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Makris G, Veit L, Rüfenacht V, Klassa S, Zürcher N, Matsumoto S, Poms M, Häberle J. Expression and function of the urea cycle in widely-used hepatic cellular models. J Inherit Metab Dis 2024. [PMID: 38192032 DOI: 10.1002/jimd.12701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 01/10/2024]
Abstract
The group of rare metabolic defects termed urea cycle disorders (UCDs) occur within the ammonia elimination pathway and lead to significant neurocognitive sequelae for patients surviving decompensation episodes. Besides orthotopic liver transplantation, curative options are lacking for UCDs, with dietary management being the gold clinical standard. Novel therapeutic approaches are essential for UCDs; however, such effort presupposes preclinical testing in cellular models that effectively capture disease manifestation. Several cellular and animal models exist and aim to recapitulate the broad phenotypic spectrum of UCDs; however, the majority of those lack extensive molecular and biochemical characterization. The development of cellular models is emerging since animal models are extremely time and cost consuming, and subject to ethical considerations, including the 3R principle that endorses animal welfare over unchecked preclinical testing. The aim of this study was to compare the extent of expression and functionality of the urea cycle in two commercial hepatoma-derived cell lines, induced pluripotent stem cell hepatocytes (iPSC-Heps), primary human hepatocytes (PHHs) and human liver cell preparations. Using immunoblotting, immunocytochemistry, and stable isotope tracing of the urea cycle metabolites, we identified that the hepatoma-derived, 2-week differentiated HepaRG cells are urea cycle proficient and behave as cellular alternatives to PHHs. Furthermore, HepaRG cells were superior to iPSC-Heps, which are known to exhibit batch-to-batch variabilities in terms of hepatic maturity and enzyme expression. Finally, HepG2 cells lack the urea cycle enzymes ornithine transcarbamylase and arginase 1, the transporter ORNT1, which limits their suitability as model for the study of UCDs.
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Affiliation(s)
- Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
- Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Lara Veit
- 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
| | - Sven Klassa
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Nadia Zürcher
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Shirou Matsumoto
- Department of Pediatrics, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Martin Poms
- Division of Clinical Chemistry and Biochemistry, 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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Scharre S, Posset R, Garbade SF, Gleich F, Seidl MJ, Druck AC, Okun JG, Gropman AL, Nagamani SCS, Hoffmann GF, Kölker S, Zielonka M. Predicting the disease severity in male individuals with ornithine transcarbamylase deficiency. Ann Clin Transl Neurol 2022; 9:1715-1726. [PMID: 36217298 PMCID: PMC9639638 DOI: 10.1002/acn3.51668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE Ornithine transcarbamylase deficiency (OTC-D) is an X-linked metabolic disease and the most common urea cycle disorder. Due to high phenotypic heterogeneity, ranging from lethal neonatal hyperammonemic events to moderate symptoms and even asymptomatic individuals, the prediction of the disease course at an early disease stage is very important to individually adjust therapies such as medical treatment or liver transplantation. In this translational study, we developed a severity-adjusted classification system based on in vitro residual enzymatic OTC activity. METHODS Applying a cell-based expression system, residual enzymatic OTC activities of 71 pathogenic OTC variants were spectrophotometrically determined and subsequently correlated with clinical and biochemical outcome parameters of 119 male individuals with OTC-D (mOTC-D) as reported in the UCDC and E-IMD registries. RESULTS Integration of multiple data sources enabled the establishment of a robust disease prediction model for mOTC-D. Residual enzymatic OTC activity not only correlates with age at first symptoms, initial peak plasma ammonium concentration and frequency of metabolic decompensations but also predicts mortality. The critical threshold of 4.3% residual enzymatic activity distinguishes a severe from an attenuated phenotype. INTERPRETATION Residual enzymatic OTC activity reliably predicts the disease severity in mOTC-D and could thus serve as a tool for severity-adjusted evaluation of therapeutic strategies and counselling patients and parents.
