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Alpha synuclein processing by MMP-3 - implications for synucleinopathies. Behav Brain Res 2022; 434:114020. [PMID: 35870616 DOI: 10.1016/j.bbr.2022.114020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/01/2022] [Accepted: 07/19/2022] [Indexed: 11/22/2022]
Abstract
α-Synuclein (aSyn) is a protein implicated in physiological functions such as neurotransmitter release at the synapse and the regulation of gene expression in the nucleus. In addition, pathological aSyn assemblies are characteristic for a class of protein aggregation disorders referred to as synucleinopathies, where aSyn aggregates appear as Lewy bodies and Lewy neurites. We recently discovered a novel post-translational pyroglutamate (pGlu) modification at Gln79 of N-truncated aSyn that promotes oligomer formation and neurotoxicity in human synucleinopathies. A priori, the appearance of pGlu79-aSyn in vivo involves a two-step process of free N-terminal Gln79 residue generation and subsequent cyclization of Gln79 into pGlu79. Prime candidate enzymes for these processes are matrix metalloproteinase-3 (MMP-3) and glutaminyl cyclase (QC). Here, we analyzed the expression of aSyn, MMP-3, QC and pGlu79-aSyn in brains of two transgenic mouse models for synucleinopathies (BAC-SNCA and ASO) by triple immunofluorescent labellings and confocal laser scanning microscopy. We report a co-localization of these proteins in brain structures typically affected by aSyn pathology, namely hippocampus in BAC-SNCA mice and substantia nigra in ASO mice. In addition, Western blot analyses revealed a high abundance of QC, MMP-3 and transgenic human aSyn in brain stem and thalamus but lower levels in cortex/hippocampus, whereas endogenous mouse aSyn was found to be most abundant in cortex/hippocampus, followed by thalamus and brain stem. During aging of ASO mice, we observed no differences between controls and transgenic mice in MMP-3 levels but higher QC content in thalamus of 6-month-old transgenic mice. Transgenic human aSyn abundance transiently increased and then showed decrease in oldest ASO mice analyzed. Immunohistochemistry revealed a successive increase in intraneuronal and extracellular formation of pGlu79-aSyn in substantia nigra during aging of ASO mice. Together, our data are supportive for a role of MMP-3 and QC in the generation of pGlu79-aSyn in brains affected by aSyn pathology.
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2
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Bluhm A, Schrempel S, Schilling S, von Hörsten S, Schulze A, Roßner S, Hartlage-Rübsamen M. Immunohistochemical Demonstration of the pGlu79 α-Synuclein Fragment in Alzheimer’s Disease and Its Tg2576 Mouse Model. Biomolecules 2022; 12:biom12071006. [PMID: 35883562 PMCID: PMC9312983 DOI: 10.3390/biom12071006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 02/04/2023] Open
Abstract
The deposition of β-amyloid peptides and of α-synuclein proteins is a neuropathological hallmark in the brains of Alzheimer’s disease (AD) and Parkinson’s disease (PD) subjects, respectively. However, there is accumulative evidence that both proteins are not exclusive for their clinical entity but instead co-exist and interact with each other. Here, we investigated the presence of a newly identified, pyroglutamate79-modified α-synuclein variant (pGlu79-aSyn)—along with the enzyme matrix metalloproteinase-3 (MMP-3) and glutaminyl cyclase (QC) implicated in its formation—in AD and in the transgenic Tg2576 AD mouse model. In the human brain, pGlu79-aSyn was detected in cortical pyramidal neurons, with more distinct labeling in AD compared to control brain tissue. Using immunohistochemical double and triple labelings and confocal laser scanning microscopy, we demonstrate an association of pGlu79-aSyn, MMP-3 and QC with β-amyloid plaques. In addition, pGlu79-aSyn and QC were present in amyloid plaque-associated reactive astrocytes that were also immunoreactive for the chaperone heat shock protein 27 (HSP27). Our data are consistent for the transgenic mouse model and the human clinical condition. We conclude that pGlu79-aSyn can be generated extracellularly or within reactive astrocytes, accumulates in proximity to β-amyloid plaques and induces an astrocytic protein unfolding mechanism involving HSP27.
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Affiliation(s)
- Alexandra Bluhm
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany; (A.B.); (Sa.S.); (M.H.-R.)
| | - Sarah Schrempel
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany; (A.B.); (Sa.S.); (M.H.-R.)
| | - Stephan Schilling
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, 06120 Halle (Saale), Germany; (S.S.); (A.S.)
- Faculty of Applied Biosciences and Process Engineering, Anhalt University of Applied Sciences, 06366 Köthen, Germany
| | - Stephan von Hörsten
- Department for Experimental Therapy, University Clinics Erlangen and Preclinical Experimental Center, University of Erlangen-Nuremberg, 91054 Erlangen, Germany;
| | - Anja Schulze
- Fraunhofer Institute for Cell Therapy and Immunology, Department of Drug Design and Target Validation, 06120 Halle (Saale), Germany; (S.S.); (A.S.)
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany; (A.B.); (Sa.S.); (M.H.-R.)
- Correspondence: ; Tel.: +49-341-9725758
| | - Maike Hartlage-Rübsamen
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany; (A.B.); (Sa.S.); (M.H.-R.)
