests and preclinical imaging techniques used for diagnose and describe the vascular pathological features associated to these diseases.
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10
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Chen K, Cui M. Recent progress in the development of metal complexes as β-amyloid imaging probes in the brain. MEDCHEMCOMM 2017; 8:1393-1407. [PMID: 30108850 PMCID: PMC6072098 DOI: 10.1039/c7md00064b] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 05/11/2017] [Indexed: 01/28/2023]
Abstract
In this review, we have focused on the recent progress in metal complexes that are able to bind to β-amyloid (Aβ) species. We have discussed various radioactive complexes of 99mTc, 68Ga, 64Cu, 89Zr, and 111In, which were designed as Aβ imaging agents for positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging, non-radioactive Re and Ru complexes as Aβ sensors using luminescence methods, and Gd3+ complexes as contrast agents for magnetic resonance imaging (MRI).
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Affiliation(s)
- Kaihua Chen
- Key Laboratory of Radiopharmaceuticals , Ministry of Education , College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China . ; ; Tel: +86 10 58808891
| | - Mengchao Cui
- Key Laboratory of Radiopharmaceuticals , Ministry of Education , College of Chemistry , Beijing Normal University , Beijing 100875 , P. R. China . ; ; Tel: +86 10 58808891
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11
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Hatami A, Monjazeb S, Milton S, Glabe CG. Familial Alzheimer's Disease Mutations within the Amyloid Precursor Protein Alter the Aggregation and Conformation of the Amyloid-β Peptide. J Biol Chem 2017; 292:3172-3185. [PMID: 28049728 DOI: 10.1074/jbc.m116.755264] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/28/2016] [Indexed: 11/06/2022] Open
Abstract
Most cases of Alzheimer's disease (AD) are sporadic, but a small percentage of AD cases, called familial AD (FAD), are associated with mutations in presenilin 1, presenilin 2, or the amyloid precursor protein. Amyloid precursor protein mutations falling within the amyloid-β (Aβ) sequence lead to a wide range of disease phenotypes. There is increasing evidence that distinct amyloid structures distinguished by amyloid conformation-dependent monoclonal antibodies have similarly distinct roles in pathology. It is possible that this phenotypic diversity of FAD associated with mutations within the Aβ sequence is due to differences in the conformations adopted by mutant Aβ peptides, but the effects of FAD mutations on aggregation kinetics and conformational and morphological changes of the Aβ peptide are poorly defined. To gain more insight into this possibility, we therefore investigated the effects of 11 FAD mutations on the aggregation kinetics of Aβ, as well as its ability to form distinct conformations recognized by a panel of amyloid conformation-specific monoclonal antibodies. We found that most FAD mutations increased the rate of aggregation of Aβ. The FAD mutations also led to the adoption of alternative amyloid conformations distinguished by monoclonal antibodies and resulted in the formation of distinct aggregate morphologies as determined by transmission electron microscopy. In addition, several of the mutant peptides displayed a large reduction in thioflavin T fluorescence, despite forming abundant fibrils indicating that thioflavin T is a probe of conformational polymorphisms rather than a reliable indicator of fibrillization. Taken together, these results indicate that FAD mutations falling within the Aβ sequence lead to dramatic changes in aggregation kinetics and influence the ability of Aβ to form immunologically and morphologically distinct amyloid structures.
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Affiliation(s)
- Asa Hatami
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697; Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Sanaz Monjazeb
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697
| | - Saskia Milton
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697; Biochemistry Department, Faculty of Science and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, 23218 Jeddah, Saudi Arabia.
