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Delbreil P, Dhondt S, Kenaan El Rahbani RM, Banquy X, Mitchell JJ, Brambilla D. Current Advances and Material Innovations in the Search for Novel Treatments of Phenylketonuria. Adv Healthc Mater 2024:e2401353. [PMID: 38801163 DOI: 10.1002/adhm.202401353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Phenylketonuria (PKU) is a genetically inherited disease caused by a mutation of the gene encoding phenylalanine hydroxylase (PAH) and is the most common inborn error of amino acid metabolism. A deficiency of PAH leads to increased blood and brain levels of phenylalanine (Phe), which may cause permanent neurocognitive symptoms and developmental delays if untreated. Current management strategies for PKU consist of early detection through neonatal screening and implementation of a restrictive diet with minimal amounts of natural protein in combination with Phe-free supplements and low-protein foods to meet nutritional requirements. For milder forms of PKU, oral treatment with synthetic sapropterin (BH4), the cofactor of PAH, may improve metabolic control of Phe and allow for more natural protein to be included in the patient's diet. For more severe forms, daily injections of pegvaliase, a PEGylated variant of phenylalanine ammonia-lyase (PAL), may allow for normalization of blood Phe levels. However, the latter treatment has considerable drawbacks, notably a strong immunogenicity of the exogenous enzyme and the attached polymeric chains. Research for novel therapies of PKU makes use of innovative materials for drug delivery and state-of-the-art protein engineering techniques to develop treatments which are safer, more effective, and potentially permanent.
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Affiliation(s)
- Philippe Delbreil
- Faculty of Pharmacy, Université de Montréal, Québec, H3T 1J4, Canada
| | - Sofie Dhondt
- Faculty of Pharmacy, Université de Montréal, Québec, H3T 1J4, Canada
| | | | - Xavier Banquy
- Faculty of Pharmacy, Université de Montréal, Québec, H3T 1J4, Canada
| | - John J Mitchell
- Department of Pediatrics, Faculty of Medicine and Health Sciences, McGill University, Québec, H4A 3J1, Canada
| | - Davide Brambilla
- Faculty of Pharmacy, Université de Montréal, Québec, H3T 1J4, Canada
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2
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Martinez M, Harding CO, Schwank G, Thöny B. State-of-the-art 2023 on gene therapy for phenylketonuria. J Inherit Metab Dis 2024; 47:80-92. [PMID: 37401651 PMCID: PMC10764640 DOI: 10.1002/jimd.12651] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/13/2023] [Accepted: 06/30/2023] [Indexed: 07/05/2023]
Abstract
Phenylketonuria (PKU) or hyperphenylalaninemia is considered a paradigm for an inherited (metabolic) liver defect and is, based on murine models that replicate all human pathology, an exemplar model for experimental studies on liver gene therapy. Variants in the PAH gene that lead to hyperphenylalaninemia are never fatal (although devastating if untreated), newborn screening has been available for two generations, and dietary treatment has been considered for a long time as therapeutic and satisfactory. However, significant shortcomings of contemporary dietary treatment of PKU remain. A long list of various gene therapeutic experimental approaches using the classical model for human PKU, the homozygous enu2/2 mouse, witnesses the value of this model to develop treatment for a genetic liver defect. The list of experiments for proof of principle includes recombinant viral (AdV, AAV, and LV) and non-viral (naked DNA or LNP-mRNA) vector delivery methods, combined with gene addition, genome, gene or base editing, and gene insertion or replacement. In addition, a list of current and planned clinical trials for PKU gene therapy is included. This review summarizes, compares, and evaluates the various approaches for the sake of scientific understanding and efficacy testing that may eventually pave the way for safe and efficient human application.