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3
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Hartlage-Rübsamen M, Bluhm A, Moceri S, Machner L, Köppen J, Schenk M, Hilbrich I, Holzer M, Weidenfeller M, Richter F, Coras R, Serrano GE, Beach TG, Schilling S, von Hörsten S, Xiang W, Schulze A, Roßner S. A glutaminyl cyclase-catalyzed α-synuclein modification identified in human synucleinopathies. Acta Neuropathol 2021; 142:399-421. [PMID: 34309760 PMCID: PMC8357657 DOI: 10.1007/s00401-021-02349-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 12/22/2022]
Abstract
Parkinson’s disease (PD) is a progressive neurodegenerative disorder that is neuropathologically characterized by degeneration of dopaminergic neurons of the substantia nigra (SN) and formation of Lewy bodies and Lewy neurites composed of aggregated α-synuclein. Proteolysis of α-synuclein by matrix metalloproteinases was shown to facilitate its aggregation and to affect cell viability. One of the proteolysed fragments, Gln79-α-synuclein, possesses a glutamine residue at its N-terminus. We argue that glutaminyl cyclase (QC) may catalyze the pyroglutamate (pGlu)79-α-synuclein formation and, thereby, contribute to enhanced aggregation and compromised degradation of α-synuclein in human synucleinopathies. Here, the kinetic characteristics of Gln79-α-synuclein conversion into the pGlu-form by QC are shown using enzymatic assays and mass spectrometry. Thioflavin T assays and electron microscopy demonstrated a decreased potential of pGlu79-α-synuclein to form fibrils. However, size exclusion chromatography and cell viability assays revealed an increased propensity of pGlu79-α-synuclein to form oligomeric aggregates with high neurotoxicity. In brains of wild-type mice, QC and α-synuclein were co-expressed by dopaminergic SN neurons. Using a specific antibody against the pGlu-modified neo-epitope of α-synuclein, pGlu79-α-synuclein aggregates were detected in association with QC in brains of two transgenic mouse lines with human α-synuclein overexpression. In human brain samples of PD and dementia with Lewy body subjects, pGlu79-α-synuclein was shown to be present in SN neurons, in a number of Lewy bodies and in dystrophic neurites. Importantly, there was a spatial co-occurrence of pGlu79-α-synuclein with the enzyme QC in the human SN complex and a defined association of QC with neuropathological structures. We conclude that QC catalyzes the formation of oligomer-prone pGlu79-α-synuclein in human synucleinopathies, which may—in analogy to pGlu-Aβ peptides in Alzheimer’s disease—act as a seed for pathogenic protein aggregation.
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4
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Gunn AP, Wong BX, McLean C, Fowler C, Barnard PJ, Duce JA, Roberts BR. Increased glutaminyl cyclase activity in brains of Alzheimer's disease individuals. J Neurochem 2020; 156:979-987. [PMID: 32614980 DOI: 10.1111/jnc.15114] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/27/2020] [Accepted: 06/24/2020] [Indexed: 12/23/2022]
Abstract
Glutaminyl cyclases (QC) catalyze the formation of neurotoxic pGlu-modified amyloid-β peptides found in the brains of people with Alzheimer's disease (AD). Reports of several-fold increases in soluble QC (sQC) expression in the brain and peripheral circulation of AD individuals has prompted the development of QC inhibitors as potential AD therapeutics. There is, however, a lack of standardized quantitative data on QC expression in human tissues, precluding inter-laboratory comparison and validation. We tested the hypothesis that QC is elevated in AD tissues by quantifying levels of sQC protein and activity in post-mortem brain tissues from AD and age-matched control individuals. We found a modest but statistically significant increase in sQC protein, which paralleled a similar increase in enzyme activity. In plasma samples sourced from the Australian Imaging, Biomarker and Lifestyle study we determined that QC activity was not different between the AD and control group, though a modest increase was observed in female AD individuals compared to controls. Plasma QC activity was further correlated with levels of circulating monocytes in AD individuals. These data provide quantitative evidence that alterations in QC expression are associated with AD pathology.
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Affiliation(s)
- Adam P Gunn
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Vic, Australia.,Analytical Chemistry, Faculty of Science and Technology, University of Canberra, Canberra, ACT, Australia
| | - Bruce X Wong
- The ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge, UK
| | - Catriona McLean
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Vic, Australia
| | - Chris Fowler
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Vic, Australia
| | - Peter J Barnard
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Vic, Australia
| | - James A Duce
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Vic, Australia.,The ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge, UK
| | - Blaine R Roberts
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Vic, Australia.,Department of Biochemistry, Emory School of Medicine, Atlanta, GA, USA.,Department of Neurology, Emory School of Medicine, Atlanta, GA, USA
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5
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Tonon MC, Vaudry H, Chuquet J, Guillebaud F, Fan J, Masmoudi-Kouki O, Vaudry D, Lanfray D, Morin F, Prevot V, Papadopoulos V, Troadec JD, Leprince J. Endozepines and their receptors: Structure, functions and pathophysiological significance. Pharmacol Ther 2020; 208:107386. [DOI: 10.1016/j.pharmthera.2019.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
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6
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Yates SC, Groeneboom NE, Coello C, Lichtenthaler SF, Kuhn PH, Demuth HU, Hartlage-Rübsamen M, Roßner S, Leergaard T, Kreshuk A, Puchades MA, Bjaalie JG. QUINT: Workflow for Quantification and Spatial Analysis of Features in Histological Images From Rodent Brain. Front Neuroinform 2019; 13:75. [PMID: 31849633 PMCID: PMC6901597 DOI: 10.3389/fninf.2019.00075] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 11/15/2019] [Indexed: 01/22/2023] Open
Abstract
Transgenic animal models are invaluable research tools for elucidating the pathways and mechanisms involved in the development of neurodegenerative diseases. Mechanistic clues can be revealed by applying labelling techniques such as immunohistochemistry or in situ hybridisation to brain tissue sections. Precision in both assigning anatomical location to the sections and quantifying labelled features is crucial for output validity, with a stereological approach or image-based feature extraction typically used. However, both approaches are restricted by the need to manually delineate anatomical regions. To circumvent this limitation, we present the QUINT workflow for quantification and spatial analysis of labelling in series of rodent brain section images based on available 3D reference atlases. The workflow is semi-automated, combining three open source software that can be operated without scripting knowledge, making it accessible to most researchers. As an example, a brain region-specific quantification of amyloid plaques across whole transgenic Tg2576 mouse brain series, immunohistochemically labelled for three amyloid-related antigens is demonstrated. First, the whole brain image series were registered to the Allen Mouse Brain Atlas to produce customised atlas maps adapted to match the cutting plan and proportions of the sections (QuickNII software). Second, the labelling was segmented from the original images by the Random Forest Algorithm for supervised classification (ilastik software). Finally, the segmented images and atlas maps were used to generate plaque quantifications for each region in the reference atlas (Nutil software). The method yielded comparable results to manual delineations and to the output of a stereological method. While the use case demonstrates the QUINT workflow for quantification of amyloid plaques only, the workflow is suited to all mouse or rat brain series with labelling that is visually distinct from the background, for example for the quantification of cells or labelled proteins.