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12
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Bilousova T, Miller CA, Poon WW, Vinters HV, Corrada M, Kawas C, Hayden EY, Teplow DB, Glabe C, Albay R, Cole GM, Teng E, Gylys KH. Synaptic Amyloid-β Oligomers Precede p-Tau and Differentiate High Pathology Control Cases. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:185-98. [PMID: 26718979 DOI: 10.1016/j.ajpath.2015.09.018] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 01/03/2023]
Abstract
Amyloid-β (Aβ) and hyperphosphorylated tau (p-tau) aggregates form the two discrete pathologies of Alzheimer disease (AD), and oligomeric assemblies of each protein are localized to synapses. To determine the sequence by which pathology appears in synapses, Aβ and p-tau were quantified across AD disease stages in parietal cortex. Nondemented cases with high levels of AD-related pathology were included to determine factors that confer protection from clinical symptoms. Flow cytometric analysis of synaptosome preparations was used to quantify Aβ and p-tau in large populations of individual synaptic terminals. Soluble Aβ oligomers were assayed by a single antibody sandwich enzyme-linked immunosorbent assay. Total in situ Aβ was elevated in patients with early- and late-stage AD dementia, but not in high pathology nondemented controls compared with age-matched normal controls. However, soluble Aβ oligomers were highest in early AD synapses, and this assay distinguished early AD cases from high pathology controls. Overall, synapse-associated p-tau did not increase until late-stage disease in human and transgenic rat cortex, and p-tau was elevated in individual Aβ-positive synaptosomes in early AD. These results suggest that soluble oligomers in surviving neocortical synaptic terminals are associated with dementia onset and suggest an amyloid cascade hypothesis in which oligomeric Aβ drives phosphorylated tau accumulation and synaptic spread. These results indicate that antiamyloid therapies will be less effective once p-tau pathology is developed.
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Affiliation(s)
- Tina Bilousova
- University of California Los Angeles School of Nursing, Los Angeles, California; Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California
| | - Carol A Miller
- Departments of Pathology, Neurology, and the Program in Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, California
| | - Wayne W Poon
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California
| | - Harry V Vinters
- Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Department of Pathology and Laboratory Medicine, University of California Los Angeles School of Medicine, Los Angeles, California
| | - Maria Corrada
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California; Department of Neurology, University of California Irvine, Irvine, California
| | - Claudia Kawas
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, California; Department of Neurology, University of California Irvine, Irvine, California; Department of Neurobiology & Behavior, University of California Irvine, Irvine, California
| | - Eric Y Hayden
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California
| | - David B Teplow
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California
| | - Charles Glabe
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California
| | - Ricardo Albay
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California
| | - Gregory M Cole
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Department of Medicine, University of California Los Angeles School of Medicine, Los Angeles, California; Geriatric Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, California
| | - Edmond Teng
- Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California; Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, California; Geriatric Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, California
| | - Karen H Gylys
- University of California Los Angeles School of Nursing, Los Angeles, California; Mary S. Easton Center for Alzheimer's Research at the University of California Los Angeles, Los Angeles, California.
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13
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LeVine H, Walker LC. What amyloid ligands can tell us about molecular polymorphism and disease. Neurobiol Aging 2016; 42:205-12. [PMID: 27143437 DOI: 10.1016/j.neurobiolaging.2016.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 12/19/2022]
Abstract
Brain-penetrant positron emission tomography imaging ligands selective for amyloid pathology in living subjects have sparked a revolution in presymptomatic biomarkers for Alzheimer's disease progression. As additional chemical structures were investigated, the heterogeneity of ligand-binding sites became apparent, as did discrepancies in binding of some ligands between human disease and animal models. These differences and their implications have received little attention. This review discusses the impact of different ligand-binding sites and misfolded protein conformational polymorphism on the interpretation of imaging data acquired with different ligands. Investigation of the differences in binding in animal models may identify pathologic processes informing improvements to these models for more faithful recapitulation of this uniquely human disease. The differential selectivity for binding of particular ligands to different conformational states could potentially be harnessed to better define disease progression and improve the prediction of clinical outcomes.
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Affiliation(s)
- Harry LeVine
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Molecular and Cellular Biochemistry, Center for Structural Biology, University of Kentucky, Lexington, KY, USA.