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Affiliation(s)
- Michael Martinez
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
| | - Cary O. Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
| | - Gerald Schwank
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Beat Thöny
- Division of Metabolism, University Children’s Hospital Zurich and Children’s Research Centre, Zurich, Switzerland
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3
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Brooks DL, Carrasco MJ, Qu P, Peranteau WH, Ahrens-Nicklas RC, Musunuru K, Alameh MG, Wang X. Rapid and definitive treatment of phenylketonuria in variant-humanized mice with corrective editing. Nat Commun 2023; 14:3451. [PMID: 37301931 PMCID: PMC10257655 DOI: 10.1038/s41467-023-39246-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023] Open
Abstract
Phenylketonuria (PKU), an autosomal recessive disorder caused by pathogenic variants in the phenylalanine hydroxylase (PAH) gene, results in the accumulation of blood phenylalanine (Phe) to neurotoxic levels. Current dietary and medical treatments are chronic and reduce, rather than normalize, blood Phe levels. Among the most frequently occurring PAH variants in PKU patients is the P281L (c.842C>T) variant. Using a CRISPR prime-edited hepatocyte cell line and a humanized PKU mouse model, we demonstrate efficient in vitro and in vivo correction of the P281L variant with adenine base editing. With the delivery of ABE8.8 mRNA and either of two guide RNAs in vivo using lipid nanoparticles (LNPs) in humanized PKU mice, we observe complete and durable normalization of blood Phe levels within 48 h of treatment, resulting from corrective PAH editing in the liver. These studies nominate a drug candidate for further development as a definitive treatment for a subset of PKU patients.
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Affiliation(s)
- Dominique L Brooks
- Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Division of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Manuel J Carrasco
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA
| | - Ping Qu
- Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Division of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - William H Peranteau
- The Center for Fetal Research, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Division of Pediatric General, Thoracic, and Fetal Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rebecca C Ahrens-Nicklas
- Division of Human Genetics and Metabolism, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Kiran Musunuru
- Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
- Division of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Mohamad-Gabriel Alameh
- Department of Bioengineering, George Mason University, Fairfax, Virginia, USA.
- Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Xiao Wang
- Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
- Division of Cardiovascular Medicine, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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4
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Chen A, Pan Y, Chen J. Clinical, genetic, and experimental research of hyperphenylalaninemia. Front Genet 2023; 13:1051153. [PMID: 36685931 PMCID: PMC9845280 DOI: 10.3389/fgene.2022.1051153] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
Hyperphenylalaninemia (HPA) is the most common amino acid metabolism defect in humans. It is an autosomal-recessive disorder of the phenylalanine (Phe) metabolism, in which high Phe concentrations and low tyrosine (Tyr) concentrations in the blood cause phenylketonuria (PKU), brain dysfunction, light pigmentation and musty odor. Newborn screening data of HPA have revealed that the prevalence varies worldwide, with an average of 1:10,000. Most cases of HPA result from phenylalanine hydroxylase (PAH) deficiency, while a small number of HPA are caused by defects in the tetrahydrobiopterin (BH4) metabolism and DnaJ heat shock protein family (Hsp40) member C12 (DNAJC12) deficiency. Currently, the molecular pathophysiology of the neuropathology associated with HPA remains incompletely understood. Dietary restriction of Phe has been highly successful, although outcomes are still suboptimal and patients find it difficult to adhere to the treatment. Pharmacological treatments, such as BH4 and phenylalanine ammonia lyase, are available. Gene therapy for HPA is still in development.
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Affiliation(s)
- Anqi Chen
- Department of Forensic Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yukun Pan
- Barbell Therapeutics Co. Ltd., Shanghai, China,*Correspondence: Yukun Pan, ; Jinzhong Chen,
| | - Jinzhong Chen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, China,*Correspondence: Yukun Pan, ; Jinzhong Chen,
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Zhou L, Su J, Long J, Tao R, Tang W, Qin F, Liu N, Wang Y, Jiao Y, Hu Y, Jiang L, Li L, Yang Y, Yao S. A universal strategy for AAV delivery of base editors to correct genetic point mutations in neonatal PKU mice. Mol Ther Methods Clin Dev 2022; 24:230-240. [PMID: 35141352 PMCID: PMC8803597 DOI: 10.1016/j.omtm.2022.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 01/05/2022] [Indexed: 02/08/2023]
Abstract
Base editing tools enabled efficient conversion of C:G or A:T base pairs to T:A or G:C, which are especially powerful for targeting monogenic lesions. However, in vivo correction of disease-causing mutations is still less efficient because of the large size of base editors. Here, we designed a dual adeno-associated virus (AAV) strategy for in vivo delivery of base editors, in which deaminases were linked to Cas9 through the interaction of GCN4 peptide and its single chain variable fragment (scFv) antibody. We found that one or two copies of GCN4 peptide were enough for the assembly of base editors and produced robust targeted editing. By optimization of single-guide RNAs (sgRNAs) that target phenylketonuria (PKU) mutation, we were able to achieve up to 27.7% correction in vitro. In vivo delivery of this dual AAV base editing system resulted in efficient correction of PKU-related mutation in neonatal mice and subsequent rescue of hyperphenylalaninemia-associated syndromes. Considering the similarity between Cas9 proteins from different organisms, our delivery strategy will be compatible with other Cas9-derived base editors.