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Affiliation(s)
- Sharon C Yates
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Nicolaas E Groeneboom
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Christopher Coello
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Study, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Peer-Hendrik Kuhn
- Institute of Pathology, Technical University of Munich, Munich, Germany
| | - Hans-Ulrich Demuth
- Department of Molecular Drug Design and Target Validation Fraunhofer Institute for Cell Therapy and Immunology, Halle (Saale), Leipzig, Germany
| | | | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Trygve Leergaard
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Anna Kreshuk
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Maja A Puchades
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Jan G Bjaalie
- Neural Systems Laboratory, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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7
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Wang X, Wang L, Yu X, Li Y, Liu Z, Zou Y, Zheng Y, He Z, Wu H. Glutaminyl cyclase inhibitor exhibits anti-inflammatory effects in both AD and LPS-induced inflammatory model mice. Int Immunopharmacol 2019; 75:105770. [DOI: 10.1016/j.intimp.2019.105770] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/13/2019] [Accepted: 07/18/2019] [Indexed: 01/08/2023]
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8
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Hartlage-Rübsamen M, Bluhm A, Piechotta A, Linnert M, Rahfeld JU, Demuth HU, Lues I, Kuhn PH, Lichtenthaler SF, Roßner S, Höfling C. Immunohistochemical Evidence from APP-Transgenic Mice for Glutaminyl Cyclase as Drug Target to Diminish pE-Abeta Formation. Molecules 2018; 23:molecules23040924. [PMID: 29673150 PMCID: PMC6017857 DOI: 10.3390/molecules23040924] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/05/2018] [Accepted: 04/10/2018] [Indexed: 02/06/2023] Open
Abstract
Oligomeric assemblies of neurotoxic amyloid beta (Abeta) peptides generated by proteolytical processing of the amyloid precursor protein (APP) play a key role in the pathogenesis of Alzheimer’s disease (AD). In recent years, a substantial heterogeneity of Abeta peptides with distinct biophysical and cell biological properties has been demonstrated. Among these, a particularly neurotoxic and disease-specific Abeta variant is N-terminally truncated and modified to pyroglutamate (pE-Abeta). Cell biological and animal experimental studies imply the catalysis of this modification by the enzyme glutaminyl cyclase (QC). However, direct histopathological evidence in transgenic animals from comparative brain region and cell type-specific expression of transgenic hAPP and QC, on the one hand, and on the formation of pE-Abeta aggregates, on the other, is lacking. Here, using single light microscopic, as well as triple immunofluorescent, labeling, we report the deposition of pE-Abeta only in the brain regions of APP-transgenic Tg2576 mice with detectable human APP and endogenous QC expression, such as the hippocampus, piriform cortex, and amygdala. Brain regions showing human APP expression without the concomitant presence of QC (the anterodorsal thalamic nucleus and perifornical nucleus) do not display pE-Abeta plaque formation. However, we also identified brain regions with substantial expression of human APP and QC in the absence of pE-Abeta deposition (the Edinger-Westphal nucleus and locus coeruleus). In these brain regions, the enzymes required to generate N-truncated Abeta peptides as substrates for QC might be lacking. Our observations provide additional evidence for an involvement of QC in AD pathogenesis via QC-catalyzed pE-Abeta formation.
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Affiliation(s)
| | - Alexandra Bluhm
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany.
| | - Anke Piechotta
- Department of Molecular Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120 Halle (Saale), Germany.
| | - Miriam Linnert
- Department of Molecular Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120 Halle (Saale), Germany.
| | - Jens-Ulrich Rahfeld
- Department of Molecular Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120 Halle (Saale), Germany.
| | - Hans-Ulrich Demuth
- Department of Molecular Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120 Halle (Saale), Germany.
| | - Inge Lues
- Probiodrug AG, 06120 Halle (Saale), Germany.
| | - Peer-Hendrik Kuhn
- Institute of Pathology, Technical University of Munich, 81675 Munich, Germany.
| | - Stefan F Lichtenthaler
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), 81377 Munich, Germany.
- Munich Cluster of Systems Neurology (SyNergy), 81377 Munich, Germany.
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany.
- Institute for Advanced Study, Technical University of Munich, 85748 Garching, Germany.
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany.
| | - Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, 04103 Leipzig, Germany.
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Khan RAW, Chen J, Shen J, Li Z, Wang M, Wen Z, Song Z, Li W, Xu Y, Shi Y, Yi Q, Ji W. Common variants in QPCT gene confer risk of schizophrenia in the Han Chinese population. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:237-42. [PMID: 26492838 DOI: 10.1002/ajmg.b.32397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/14/2015] [Indexed: 11/11/2022]
Abstract
Schizophrenia (SCZ) is a common and severe mental disorder, its etiology has not been elucidated completely. In one previous genome-wide association study (GWAS) of SCZ in the Caucasian population, the QPCT has been reported as susceptible gene for SCZ. The QPCT gene encodes Glutaminyl cyclase (QC), an enzyme which is involved in the post translational modification by converting N-terminal glutamate of protein to pyroglutamate, which is resistant to protease degradation, more hydrophobic, and prone to aggregation and neurotoxic. To further investigate the role of this gene in the pathogenesis of schizophrenia in the Han Chinese population, we conducted this study in 1,248 (Mean age ± S.D, 36.44 years ± 9.0) SCZ cases, 1,248 (Mean age ± S.D, 30.62 years ± 11.35) healthy control samples for a case control study. We genotyped six SNPs in this study, including one positive SNP of the previous study, using the Sequenom MassARRAY platform. We found that rs2373000 was significantly associated with SCZ before correction [rs2373000: P allele = 0.016, χ(2) = 5.784, OR [95%CI] = 0.861 [0.762-0.972], P genotype = 0.018, χ(2) = 0.069]. After permutation correction for multiple testing, rs2373000 [rs2373000: P Allele corrected = 0.063, P genotype corrected = 0.069] showed marginal association with SCZ. Additionally, one pathogenic haplotype (TGT) containing rs2373000 was also significantly associated with SCZ. Our results are consistent with the findings of previous study and the genetic risk of QPCT gene for SCZ also exists in the Han Chinese population.
