1
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Gougeard N, Sancho-Vaello E, Fernández-Murga ML, Martínez-Sinisterra B, Loukili-Hassani B, Häberle J, Marco-Marín C, Rubio V. Use of pure recombinant human enzymes to assess the disease-causing potential of missense mutations in urea cycle disorders, applied to N-acetylglutamate synthase deficiency. J Inherit Metab Dis 2024. [PMID: 38740568 DOI: 10.1002/jimd.12747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/16/2024]
Abstract
N-acetylglutamate synthase (NAGS) makes acetylglutamate, the essential activator of the first, regulatory enzyme of the urea cycle, carbamoyl phosphate synthetase 1 (CPS1). NAGS deficiency (NAGSD) and CPS1 deficiency (CPS1D) present identical phenotypes. However, they must be distinguished, because NAGSD is cured by substitutive therapy with the N-acetyl-L-glutamate analogue N-carbamyl-L-glutamate, while curative therapy of CPS1D requires liver transplantation. Since their differentiation is done genetically, it is important to ascertain the disease-causing potential of CPS1 and NAGS genetic variants. With this goal, we previously carried out site-directed mutagenesis studies with pure recombinant human CPS1. We could not do the same with human NAGS (HuNAGS) because of enzyme instability, leading to our prior utilization of a bacterial NAGS as an imperfect surrogate of HuNAGS. We now use genuine HuNAGS, stabilized as a chimera of its conserved domain (cHuNAGS) with the maltose binding protein (MBP), and produced in Escherichia coli. MBP-cHuNAGS linker cleavage allowed assessment of the enzymatic properties and thermal stability of cHuNAGS, either wild-type or hosting each one of 23 nonsynonymous single-base changes found in NAGSD patients. For all but one change, disease causation was accounted by the enzymatic alterations identified, including, depending on the variant, loss of arginine activation, increased Km Glutamate, active site inactivation, decreased thermal stability, and protein misfolding. Our present approach outperforms experimental in vitro use of bacterial NAGS or in silico utilization of prediction servers (including AlphaMissense), illustrating with HuNAGS the value for UCDs of using recombinant enzymes for assessing disease-causation and molecular pathogenesis, and for therapeutic guidance.
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Affiliation(s)
- Nadine Gougeard
- Instituto de Biomedicina de Valencia, IBV-CSIC, Valencia, Spain
- Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER-ISCIII) at the IBV-CSIC, Valencia, Spain
| | | | | | | | | | - Johannes Häberle
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Clara Marco-Marín
- Instituto de Biomedicina de Valencia, IBV-CSIC, Valencia, Spain
- Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER-ISCIII) at the IBV-CSIC, Valencia, Spain
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia, IBV-CSIC, Valencia, Spain
- Group 739, Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER-ISCIII) at the IBV-CSIC, Valencia, Spain
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2
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Soria LR, Makris G, D'Alessio AM, De Angelis A, Boffa I, Pravata VM, Rüfenacht V, Attanasio S, Nusco E, Arena P, Ferenbach AT, Paris D, Cuomo P, Motta A, Nitzahn M, Lipshutz GS, Martínez-Pizarro A, Richard E, Desviat LR, Häberle J, van Aalten DMF, Brunetti-Pierri N. O-GlcNAcylation enhances CPS1 catalytic efficiency for ammonia and promotes ureagenesis. Nat Commun 2022; 13:5212. [PMID: 36064721 PMCID: PMC9445089 DOI: 10.1038/s41467-022-32904-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 08/24/2022] [Indexed: 11/09/2022] Open
Abstract
Life-threatening hyperammonemia occurs in both inherited and acquired liver diseases affecting ureagenesis, the main pathway for detoxification of neurotoxic ammonia in mammals. Protein O-GlcNAcylation is a reversible and nutrient-sensitive post-translational modification using as substrate UDP-GlcNAc, the end-product of hexosamine biosynthesis pathway. Here we show that increased liver UDP-GlcNAc during hyperammonemia increases protein O-GlcNAcylation and enhances ureagenesis. Mechanistically, O-GlcNAcylation on specific threonine residues increased the catalytic efficiency for ammonia of carbamoyl phosphate synthetase 1 (CPS1), the rate-limiting enzyme in ureagenesis. Pharmacological inhibition of O-GlcNAcase, the enzyme removing O-GlcNAc from proteins, resulted in clinically relevant reductions of systemic ammonia in both genetic (hypomorphic mouse model of propionic acidemia) and acquired (thioacetamide-induced acute liver failure) mouse models of liver diseases. In conclusion, by fine-tuned control of ammonia entry into ureagenesis, hepatic O-GlcNAcylation of CPS1 increases ammonia detoxification and is a novel target for therapy of hyperammonemia in both genetic and acquired diseases.
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Affiliation(s)
- Leandro R Soria
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.
| | - Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | | | | | - Iolanda Boffa
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | | | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | | | - Edoardo Nusco
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Paola Arena
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | | | - Debora Paris
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - Paola Cuomo
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - Andrea Motta
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Gerald S Lipshutz
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Ainhoa Martínez-Pizarro
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | | | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.
- Department of Translational Medicine, Federico II University, Naples, Italy.
- Scuola Superiore Meridionale (SSM, School of Advanced Studies), Genomics and Experimental Medicine Program, University of Naples Federico II, Naples, Italy.
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3
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Ali ES, Lipońska A, O'Hara BP, Amici DR, Torno MD, Gao P, Asara JM, Yap MNF, Mendillo ML, Ben-Sahra I. The mTORC1-SLC4A7 axis stimulates bicarbonate import to enhance de novo nucleotide synthesis. Mol Cell 2022; 82:3284-3298.e7. [PMID: 35772404 PMCID: PMC9444906 DOI: 10.1016/j.molcel.2022.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/15/2022] [Accepted: 06/07/2022] [Indexed: 12/12/2022]
Abstract
Bicarbonate (HCO3-) ions maintain pH homeostasis in eukaryotic cells and serve as a carbonyl donor to support cellular metabolism. However, whether the abundance of HCO3- is regulated or harnessed to promote cell growth is unknown. The mechanistic target of rapamycin complex 1 (mTORC1) adjusts cellular metabolism to support biomass production and cell growth. We find that mTORC1 stimulates the intracellular transport of HCO3- to promote nucleotide synthesis through the selective translational regulation of the sodium bicarbonate cotransporter SLC4A7. Downstream of mTORC1, SLC4A7 mRNA translation required the S6K-dependent phosphorylation of the translation factor eIF4B. In mTORC1-driven cells, loss of SLC4A7 resulted in reduced cell and tumor growth and decreased flux through de novo purine and pyrimidine synthesis in human cells and tumors without altering the intracellular pH. Thus, mTORC1 signaling, through the control of SLC4A7 expression, harnesses environmental bicarbonate to promote anabolic metabolism, cell biomass, and growth.
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Affiliation(s)
- Eunus S Ali
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Anna Lipońska
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Brendan P O'Hara
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - David R Amici
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Michael D Torno
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Peng Gao
- Metabolomics Core Facility, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - John M Asara
- Mass Spectrometry Core, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Mee-Ngan F Yap
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Marc L Mendillo
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
| | - Issam Ben-Sahra
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA.
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4
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Haskins N, Bhuvanendran S, Anselmi C, Gams A, Kanholm T, Kocher KM, LoTempio J, Krohmaly KI, Sohai D, Stearrett N, Bonner E, Tuchman M, Morizono H, Jaiswal JK, Caldovic L. Mitochondrial Enzymes of the Urea Cycle Cluster at the Inner Mitochondrial Membrane. Front Physiol 2021; 11:542950. [PMID: 33551825 PMCID: PMC7860981 DOI: 10.3389/fphys.2020.542950] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 12/09/2020] [Indexed: 01/13/2023] Open
Abstract
Mitochondrial enzymes involved in energy transformation are organized into multiprotein complexes that channel the reaction intermediates for efficient ATP production. Three of the mammalian urea cycle enzymes: N-acetylglutamate synthase (NAGS), carbamylphosphate synthetase 1 (CPS1), and ornithine transcarbamylase (OTC) reside in the mitochondria. Urea cycle is required to convert ammonia into urea and protect the brain from ammonia toxicity. Urea cycle intermediates are tightly channeled in and out of mitochondria, indicating that efficient activity of these enzymes relies upon their coordinated interaction with each other, perhaps in a cluster. This view is supported by mutations in surface residues of the urea cycle proteins that impair ureagenesis in the patients, but do not affect protein stability or catalytic activity. We find the NAGS, CPS1, and OTC proteins in liver mitochondria can associate with the inner mitochondrial membrane (IMM) and can be co-immunoprecipitated. Our in-silico analysis of vertebrate NAGS proteins, the least abundant of the urea cycle enzymes, identified a protein-protein interaction region present only in the mammalian NAGS protein—“variable segment,” which mediates the interaction of NAGS with CPS1. Use of super resolution microscopy showed that NAGS, CPS1 and OTC are organized into clusters in the hepatocyte mitochondria. These results indicate that mitochondrial urea cycle proteins cluster, instead of functioning either independently or in a rigid multienzyme complex.