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Affiliation(s)
- Lifang Zhou
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Jing Su
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Jie Long
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Rui Tao
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Wenling Tang
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Fengming Qin
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Nan Liu
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Yanhong Wang
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Yaoge Jiao
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Yun Hu
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Lurong Jiang
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Li Li
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Yang Yang
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
| | - Shaohua Yao
- Laboratory of Biotherapy, National Key Laboratory of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Renmin Nanlu 17, Chengdu 610041, Sichuan, China
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Kaiser RA, Weber ND, Trigueros‐Motos L, Allen KL, Martinez M, Cao W, VanLith CJ, Hillin LG, Douar A, González‐Aseguinolaza G, Aldabe R, Lillegard JB. Use of an adeno-associated virus serotype Anc80 to provide durable cure of phenylketonuria in a mouse model. J Inherit Metab Dis 2021; 44:1369-1381. [PMID: 33896013 PMCID: PMC9291745 DOI: 10.1002/jimd.12392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 12/02/2022]
Abstract
Phenylketonuria (PKU) is the most common inborn error of metabolism of the liver, and results from mutations of both alleles of the phenylalanine hydroxylase gene (PAH). As such, it is a suitable target for gene therapy via gene delivery with a recombinant adeno-associated virus (AAV) vector. Here we use the synthetic AAV vector Anc80 via systemic administration to deliver a functional copy of a codon-optimized human PAH gene, with or without an intron spacer, to the Pahenu2 mouse model of PKU. Dose-dependent transduction of the liver and expression of PAH mRNA were present with both vectors, resulting in significant and durable reduction of circulating phenylalanine, reaching near control levels in males. Coat color of treated Pahenu2 mice reflected an increase in pigmentation from brown to the black color of control animals, further indicating functional restoration of phenylalanine metabolism and its byproduct melanin. There were no adverse effects associated with administration of AAV up to 5 × 1012 VG/kg, the highest dose tested. Only minor and/or transient variations in some liver enzymes were observed in some of the AAV-dosed animals which were not associated with pathology findings in the liver. Finally, there was no impact on cell turnover or apoptosis as evaluated by Ki-67 and TUNEL staining, further supporting the safety of this approach. This study demonstrates the therapeutic potential of AAV Anc80 to safely and durably cure PKU in a mouse model, supporting development for clinical consideration.