| | - Lary C Walker
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA; Department of Neurology, Emory University, Atlanta, GA, USA
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14
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Synthesis and Evaluation of a Zr-89-Labeled Monoclonal Antibody for Immuno-PET Imaging of Amyloid-β Deposition in the Brain. Mol Imaging Biol 2016; 18:598-605. [DOI: 10.1007/s11307-016-0935-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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15
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Hatami A, Albay R, Monjazeb S, Milton S, Glabe C. Monoclonal antibodies against Aβ42 fibrils distinguish multiple aggregation state polymorphisms in vitro and in Alzheimer disease brain. J Biol Chem 2014; 289:32131-32143. [PMID: 25281743 DOI: 10.1074/jbc.m114.594846] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amyloidogenic proteins generally form intermolecularly hydrogen-bonded β-sheet aggregates, including parallel, in-register β-sheets (recognized by antiserum OC) or antiparallel β-sheets, β-solenoids, β-barrels, and β-cylindrins (recognized by antiserum A11). Although these groups share many common properties, some amyloid sequences have been reported to form polymorphic structural variants or strains. We investigated the humoral immune response to Aβ42 fibrils and produced 23 OC-type monoclonal antibodies recognizing distinct epitopes differentially associated with polymorphic structural variants. These mOC antibodies define at least 18 different immunological profiles represented in aggregates of amyloid-β (Aβ). All of the antibodies strongly prefer amyloid aggregates over monomer, indicating that they recognize conformational epitopes. Most of the antibodies react with N-terminal linear segments of Aβ, although many recognize a discontinuous epitope consisting of an N-terminal domain and a central domain. Several of the antibodies that recognize linear Aβ segments also react with fibrils formed from unrelated amyloid sequences, indicating that reactivity with linear segments of Aβ does not mean the antibody is sequence-specific. The antibodies display strikingly different patterns of immunoreactivity in Alzheimer disease and transgenic mouse brain and identify spatially and temporally unique amyloid deposits. Our results indicate that the immune response to Aβ42 fibrils is diverse and reflects the structural polymorphisms in fibrillar amyloid structures. These polymorphisms may contribute to differences in toxicity and consequent effects on pathological processes. Thus, a single therapeutic monoclonal antibody may not be able to target all of the pathological aggregates necessary to make an impact on the overall disease process.
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Affiliation(s)
- Asa Hatami
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697-3900 and
| | - Ricardo Albay
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697-3900 and
| | - Sanaz Monjazeb
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697-3900 and
| | - Saskia Milton
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697-3900 and
| | - Charles Glabe
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, California 92697-3900 and; Biochemistry Department, Faculty of Science and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, 21589 Jeddah, Saudi Arabia.
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16
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Pensalfini A, Albay R, Rasool S, Wu JW, Hatami A, Arai H, Margol L, Milton S, Poon WW, Corrada MM, Kawas CH, Glabe CG. Intracellular amyloid and the neuronal origin of Alzheimer neuritic plaques. Neurobiol Dis 2014; 71:53-61. [PMID: 25092575 DOI: 10.1016/j.nbd.2014.07.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 05/24/2014] [Accepted: 07/08/2014] [Indexed: 01/19/2023] Open
Abstract
Genetic analysis of familial forms of Alzheimer's disease (AD) causally links the proteolytic processing of the amyloid precursor protein (APP) and AD. However, the specific type of amyloid and mechanisms of amyloid pathogenesis remain unclear. We conducted a detailed analysis of intracellular amyloid with an aggregation specific conformation dependent monoclonal antibody, M78, raised against fibrillar Aß42. M78 immunoreactivity colocalizes with Aß and the carboxyl terminus of APP (APP-CTF) immunoreactivities in perinuclear compartments at intermediate times in 10month 3XTg-AD mice, indicating that this represents misfolded and aggregated protein rather than normally folded APP. At 12months, M78 immunoreactivity also accumulates in the nucleus. Neuritic plaques at 12months display the same spatial organization of centrally colocalized M78, diffuse chromatin and neuronal nuclear NeuN staining surrounded by peripheral M78 and APP-CTF immunoreactivity as observed in neurons, indicating that neuritic plaques arise from degenerating neurons with intracellular amyloid immunoreactivity. The same staining pattern was observed in neuritic plaques in human AD brains, showing elevated intracellular M78 immunoreactivity at intermediate stages of amyloid pathology (Braak A and B) compared to no amyloid pathology and late stage amyloid pathology (Braak 0 and C, respectively). These results indicate that intraneuronal protein aggregation and amyloid accumulation is an early event in AD and that neuritic plaques are initiated by the degeneration and death of neurons by a mechanism that may be related to the formation of extracellular traps by neutrophils.