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Affiliation(s)
- Nantaporn Haskins
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States
| | - Shivaprasad Bhuvanendran
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States
| | - Claudio Anselmi
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States.,Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
| | - Anna Gams
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, The George Washington University, Washington, DC, United States
| | - Tomas Kanholm
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Kristen M Kocher
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Jonathan LoTempio
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Kylie I Krohmaly
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Danielle Sohai
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Nathaniel Stearrett
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States.,Computational Biology Institute, Milken Institute School of Public Health, The George Washington University, Washington, DC, United States
| | - Erin Bonner
- School of Medicine and Health Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, United States
| | - Mendel Tuchman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States
| | - Hiroki Morizono
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States.,Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
| | - Jyoti K Jaiswal
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States.,Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States.,Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, United States
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5
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Zabulica M, Srinivasan RC, Akcakaya P, Allegri G, Bestas B, Firth M, Hammarstedt C, Jakobsson T, Jakobsson T, Ellis E, Jorns C, Makris G, Scherer T, Rimann N, van Zuydam NR, Gramignoli R, Forslöw A, Engberg S, Maresca M, Rooyackers O, Thöny B, Häberle J, Rosen B, Strom SC. Correction of a urea cycle defect after ex vivo gene editing of human hepatocytes. Mol Ther 2021; 29:1903-1917. [PMID: 33484963 PMCID: PMC8116578 DOI: 10.1016/j.ymthe.2021.01.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 11/17/2020] [Accepted: 01/12/2021] [Indexed: 12/25/2022] Open
Abstract
Ornithine transcarbamylase deficiency (OTCD) is a monogenic disease of ammonia metabolism in hepatocytes. Severe disease is frequently treated by orthotopic liver transplantation. An attractive approach is the correction of a patient’s own cells to regenerate the liver with gene-repaired hepatocytes. This study investigates the efficacy and safety of ex vivo correction of primary human hepatocytes. Hepatocytes isolated from an OTCD patient were genetically corrected ex vivo, through the deletion of a mutant intronic splicing site achieving editing efficiencies >60% and the restoration of the urea cycle in vitro. The corrected hepatocytes were transplanted into the liver of FRGN mice and repopulated to high levels (>80%). Animals transplanted and liver repopulated with genetically edited patient hepatocytes displayed normal ammonia, enhanced clearance of an ammonia challenge and OTC enzyme activity, as well as lower urinary orotic acid when compared to mice repopulated with unedited patient hepatocytes. Gene expression was shown to be similar between mice transplanted with unedited or edited patient hepatocytes. Finally, a genome-wide screening by performing CIRCLE-seq and deep sequencing of >70 potential off-targets revealed no unspecific editing. Overall analysis of disease phenotype, gene expression, and possible off-target editing indicated that the gene editing of a severe genetic liver disease was safe and effective.
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Affiliation(s)
- Mihaela Zabulica
- Department of Laboratory Medicine, Karolinska Institutet, 141 52 Huddinge, Sweden
| | | | - Pinar Akcakaya
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Gabriella Allegri
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Burcu Bestas
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Mike Firth
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Cambridge, UK
| | | | - Tomas Jakobsson
- Department of Laboratory Medicine, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Towe Jakobsson
- Department of Clinical Sciences Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Ewa Ellis
- Department of Clinical Sciences Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Carl Jorns
- Department of Clinical Sciences Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Tanja Scherer
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Nicole Rimann
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Natalie R van Zuydam
- Department of Quantitative Biology, Discovery Sciences, R&D BioPharmaceuticals, AstraZeneca, Gothenburg, Sweden
| | - Roberto Gramignoli
- Department of Laboratory Medicine, Karolinska Institutet, 141 52 Huddinge, Sweden
| | - Anna Forslöw
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Susanna Engberg
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Marcello Maresca
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Gothenburg, Sweden
| | - Olav Rooyackers
- Department of Clinical Sciences Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Beat Thöny
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zürich, Switzerland
| | - Barry Rosen
- Discovery Sciences, BioPharmaceuticals R&D Unit, AstraZeneca, Cambridge, UK
| | - Stephen C Strom
- Department of Laboratory Medicine, Karolinska Institutet, 141 52 Huddinge, Sweden.
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6
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Makris G, Lauber M, Rüfenacht V, Gemperle C, Diez-Fernandez C, Caldovic L, Froese DS, Häberle J. Clinical and structural insights into potential dominant negative triggers of proximal urea cycle disorders. Biochimie 2020; 183:89-99. [PMID: 33309754 DOI: 10.1016/j.biochi.2020.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 12/31/2022]
Abstract
Despite biochemical and genetic testing being the golden standards for identification of proximal urea cycle disorders (UCDs), genotype-phenotype correlations are often unclear. Co-occurring partial defects affecting more than one gene have not been demonstrated so far in proximal UCDs. Here, we analyzed the mutational spectrum of 557 suspected proximal UCD individuals. We probed oligomerizing forms of NAGS, CPS1 and OTC, and evaluated the surface exposure of residues mutated in heterozygously affected individuals. BN-PAGE and gel-filtration chromatography were employed to discover protein-protein interactions within recombinant enzymes. From a total of 281 confirmed patients, only 15 were identified as "heterozygous-only" candidates (i.e. single defective allele). Within these cases, the only missense variants to potentially qualify as dominant negative triggers were CPS1 p.Gly401Arg and NAGS p.Thr181Ala and p.Tyr512Cys, as assessed by residue oligomerization capacity and surface exposure. However, all three candidates seem to participate in critical intramolecular functions, thus, unlikely to facilitate protein-protein interactions. This interpretation is further supported by BN-PAGE and gel-filtration analyses revealing no multiprotein proximal urea cycle complex formation. Collectively, genetic analysis, structural considerations and in vitro experiments point against a prominent role of dominant negative effects in human proximal UCDs.
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Affiliation(s)
- Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Matthias Lauber
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Corinne Gemperle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Carmen Diez-Fernandez
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland; Nextech Invest, Bahnhofstrasse 18, 8001, Zurich, Switzerland
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Hospital, Washington, DC, USA
| | - D Sean Froese
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
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7
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Nitzahn M, Lipshutz GS. CPS1: Looking at an ancient enzyme in a modern light. Mol Genet Metab 2020; 131:289-298. [PMID: 33317798 PMCID: PMC7738762 DOI: 10.1016/j.ymgme.2020.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 02/06/2023]
Abstract
The mammalian urea cycle (UC) is responsible for siphoning catabolic waste nitrogen into urea for excretion. Disruptions of the functions of any of the enzymes or transporters lead to elevated ammonia and neurological injury. Carbamoyl phosphate synthetase 1 (CPS1) is the first and rate-limiting UC enzyme responsible for the direct incorporation of ammonia into UC intermediates. Symptoms in CPS1 deficiency are typically the most severe of all UC disorders, and current clinical management is insufficient to prevent the associated morbidities and high mortality. With recent advances in basic and translational studies of CPS1, appreciation for this enzyme's essential role in the UC has been broadened to include systemic metabolic regulation during homeostasis and disease. Here, we review recent advances in CPS1 biology and contextualize them around the role of CPS1 in health and disease.
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Affiliation(s)
- Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gerald S Lipshutz
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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8
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Sugiyama Y, Shimura M, Ogawa-Tominaga M, Ebihara T, Kinouchi Y, Isozaki K, Matsuhashi T, Tajika M, Fushimi T, Ichimoto K, Matsunaga A, Ishida T, Mizutani K, Tsuruoka T, Murayama K. Therapeutic effect of N-carbamylglutamate in CPS1 deficiency. Mol Genet Metab Rep 2020; 24:100622. [PMID: 32670798 PMCID: PMC7347628 DOI: 10.1016/j.ymgmr.2020.100622] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/24/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022] Open
Abstract
The detoxification of ammonia to urea requires a functional hepatic urea cycle, which consists of six enzymes and two mitochondrial membrane transporters. The initial step of the urea cycle is catalyzed by carbamyl phosphate synthetase 1 (CPS1). CPS1 deficiency (CPS1D) is a rare autosomal recessive disorder. N-Carbamylglutamate (NCG), a deacylase-resistant analogue of N-acetylglutamate, can activate CPS1. We describe the therapeutic course of a patient suffering from neonatal onset CPS1D with compound heterozygosity for the c.2359C > T (p.Arg787*) and c.3559G > T (p.Val1187Phe) variants in CPS1, treated with NCG. She presented with hyperammonemia, which reached 944 μmol/L at the age of 2 days. The ammonia concentration decreased after treatment with continuous hemodiafiltration, NCG, sodium benzoate, sodium phenylbutyrate, L-arginine, vitamin cocktail (vitamin B1, vitamin B12, vitamin C, vitamin E, biotin), l-carnitine, coenzyme Q10, and parenteral nutrition. Her ammonia and glutamine levels remained low; thus, protein intake was increased to 1.2 g/kg/day. Furthermore, the amount of sodium benzoate and sodium phenylbutyrate were reduced. She remained metabolically stable and experienced no metabolic crisis following treatment with oral NCG, sodium benzoate, sodium phenylbutyrate, citrulline, vitamin cocktail, l-carnitine, and coenzyme Q10 until she underwent liver transplantation at 207 days of age. She had no neurological complications at the age of 15 months. Ammonia and glutamine levels of the patient were successfully maintained at a low level via NCG treatment with increased protein intake, which led to normal neurological development. Thus, undiagnosed urea cycle disorders should be treated rapidly with acute therapy including NCG, which should be maintained until a genetic diagnosis is reached. It is essential to prevent metabolic crises in patients with CPS1D until liver transplantation to improve their prognoses.