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Affiliation(s)
- Robert A. Kaiser
- Children's Hospitals and Clinics of MinnesotaMinneapolisMinnesotaUSA
- Department of SurgeryMayo ClinicRochesterMinnesotaUSA
| | | | | | - Kari L. Allen
- Department of SurgeryMayo ClinicRochesterMinnesotaUSA
| | - Michael Martinez
- Department of Molecular and Medical GeneticsOregon Health & Science UniversityPortlandOregonUSA
| | - William Cao
- Department of SurgeryMayo ClinicRochesterMinnesotaUSA
| | | | | | | | - Gloria González‐Aseguinolaza
- Vivet Therapeutics S.L.PamplonaSpain
- Division of Gene Therapy and Regulation of Gene ExpressionCIMA Universidad de NavarraPamplonaSpain
- Instituto de Investigación Sanitaria de Navarra (IdISNA)PamplonaSpain
| | - Rafael Aldabe
- Division of Gene Therapy and Regulation of Gene ExpressionCIMA Universidad de NavarraPamplonaSpain
| | - Joseph B. Lillegard
- Children's Hospitals and Clinics of MinnesotaMinneapolisMinnesotaUSA
- Department of SurgeryMayo ClinicRochesterMinnesotaUSA
- Pediatric Surgical AssociatesMinneapolisMinnesotaUSA
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7
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Jensen TL, Gøtzsche CR, Woldbye DPD. Current and Future Prospects for Gene Therapy for Rare Genetic Diseases Affecting the Brain and Spinal Cord. Front Mol Neurosci 2021; 14:695937. [PMID: 34690692 PMCID: PMC8527017 DOI: 10.3389/fnmol.2021.695937] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 09/02/2021] [Indexed: 12/12/2022] Open
Abstract
In recent years, gene therapy has been raising hopes toward viable treatment strategies for rare genetic diseases for which there has been almost exclusively supportive treatment. We here review this progress at the pre-clinical and clinical trial levels as well as market approvals within diseases that specifically affect the brain and spinal cord, including degenerative, developmental, lysosomal storage, and metabolic disorders. The field reached an unprecedented milestone when Zolgensma® (onasemnogene abeparvovec) was approved by the FDA and EMA for in vivo adeno-associated virus-mediated gene replacement therapy for spinal muscular atrophy. Shortly after EMA approved Libmeldy®, an ex vivo gene therapy with lentivirus vector-transduced autologous CD34-positive stem cells, for treatment of metachromatic leukodystrophy. These successes could be the first of many more new gene therapies in development that mostly target loss-of-function mutation diseases with gene replacement (e.g., Batten disease, mucopolysaccharidoses, gangliosidoses) or, less frequently, gain-of-toxic-function mutation diseases by gene therapeutic silencing of pathologic genes (e.g., amyotrophic lateral sclerosis, Huntington's disease). In addition, the use of genome editing as a gene therapy is being explored for some diseases, but this has so far only reached clinical testing in the treatment of mucopolysaccharidoses. Based on the large number of planned, ongoing, and completed clinical trials for rare genetic central nervous system diseases, it can be expected that several novel gene therapies will be approved and become available within the near future. Essential for this to happen is the in depth characterization of short- and long-term effects, safety aspects, and pharmacodynamics of the applied gene therapy platforms.
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Affiliation(s)
- Thomas Leth Jensen
- Department of Neurology, Rigshospitalet University Hospital, Copenhagen, Denmark
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Zheng Q, Qin F, Luo R, Jin C, Huang H, Xi H, Xiao W, Guo M, Yang S, He S, Cheng L, Fan N, Yao S, Song X. mRNA‐Loaded Lipid‐Like Nanoparticles for Liver Base Editing Via the Optimization of Central Composite Design. ADVANCED FUNCTIONAL MATERIALS 2021. [DOI: 10.1002/adfm.202011068] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Qian Zheng
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Fengming Qin
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Ruijie Luo
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Chaohui Jin
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Hai Huang
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - He Xi
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Wen Xiao
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Mengran Guo
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Shuping Yang
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Siyan He
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Lizhi Cheng
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Na Fan
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Shaohua Yao
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
| | - Xiangrong Song
- Department of Critical Care Medicine Frontiers Science Center for Disease‐related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University No.17, Section 3, Renmin South Road Chengdu China
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Abstract
Phenylketonuria (PKU; also known as phenylalanine hydroxylase (PAH) deficiency) is an autosomal recessive disorder of phenylalanine metabolism, in which especially high phenylalanine concentrations cause brain dysfunction. If untreated, this brain dysfunction results in severe intellectual disability, epilepsy and behavioural problems. The prevalence varies worldwide, with an average of about 1:10,000 newborns. Early diagnosis is based on newborn screening, and if treatment is started early and continued, intelligence is within normal limits with, on average, some suboptimal neurocognitive function. Dietary restriction of phenylalanine has been the mainstay of treatment for over 60 years and has been highly successful, although outcomes are still suboptimal and patients can find the treatment difficult to adhere to. Pharmacological treatments are available, such as tetrahydrobiopterin, which is effective in only a minority of patients (usually those with milder PKU), and pegylated phenylalanine ammonia lyase, which requires daily subcutaneous injections and causes adverse immune responses. Given the drawbacks of these approaches, other treatments are in development, such as mRNA and gene therapy. Even though PAH deficiency is the most common defect of amino acid metabolism in humans, brain dysfunction in individuals with PKU is still not well understood and further research is needed to facilitate development of pathophysiology-driven treatments.