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Affiliation(s)
- Raja Amjad Waheed Khan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,University of Azad Jammu and Kashmir, Department of Chemistry, Muzaffarabad, 13100, Pakistan
| | - Jianhua Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jiawei Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zhiqiang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Meng Wang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zujia Wen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Zhijian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Wenjin Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Yifeng Xu
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Yongyong Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, People's Republic of China.,Shanghai Changning Mental Health Center, Shanghai, People's Republic of China.,Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Qizhong Yi
- Department of Psychiatry, First Teaching Hospital of Xinjiang Medical University, Urumqi, People's Republic of China
| | - Weidong Ji
- Shanghai Changning Mental Health Center, Shanghai, People's Republic of China.,Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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10
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Becker A, Eichentopf R, Sedlmeier R, Waniek A, Cynis H, Koch B, Stephan A, Bäuscher C, Kohlmann S, Hoffmann T, Kehlen A, Berg S, Freyse EJ, Osmand A, Plank AC, Roßner S, von Hörsten S, Graubner S, Demuth HU, Schilling S. IsoQC (QPCTL) knock-out mice suggest differential substrate conversion by glutaminyl cyclase isoenzymes. Biol Chem 2016; 397:45-55. [DOI: 10.1515/hsz-2015-0192] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/12/2015] [Indexed: 11/15/2022]
Abstract
Abstract
Secretory peptides and proteins are frequently modified by pyroglutamic acid (pE, pGlu) at their N-terminus. This modification is catalyzed by the glutaminyl cyclases QC and isoQC. Here, we decipher the roles of the isoenzymes by characterization of IsoQC-/- mice. These mice show a significant reduction of glutaminyl cyclase activity in brain and peripheral tissue, suggesting ubiquitous expression of the isoQC enzyme. An assay of substrate conversion in vivo reveals impaired generation of the pGlu-modified C-C chemokine ligand 2 (CCL2, MCP-1) in isoQC-/- mice. The pGlu-formation was also impaired in primary neurons, which express significant levels of QC. Interestingly, however, the formation of the neuropeptide hormone thyrotropin-releasing hormone (TRH), assessed by immunohistochemistry and hormonal analysis of hypothalamic-pituitary-thyroid axis, was not affected in isoQC-/-, which contrasts to QC-/-. Thus, the results reveal differential functions of isoQC and QC in the formation of the pGlu-peptides CCL2 and TRH. Substrates requiring extensive prohormone processing in secretory granules, such as TRH, are primarily converted by QC. In contrast, protein substrates such as CCL2 appear to be primarily converted by isoQC. The results provide a new example, how subtle differences in subcellular localization of enzymes and substrate precursor maturation might influence pGlu-product formation.
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11
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Guo J, He H, Liu Q, Zhang F, Lv J, Zeng T, Gu N, Wu Q. Identification and Epigenetic Analysis of a Maternally Imprinted Gene Qpct. Mol Cells 2015; 38:859-65. [PMID: 26447138 PMCID: PMC4625067 DOI: 10.14348/molcells.2015.0098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 07/09/2015] [Accepted: 07/13/2015] [Indexed: 11/27/2022] Open
Abstract
Most imprinted genes are concerned with embryonic development, especially placental development. Here, we identified a placenta-specific imprinted gene Qpct. Our results show that Qpct is widely expressed during early embryonic development and can be detected in the telecephalon, midbrain, and rhombencephalon at E9.5b-E11.5. Moreover, Qpct is strikingly expressed in the brain, lung and liver in E15.5. Expression signals for Qpct achieved a peak at E15.5 during placental development and were only detected in the labyrinth layer in E15.5 placenta. ChIP assay results suggest that the modification of histone H3K4me3 can result in maternal activating of Qpct.
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Affiliation(s)
- Jing Guo
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Hongjuan He
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Qi Liu
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Fengwei Zhang
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Jie Lv
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Tiebo Zeng
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Ning Gu
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
| | - Qiong Wu
- School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150001, Heilongjiang,
China
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12
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Isoglutaminyl cyclase contributes to CCL2-driven neuroinflammation in Alzheimer's disease. Acta Neuropathol 2015; 129:565-83. [PMID: 25666182 PMCID: PMC4366547 DOI: 10.1007/s00401-015-1395-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/27/2015] [Accepted: 01/28/2015] [Indexed: 11/30/2022]
Abstract
The brains of Alzheimer’s disease (AD) patients are characterized by deposits of Abeta peptides and by accompanying chronic inflammation. Here, we provide evidence that the enzyme isoglutaminyl cyclase (isoQC) is a novel factor contributing to both aspects of AD pathology. Two putative substrates of isoQC, N-truncated Abeta peptides and the monocyte chemoattractant chemokine CCL2, undergo isoQC-catalyzed pyroglutamate (pGlu) modification. This triggers Abeta aggregation and facilitates the biological activity of CCL2, which collectively results in the formation of high molecular weight Abeta aggregates, glial cell activation, neuroinflammation and neuronal cell death. In mouse brain, we found isoQC to be neuron-specifically expressed in neocortical, hippocampal and subcortical structures, localized to the endoplasmic reticulum and Golgi apparatus as well as co-expressed with its substrate CCL2. In aged APP transgenic Tg2576 mice, both isoQC and CCL2 mRNA levels are up-regulated and isoQC and CCL2 proteins were found to be co-induced in Abeta plaque-associated reactive astrocytes. Also, in mouse primary astrocyte culture, a simultaneous up-regulation of isoQC and CCL2 expression was revealed upon Abeta and pGlu-Abeta stimulation. In brains of AD patients, the expression of isoQC and CCL2 mRNA and protein is up-regulated compared to controls and correlates with pGlu-Abeta load and with the decline in mini-mental state examination. Our observations provide evidence for a dual involvement of isoQC in AD pathogenesis by catalysis of pGlu-Abeta and pGlu-CCL2 formation which mutually stimulate inflammatory events and affect cognition. We conclude that isoQC inhibition may target both major pathological events in the development of AD.