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Affiliation(s)
- Yohei Sugiyama
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Neonatology, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Masaru Shimura
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Minako Ogawa-Tominaga
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Tomohiro Ebihara
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Neonatology, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Yoshina Kinouchi
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Neonatology, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Keitaro Isozaki
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Neonatology, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Tetsuro Matsuhashi
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Makiko Tajika
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Takuya Fushimi
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Keiko Ichimoto
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Ayako Matsunaga
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Tomoki Ishida
- Department of Neonatology, Kimitsu Chuo Hospital, 1010 sakurai, Kisarazu city, Chiba 292-8535, Japan
| | - Kayo Mizutani
- Department of Neonatology, Kameda Medical Center, 929 Higashi-cho, Kamogawa City, Chiba 296-8602, Japan
| | - Tomoko Tsuruoka
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Neonatology, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
| | - Kei Murayama
- Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Department of Metabolism, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan
- Corresponding author at: Center for Medical Genetics, Chiba Children's Hospital, 579-1 Heta-cho, Midori-ku, Chiba city, Chiba 266-0007, Japan.
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9
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Galsgaard KD, Pedersen J, Kjeldsen SAS, Winther-Sørensen M, Stojanovska E, Vilstrup H, Ørskov C, Wewer Albrechtsen NJ, Holst JJ. Glucagon receptor signaling is not required for N-carbamoyl glutamate- and l-citrulline-induced ureagenesis in mice. Am J Physiol Gastrointest Liver Physiol 2020; 318:G912-G927. [PMID: 32174131 DOI: 10.1152/ajpgi.00294.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon regulates the hepatic amino acid metabolism and increases ureagenesis. Ureagenesis is activated by N-acetylglutamate (NAG), formed via activation of N-acetylglutamate synthase (NAGS). With the aim to identify the steps whereby glucagon both acutely and chronically regulates ureagenesis, we investigated whether glucagon receptor-mediated activation of ureagenesis is required in a situation where NAGS activity and/or NAG levels are sufficient to activate the first step of the urea cycle in vivo. Female C57BL/6JRj mice treated with a glucagon receptor antagonist (GRA), glucagon receptor knockout (Gcgr-/-) mice, and wild-type (Gcgr+/+) littermates received an intraperitoneal injection of N-carbamoyl glutamate (Car; a stable variant of NAG), l-citrulline (Cit), Car and Cit (Car + Cit), or PBS. In separate experiments, Gcgr-/- and Gcgr+/+ mice were administered N-carbamoyl glutamate and l-citrulline (wCar + wCit) in the drinking water for 8 wk. Car, Cit, and Car + Cit significantly (P < 0.05) increased plasma urea concentrations, independently of pharmacological and genetic disruption of glucagon receptor signaling (P = 0.9). Car increased blood glucose concentrations equally in GRA- and vehicle-treated mice (P = 0.9), whereas the increase upon Car + Cit was impaired in GRA-treated mice (P = 0.008). Blood glucose concentrations remained unchanged in Gcgr-/- mice upon Car (P = 0.2) and Car + Cit (P = 0.9). Eight weeks administration of wCar + wCit did not change blood glucose (P > 0.2), plasma amino acid (P > 0.4), and urea concentrations (P > 0.3) or the area of glucagon-positive cells (P > 0.3) in Gcgr-/- and Gcgr+/+ mice. Our data suggest that glucagon-mediated activation of ureagenesis is not required when NAGS activity and/or NAG levels are sufficient to activate the first step of the urea cycle.NEW & NOTEWORTHY Hepatic ureagenesis is essential in amino acid metabolism and is importantly regulated by glucagon, but the exact mechanism is unclear. With the aim to identify the steps whereby glucagon both acutely and chronically regulates ureagenesis, we here show, contrary to our hypothesis, that glucagon receptor-mediated activation of ureagenesis is not required when N-acetylglutamate synthase activity and/or N-acetylglutamate levels are sufficient to activate the first step of the urea cycle in vivo.
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Affiliation(s)
- Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Endocrinology and Nephrology, Nordsjaellands Hospital Hilleroed, Hilleroed, Denmark
| | - Sasha A S Kjeldsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elena Stojanovska
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Nitzahn M, Allegri G, Khoja S, Truong B, Makris G, Häberle J, Lipshutz GS. Split AAV-Mediated Gene Therapy Restores Ureagenesis in a Murine Model of Carbamoyl Phosphate Synthetase 1 Deficiency. Mol Ther 2020; 28:1717-1730. [PMID: 32359471 DOI: 10.1016/j.ymthe.2020.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/25/2020] [Accepted: 04/09/2020] [Indexed: 02/07/2023] Open
Abstract
The urea cycle enzyme carbamoyl phosphate synthetase 1 (CPS1) catalyzes the initial step of the urea cycle; bi-allelic mutations typically present with hyperammonemia, vomiting, ataxia, lethargy progressing into coma, and death due to brain edema if ineffectively treated. The enzyme deficiency is particularly difficult to treat; early recognition is essential to minimize injury to the brain. Even under optimal conditions, therapeutic interventions are of limited scope and efficacy, with most patients developing long-term neurologic sequelae. One significant encumberment to gene therapeutic development is the size of the CPS1 cDNA, which, at 4.5 kb, nears the packaging capacity of adeno-associated virus (AAV). Herein we developed a split AAV (sAAV)-based approach, packaging the large transgene and its regulatory cassette into two separate vectors, thereby delivering therapeutic CPS1 by a dual vector system with testing in a murine model of the disorder. Cps1-deficient mice treated with sAAVs survive long-term with markedly improved ammonia levels, diminished dysregulation of circulating amino acids, and increased hepatic CPS1 expression and activity. In response to acute ammonia challenging, sAAV-treated female mice rapidly incorporated nitrogen into urea. This study demonstrates the first proof-of-principle that sAAV-mediated therapy is a viable, potentially clinically translatable approach to CPS1 deficiency, a devastating urea cycle disorder.
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Affiliation(s)
- Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gabriella Allegri
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Brian Truong
- Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland
| | - Gerald S Lipshutz
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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11
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Del Caño-Ochoa F, Moreno-Morcillo M, Ramón-Maiques S. CAD, A Multienzymatic Protein at the Head of de Novo Pyrimidine Biosynthesis. Subcell Biochem 2020; 93:505-538. [PMID: 31939163 DOI: 10.1007/978-3-030-28151-9_17] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CAD is a 1.5 MDa particle formed by hexameric association of a 250 kDa protein that carries the enzymatic activities for the first three steps in the de novo biosynthesis of pyrimidine nucleotides: glutamine-dependent Carbamoyl phosphate synthetase, Aspartate transcarbamoylase and Dihydroorotase. This metabolic pathway is essential for cell growth and proliferation and is conserved in all living organisms. However, the fusion of the first three enzymatic activities of the pathway into a single multienzymatic protein only occurs in animals. In prokaryotes, by contrast, these activities are encoded as distinct monofunctional enzymes that function independently or by forming more or less transient complexes. Whereas the structural information about these enzymes in bacteria is abundant, the large size and instability of CAD has only allowed a fragmented characterization of its structure. Here we retrace some of the most significant efforts to decipher the architecture of CAD and to understand its catalytic and regulatory mechanisms.
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Affiliation(s)
- Francisco Del Caño-Ochoa
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Nicolas Cabrera 1, 28049, Madrid, Spain
| | - María Moreno-Morcillo
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Nicolas Cabrera 1, 28049, Madrid, Spain
| | - Santiago Ramón-Maiques
- Department of Genome Dynamics and Function, Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Nicolas Cabrera 1, 28049, Madrid, Spain.
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12
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Yao S, Nguyen TV, Rolfe A, Agrawal AA, Ke J, Peng S, Colombo F, Yu S, Bouchard P, Wu J, Huang KC, Bao X, Omoto K, Selvaraj A, Yu L, Ioannidis S, Vaillancourt FH, Zhu P, Larsen NA, Bolduc DM. Small Molecule Inhibition of CPS1 Activity through an Allosteric Pocket. Cell Chem Biol 2020; 27:259-268.e5. [PMID: 32017919 DOI: 10.1016/j.chembiol.2020.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/09/2019] [Accepted: 01/13/2020] [Indexed: 02/06/2023]
Abstract
Carbamoyl phosphate synthetase 1 (CPS1) catalyzes the first step in the ammonia-detoxifying urea cycle, converting ammonia to carbamoyl phosphate under physiologic conditions. In cancer, CPS1 overexpression supports pyrimidine synthesis to promote tumor growth in some cancer types, while in others CPS1 activity prevents the buildup of toxic levels of intratumoral ammonia to allow for sustained tumor growth. Targeted CPS1 inhibitors may, therefore, provide a therapeutic benefit for cancer patients with tumors overexpressing CPS1. Herein, we describe the discovery of small-molecule CPS1 inhibitors that bind to a previously unknown allosteric pocket to block ATP hydrolysis in the first step of carbamoyl phosphate synthesis. CPS1 inhibitors are active in cellular assays, blocking both urea synthesis and CPS1 support of the pyrimidine biosynthetic pathway, while having no activity against CPS2. These newly discovered CPS1 inhibitors are a first step toward providing researchers with valuable tools for probing CPS1 cancer biology.
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Affiliation(s)
- Shihua Yao
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Tuong-Vi Nguyen
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Alan Rolfe
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Anant A Agrawal
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Jiyuan Ke
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Shouyong Peng
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Federico Colombo
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Sean Yu
- RMI Laboratories LLC, 418 Industrial Drive, North Wales, PA 19454, USA
| | - Patricia Bouchard
- NMX Research and Solutions, Inc., 500 Cartier Boulevard W., Laval, Quebec H7V 5B7, Canada
| | - Jiayi Wu
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Kuan-Chun Huang
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Xingfeng Bao
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Kiyoyuki Omoto
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Anand Selvaraj
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Lihua Yu
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | | | | | - Ping Zhu
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - Nicholas A Larsen
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA
| | - David M Bolduc
- H3 Biomedicine Inc., 300 Technology Square, Cambridge, MA 02139, USA.