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Affiliation(s)
- Francjan J van Spronsen
- Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, Groningen, Netherlands.
| | - Nenad Blau
- University Children's Hospital in Zurich, Zurich, Switzerland
| | - Cary Harding
- Department of Molecular and Medical Genetics and Department of Pediatrics, Oregon Health & Science University, Oregon, USA
| | | | - Nicola Longo
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Annet M Bosch
- University of Amsterdam, Department of Pediatrics, Division of Metabolic Disorders, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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10
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Tao R, Xiao L, Zhou L, Zheng Z, Long J, Zhou L, Tang M, Dong B, Yao S. Long-Term Metabolic Correction of Phenylketonuria by AAV-Delivered Phenylalanine Amino Lyase. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 19:507-517. [PMID: 33335942 PMCID: PMC7733040 DOI: 10.1016/j.omtm.2019.12.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 12/27/2019] [Indexed: 02/05/2023]
Abstract
Phenylketonuria (PKU) is an inherited metabolic disorder caused by mutation within phenylalanine hydroxylase (PAH) gene. Loss-of-function of PAH leads to accumulation of phenylalanine in the blood/body of an untreated patient, which damages the developing brain, causing severe mental retardation. Current gene therapy strategies based on adeno-associated vector (AAV) delivery of PAH gene were effective in male animals but had little long-term effects on blood hyperphenylalaninemia in females. Here, we designed a gene therapy strategy using AAV to deliver a human codon-optimized phenylalanine amino lyase in a liver-specific manner. It was shown that PAL was active in lysing phenylalanine when it was expressed in mammalian cells. We produced a recombinant adeno-associated vector serotype 8 (AAV8) viral vector expressing the humanized PAL under the control of human antitrypsin (hAAT) promoter (AAV8-PAL). A single intravenous administration of AAV8-PAL caused long-term correction of hyperphenylalaninemia in both male and female PKU mice (strain Pahenu2). Besides, no obvious liver injury was observed throughout the treatment process. Thus, our results established that AAV-mediated liver delivery of PAL gene is a promising strategy in the treatment of PKU.
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Affiliation(s)
- Rui Tao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Lin Xiao
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lifang Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Zhaoyue Zheng
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jie Long
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Lixing Zhou
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Minghai Tang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Biao Dong
- National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Shaohua Yao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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Yin S, Ma L, Shao T, Zhang M, Guan Y, Wang L, Hu Y, Chen X, Han H, Shen N, Qiu W, Geng H, Yu Y, Li S, Yu W, Liu M, Li D. Enhanced genome editing to ameliorate a genetic metabolic liver disease through co-delivery of adeno-associated virus receptor. SCIENCE CHINA-LIFE SCIENCES 2020; 65:718-730. [PMID: 32815069 DOI: 10.1007/s11427-020-1744-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/20/2020] [Indexed: 12/24/2022]
Abstract
Genome editing through adeno-associated viral (AAV) vectors is a promising gene therapy strategy for various diseases, especially genetic disorders. However, homologous recombination (HR) efficiency is extremely low in adult animal models. We assumed that increasing AAV transduction efficiency could increase genome editing activity, especially HR efficiency, for in vivo gene therapy. Firstly, a mouse phenylketonuria (PKU) model carrying a pathogenic R408W mutation in phenylalanine hydroxylase (Pah) was generated. Through co-delivery of the general AAV receptor (AAVR), we found that AAVR could dramatically increase AAV transduction efficiency in vitro and in vivo. Furthermore, co-delivery of SaCas9/sgRNA/donor templates with AAVR via AAV8 vectors increased indel rate over 2-fold and HR rate over 15-fold for the correction of the single mutation in PahR408W mice. Moreover, AAVR co-injection successfully increased the site-specific insertion rate of a 1.4 kb Pah cDNA by 11-fold, bringing the HR rate up to 7.3% without detectable global off-target effects. Insertion of Pah cDNA significantly decreased the Phe level and ameliorated PKU symptoms. This study demonstrates a novel strategy to dramatically increase AAV transduction which substantially enhanced in vivo genome editing efficiency in adult animal models, showing clinical potential for both conventional and genome editing-based gene therapy.