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Affiliation(s)
- Svenja Scharre
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Roland Posset
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sven F Garbade
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Florian Gleich
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Marie J Seidl
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ann-Catrin Druck
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jürgen G Okun
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Andrea L Gropman
- Division of Neurodevelopmental Pediatrics and Neurogenetics, Children's National Health System and The George Washington School of Medicine, Washington, District of Columbia, USA
| | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Georg F Hoffmann
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Kölker
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Zielonka
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany.,Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany
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Duff C, Baruteau J. Modelling urea cycle disorders using iPSCs. NPJ Regen Med 2022; 7:56. [PMID: 36163209 PMCID: PMC9513077 DOI: 10.1038/s41536-022-00252-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 08/10/2022] [Indexed: 11/23/2022] Open
Abstract
The urea cycle is a liver-based pathway enabling disposal of nitrogen waste. Urea cycle disorders (UCDs) are inherited metabolic diseases caused by deficiency of enzymes or transporters involved in the urea cycle and have a prevalence of 1:35,000 live births. Patients present recurrent acute hyperammonaemia, which causes high rate of death and neurological sequelae. Long-term therapy relies on a protein-restricted diet and ammonia scavenger drugs. Currently, liver transplantation is the only cure. Hence, high unmet needs require the identification of effective methods to model these diseases to generate innovative therapeutics. Advances in both induced pluripotent stem cells (iPSCs) and genome editing technologies have provided an invaluable opportunity to model patient-specific phenotypes in vitro by creating patients’ avatar models, to investigate the pathophysiology, uncover novel therapeutic targets and provide a platform for drug discovery. This review summarises the progress made thus far in generating 2- and 3-dimensional iPSCs models for UCDs, the challenges encountered and how iPSCs offer future avenues for innovation in developing the next-generation of therapies for UCDs.
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Affiliation(s)
- Claire Duff
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Julien Baruteau
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London, UK. .,National Institute of Health Research Great Ormond Street Biomedical Research Centre, London, UK. .,Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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Imoto K, Tanaka M, Goya T, Aoyagi T, Takahashi M, Kurokawa M, Tashiro S, Kato M, Kohjima M, Ogawa Y. Corticosteroid suppresses urea-cycle-related gene expressions in ornithine transcarbamylase deficiency. BMC Gastroenterol 2022; 22:144. [PMID: 35346058 PMCID: PMC8962007 DOI: 10.1186/s12876-022-02213-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/14/2022] [Indexed: 12/11/2022] Open
Abstract
Background Ornithine transcarbamylase deficiency (OTCD) is most common among urea cycle disorders (UCDs), defined by defects in enzymes associated with ureagenesis. Corticosteroid administration to UCD patients, including OTCD patients, is suggested to be avoided, as it may induce life-threatening hyperammonemia. The mechanism has been considered nitrogen overload due to the catabolic effect of corticosteroids; however, the pathophysiological process is unclear. Methods To elucidate the mechanism of hyperammonemia induced by corticosteroid administration in OTCD patients, we analyzed a mouse model by administering corticosteroids to OTCspf−ash mice deficient in the OTC gene. Dexamethasone (DEX; 20 mg/kg) was administered to the OTCspf−ash and wild-type (WT) mice at 0 and 24 h, and the serum ammonia concentrations, the levels of the hepatic metabolites, and the gene expressions related with ammonia metabolism in the livers and muscles were analyzed. Results The ammonia levels in Otcspf−ash mice that were administered DEX tended to increase at 24 h and increased significantly at 48 h. The metabolomic analysis showed that the levels of citrulline, arginine, and ornithine did not differ significantly between Otcspf−ash mice that were administered DEX and normal saline; however, the level of aspartate was increased drastically in Otcspf−ash mice owing to DEX administration (P < 0.01). Among the enzymes associated with the urea cycle, mRNA expressions of carbamoyl-phosphate synthase 1, ornithine transcarbamylase, arginosuccinate synthase 1, and arginosuccinate lyase in the livers were significantly downregulated by DEX administration in both the Otcspf−ash and WT mice (P < 0.01). Among the enzymes associated with catabolism, mRNA expression of Muscle RING-finger protein-1 in the muscles was significantly upregulated in the muscles of WT mice by DEX administration (P < 0.05). Conclusions We elucidated that corticosteroid administration induced hyperammonemia in Otcspf−ash mice by not only muscle catabolism but also suppressing urea-cycle-related gene expressions. Since the urea cycle intermediate amino acids, such as arginine, might not be effective because of the suppressed expression of urea-cycle-related genes by corticosteroid administration, we should consider an early intervention by renal replacement therapy in cases of UCD patients induced by corticosteroids to avoid brain injuries or fatal outcomes. Supplementary Information The online version contains supplementary material available at 10.1186/s12876-022-02213-0.