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13
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Fan L, Zhao J, Jiang L, Xie L, Ma J, Li X, Cheng M. Molecular, biochemical, and clinical analyses of five patients with carbamoyl phosphate synthetase 1 deficiency. J Clin Lab Anal 2019; 34:e23124. [PMID: 31749211 PMCID: PMC7171324 DOI: 10.1002/jcla.23124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is a rare urea cycle disorder. The aim of this study was to present the clinical findings, management, biochemical data, molecular genetic analysis, and short-term prognosis of five children with CPS1D. METHODS The information of five CPS1D patients was retrospectively studied. We used targeted next-generation sequencing to identify carbamoyl phosphate synthetase 1 (CPS1) variants in patients suspected to have CPS1D. Candidate mutations were validated by Sanger sequencing. In silico and structure analyses were processed for the pathogenicity predictions of the identified mutations. RESULTS The patients had typically clinical manifestations and biochemical data of CPS1D. Genetic analysis revealed nine mutations in the CPS1 gene, including recurrence of c.1145C > T, five of which were firstly reported. Seven mutations were missense changes, while the remaining two were predicted to create premature stop codons. In silico and structure analyses showed that these genetic lesions were predicted to affect the function or stability of the enzyme. CONCLUSION We reported five cases of CPS1D. Five novel mutations of CPS1 gene were found. Mutations of CPS1 have private nature, and most of them are missense compound heterozygous. The mutation affecting residue predicted to interfere the catalytic sites, the internal tunnel, or the regulatory domain results in severe phenotype.
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Affiliation(s)
- Lijuan Fan
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Jing Zhao
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Li Jiang
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Lingling Xie
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Jiannan Ma
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Xiujuan Li
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
| | - Min Cheng
- Department of NeurologyChildren's Hospital of Chongqing Medical UniversityChongqingChina
- Ministry of Education Key Laboratory of Child Development and DisordersChongqingChina
- China International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqingChina
- Chongqing Key Laboratory of PediatricsChongqingChina
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14
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Khoja S, Nitzahn M, Truong B, Lambert J, Willis B, Allegri G, Rüfenacht V, Häberle J, Lipshutz GS. A constitutive knockout of murine carbamoyl phosphate synthetase 1 results in death with marked hyperglutaminemia and hyperammonemia. J Inherit Metab Dis 2019; 42:1044-1053. [PMID: 30835861 PMCID: PMC6728231 DOI: 10.1002/jimd.12048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/31/2018] [Indexed: 12/25/2022]
Abstract
The enzyme carbamoyl phosphate synthetase 1 (CPS1; EC 6.3.4.16) forms carbamoyl phosphate from bicarbonate, ammonia, and adenosine triphosphate (ATP) and is activated allosterically by N-acetylglutamate. The neonatal presentation of bi-allelic mutations of CPS1 results in hyperammonemia with reduced citrulline and is reported as the most challenging nitrogen metabolism disorder to treat. As therapeutic interventions are limited, patients often develop neurological injury or die from hyperammonemia. Survivors remain vulnerable to nitrogen overload, being at risk for repetitive neurological injury. With transgenic technology, our lab developed a constitutive Cps1 mutant mouse and reports its characterization herein. Within 24 hours of birth, all Cps1 -/- mice developed hyperammonemia and expired. No CPS1 protein by Western blot or immunostaining was detected in livers nor was Cps1 mRNA present. CPS1 enzymatic activity was markedly decreased in knockout livers and reduced in Cps1+/- mice. Plasma analysis found markedly reduced citrulline and arginine and markedly increased glutamine and alanine, both intermolecular carriers of nitrogen, along with elevated ammonia, taurine, and lysine. Derangements in multiple other amino acids were also detected. While hepatic amino acids also demonstrated markedly reduced citrulline, arginine, while decreased, was not statistically significant; alanine and lysine were markedly increased while glutamine was trending towards significance. In conclusion we have determined that this constitutive neonatal mouse model of CPS1 deficiency replicates the neonatal human phenotype and demonstrates the key biochemical features of the disorder. These mice will be integral for addressing the challenges of developing new therapeutic approaches for this, at present, poorly treated disorder.
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Affiliation(s)
- Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Matthew Nitzahn
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Brian Truong
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Jenna Lambert
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Brandon Willis
- Mouse Biology Program, University of California, Davis, California
| | - Gabriella Allegri
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Gerald S Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, California
- Intellectual and Developmental Disabilities Research Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, California
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, California
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15
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Häberle J, Burlina A, Chakrapani A, Dixon M, Karall D, Lindner M, Mandel H, Martinelli D, Pintos-Morell G, Santer R, Skouma A, Servais A, Tal G, Rubio V, Huemer M, Dionisi-Vici C. Suggested guidelines for the diagnosis and management of urea cycle disorders: First revision. J Inherit Metab Dis 2019; 42:1192-1230. [PMID: 30982989 DOI: 10.1002/jimd.12100] [Citation(s) in RCA: 229] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 02/06/2023]
Abstract
In 2012, we published guidelines summarizing and evaluating late 2011 evidence for diagnosis and therapy of urea cycle disorders (UCDs). With 1:35 000 estimated incidence, UCDs cause hyperammonemia of neonatal (~50%) or late onset that can lead to intellectual disability or death, even while effective therapies do exist. In the 7 years that have elapsed since the first guideline was published, abundant novel information has accumulated, experience on newborn screening for some UCDs has widened, a novel hyperammonemia-causing genetic disorder has been reported, glycerol phenylbutyrate has been introduced as a treatment, and novel promising therapeutic avenues (including gene therapy) have been opened. Several factors including the impact of the first edition of these guidelines (frequently read and quoted) may have increased awareness among health professionals and patient families. However, under-recognition and delayed diagnosis of UCDs still appear widespread. It was therefore necessary to revise the original guidelines to ensure an up-to-date frame of reference for professionals and patients as well as for awareness campaigns. This was accomplished by keeping the original spirit of providing a trans-European consensus based on robust evidence (scored with GRADE methodology), involving professionals on UCDs from nine countries in preparing this consensus. We believe this revised guideline, which has been reviewed by several societies that are involved in the management of UCDs, will have a positive impact on the outcomes of patients by establishing common standards, and spreading and harmonizing good practices. It may also promote the identification of knowledge voids to be filled by future research.
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Affiliation(s)
- Johannes Häberle
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Alberto Burlina
- Division of Inborn Metabolic Disease, Department of Pediatrics, University Hospital Padua, Padova, Italy
| | - Anupam Chakrapani
- Department of Metabolic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Marjorie Dixon
- Dietetics, Great Ormond Street Hospital for Children, NHS Trust, London, UK
| | - Daniela Karall
- Clinic for Pediatrics, Division of Inherited Metabolic Disorders, Medical University of Innsbruck, Innsbruck, Austria
| | - Martin Lindner
- University Children's Hospital, Frankfurt am Main, Germany
| | - Hanna Mandel
- Institute of Human Genetics and metabolic disorders, Western Galilee Medical Center, Nahariya, Israel
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesù Children's Hospital, Rome, Italy
| | - Guillem Pintos-Morell
- Centre for Rare Diseases, University Hospital Vall d'Hebron, Barcelona, Spain
- CIBERER_GCV08, Research Institute IGTP, Barcelona, Spain
- Universitat Autònoma de Barcelona, Barcelona, Spain
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anastasia Skouma
- Institute of Child Health, Agia Sofia Children's Hospital, Athens, Greece
| | - Aude Servais
- Service de Néphrologie et maladies métaboliques adulte Hôpital Necker 149, Paris, France
| | - Galit Tal
- The Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia (IBV-CSIC), Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER), Valencia, Spain
| | - Martina Huemer
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
- Department of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
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16
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Yan B, Wang C, Zhang K, Zhang H, Gao M, Lv Y, Li X, Liu Y, Gai Z. Novel Neonatal Variants of the Carbamoyl Phosphate Synthetase 1 Deficiency: Two Case Reports and Review of Literature. Front Genet 2019; 10:718. [PMID: 31507628 PMCID: PMC6713721 DOI: 10.3389/fgene.2019.00718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 07/09/2019] [Indexed: 12/31/2022] Open
Abstract
Carbamoyl phosphate synthetase I (CPS1) deficiency (CPS1D), is a rare autosomal recessive disorder, characterized by life-threatening hyperammonemia. In this study, we presented the detailed clinical features and genetic analysis of two patients with neonatal-onset CPS1D carrying two compound heterozygous variants of c.1631C > T (p.T544M)/c.1981G > T (p.G661C), and c.2896G > T (p.E966X)/c622-3C > G in CPS1 gene, individually. Out of them, three variants are novel, unreported including a missense (c.1981G > T, p.G661C), a nonsense (c.2896G > T, p.E966X), and a splicing change of c.622-3C > G. We reviewed all available publications regarding CPS1 mutations, and in total 264 different variants have been reported, with majority of 157 (59.5%) missense, followed by 35 (13.2%) small deletions. This study expanded the mutational spectrum of CPS1. Moreover, our cases and review further support the idea that most (≥90%) of the mutations were "private" and only ∼10% recurred in unrelated families.