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Affiliation(s)
- Shuming Yin
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Lie Ma
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Tingting Shao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Mei Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yuting Guan
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Liren Wang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Yaqiang Hu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Xi Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Honghui Han
- Bioray Laboratories Inc., Shanghai, 200241, China
| | - Nan Shen
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Wenjuan Qiu
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Hongquan Geng
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Yongguo Yu
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Shichang Li
- College of Physical Education and Health, East China Normal University, Shanghai, 200241, China.,Key Laboratory of Adolescent Health Assessment and Exercise Intervention, Ministry of Education, College of Physical Education and Health, East China Normal University, Shanghai, 200241, China
| | - Weishi Yu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China.,CIPHER GENE LLC, Beijing, 100089, China
| | - Mingyao Liu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China
| | - Dali Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200241, China.
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12
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Harding CO. Prospects for Cell-Directed Curative Therapy of Phenylketonuria (PKU). MOLECULAR FRONTIERS JOURNAL 2019; 3:110-121. [PMID: 32524084 PMCID: PMC7286632 DOI: 10.1142/s2529732519400145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Phenylketonuria (PKU) due to recessively inherited phenylalanine hydroxylase (PAH) deficiency is among the most common inborn errors of metabolism. Dietary therapy begun early in infancy prevents the major manifestations of the disease but shortcomings to treatment continue to exist including lifelong commitment to a complicated and unpalatable diet, poor adherence to diet in adolescence and adulthood, and consequently a range of unsatisfactory outcomes, including neuropsychiatric disorders, frequently develop. Novel treatments that do not strictly depend upon dietary protein restriction are actively sought. This review discusses the potential for and the limitations of permanently curative cell-directed treatment of PKU, including liver-directed gene therapy and gene editing, if initiated during early infancy. A fictional but realistic vignette of a family with a new baby girl recently diagnosed with PKU is presented. What is needed to permanently cure her?
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Affiliation(s)
- Cary O Harding
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
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13
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Zabaleta N, Hommel M, Salas D, Gonzalez-Aseguinolaza G. Genetic-Based Approaches to Inherited Metabolic Liver Diseases. Hum Gene Ther 2019; 30:1190-1203. [DOI: 10.1089/hum.2019.140] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Nerea Zabaleta
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - Mirja Hommel
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - David Salas
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
| | - Gloria Gonzalez-Aseguinolaza
- Gene Therapy and Regulation of Gene Expression Program, Centro de Investigación Médica Aplicada, IDISNA, Universidad de Navarra, Pamplona, Spain
- Vivet Therapeutics, Pamplona, Spain
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14
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Grisch-Chan HM, Schwank G, Harding CO, Thöny B. State-of-the-Art 2019 on Gene Therapy for Phenylketonuria. Hum Gene Ther 2019; 30:1274-1283. [PMID: 31364419 PMCID: PMC6763965 DOI: 10.1089/hum.2019.111] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/22/2019] [Indexed: 12/21/2022] Open
Abstract
Phenylketonuria (PKU) is considered to be a paradigm for a monogenic metabolic disorder but was never thought to be a primary application for human gene therapy due to established alternative treatment. However, somewhat unanticipated improvement in neuropsychiatric outcome upon long-term treatment of adults with PKU with enzyme substitution therapy might slowly change this assumption. In parallel, PKU was for a long time considered to be an excellent test system for experimental gene therapy of a Mendelian autosomal recessive defect of the liver due to an outstanding mouse model and the easy to analyze and well-defined therapeutic end point, that is, blood l-phenylalanine concentration. Lifelong treatment by targeting the mouse liver (or skeletal muscle) was achieved using different approaches, including (1) recombinant adeno-associated viral (rAAV) or nonviral naked DNA vector-based gene addition, (2) genome editing using base editors delivered by rAAV vectors, and (3) by delivering rAAVs for promoter-less insertion of the PAH-cDNA into the Pah locus. In this article we summarize the gene therapeutic attempts of correcting a mouse model for PKU and discuss the future implications for human gene therapy.
