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Hoffmann T, Meyer A, Heiser U, Kurat S, Böhme L, Kleinschmidt M, Bühring KU, Hutter-Paier B, Farcher M, Demuth HU, Lues I, Schilling S. Glutaminyl Cyclase Inhibitor PQ912 Improves Cognition in Mouse Models of Alzheimer's Disease-Studies on Relation to Effective Target Occupancy. J Pharmacol Exp Ther 2017; 362:119-130. [PMID: 28446518 DOI: 10.1124/jpet.117.240614] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/24/2017] [Indexed: 12/22/2022] Open
Abstract
Numerous studies suggest that the majority of amyloid-β (Aβ) peptides deposited in Alzheimer's disease (AD) are truncated and post-translationally modified at the N terminus. Among these modified species, pyroglutamyl-Aβ (pE-Aβ, including N3pE-Aβ40/42 and N11pE-Aβ40/42) has been identified as particularly neurotoxic. The N-terminal modification renders the peptide hydrophobic, accelerates formation of oligomers, and reduces degradation by peptidases, leading ultimately to the accumulation of the peptide and progression of AD. It has been shown that the formation of pyroglutamyl residues is catalyzed by glutaminyl cyclase (QC). Here, we present data about the pharmacological in vitro and in vivo efficacy of the QC inhibitor (S)-1-(1H-benzo[d]imidazol-5-yl)-5-(4-propoxyphenyl)imidazolidin-2-one (PQ912), the first-in-class compound that is in clinical development. PQ912 inhibits human, rat, and mouse QC activity, with Ki values ranging between 20 and 65 nM. Chronic oral treatment of hAPPSLxhQC double-transgenic mice with approximately 200 mg/kg/day via chow shows a significant reduction of pE-Aβ levels and concomitant improvement of spatial learning in a Morris water maze test paradigm. This dose results in a brain and cerebrospinal fluid concentration of PQ912 which relates to a QC target occupancy of about 60%. Thus, we conclude that >50% inhibition of QC activity in the brain leads to robust treatment effects. Secondary pharmacology experiments in mice indicate a fairly large potency difference for Aβ cyclization compared with cyclization of physiologic substrates, suggesting a robust therapeutic window in humans. This information constitutes an important translational guidance for predicting the therapeutic dose range in clinical studies with PQ912.
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Affiliation(s)
- Torsten Hoffmann
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Antje Meyer
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Ulrich Heiser
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Stephan Kurat
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Livia Böhme
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Martin Kleinschmidt
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Karl-Ulrich Bühring
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Birgit Hutter-Paier
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Martina Farcher
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Hans-Ulrich Demuth
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Inge Lues
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
| | - Stephan Schilling
- Probiodrug AG, Halle, Germany (T.H., A.M., U.H., L.B., K.-U.B., I.L.); QPS Austria, Grambach, Austria (S.K., B.H.-P., M.F.); and Fraunhofer Institute for Cell Therapy and Immunology, Department for Drug Design and Target Validation, Halle, Germany (M.K., H.-U.D., S.S.)
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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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