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Affiliation(s)
- Beibei Yan
- Neonatology Department, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Chao Wang
- Shandong Freshwater Fisheries Research Institute, Ji’nan, China
| | - Kaihui Zhang
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Haiyan Zhang
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Min Gao
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Yuqiang Lv
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Xiaoying Li
- Neonatology Department, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Yi Liu
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
| | - Zhongtao Gai
- Pediatric Research Institute, Qilu Children’s Hospital of Shandong University, Ji’nan, China
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Magini P, Marco-Marin C, Escamilla-Honrubia JM, Martinelli D, Dionisi-Vici C, Faravelli F, Forzano F, Seri M, Rubio V, Panza E. P5CS expression study in a new family with ALDH18A1-associated hereditary spastic paraplegia SPG9. Ann Clin Transl Neurol 2019; 6:1533-1540. [PMID: 31402623 PMCID: PMC6689680 DOI: 10.1002/acn3.50821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/14/2019] [Accepted: 05/28/2019] [Indexed: 12/14/2022] Open
Abstract
In 2015–2016, we and others reported ALDH18A1 mutations causing dominant (SPG9A) or recessive (SPG9B) spastic paraplegia. In vitro production of the ALDH18A1 product, Δ1‐pyrroline‐5‐carboxylate synthetase (P5CS), appeared necessary for cracking SPG9 disease‐causing mechanisms. We now describe a baculovirus–insect cell system that yields mgs of pure human P5CS and that has proven highly valuable with two novel P5CS mutations reported here in new SPG9B patients. We conclude that both mutations are disease‐causing, that SPG9B associates with partial P5CS deficiency and that it is clinically more severe than SPG9A, as reflected in onset age, disability, cognitive status, growth, and dysmorphic traits.
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Affiliation(s)
- Pamela Magini
- Medical Genetics Unit, S. Orsola-Malpighi Hospital, Bologna, Italy
| | - Clara Marco-Marin
- Instituto de Biomedicina de Valencia of the CSIC, Valencia, Spain.,Centro para Investigación Biomédica en Red sobre Enfermedades Raras CIBERER-ISCIII, Valencia, Spain
| | - Juan M Escamilla-Honrubia
- Instituto de Biomedicina de Valencia of the CSIC, Valencia, Spain.,Centro para Investigación Biomédica en Red sobre Enfermedades Raras CIBERER-ISCIII, Valencia, Spain
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesù Children's Research Hospital, Rome, Italy
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Research Hospital, Rome, Italy
| | - Francesca Faravelli
- Clinical Genetics, NE Thames Regional Genetics Service, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, United Kingdom
| | - Francesca Forzano
- Clinical Genetics Department, SE Thames Regional Genetics Service, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Marco Seri
- Medical Genetics Unit, S. Orsola-Malpighi Hospital, Bologna, Italy.,Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia of the CSIC, Valencia, Spain.,Centro para Investigación Biomédica en Red sobre Enfermedades Raras CIBERER-ISCIII, Valencia, Spain
| | - Emanuele Panza
- Medical Genetics Unit, S. Orsola-Malpighi Hospital, Bologna, Italy.,Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
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18
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Yap S, Gougeard N, Hart AR, Barcelona B, Rubio V. N-carbamoylglutamate-responsive carbamoyl phosphate synthetase 1 (CPS1) deficiency: A patient with a novel CPS1 mutation and an experimental study on the mutation's effects. JIMD Rep 2019; 48:36-44. [PMID: 31392111 PMCID: PMC6606979 DOI: 10.1002/jmd2.12034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/01/2019] [Indexed: 12/16/2022] Open
Abstract
N-carbamoyl-l-glutamate (NCG), the N-acetyl-l-glutamate analogue used to treat N-acetylglutamate synthase deficiency, has been proposed as potential therapy of carbamoyl phosphate synthetase 1 deficiency (CPS1D). Previous findings in five CPS1D patients suggest that NCG-responsiveness could be mutation-specific. We report on a patient with CPS1D, homozygous for the novel p.(Pro1211Arg) CPS1 mutation, who presented at 9 days of life with hyperammonemic coma which was successfully treated with emergency measures. He remained metabolically stable on merely oral NCG, arginine, and modest protein restriction. Ammonia scavengers were only added after poor dietary compliance following solid food intake at age 1 year. The patient received a liver transplantation at 3.9 years of age, having normal cognitive, motor, and quality of life scores despite repeated but successfully treated episodes of hyperammonemia. Studies using recombinantly produced mutant CPS1 confirmed the partial nature of the CPS1D triggered by the p.(Pro1211Arg) mutation. This mutation decreased the solubility and yield of CPS1 as expected for increased tendency to misfold, and reduced the thermal stability, maximum specific activity (V max; ~2-fold reduction), and apparent affinity (~5-fold reduction) for ATP of the purified enzyme. By increasing the saturation of the NAG site in vivo, NCG could stabilize CPS1 and minimize the decrease in the effective affinity of the enzyme for ATP. These observations, together with prior experience, support the ascertainment of clinical responsiveness to NCG in CPS1 deficient patients, particularly when decreased stability or lowered affinity for NAG of the mutant enzyme are suspected or proven.
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Affiliation(s)
- Sufin Yap
- Department of Inherited Metabolic DisordersSheffield Children's HospitalSheffieldUK
| | - Nadine Gougeard
- Structural Enzymopathology UnitInstituto de Biomedicina de Valencia of the CSIC (IBV‐CSIC)ValenciaSpain
- Group 739, Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER‐ISCIII)MadridSpain
| | - Anthony R. Hart
- Department of NeurologySheffield Children's HospitalSheffieldUK
| | - Belén Barcelona
- Structural Enzymopathology UnitInstituto de Biomedicina de Valencia of the CSIC (IBV‐CSIC)ValenciaSpain
- Group 739, Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER‐ISCIII)MadridSpain
| | - Vicente Rubio
- Structural Enzymopathology UnitInstituto de Biomedicina de Valencia of the CSIC (IBV‐CSIC)ValenciaSpain
- Group 739, Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER‐ISCIII)MadridSpain
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19
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Constitutive release of CPS1 in bile and its role as a protective cytokine during acute liver injury. Proc Natl Acad Sci U S A 2019; 116:9125-9134. [PMID: 30979808 DOI: 10.1073/pnas.1822173116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Carbamoyl phosphate synthetase-1 (CPS1) is the major mitochondrial urea cycle enzyme in hepatocytes. It is released into mouse and human blood during acute liver injury, where is has a short half-life. The function of CPS1 in blood and the reason for its short half-life in serum are unknown. We show that CPS1 is released normally into mouse and human bile, and pathologically into blood during acute liver injury. Other cytoplasmic and mitochondrial urea cycle enzymes are also found in normal mouse bile. Serum, bile, and purified CPS1 manifest sedimentation properties that overlap with extracellular vesicles, due to the propensity of CPS1 to aggregate despite being released primarily as a soluble protein. During liver injury, CPS1 in blood is rapidly sequestered by monocytes, leading to monocyte M2-polarization and homing to the liver independent of its enzyme activity. Recombinant CPS1 (rCPS1), but not control r-transferrin, increases hepatic macrophage numbers and phagocytic activity. Notably, rCPS1 does not activate hepatic macrophages directly; rather, it activates bone marrow and circulating monocytes that then home to the liver. rCPS1 administration prevents mouse liver damage induced by Fas ligand or acetaminophen, but this protection is absent in macrophage-deficient mice. Moreover, rCPS1 protects from acetaminophen-induced liver injury even when given therapeutically after injury induction. In summary, CPS1 is normally found in bile but is released by hepatocytes into blood upon liver damage. We demonstrate a nonenzymatic function of CPS1 as an antiinflammatory protective cytokine during acute liver injury.
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Shi D, Caldovic L, Tuchman M. Sources and Fates of Carbamyl Phosphate: A Labile Energy-Rich Molecule with Multiple Facets. BIOLOGY 2018; 7:biology7020034. [PMID: 29895729 PMCID: PMC6022934 DOI: 10.3390/biology7020034] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/25/2018] [Accepted: 06/07/2018] [Indexed: 11/16/2022]
Abstract
Carbamyl phosphate (CP) is well-known as an essential intermediate of pyrimidine and arginine/urea biosynthesis. Chemically, CP can be easily synthesized from dihydrogen phosphate and cyanate. Enzymatically, CP can be synthesized using three different classes of enzymes: (1) ATP-grasp fold protein based carbamyl phosphate synthetase (CPS); (2) Amino-acid kinase fold carbamate kinase (CK)-like CPS (anabolic CK or aCK); and (3) Catabolic transcarbamylase. The first class of CPS can be further divided into three different types of CPS as CPS I, CPS II, and CPS III depending on the usage of ammonium or glutamine as its nitrogen source, and whether N-acetyl-glutamate is its essential co-factor. CP can donate its carbamyl group to the amino nitrogen of many important molecules including the most well-known ornithine and aspartate in the arginine/urea and pyrimidine biosynthetic pathways. CP can also donate its carbamyl group to the hydroxyl oxygen of a variety of molecules, particularly in many antibiotic biosynthetic pathways. Transfer of the carbamyl group to the nitrogen group is catalyzed by the anabolic transcarbamylase using a direct attack mechanism, while transfer of the carbamyl group to the oxygen group is catalyzed by a different class of enzymes, CmcH/NodU CTase, using a different mechanism involving a three-step reaction, decomposition of CP to carbamate and phosphate, transfer of the carbamyl group from carbamate to ATP to form carbamyladenylate and pyrophosphate, and transfer of the carbamyl group from carbamyladenylate to the oxygen group of the substrate. CP is also involved in transferring its phosphate group to ADP to generate ATP in the fermentation of many microorganisms. The reaction is catalyzed by carbamate kinase, which may be termed as catabolic CK (cCK) in order to distinguish it from CP generating CK. CP is a thermally labile molecule, easily decomposed into phosphate and cyanate, or phosphate and carbamate depending on the pH of the solution, or the presence of enzyme. Biological systems have developed several mechanisms including channeling between enzymes, increased affinity of CP to enzymes, and keeping CP in a specific conformation to protect CP from decomposition. CP is highly important for our health as both a lack of, or decreased, CP production and CP accumulation results in many disease conditions.