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Affiliation(s)
- Hiu Man Grisch-Chan
- Division of Metabolism, University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Gerald Schwank
- Department of Biology, Institute for Molecular Health Sciences, ETH Zurich, Zurich, Switzerland
| | - Cary O. Harding
- Department of Molecular and Medical Genetics, School of Medicine, Oregon Science and Health University, Portland, Oregon
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
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15
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Chavez DE, Gronau I, Hains T, Kliver S, Koepfli KP, Wayne RK. Comparative genomics provides new insights into the remarkable adaptations of the African wild dog (Lycaon pictus). Sci Rep 2019; 9:8329. [PMID: 31171819 PMCID: PMC6554312 DOI: 10.1038/s41598-019-44772-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/22/2019] [Indexed: 12/02/2022] Open
Abstract
Within the Canidae, the African wild dog (Lycaon pictus) is the most specialized with regards to cursorial adaptations (specialized for running), having only four digits on their forefeet. In addition, this species is one of the few canids considered to be an obligate meat-eater, possessing a robust dentition for taking down large prey, and displays one of the most variable coat colorations amongst mammals. Here, we used comparative genomic analysis to investigate the evolutionary history and genetic basis for adaptations associated with cursoriality, hypercanivory, and coat color variation in African wild dogs. Genome-wide scans revealed unique amino acid deletions that suggest a mode of evolutionary digit loss through expanded apoptosis in the developing first digit. African wild dog-specific signals of positive selection also uncovered a putative mechanism of molar cusp modification through changes in genes associated with the sonic hedgehog (SHH) signaling pathway, required for spatial patterning of teeth, and three genes associated with pigmentation. Divergence time analyses suggest the suite of genomic changes we identified evolved ~1.7 Mya, coinciding with the diversification of large-bodied ungulates. Our results show that comparative genomics is a powerful tool for identifying the genetic basis of evolutionary changes in Canidae.
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Affiliation(s)
- Daniel E Chavez
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA.
| | - Ilan Gronau
- Efi Arazi School of Computer Science, Herzliya Interdisciplinary Center (IDC), Herzliya, 46150, Israel
| | - Taylor Hains
- Environmental Science and Policy, Johns Hopkins University, Washington, D.C., 20036, USA
| | - Sergei Kliver
- Institute of Molecular and Cellular Biology, Novosibirsk, 630090, Russian Federation
| | - Klaus-Peter Koepfli
- Smithsonian Conservation Biology Institute, National Zoological Park, Washington, D.C., 20008, USA
- Theodosius Dobzhansky Center for Genome Bioinformatics, Saint Petersburg State University, Saint Petersburg, 199034, Russian Federation
| | - Robert K Wayne
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA
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16
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Villiger L, Grisch-Chan HM, Lindsay H, Ringnalda F, Pogliano CB, Allegri G, Fingerhut R, Häberle J, Matos J, Robinson MD, Thöny B, Schwank G. Treatment of a metabolic liver disease by in vivo genome base editing in adult mice. Nat Med 2018; 24:1519-1525. [DOI: 10.1038/s41591-018-0209-1] [Citation(s) in RCA: 210] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/22/2018] [Indexed: 01/05/2023]
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17
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Improved Lentiviral Gene Delivery to Mouse Liver by Hydrodynamic Vector Injection through Tail Vein. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 12:672-683. [PMID: 30092403 PMCID: PMC6083003 DOI: 10.1016/j.omtn.2018.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 07/09/2018] [Accepted: 07/09/2018] [Indexed: 12/15/2022]
Abstract
Delivery of genes to mouse liver is routinely accomplished by tail-vein injections of viral vectors or naked plasmid DNA. While viral vectors are typically injected in a low-pressure and -volume fashion, uptake of naked plasmid DNA to hepatocytes is facilitated by high pressure and volumes, also known as hydrodynamic delivery. In this study, we compare the efficacy and specificity of delivery of vesicular stomatitis virus G glycoprotein (VSV-G) pseudotyped lentiviral vectors to mouse liver by a number of injection schemes. Exploiting in vivo bioluminescence imaging as a readout after lentiviral gene transfer, we compare delivery by (1) “conventional” tail-vein injections, (2) “primed” injections, (3) “hydrodynamic” injections, or (4) direct “intrahepatic” injections into exposed livers. Reporter gene activity demonstrate potent and targeted delivery to liver by hydrodynamic injections. Enhanced efficacy is confirmed by analysis of liver sections from mice treated with GFP-encoding vectors, demonstrating 10-fold higher transduction rates and gene delivery to ∼80% of hepatocytes after hydrodynamic vector delivery. In summary, lentiviral vector transfer to mouse liver can be strongly augmented by hydrodynamic tail-vein injections, resulting in both reduced off-target delivery and transduction of the majority of hepatocytes. Our findings pave the way for more effective use of lentiviral gene delivery in the mouse.