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13
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Waniek A, Hartlage-Rübsamen M, Höfling C, Kehlen A, Schilling S, Demuth HU, Roßner S. Identification of thyrotropin-releasing hormone as hippocampal glutaminyl cyclase substrate in neurons and reactive astrocytes. Biochim Biophys Acta Mol Basis Dis 2014; 1852:146-55. [PMID: 25446989 DOI: 10.1016/j.bbadis.2014.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/29/2014] [Accepted: 11/11/2014] [Indexed: 01/07/2023]
Abstract
Recently, Aβ peptide variants with an N-terminal truncation and pyroglutamate modification were identified and shown to be highly neurotoxic and prone to aggregation. This modification of Aβ is catalyzed by glutaminyl cyclase (QC) and pharmacological inhibition of QC diminishes Aβ deposition and accompanying gliosis and ameliorates memory impairment in transgenic mouse models of Alzheimer's disease (AD). QC expression was initially described in the hypothalamus, where thyrotropin-releasing hormone (TRH) is one of its physiological substrates. In addition to its hormonal role, a novel neuroprotective function of TRH following excitotoxicity and Aβ-mediated neurotoxicity has been reported in the hippocampus. Functionally matching this finding, we recently demonstrated QC expression by hippocampal interneurons in mouse brain. Here, we detected neuronal co-expression of QC and TRH in the hippocampus of young adult wild type mice using double immunofluorescence labeling. This provides evidence for TRH being a physiological QC substrate in hippocampus. Additionally, in neocortex of aged but not of young mice transgenic for amyloid precursor protein an increase of QC mRNA levels was found compared to wild type littermates. This phenomenon was not observed in hippocampus, which is later affected by Aβ pathology. However, in hippocampus of transgenic - but not of wild type mice - a correlation between QC and TRH mRNA levels was revealed. This co-regulation of the enzyme QC and its substrate TRH was reflected by a co-induction of both proteins in reactive astrocytes in proximity of Aβ deposits. Also, in primary mouse astrocytes a co-induction of QC and TRH was demonstrated upon Aβ stimulation.
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Affiliation(s)
- Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany
| | | | - Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany
| | - Astrid Kehlen
- Institute for Medical Microbiology, Martin-Luther-University Halle-Wittenberg, Germany
| | - Stephan Schilling
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT Halle, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT Halle, Germany.
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Germany.
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14
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Höfling C, Indrischek H, Höpcke T, Waniek A, Cynis H, Koch B, Schilling S, Morawski M, Demuth HU, Roßner S, Hartlage-Rübsamen M. Mouse strain and brain region-specific expression of the glutaminyl cyclases QC and isoQC. Int J Dev Neurosci 2014; 36:64-73. [PMID: 24886834 DOI: 10.1016/j.ijdevneu.2014.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 05/20/2014] [Indexed: 11/25/2022] Open
Abstract
Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) from glutamine precursors at the N-terminus of a number of peptide hormones, neuropeptides and chemokines. This post-translational modification stabilizes these peptides, protects them from proteolytical degradation or is important for their biological activity. However, QC is also involved in a pathogenic pGlu modification of peptides accumulating in protein aggregation disorders such as Alzheimer's disease and familial Danish and familial British dementia. Its isoenzyme (isoQC) was shown to contribute to aspects of inflammation by pGlu-modifying and thereby stabilizing the monocyte chemoattractant protein CCL2. For the generation of respective animal models and for pharmacological treatment studies the characterization of the mouse strain and brain region-specific expression of QC and isoQC is indispensible. In order to address this issue, we used enzymatic activity assays and specific antibodies to detect both QC variants by immunohistochemistry in nine different mouse strains. Comparing different brain regions, the highest enzymatic QC/isoQC activity was detected in ventral brain, followed by cortex and hippocampus. Immunohistochemical stainings revealed that QC/isoQC activity in cortex mostly arises from isoQC expression. For most brain regions, the highest QC/isoQC activity was detected in C3H and FVB mice, whereas low QC/isoQC activity was present in CD1, SJL and C57 mice. Quantification of QC- and isoQC-immunoreactive cells by unbiased stereology revealed a higher abundance of isoQC- than of QC-immunoreactive neurons in Edinger-Westphal nucleus and in substantia nigra. In the locus coeruleus, however, there were comparable densities of QC- and of isoQC-immunoreactive neurons. These observations are of considerable importance with regard to the selection of appropriate mouse strains for the study of QC/isoQC relevance in mouse models of neurodegeneration and neuroinflammation and for the testing of therapeutical interventions in these models.
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Affiliation(s)
- Corinna Höfling
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Henrike Indrischek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Theodor Höpcke
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Holger Cynis
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Birgit Koch
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Stephan Schilling
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Hans-Ulrich Demuth
- Fraunhofer Institute of Cell Therapy and Immunology IZI Leipzig, Department of Drug Design and Target Validation MWT, Halle, Germany.
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany.
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15
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Frost JL, Le KX, Cynis H, Ekpo E, Kleinschmidt M, Palmour RM, Ervin FR, Snigdha S, Cotman CW, Saido TC, Vassar RJ, St George-Hyslop P, Ikezu T, Schilling S, Demuth HU, Lemere CA. Pyroglutamate-3 amyloid-β deposition in the brains of humans, non-human primates, canines, and Alzheimer disease-like transgenic mouse models. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:369-81. [PMID: 23747948 DOI: 10.1016/j.ajpath.2013.05.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 01/27/2023]
Abstract
Amyloid-β (Aβ) peptides, starting with pyroglutamate at the third residue (pyroGlu-3 Aβ), are a major species deposited in the brain of Alzheimer disease (AD) patients. Recent studies suggest that this isoform shows higher toxicity and amyloidogenecity when compared to full-length Aβ peptides. Here, we report the first comprehensive and comparative IHC evaluation of pyroGlu-3 Aβ deposition in humans and animal models. PyroGlu-3 Aβ immunoreactivity (IR) is abundant in plaques and cerebral amyloid angiopathy of AD and Down syndrome patients, colocalizing with general Aβ IR. PyroGlu-3 Aβ is further present in two nontransgenic mammalian models of cerebral amyloidosis, Caribbean vervets, and beagle canines. In addition, pyroGlu-3 Aβ deposition was analyzed in 12 different AD-like transgenic mouse models. In contrast to humans, all transgenic models showed general Aβ deposition preceding pyroGlu-3 Aβ deposition. The findings varied greatly among the mouse models concerning age of onset and cortical brain region. In summary, pyroGlu-3 Aβ is a major species of β-amyloid deposited early in diffuse and focal plaques and cerebral amyloid angiopathy in humans and nonhuman primates, whereas it is deposited later in a subset of focal and vascular amyloid in AD-like transgenic mouse models. Given the proposed decisive role of pyroGlu-3 Aβ peptides for the development of human AD pathology, this study provides insights into the usage of animal models in AD studies.