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Affiliation(s)
- Dashuang Shi
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC 20010, USA.
- Department of Genomics and Precision Medicine, The George Washington University, Washington, DC 20010, USA.
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC 20010, USA.
- Department of Genomics and Precision Medicine, The George Washington University, Washington, DC 20010, USA.
| | - Mendel Tuchman
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC 20010, USA.
- Department of Genomics and Precision Medicine, The George Washington University, Washington, DC 20010, USA.
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21
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Wang Y, Chang L, Zhai J, Wu Q, Wang D, Wang Y. Generation of carbamoyl phosphate synthetase 1 reporter cell lines for the assessment of ammonia metabolism. J Cell Mol Med 2017; 21:3214-3223. [PMID: 28557353 PMCID: PMC5706564 DOI: 10.1111/jcmm.13225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 04/09/2017] [Indexed: 01/25/2023] Open
Abstract
Both primary hepatocytes and stem cells-derived hepatocyte-like cells (HLCs) are major sources for bioartificial liver (BAL). Maintenance of hepatocellular functions and induction of functional maturity of HLCs are critical for BAL's support effect. It remains difficult to assess and improve detoxification functions inherent to hepatocytes, including ammonia clearance. Here, we aim to assess ammonia metabolism and identify ammonia detoxification enhancer by developing an imaging strategy. In hepatoma cell line HepG2, and immortalized hepatic cell line LO2, carbamoyl phosphate synthetase 1 (CPS1) gene, the first enzyme of ammonia-eliminating urea cycle, was labelled with fluorescence protein via CRISPR/Cas9 system. With the reporter-based screening approach, cellular detoxification enhancers were selected among a collection of 182 small molecules. In both CPS1 reporter cell lines, the fluorescence intensity is positively correlated with cellular CPS1 mRNA expression, ammonia elimination and secreted urea, and reflected ammonia detoxification in a dose-dependent manner. Surprisingly, high-level CPS1 reporter clones also reserved many other critical hepatocellular functions, for example albumin secretion and cytochrome 450 metabolic functions. Sodium phenylbutyrate and resveratrol were identified to enhance metabolism-related gene expression and liver-enriched transcription factors C/EBPα, HNF4α. In conclusion, the CPS1-reporter system provides an economic and effective platform for assessment of cellular metabolic function and high-throughput identification of chemical compounds that improve detoxification activities in hepatic lineage cells.
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Affiliation(s)
- Yi Wang
- Stem Cell and Tissue Engineering LabBeijing Institute of Transfusion MedicineBeijingChina
| | - Le Chang
- Stem Cell and Tissue Engineering LabBeijing Institute of Transfusion MedicineBeijingChina
| | - Jiahui Zhai
- Stem Cell and Tissue Engineering LabBeijing Institute of Transfusion MedicineBeijingChina
| | - Qiao Wu
- Capital Medical University Youan hospitalBeijingChina
| | - Donggen Wang
- Stem Cell and Tissue Engineering LabBeijing Institute of Transfusion MedicineBeijingChina
| | - Yunfang Wang
- Stem Cell and Tissue Engineering LabBeijing Institute of Transfusion MedicineBeijingChina
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22
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Moedas M, Adam A, Farelo M, IJlst L, Chamuleau R, Hoekstra R, Wanders R, Silva M. Advances in methods for characterization of hepatic urea cycle enzymatic activity in HepaRG cells using UPLC-MS/MS. Anal Biochem 2017; 535:47-55. [DOI: 10.1016/j.ab.2017.07.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/12/2017] [Accepted: 07/26/2017] [Indexed: 12/30/2022]
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23
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Shi D, Zhao G, Ah Mew N, Tuchman M. Precision medicine in rare disease: Mechanisms of disparate effects of N-carbamyl-l-glutamate on mutant CPS1 enzymes. Mol Genet Metab 2017; 120:198-206. [PMID: 28007335 PMCID: PMC5346444 DOI: 10.1016/j.ymgme.2016.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/05/2016] [Accepted: 12/05/2016] [Indexed: 02/07/2023]
Abstract
This study documents the disparate therapeutic effect of N-carbamyl-l-glutamate (NCG) in the activation of two different disease-causing mutants of carbamyl phosphate synthetase 1 (CPS1). We investigated the effects of NCG on purified recombinant wild-type (WT) mouse CPS1 and its human corresponding E1034G (increased ureagenesis on NCG) and M792I (decreased ureagenesis on NCG) mutants. NCG activates WT CPS1 sub-optimally compared to NAG. Similar to NAG, NCG, in combination with MgATP, stabilizes the enzyme, but competes with NAG binding to the enzyme. NCG supplementation activates available E1034G mutant CPS1 molecules not bound to NAG enhancing ureagenesis. Conversely, NCG competes with NAG binding to the scarce M792I mutant enzyme further decreasing residual ureagenesis. These results correlate with the respective patient's response to NCG. Particular caution should be taken in the administration of NCG to patients with hyperammonemia before their molecular bases of their urea cycle disorders is known.
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Affiliation(s)
- Dashuang Shi
- Center for Genetic Medicine Research, Department of Integrative Systems Biology, Children's Research Institute, Children's National Health System, The George Washington University, Washington, DC 20010, USA.
| | - Gengxiang Zhao
- Center for Genetic Medicine Research, Department of Integrative Systems Biology, Children's Research Institute, Children's National Health System, The George Washington University, Washington, DC 20010, USA
| | - Nicholas Ah Mew
- Center for Genetic Medicine Research, Department of Integrative Systems Biology, Children's Research Institute, Children's National Health System, The George Washington University, Washington, DC 20010, USA
| | - Mendel Tuchman
- Center for Genetic Medicine Research, Department of Integrative Systems Biology, Children's Research Institute, Children's National Health System, The George Washington University, Washington, DC 20010, USA
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24
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Diez-Fernandez C, Häberle J. Targeting CPS1 in the treatment of Carbamoyl phosphate synthetase 1 (CPS1) deficiency, a urea cycle disorder. Expert Opin Ther Targets 2017; 21:391-399. [PMID: 28281899 DOI: 10.1080/14728222.2017.1294685] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Carbamoyl phosphate synthetase 1 (CPS1) deficiency (CPS1D) is a rare autosomal recessive urea cycle disorder (UCD), which can lead to life-threatening hyperammonemia. Unless promptly treated, it can result in encephalopathy, coma and death, or intellectual disability in surviving patients. Over recent decades, therapies for CPS1D have barely improved leaving the management of these patients largely unchanged. Additionally, in many cases, current management (protein-restriction and supplementation with citrulline and/or arginine and ammonia scavengers) is insufficient for achieving metabolic stability, highlighting the importance of developing alternative therapeutic approaches. Areas covered: After describing UCDs and CPS1D, we give an overview of the structure- function of CPS1. We then describe current management and potential novel treatments including N-carbamoyl-L-glutamate (NCG), pharmacological chaperones, and gene therapy to treat hyperammonemia. Expert opinion: Probably, the first novel CPS1D therapies to reach the clinics will be the already commercial substance NCG, which is the standard treatment for N-acetylglutamate synthase deficiency and has been proven to rescue specific CPS1D mutations. Pharmacological chaperones and gene therapy are under development too, but these two technologies still have key challenges to be overcome. In addition, current experimental therapies will hopefully add further treatment options.
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Affiliation(s)
- Carmen Diez-Fernandez
- a Division of Metabolism , University Children's Hospital Zurich and Children's Research Center , Zurich , Switzerland
| | - Johannes Häberle
- a Division of Metabolism , University Children's Hospital Zurich and Children's Research Center , Zurich , Switzerland
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Cüre MC, Cüre E, Kalkan Y, Kırbaş A, Tümkaya L, Yılmaz A, Türkyılmaz AK, Şehitoğlu İ, Yüce S. Infliximab Modulates Cisplatin-Induced Hepatotoxicity in Rats. Balkan Med J 2016. [PMID: 27761277 DOI: 10.5152/balkanmedj.2016.150576.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Cisplatin (Cis) is one of the most commonly used antineoplastic drugs. It is used as chemotherapy for many solid organ malignancies such as brain, neck, male and female urogenital, vesical and pulmonary cancers. Infliximab blocks tumor necrosis factor alpha (TNF-α). Several studies have reported that infliximab ameliorates cell damage by reducing cytokine levels. AIMS We aimed to investigate whether infliximab has a preventive effect against cisplatin-induced hepatotoxicity and whether it has a synergistic effect when combined with Cis. STUDY DESIGN Animal experimentation. METHODS Male Wistar albino rats were divided in three groups as follows: Cis group, infliximab + Cis (CIN) group and the control group. Each group comprised 10 animals. Animals in the Cis group received an intraperitoneal single-dose injection of Cis (7 mg/kg). In the CIN group, a single dose of infliximab (7 mg/kg) was administered 72 h prior to the Cis injection. After 72 h, a single dose of Cis (7 mg/kg) was administered. All rats were sacrificed five days after Cis injection. RESULTS TNF-α levels in the Cis group were significantly higher (345.5±40.0 pg/mg protein) than those of the control (278.7±62.1 pg/mg protein, p=0.003) and CIN groups (239.0±64.2 pg/mg protein, p=0.013). The Cis group was found to have high carbonic anhydrase (CA)-II and low carbamoyl phosphate synthetase-1 (CPS-1) levels. Aspartate transaminase (AST) and alanine transaminase (ALT) levels were lower in the CIN group as compared to the Cis group. Total histological damage was greater in the Cis group as compared to the control and CIN groups. CONCLUSION Cis may lead to liver damage by increasing cytokine levels. It may increase oxidative stress-induced tissue damage by increasing carbonic anhydrase II (CA-II) enzyme levels and decreasing CPS-1 enzyme levels. Infliximab decreases Cis-induced hepatic damage by blocking TNF-α and it may also protect against liver damage by regulating CPS-1 and CA-II enzyme levels.