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Affiliation(s)
- Anna Pensalfini
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.
| | - Ricardo Albay
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Suhail Rasool
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Jessica W Wu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Asa Hatami
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Hiromi Arai
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Lawrence Margol
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Saskia Milton
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
| | - Wayne W Poon
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - Maria M Corrada
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurology, University of California, Irvine, CA 92697, USA
| | - Claudia H Kawas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA; Department of Neurology, University of California, Irvine, CA 92697, USA; Department of Neurobiology & Behavior, University of California, Irvine, CA 92697, USA
| | - Charles G Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA; Biochemistry Department and Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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17
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Klohs J, Rudin M, Shimshek DR, Beckmann N. Imaging of cerebrovascular pathology in animal models of Alzheimer's disease. Front Aging Neurosci 2014; 6:32. [PMID: 24659966 PMCID: PMC3952109 DOI: 10.3389/fnagi.2014.00032] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/19/2014] [Indexed: 01/04/2023] Open
Abstract
In Alzheimer's disease (AD), vascular pathology may interact with neurodegeneration and thus aggravate cognitive decline. As the relationship between these two processes is poorly understood, research has been increasingly focused on understanding the link between cerebrovascular alterations and AD. This has at last been spurred by the engineering of transgenic animals, which display pathological features of AD and develop cerebral amyloid angiopathy to various degrees. Transgenic models are versatile for investigating the role of amyloid deposition and vascular dysfunction, and for evaluating novel therapeutic concepts. In addition, research has benefited from the development of novel imaging techniques, which are capable of characterizing vascular pathology in vivo. They provide vascular structural read-outs and have the ability to assess the functional consequences of vascular dysfunction as well as to visualize and monitor the molecular processes underlying these pathological alterations. This article focusses on recent in vivo small animal imaging studies addressing vascular aspects related to AD. With the technical advances of imaging modalities such as magnetic resonance, nuclear and microscopic imaging, molecular, functional and structural information related to vascular pathology can now be visualized in vivo in small rodents. Imaging vascular and parenchymal amyloid-β (Aβ) deposition as well as Aβ transport pathways have been shown to be useful to characterize their dynamics and to elucidate their role in the development of cerebral amyloid angiopathy and AD. Structural and functional imaging read-outs have been employed to describe the deleterious affects of Aβ on vessel morphology, hemodynamics and vascular integrity. More recent imaging studies have also addressed how inflammatory processes partake in the pathogenesis of the disease. Moreover, imaging can be pivotal in the search for novel therapies targeting the vasculature.
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Affiliation(s)
- Jan Klohs
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich Zurich, Switzerland
| | - Markus Rudin
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich Zurich, Switzerland ; Neuroscience Center Zurich, University of Zurich and ETH Zurich Zurich, Switzerland ; Institute of Pharmacology and Toxicology, University of Zurich Zurich, Switzerland
| | - Derya R Shimshek
- Autoimmunity, Transplantation and Inflammation/Neuroinflammation Department, Novartis Institutes for BioMedical Research Basel, Switzerland
| | - Nicolau Beckmann
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research Basel, Switzerland
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18
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Current status of PET-imaging probes of β-amyloid plaques. Arch Pharm Res 2013; 36:1178-84. [PMID: 23812777 DOI: 10.1007/s12272-013-0193-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/16/2013] [Indexed: 10/26/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia and is characterized by progressive cognitive decline and memory loss. One of pathological hallmarks of AD is the accumulation and deposition of β-amyloid (Aβ) plaques which is a potential target for the early diagnosis of AD. Positron emission tomography (PET), a sensitive radionuclide imaging technique, has provided opportunities to detect Aβ plaques of AD. PET-imaging probes of Aβ plaques have been extensively developed during the last decade. [(18)F]Florbetapir, the (18)F-labeled PET-imaging probe of Aβ plaques, was recently approved by US Food and Drug Administration. A number of follow-on PET-imaging probes are currently being developed in academia and pharmaceutical companies. This article will discuss the recent development of PET-imaging probes from [(11)C]PIB to [(18)F]Florbetapir, which are in clinic trials, and several follow-on probes in preclinical stage.
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