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Santamaria R, Ballester M, Garcia-Llorens G, Martinez F, Blazquez M, Ribes-Koninckx C, Castell JV, Wuestefeld T, Bort R. Derivation of healthy hepatocyte-like cells from a female patient with ornithine transcarbamylase deficiency through X-inactivation selection. Sci Rep 2022; 12:2308. [PMID: 35145162 PMCID: PMC8831560 DOI: 10.1038/s41598-022-06184-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 01/18/2022] [Indexed: 11/09/2022] Open
Abstract
Autologous cell replacement therapy for inherited metabolic disorders requires the correction of the underlying genetic mutation in patient's cells. An unexplored alternative for females affected from X-linked diseases is the clonal selection of cells randomly silencing the X-chromosome containing the mutant allele, without in vivo or ex vivo genome editing. In this report, we have isolated dermal fibroblasts from a female patient affected of ornithine transcarbamylase deficiency and obtained clones based on inactivation status of either maternally or paternally inherited X chromosome, followed by differentiation to hepatocytes. Hepatocyte-like cells derived from these clones display indistinct features characteristic of hepatocytes, but express either the mutant or wild type OTC allele depending on X-inactivation pattern. When clonally derived hepatocyte-like cells were transplanted into FRG® KO mice, they were able to colonize the liver and recapitulate OTC-dependent phenotype conditioned by X-chromosome inactivation pattern. This approach opens new strategies for cell therapy of X-linked metabolic diseases and experimental in vitro models for drug development for such diseases.
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Affiliation(s)
- Ramon Santamaria
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Maria Ballester
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Guillem Garcia-Llorens
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain
- Biochemistry and Molecular Biology Department, Universidad de Valencia, Valencia, Spain
| | - Francisco Martinez
- Genetics Unit, Instituto de Investigación Sanitaria La Fe, Hospital Universitari i Politècnic La Fe, 46026, Valencia, Spain
| | - Marina Blazquez
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Carmen Ribes-Koninckx
- Coeliac Disease and Inmunopathology Research Unit, Instituto de Investigación Sanitaria La Fe, Pediatric Gastroenterology, Hospital Universitari i Politècnic La Fe, 46026, Valencia, Spain
| | - Jose V Castell
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain
- Biochemistry and Molecular Biology Department, Universidad de Valencia, Valencia, Spain
| | - Torsten Wuestefeld
- Laboratory for In Vivo Genetics & Gene Therapy, Genome Institute of Singapore, A*STAR & National Cancer Centre Singapore, School of Biological Science, SingHealth & Adj. Ass.-Prof. Nanyang Technological University, 60 Biopolis Street, #02-01 Genome, Singapore, 138672, Singapore
| | - Roque Bort
- Experimental Hepatology Unit, Instituto de Investigación Sanitaria La Fe, CIBERehd, Hospital Universitari i Politècnic La Fe, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain.
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Timmer C, Davids M, Nieuwdorp M, Levels JHM, Langendonk JG, Breederveld M, Ahmadi Mozafari N, Langeveld M. Differences in faecal microbiome composition between adult patients with UCD and PKU and healthy control subjects. Mol Genet Metab Rep 2021; 29:100794. [PMID: 34527515 PMCID: PMC8433284 DOI: 10.1016/j.ymgmr.2021.100794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 01/07/2023] Open
Abstract
Urea cycle disorders (UCDs) are a group of rare inherited metabolic diseases causing hyperammonemic encephalopathy. Despite intensive dietary and pharmacological therapy, outcome is poor in a subset of UCD patients. Reducing ammonia production by changing faecal microbiome in UCD is an attractive treatment approach. We compared faecal microbiome composition of 10 UCD patients, 10 healthy control subjects and 10 phenylketonuria (PKU) patients. PKU patients on a low protein diet were included to differentiate between the effect of a low protein diet and the UCD itself on microbial composition. Participants were asked to collect a faecal sample and to fill out a 24 h dietary journal. DNA was extracted from faecal material, taxonomy was assigned and microbiome data was analyzed, with a focus on microbiota involved in ammonia metabolism.In this study we show an altered faecal microbiome in UCD patients, different from both PKU and healthy controls. UCD patients on dietary and pharmacological treatment had a less diverse faecal microbiome, and the faecal microbiome of PKU patients on a protein restricted diet with amino acid supplementation showed reduced richness compared to healthy adults without a specific diet. The differences in the microbiome composition of UCD patients compared to healthy controls were in part related to lactulose use. Other genomic process encodings involved in ammonia metabolism, did not seem to differ. Since manipulation of the microbiome is possible, this could be a potential treatment modality. We propose as a first next step, to study the impact of these faecal microbiome alterations on metabolic stability. TAKE HOME MESSAGE The faecal microbiome of UCD patients was less diverse compared to PKU patients and even more compared to healthy controls.