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Affiliation(s)
- Medine Cumhur Cüre
- Department of Biochemistry, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Erkan Cüre
- Department of Internal Medicine, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Yıldıray Kalkan
- Department of Histology and Embryology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Aynur Kırbaş
- Department of Biochemistry, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Levent Tümkaya
- Department of Histology and Embryology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Arif Yılmaz
- Department of Gastroenterology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Ayşegül Küçükali Türkyılmaz
- Department of Physical Medicine and Rehabilitation, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - İbrahim Şehitoğlu
- Department of Pathology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Süleyman Yüce
- Department of Internal Medicine, Kumru State Hospital, Rize, Turkey
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26
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Chapel-Crespo CC, Diaz GA, Oishi K. Efficacy of N-carbamoyl-L-glutamic acid for the treatment of inherited metabolic disorders. Expert Rev Endocrinol Metab 2016; 11:467-473. [PMID: 30034506 PMCID: PMC6054484 DOI: 10.1080/17446651.2016.1239526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION N-carbamoyl-L-glutamic acid (NCG) is a synthetic analogue of N-acetyl glutamate (NAG) that works effectively as a cofactor for carbamoyl phosphate synthase 1 and enhances ureagenesis by activating the urea cycle. NCG (brand name, Carbaglu) was recently approved by the United States Food and Drug Administration (US FDA) for the management of NAGS deficiency and by the European Medicines Agency (EMA) for the treatment of NAGS deficiency as well as for the treatment of hyperammonenia in propionic, methylmalonic and isovaleric acidemias in Europe. AREAS COVERED The history, mechanism of action, and efficacy of this new drug are described. Moreover, clinical utility of NCG in a variety of inborn errors of metabolism with secondary NAGS deficiency is discussed. EXPERT COMMENTARY NCG has favorable pharmacological features including better bioavailability compared to NAG. The clinical use of NCG has proven to be so effective as to make dietary protein restriction unnecessary for patients with NAGS deficiency. It has been also demonstrated to be effective for hyperammonemia secondary to other types of inborn errors of metabolism. NCG may have additional therapeutic potential in conditions such as hepatic hyperammonemic encephalopathy secondary to chemotherapies or other liver pathology.
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Affiliation(s)
- Cristel C Chapel-Crespo
- Department of Genetics and Genomic Sciences, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George A Diaz
- Department of Genetics and Genomic Sciences, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kimihiko Oishi
- Department of Genetics and Genomic Sciences, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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27
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Cüre MC, Cüre E, Kalkan Y, Kırbaş A, Tümkaya L, Yılmaz A, Türkyılmaz AK, Şehitoğlu İ, Yüce S. Infliximab Modulates Cisplatin-Induced Hepatotoxicity in Rats. Balkan Med J 2016; 33:504-511. [PMID: 27761277 PMCID: PMC5056652 DOI: 10.5152/balkanmedj.2016.150576] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 02/03/2016] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Cisplatin (Cis) is one of the most commonly used antineoplastic drugs. It is used as chemotherapy for many solid organ malignancies such as brain, neck, male and female urogenital, vesical and pulmonary cancers. Infliximab blocks tumor necrosis factor alpha (TNF-α). Several studies have reported that infliximab ameliorates cell damage by reducing cytokine levels. AIMS We aimed to investigate whether infliximab has a preventive effect against cisplatin-induced hepatotoxicity and whether it has a synergistic effect when combined with Cis. STUDY DESIGN Animal experimentation. METHODS Male Wistar albino rats were divided in three groups as follows: Cis group, infliximab + Cis (CIN) group and the control group. Each group comprised 10 animals. Animals in the Cis group received an intraperitoneal single-dose injection of Cis (7 mg/kg). In the CIN group, a single dose of infliximab (7 mg/kg) was administered 72 h prior to the Cis injection. After 72 h, a single dose of Cis (7 mg/kg) was administered. All rats were sacrificed five days after Cis injection. RESULTS TNF-α levels in the Cis group were significantly higher (345.5±40.0 pg/mg protein) than those of the control (278.7±62.1 pg/mg protein, p=0.003) and CIN groups (239.0±64.2 pg/mg protein, p=0.013). The Cis group was found to have high carbonic anhydrase (CA)-II and low carbamoyl phosphate synthetase-1 (CPS-1) levels. Aspartate transaminase (AST) and alanine transaminase (ALT) levels were lower in the CIN group as compared to the Cis group. Total histological damage was greater in the Cis group as compared to the control and CIN groups. CONCLUSION Cis may lead to liver damage by increasing cytokine levels. It may increase oxidative stress-induced tissue damage by increasing carbonic anhydrase II (CA-II) enzyme levels and decreasing CPS-1 enzyme levels. Infliximab decreases Cis-induced hepatic damage by blocking TNF-α and it may also protect against liver damage by regulating CPS-1 and CA-II enzyme levels.
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Affiliation(s)
- Medine Cumhur Cüre
- Department of Biochemistry, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
- Address for Correspondence: Dr. Medine Cumhur Cüre, Department of Biochemistry, Recep Tayyip Erdogan University School of Medicine, Rize, Turkey, Phone: +90 538 930 05 75, e-mail:
| | - Erkan Cüre
- Department of Internal Medicine, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Yıldıray Kalkan
- Department of Histology and Embryology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Aynur Kırbaş
- Department of Biochemistry, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Levent Tümkaya
- Department of Histology and Embryology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Arif Yılmaz
- Department of Gastroenterology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Ayşegül Küçükali Türkyılmaz
- Department of Physical Medicine and Rehabilitation, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - İbrahim Şehitoğlu
- Department of Pathology, Recep Tayyip Erdoğan University School of Medicine, Rize, Turkey
| | - Süleyman Yüce
- Department of Internal Medicine, Kumru State Hospital, Rize, Turkey
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Defective hepatic bicarbonate production due to carbonic anhydrase VA deficiency leads to early-onset life-threatening metabolic crisis. Genet Med 2016; 18:991-1000. [DOI: 10.1038/gim.2015.201] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/30/2015] [Indexed: 12/25/2022] Open
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Structure of human carbamoyl phosphate synthetase: deciphering the on/off switch of human ureagenesis. Sci Rep 2015; 5:16950. [PMID: 26592762 PMCID: PMC4655335 DOI: 10.1038/srep16950] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/22/2015] [Indexed: 01/07/2023] Open
Abstract
Human carbamoyl phosphate synthetase (CPS1), a 1500-residue multidomain enzyme, catalyzes the first step of ammonia detoxification to urea requiring N-acetyl-L-glutamate (NAG) as essential activator to prevent ammonia/amino acids depletion. Here we present the crystal structures of CPS1 in the absence and in the presence of NAG, clarifying the on/off-switching of the urea cycle by NAG. By binding at the C-terminal domain of CPS1, NAG triggers long-range conformational changes affecting the two distant phosphorylation domains. These changes, concerted with the binding of nucleotides, result in a dramatic remodeling that stabilizes the catalytically competent conformation and the building of the ~35 Å-long tunnel that allows migration of the carbamate intermediate from its site of formation to the second phosphorylation site, where carbamoyl phosphate is produced. These structures allow rationalizing the effects of mutations found in patients with CPS1 deficiency (presenting hyperammonemia, mental retardation and even death), as exemplified here for some mutations.