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Affiliation(s)
- Jeffrey L Frost
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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16
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β-Amyloid-aluminum complex alters cytoskeletal stability and increases ROS production in cortical neurons. Neurochem Int 2013; 62:566-74. [DOI: 10.1016/j.neuint.2013.02.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 01/31/2013] [Accepted: 02/04/2013] [Indexed: 12/15/2022]
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17
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Kehlen A, Haegele M, Menge K, Gans K, Immel UD, Hoang-Vu C, Klonisch T, Demuth HU. Role of glutaminyl cyclases in thyroid carcinomas. Endocr Relat Cancer 2013. [PMID: 23183267 DOI: 10.1530/erc-12-0053] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CCL2 is a chemokine known to recruit monocytes/macrophages to sites of inflammation. CCL2 is also associated with tumor progression in several cancer types. Recently, we showed that the N-terminus of CCL2 is modified to a pyroglutamate (pE)-residue by both glutaminyl cyclases (QC (QPCT)) and its isoenzyme (isoQC (QPCTL)). The pE-residue increases stability against N-terminal degradation by aminopeptidases. Here, we report an upregulation of QPCT expression in tissues of patients with thyroid carcinomas compared with goiter tissues, whereas QPCTL was not regulated. In thyroid carcinoma cell lines, QPCT gene expression correlates with the mRNA levels of its substrate CCL2. Both QPCT and CCL2 are regulated in a NF-κB-dependent pathway shown by stimulation with TNFa and IL1b as well as by inhibition with the IKK2 inhibitor and RNAi of p50. In the culture supernatant of thyroid carcinoma cells, equal amounts of pECCL2 and total CCL2 were detected by two ELISAs discriminating between total CCL2 and pECCL2, concluding that all CCL2 is secreted as pECCL2. Activation of the CCL2/CCR2 pathway by recombinant CCL2 increased tumor cell migration of FTC238 cells in scratch assays as well as thyroid carcinoma cell-derived CCL2-induced migration of monocytic THP1 cells. Suppression of CCL2 signaling by CCR2 antagonist, IKK2 inhibitor, and QPCT RNAi reduced FTC238 cell growth measured by WST8 proliferation assays. Our results reveal new evidence for a novel role of QC in thyroid carcinomas and provide an intriguing rationale for the use of QC inhibitors as a means of blocking pECCL2 formation and preventing thyroid cancer metastasis.
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Affiliation(s)
- Astrid Kehlen
- Probiodrug AG, Weinbergweg 22, Halle, Saale, Germany.
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18
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Koch B, Kolenko P, Buchholz M, Carrillo DR, Parthier C, Wermann M, Rahfeld JU, Reuter G, Schilling S, Stubbs MT, Demuth HU. Crystal structures of glutaminyl cyclases (QCs) from Drosophila melanogaster reveal active site conservation between insect and mammalian QCs. Biochemistry 2012; 51:7383-92. [PMID: 22897232 DOI: 10.1021/bi300687g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glutaminyl cyclases (QCs), which catalyze the formation of pyroglutamic acid (pGlu) at the N-terminus of a variety of peptides and proteins, have attracted particular attention for their potential role in Alzheimer's disease. In a transgenic Drosophila melanogaster (Dm) fruit fly model, oral application of the potent competitive QC inhibitor PBD150 was shown to reduce the burden of pGlu-modified Aβ. In contrast to mammals such as humans and rodents, there are at least three DmQC species, one of which (isoDromeQC) is localized to mitochondria, whereas DromeQC and an isoDromeQC splice variant possess signal peptides for secretion. Here we present the recombinant expression, characterization, and crystal structure determination of mature DromeQC and isoDromeQC, revealing an overall fold similar to that of mammalian QCs. In the case of isoDromeQC, the putative extended substrate binding site might be affected by the proximity of the N-terminal residues. PBD150 inhibition of DromeQC is roughly 1 order of magnitude weaker than that of the human and murine QCs. The inhibitor binds to isoDromeQC in a fashion similar to that observed for human QCs, whereas it adopts alternative binding modes in a DromeQC variant lacking the conserved cysteines near the active center and shows a disordered dimethoxyphenyl moiety in wild-type DromeQC, providing an explanation for the lower affinity. Our biophysical and structural data suggest that isoDromeQC and human QC are similar with regard to functional aspects. The two Dm enzymes represent a suitable model for further in-depth analysis of the catalytic mechanism of animal QCs, and isoDromeQC might serve as a model system for the structure-based design of potential AD therapeutics.
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Affiliation(s)
- Birgit Koch
- Probiodrug AG, Weinbergweg 22, D-06120 Halle (Saale), Germany
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19
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Jawhar S, Wirths O, Bayer TA. Pyroglutamate amyloid-β (Aβ): a hatchet man in Alzheimer disease. J Biol Chem 2011; 286:38825-32. [PMID: 21965666 DOI: 10.1074/jbc.r111.288308] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pyroglutamate-modified amyloid-β (Aβ(pE3)) peptides are gaining considerable attention as potential key participants in the pathology of Alzheimer disease (AD) due to their abundance in AD brain, high aggregation propensity, stability, and cellular toxicity. Transgenic mice that produce high levels of Aβ(pE3-42) show severe neuron loss. Recent in vitro and in vivo experiments have proven that the enzyme glutaminyl cyclase catalyzes the formation of Aβ(pE3). In this minireview, we summarize the current knowledge on Aβ(pE3), discussing its discovery, biochemical properties, molecular events determining formation, prevalence in the brains of AD patients, Alzheimer mouse models, and potential as a target for therapy and as a diagnostic marker.