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Key Words
- 16S rRNA, taxonomic marker genes, common to all bacteria
- ADI, Arginine Deimination. Bacteria derive energy from the deamination of arginine to citrulline and citrulline cleavage to ornithine plus carbamoyl phosphate. The latter is then converted into ATP and carbon dioxide, or used for pyrimidine biosynthesis. This route also generates two moles of ammonia (one from the arginine-citrulline conversion, the second from carbamoyl phosphate hydrolysis)
- ARG1d, arginase 1 (ARG1) deficiency
- ASLd, argininosuccinate lyase (ASL) deficiency
- ASSd, argininosuccinate synthetase (ASS) deficiency
- ASV, Amplified Sequence Variant. A specific nucleotide sequence representing a bacterial lineage
- Alpha Diversity, the species diversity in a microbial sample. Used to represent the taxonomic diversities of individual samples
- Ammonium scavengers, agents developed for the reduction of blood ammonia concentration used for the treatment of patients with urea cycle disorders. Sodiumbenzoate and phenylbutyrate are ammonium scavengers
- BCAA, branched chain amino acids: isoleucine, leucine and valine
- DEGs, differentially expressed genes
- DESeq, an R package to analyse count data from high-throughput sequencing assays such as RNA-Seq and test for differential expression
- EAA supplement, essential amino acids supplement containing L-histidine, L-isoleucine, L-leucine, l-lysine, L-methionine, L-phenylalanine, L-threonine, L-tryptofaan and L-valine with optional L-cystine and L-tyrosine added (depending on what product is used)
- FPD, Faiths Phylogenetic Diversity, alpha diversity metric accounting for genetic diversity
- Faecal
- Genus, a taxonomic rank
- Gut
- Hyperammonemia
- Metagenome, microbiome collective genome
- Microbiome
- OTCd, ornithine transcarbamylase deficiency
- PCoA, Principal Coordinate Analysis. PCoA is aimed at graphically representing a resemblance matrix between p elements (individuals, variables, objects, among others). By using PCoA we can visualize individual and/or group differences. Individual differences can be used to show outliers
- PFAA, precursor free amino acid supplement, in this case phenylalanine free
- PKU, Phenylketonuria
- Phenylketonuria
- Proteolytic capacity, the capacity to break proteins down into smaller polypeptides or amino acids. In this study: enzymes involved in protein degradation
- RT-qPCR, real-time quantitative polymerase chain reaction
- Sodium BPA, sodium phenylbutyrate
- UCD, urea cycle defect
- Urea cycle defect
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Affiliation(s)
- C Timmer
- Department of Dietetics and Nutritional science and Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - M Davids
- Department of Vascular Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - M Nieuwdorp
- Department of Vascular Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - J H M Levels
- Department of Vascular Medicine, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - J G Langendonk
- Department of Dietetics and Department of Internal Medicine, Center of Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Erasmus MC, Rotterdam, the Netherlands
| | - M Breederveld
- Department of Dietetics and Department of Internal Medicine, Center of Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Erasmus MC, Rotterdam, the Netherlands
| | - N Ahmadi Mozafari
- Department of Dietetics and Department of Internal Medicine, Center of Lysosomal and Metabolic Diseases, Erasmus University Medical Center, Erasmus MC, Rotterdam, the Netherlands
| | - M Langeveld
- Department of Dietetics and Nutritional science and Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, the Netherlands
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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