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The Study of Carbamoyl Phosphate Synthetase 1 Deficiency Sheds Light on the Mechanism for Switching On/Off the Urea Cycle. J Genet Genomics 2015; 42:249-60. [DOI: 10.1016/j.jgg.2015.03.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/22/2015] [Accepted: 03/25/2015] [Indexed: 12/31/2022]
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Hu L, Diez-Fernandez C, Rüfenacht V, Hismi BÖ, Ünal Ö, Soyucen E, Çoker M, Bayraktar BT, Gunduz M, Kiykim E, Olgac A, Pérez-Tur J, Rubio V, Häberle J. Recurrence of carbamoyl phosphate synthetase 1 (CPS1) deficiency in Turkish patients: characterization of a founder mutation by use of recombinant CPS1 from insect cells expression. Mol Genet Metab 2014; 113:267-73. [PMID: 25410056 DOI: 10.1016/j.ymgme.2014.09.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 09/30/2014] [Accepted: 09/30/2014] [Indexed: 12/26/2022]
Abstract
Carbamoyl phosphate synthetase 1 (CPS1) deficiency due to CPS1 mutations is a rare autosomal-recessive urea cycle disorder causing hyperammonemia that can lead to death or severe neurological impairment. CPS1 catalyzes carbamoyl phosphate formation from ammonia, bicarbonate and two molecules of ATP, and requires the allosteric activator N-acetyl-L-glutamate. Clinical mutations occur in the entire CPS1 coding region, but mainly in single families, with little recurrence. We characterized here the only currently known recurrent CPS1 mutation, p.Val1013del, found in eleven unrelated patients of Turkish descent using recombinant His-tagged wild type or mutant CPS1 expressed in baculovirus/insect cell system. The global CPS1 reaction and the ATPase and ATP synthesis partial reactions that reflect, respectively, the bicarbonate and the carbamate phosphorylation steps, were assayed. We found that CPS1 wild type and V1013del mutant showed comparable expression levels and purity but the mutant CPS1 exhibited no significant residual activities. In the CPS1 structural model, V1013 belongs to a highly hydrophobic β-strand at the middle of the central β-sheet of the A subdomain of the carbamate phosphorylation domain and is close to the predicted carbamate tunnel that links both phosphorylation sites. Haplotype studies suggested that p.Val1013del is a founder mutation. In conclusion, the mutation p.V1013del inactivates CPS1 but does not render the enzyme grossly unstable or insoluble. Recurrence of this particular mutation in Turkish patients is likely due to a founder effect, which is consistent with the frequent consanguinity observed in the affected population.
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Affiliation(s)
- Liyan Hu
- Division of Metabolism, University Children's Hospital, 8032 Zurich, Switzerland; Children's Research Center, 8032 Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Switzerland
| | - Carmen Diez-Fernandez
- Division of Metabolism, University Children's Hospital, 8032 Zurich, Switzerland; Children's Research Center, 8032 Zurich, Switzerland; Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain
| | - Véronique Rüfenacht
- Division of Metabolism, University Children's Hospital, 8032 Zurich, Switzerland; Children's Research Center, 8032 Zurich, Switzerland
| | - Burcu Öztürk Hismi
- Department of Pediatric Metabolic Diseases, Ihsan Dogramaci Children's Hospital, Hacettepe University, Ankara, Turkey; Gaziantep Children's Hospital, Gaziantep, Turkey
| | - Özlem Ünal
- Department of Pediatric Metabolic Diseases, Ihsan Dogramaci Children's Hospital, Hacettepe University, Ankara, Turkey; Erzurum Regional Training and Research Hospital, Erzurum, Turkey
| | - Erdogan Soyucen
- Department of Pediatric Metabolic Disease, Medical School, Akdeniz University, Antalya, Turkey
| | - Mahmut Çoker
- Department of Pediatric Metabolic Disease, Medical School, Ege University, Bornova, Izmir, Turkey
| | - Bilge Tanyeri Bayraktar
- Division of Neonatology, Department of Pediatrics, Bezmialem Vakif University, Istanbul, Turkey
| | - Mehmet Gunduz
- Ankara Cocuk Sagligi ve Hastaliklari, Cocuk Beslenme & Metabolizma Unitesi, Diskapi, Ankara, Turkey
| | - Ertugrul Kiykim
- Department of Pediatric Metabolic Diseases, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Asburce Olgac
- Division of Metabolism and Nutrition, Gazi University Hospital, Ankara, Turkey
| | - Jordi Pérez-Tur
- Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain; Centro de Investigación Biomédica en Red para Enfermedades Neurodegenerativas (CIBERNED-ISCIII), Valencia, Spain; Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia (IBV-CSIC), Valencia, Spain; Group 739, Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER-ISCIII), Valencia, Spain
| | - Johannes Häberle
- Division of Metabolism, University Children's Hospital, 8032 Zurich, Switzerland; Children's Research Center, 8032 Zurich, Switzerland; Neuroscience Center Zurich, University and ETH Zurich, Switzerland.
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Aughey GN, Tastan ÖY, Liu JL. Cellular serpents and dreaming spires: new frontiers in arginine and pyrimidine biology. J Genet Genomics 2014; 41:561-5. [PMID: 25438702 DOI: 10.1016/j.jgg.2014.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 08/30/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Gabriel N Aughey
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Ömür Y Tastan
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom.
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Lee YY, Li CF, Lin CY, Lee SW, Sheu MJ, Lin LC, Chen TJ, Wu TF, Hsing CH. Overexpression of CPS1 is an independent negative prognosticator in rectal cancers receiving concurrent chemoradiotherapy. Tumour Biol 2014; 35:11097-105. [PMID: 25099619 DOI: 10.1007/s13277-014-2425-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/29/2014] [Indexed: 12/13/2022] Open
Abstract
Locally advanced rectal cancers are currently treated with neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery, but stratification of risk and final outcomes remain suboptimal. In view of the fact that glutamine metabolism is usually altered in cancer, we profiled and validated the significance of genes involved in this pathway in rectal cancers treated with CCRT. From a published transcriptome of rectal cancers (GSE35452), we focused on glutamine metabolic process-related genes (GO:0006541) and found upregulation of carbamoyl phosphate synthetase 1 (CPS1) gene most significantly predicted poor response to CCRT. We evaluated the expression levels of CPS1 using immunohistochemistry to analyze tumor specimens obtained during colonoscopy from 172 rectal cancer patients. Expression levels of CPS1 were further correlated with major clinicopathological features and survivals in this validation cohort. To further confirm CPS1 expression levels, Western blotting was performed for human colon epithelial primary cell (HCoEpiC) and four human colon cancer cells, including HT29, SW480, LoVo, and SW620. CPS1 overexpression was significantly related to advanced posttreatment tumor (T3, T4; P = 0.006) and nodal status (N1, N2; P < 0.001), and inferior tumor regression grade (P = 0.004). In survival analyses, CPS1 overexpression was significantly associated with shorter disease-specific survival (DSS) and metastasis-free survival (MeFS). Furthermore, using multivariate analysis, it was also independently predictive of worse DSS (P = 0.021, hazard ratio = 2.762) and MeFS (P = 0.004, hazard ratio = 3.897). CPS1 protein expression, as detected by Western blotting, is more abundant in colon cancer cells than nonneoplastic HCoEpiC. Overexpression of CPS1 is associated with poor therapeutic response and adverse outcomes among rectal cancer patients receiving CCRT, justifying the potential theranostic value of CPS1 for such patients.
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Affiliation(s)
- Yi-Ying Lee
- Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan
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Díez-Fernández C, Hu L, Cervera J, Häberle J, Rubio V. Understanding carbamoyl phosphate synthetase (CPS1) deficiency by using the recombinantly purified human enzyme: effects of CPS1 mutations that concentrate in a central domain of unknown function. Mol Genet Metab 2014; 112:123-32. [PMID: 24813853 DOI: 10.1016/j.ymgme.2014.04.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/11/2014] [Accepted: 04/11/2014] [Indexed: 01/02/2023]
Abstract
Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is an inborn error of the urea cycle that is due to mutations in the CPS1 gene. In the first large repertory of mutations found in CPS1D, a small CPS1 domain of unknown function (called the UFSD) was found to host missense changes with high frequency, despite the fact that this domain does not host substrate-binding or catalytic machinery. We investigate here by in vitro expression studies using baculovirus/insect cells the reasons for the prominence of the UFSD in CPS1D, as well as the disease-causing roles and pathogenic mechanisms of the mutations affecting this domain. All but three of the 18 missense changes found thus far mapping in this domain in CPS1D patients drastically decreased the yield of pure CPS1, mainly because of decreased enzyme solubility, strongly suggesting misfolding as a major determinant of the mutations negative effects. In addition, the majority of the mutations also decreased from modestly to very drastically the specific activity of the fraction of the enzyme that remained soluble and that could be purified, apparently because they decreased V(max). Substantial although not dramatic increases in K(m) values for the substrates or for N-acetyl-L-glutamate were observed for only five mutations. Similarly, important thermal stability decreases were observed for three mutations. The results indicate a disease-causing role for all the mutations, due in most cases to the combined effects of the low enzyme level and the decreased activity. Our data strongly support the value of the present expression system for ascertaining the disease-causing potential of CPS1 mutations, provided that the CPS1 yield is monitored. The observed effects of the mutations have been rationalized on the basis of an existing structural model of CPS1. This model shows that the UFSD, which is in the middle of the 1462-residue multidomain CPS1 protein, plays a key integrating role for creating the CPS1 multidomain architecture leading us to propose here a denomination of "Integrating Domain" for this CPS1 region. The majority of these 18 mutations distort the interaction of this domain with other CPS1 domains, in many cases by causing improper folding of structural elements of the Integrating Domain that play key roles in these interactions.
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Affiliation(s)
| | - Liyan Hu
- University Children's Hospital, Zurich and Children's Research Center, Zurich, Switzerland
| | - Javier Cervera
- Instituto de Biomedicina de Valencia of the CSIC, Valencia, Spain; Group 739 of the Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER) del Instituto de Salud Carlos III, Spain
| | - Johannes Häberle
- University Children's Hospital, Zurich and Children's Research Center, Zurich, Switzerland.
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia of the CSIC, Valencia, Spain; Group 739 of the Centro de Investigación Biomédica en Red sobre Enfermedades Raras (CIBERER) del Instituto de Salud Carlos III, Spain.
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