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Affiliation(s)
- Sadim Jawhar
- Department of Molecular Psychiatry, Georg-August-University Göttingen, University Medicine Göttingen, 37075 Göttingen, Germany
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20
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Cynis H, Hoffmann T, Friedrich D, Kehlen A, Gans K, Kleinschmidt M, Rahfeld JU, Wolf R, Wermann M, Stephan A, Haegele M, Sedlmeier R, Graubner S, Jagla W, Müller A, Eichentopf R, Heiser U, Seifert F, Quax PHA, de Vries MR, Hesse I, Trautwein D, Wollert U, Berg S, Freyse EJ, Schilling S, Demuth HU. The isoenzyme of glutaminyl cyclase is an important regulator of monocyte infiltration under inflammatory conditions. EMBO Mol Med 2011; 3:545-58. [PMID: 21774078 PMCID: PMC3377097 DOI: 10.1002/emmm.201100158] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/01/2011] [Accepted: 06/08/2011] [Indexed: 02/06/2023] Open
Abstract
Acute and chronic inflammatory disorders are characterized by detrimental cytokine and chemokine expression. Frequently, the chemotactic activity of cytokines depends on a modified N-terminus of the polypeptide. Among those, the N-terminus of monocyte chemoattractant protein 1 (CCL2 and MCP-1) is modified to a pyroglutamate (pE-) residue protecting against degradation in vivo. Here, we show that the N-terminal pE-formation depends on glutaminyl cyclase activity. The pE-residue increases stability against N-terminal degradation by aminopeptidases and improves receptor activation and signal transduction in vitro. Genetic ablation of the glutaminyl cyclase iso-enzymes QC (QPCT) or isoQC (QPCTL) revealed a major role of isoQC for pE1-CCL2 formation and monocyte infiltration. Consistently, administration of QC-inhibitors in inflammatory models, such as thioglycollate-induced peritonitis reduced monocyte infiltration. The pharmacologic efficacy of QC/isoQC-inhibition was assessed in accelerated atherosclerosis in ApoE3*Leiden mice, showing attenuated atherosclerotic pathology following chronic oral treatment. Current strategies targeting CCL2 are mainly based on antibodies or spiegelmers. The application of small, orally available inhibitors of glutaminyl cyclases represents an alternative therapeutic strategy to treat CCL2-driven disorders such as atherosclerosis/restenosis and fibrosis.
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21
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Hartlage-Rübsamen M, Morawski M, Waniek A, Jäger C, Zeitschel U, Koch B, Cynis H, Schilling S, Schliebs R, Demuth HU, Roßner S. Glutaminyl cyclase contributes to the formation of focal and diffuse pyroglutamate (pGlu)-Aβ deposits in hippocampus via distinct cellular mechanisms. Acta Neuropathol 2011; 121:705-19. [PMID: 21301857 PMCID: PMC3098988 DOI: 10.1007/s00401-011-0806-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 01/27/2011] [Accepted: 01/27/2011] [Indexed: 12/18/2022]
Abstract
In the hippocampal formation of Alzheimer’s disease (AD) patients, both focal and diffuse deposits of Aβ peptides appear in a subregion- and layer-specific manner. Recently, pyroglutamate (pGlu or pE)-modified Aβ peptides were identified as a highly pathogenic and seeding Aβ peptide species. Since the pE modification is catalyzed by glutaminyl cyclase (QC) this enzyme emerged as a novel pharmacological target for AD therapy. Here, we reveal the role of QC in the formation of different types of hippocampal pE-Aβ aggregates. First, we demonstrate that both, focal and diffuse pE-Aβ deposits are present in defined layers of the AD hippocampus. While the focal type of pE-Aβ aggregates was found to be associated with the somata of QC-expressing interneurons, the diffuse type was not. To address this discrepancy, the hippocampus of amyloid precursor protein transgenic mice was analysed. Similar to observations made in AD, focal (i.e. core-containing) pE-Aβ deposits originating from QC-positive neurons and diffuse pE-Aβ deposits not associated with QC were detected in Tg2576 mouse hippocampus. The hippocampal layers harbouring diffuse pE-Aβ deposits receive multiple afferents from QC-rich neuronal populations of the entorhinal cortex and locus coeruleus. This might point towards a mechanism in which pE-Aβ and/or QC are being released from projection neurons at hippocampal synapses. Indeed, there are a number of reports demonstrating the reduction of diffuse, but not of focal, Aβ deposits in hippocampus after deafferentation experiments. Moreover, we demonstrate in neurons by live cell imaging and by enzymatic activity assays that QC is secreted in a constitutive and regulated manner. Thus, it is concluded that hippocampal pE-Aβ plaques may develop through at least two different mechanisms: intracellularly at sites of somatic QC activity as well as extracellularly through seeding at terminal fields of QC expressing projection neurons.
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Affiliation(s)
- Maike Hartlage-Rübsamen
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Markus Morawski
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Alexander Waniek
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Carsten Jäger
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Ulrike Zeitschel
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Birgit Koch
- Probiodrug AG, Biocenter, Weinbergweg 22, 06120 Halle/Saale, Germany
| | - Holger Cynis
- Probiodrug AG, Biocenter, Weinbergweg 22, 06120 Halle/Saale, Germany
| | - Stephan Schilling
- Probiodrug AG, Biocenter, Weinbergweg 22, 06120 Halle/Saale, Germany
| | - Reinhard Schliebs
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | - Hans-Ulrich Demuth
- Probiodrug AG, Biocenter, Weinbergweg 22, 06120 Halle/Saale, Germany
- Ingenium Pharmaceuticals GmbH, Fraunhoferstr. 13, 82152 Martinsried/Munich, Germany
| | - Steffen Roßner
- Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
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22
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Schilling S, Kohlmann S, Bäuscher C, Sedlmeier R, Koch B, Eichentopf R, Becker A, Cynis H, Hoffmann T, Berg S, Freyse EJ, von Hörsten S, Rossner S, Graubner S, Demuth HU. Glutaminyl cyclase knock-out mice exhibit slight hypothyroidism but no hypogonadism: implications for enzyme function and drug development. J Biol Chem 2011; 286:14199-208. [PMID: 21330373 PMCID: PMC3077621 DOI: 10.1074/jbc.m111.229385] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Indexed: 11/06/2022] Open
Abstract
Glutaminyl cyclases (QCs) catalyze the formation of pyroglutamate (pGlu) residues at the N terminus of peptides and proteins. Hypothalamic pGlu hormones, such as thyrotropin-releasing hormone and gonadotropin-releasing hormone are essential for regulation of metabolism and fertility in the hypothalamic pituitary thyroid and gonadal axes, respectively. Here, we analyzed the consequences of constitutive genetic QC ablation on endocrine functions and on the behavior of adult mice. Adult homozygous QC knock-out mice are fertile and behave indistinguishably from wild type mice in tests of motor function, cognition, general activity, and ingestion behavior. The QC knock-out results in a dramatic drop of enzyme activity in the brain, especially in hypothalamus and in plasma. Other peripheral organs like liver and spleen still contain QC activity, which is most likely caused by its homolog isoQC. The serum gonadotropin-releasing hormone, TSH, and testosterone concentrations were not changed by QC depletion. The serum thyroxine was decreased by 24% in homozygous QC knock-out animals, suggesting a mild hypothyroidism. QC knock-out mice were indistinguishable from wild type with regard to blood glucose and glucose tolerance, thus differing from reports of thyrotropin-releasing hormone knock-out mice significantly. The results suggest a significant formation of the hypothalamic pGlu hormones by alternative mechanisms, like spontaneous cyclization or conversion by isoQC. The different effects of QC depletion on the hypothalamic pituitary thyroid and gonadal axes might indicate slightly different modes of substrate conversion of both enzymes. The absence of significant abnormalities in QC knock-out mice suggests the presence of a therapeutic window for suppression of QC activity in current drug development.
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Affiliation(s)
| | | | | | | | - Birgit Koch
- From Probiodrug AG, Weinbergweg 22, 06120 Halle/Saale
| | | | | | - Holger Cynis
- From Probiodrug AG, Weinbergweg 22, 06120 Halle/Saale
| | | | - Sabine Berg
- the Institute of Diabetes, “Gerhardt Katsch,” 17495 Karlsburg
| | | | - Stephan von Hörsten
- the University of Erlangen-Nürnberg, Franz-Penzoldt-Center, Palmsanlage 5, 91054 Erlangen, and
| | - Steffen Rossner
- the Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany
| | | | - Hans-Ulrich Demuth
- From Probiodrug AG, Weinbergweg 22, 06120 Halle/Saale
- Ingenium GmbH, Fraunhoferstrasse 13, 82152 Martinsried
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23
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Jawhar S, Wirths O, Schilling S, Graubner S, Demuth HU, Bayer TA. Overexpression of glutaminyl cyclase, the enzyme responsible for pyroglutamate A{beta} formation, induces behavioral deficits, and glutaminyl cyclase knock-out rescues the behavioral phenotype in 5XFAD mice. J Biol Chem 2011; 286:4454-60. [PMID: 21148560 PMCID: PMC3039372 DOI: 10.1074/jbc.m110.185819] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 12/09/2010] [Indexed: 11/06/2022] Open
Abstract
Pyroglutamate-modified Aβ (AβpE3-42) peptides are gaining considerable attention as potential key players in the pathology of Alzheimer disease (AD) due to their abundance in AD brain, high aggregation propensity, stability, and cellular toxicity. Overexpressing AβpE3-42 induced a severe neuron loss and neurological phenotype in TBA2 mice. In vitro and in vivo experiments have recently proven that the enzyme glutaminyl cyclase (QC) catalyzes the formation of AβpE3-42. The aim of the present work was to analyze the role of QC in an AD mouse model with abundant AβpE3-42 formation. 5XFAD mice were crossed with transgenic mice expressing human QC (hQC) under the control of the Thy1 promoter. 5XFAD/hQC bigenic mice showed significant elevation in TBS, SDS, and formic acid-soluble AβpE3-42 peptides and aggregation in plaques. In 6-month-old 5XFAD/hQC mice, a significant motor and working memory impairment developed compared with 5XFAD. The contribution of endogenous QC was studied by generating 5XFAD/QC-KO mice (mouse QC knock-out). 5XFAD/QC-KO mice showed a significant rescue of the wild-type mice behavioral phenotype, demonstrating the important contribution of endogenous mouse QC and transgenic overexpressed QC. These data clearly demonstrate that QC is crucial for modulating AβpE3-42 levels in vivo and prove on a genetic base the concept that reduction of QC activity is a promising new therapeutic approach for AD.
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Affiliation(s)
- Sadim Jawhar
- From the Department of Molecular Psychiatry and Alzheimer Ph.D. Graduate School, University Medicine Goettingen, 37075 Goettingen, Germany
| | - Oliver Wirths
- From the Department of Molecular Psychiatry and Alzheimer Ph.D. Graduate School, University Medicine Goettingen, 37075 Goettingen, Germany
| | | | | | | | - Thomas A. Bayer
- From the Department of Molecular Psychiatry and Alzheimer Ph.D. Graduate School, University Medicine Goettingen, 37075 Goettingen, Germany
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Morawski M, Hartlage-Rübsamen M, Jäger C, Waniek A, Schilling S, Schwab C, McGeer PL, Arendt T, Demuth HU, Roßner S. Distinct glutaminyl cyclase expression in Edinger-Westphal nucleus, locus coeruleus and nucleus basalis Meynert contributes to pGlu-Abeta pathology in Alzheimer's disease. Acta Neuropathol 2010; 120:195-207. [PMID: 20383514 PMCID: PMC2892616 DOI: 10.1007/s00401-010-0685-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 03/31/2010] [Accepted: 04/02/2010] [Indexed: 12/11/2022]
Abstract
Glutaminyl cyclase (QC) was discovered recently as the enzyme catalyzing the pyroglutamate (pGlu or pE) modification of N-terminally truncated Alzheimer’s disease (AD) Aβ peptides in vivo. This modification confers resistance to proteolysis, rapid aggregation and neurotoxicity and can be prevented by QC inhibitors in vitro and in vivo, as shown in transgenic animal models. However, in mouse brain QC is only expressed by a relatively low proportion of neurons in most neocortical and hippocampal subregions. Here, we demonstrate that QC is highly abundant in subcortical brain nuclei severely affected in AD. In particular, QC is expressed by virtually all urocortin-1-positive, but not by cholinergic neurons of the Edinger–Westphal nucleus, by noradrenergic locus coeruleus and by cholinergic nucleus basalis magnocellularis neurons in mouse brain. In human brain, QC is expressed by both, urocortin-1 and cholinergic Edinger–Westphal neurons and by locus coeruleus and nucleus basalis Meynert neurons. In brains from AD patients, these neuronal populations displayed intraneuronal pE-Aβ immunoreactivity and morphological signs of degeneration as well as extracellular pE-Aβ deposits. Adjacent AD brain structures lacking QC expression and brains from control subjects were devoid of such aggregates. This is the first demonstration of QC expression and pE-Aβ formation in subcortical brain regions affected in AD. Our results may explain the high vulnerability of defined subcortical neuronal populations and their central target areas in AD as a consequence of QC expression and pE-Aβ formation.
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