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18
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Production of human recombinant phenylalanine hydroxylase in Lactobacillus plantarum for gastrointestinal delivery. Eur J Pharm Sci 2017; 109:48-55. [DOI: 10.1016/j.ejps.2017.07.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/24/2017] [Accepted: 07/28/2017] [Indexed: 01/08/2023]
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19
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Low-Dose Gene Therapy for Murine PKU Using Episomal Naked DNA Vectors Expressing PAH from Its Endogenous Liver Promoter. MOLECULAR THERAPY. NUCLEIC ACIDS 2017. [PMID: 28624210 PMCID: PMC5423318 DOI: 10.1016/j.omtn.2017.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Limited duration of transgene expression, insertional mutagenesis, and size limitations for transgene cassettes pose challenges and risk factors for many gene therapy vectors. Here, we report on physiological expression of liver phenylalanine hydroxylase (PAH) by delivery of naked DNA/minicircle (MC)-based vectors for correction of homozygous enu2 mice, a model of human phenylketonuria (PKU). Because MC vectors lack a defined size limit, we constructed a MC vector expressing a codon-optimized murine Pah cDNA that includes a truncated intron and is under the transcriptional control of a 3.6-kb native Pah promoter/enhancer sequence. This vector, delivered via hydrodynamic injection, yielded therapeutic liver PAH activity and sustained correction of blood phenylalanine comparable to viral or synthetic liver promoters. Therapeutic efficacy was seen with vector copy numbers of <1 vector genome per diploid hepatocyte genome and was achieved at a vector dose that was significantly lowered. Partial hepatectomy and subsequent liver regeneration was associated with >95% loss of vector genomes and PAH activity in liver, demonstrating that MC vectors had not integrated into the liver genome. In conclusion, MC vectors, which do not have a defined size-limitation, offer a favorable safety profile for hepatic gene therapy due to their non-integration in combination with native promoters.
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20
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Wang L, Bell P, Morizono H, He Z, Pumbo E, Yu H, White J, Batshaw ML, Wilson JM. AAV gene therapy corrects OTC deficiency and prevents liver fibrosis in aged OTC-knock out heterozygous mice. Mol Genet Metab 2017; 120:299-305. [PMID: 28283349 PMCID: PMC5423267 DOI: 10.1016/j.ymgme.2017.02.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/28/2017] [Accepted: 02/28/2017] [Indexed: 12/23/2022]
Abstract
Ornithine transcarbamylase (OTC) deficiency is an X-linked disorder of the urea cycle. Hemizygous males and heterozygous females may experience life-threatening elevations of ammonia in blood and brain, leading to irreversible cognitive impairment, coma, and death. Recent evidence of acute liver failure and fibrosis/cirrhosis is also emerging in OTC-deficient patients. Here, we investigated the long-term consequences of abnormal ureagenesis in female mice heterozygous (Het) for a null mutation in the OTC gene. Two-month-old Het OTC knockout (KO) mice received a single dose of self-complementary adeno-associated virus (AAV) encoding a codon-optimized human OTC gene at 1×1010, 3×1010, or 1×1011 vector genome copies per mouse. We compared liver pathology from 18-month-old treated Het OTC-KO mice, age-matched untreated Het OTC-KO mice, and WT littermates, and assessed urinary orotic acid levels and vector genome copies in liver at 4, 10, and 16months following vector administration. Het OTC-KO female mice showed evidence of liver inflammation and the eventual development of significant fibrosis. Treatment with AAV gene therapy not only corrected the underlying metabolic abnormalities, but also prevented the development of liver fibrosis. Our study demonstrates that early treatment of OTC deficiency with gene therapy may prevent clinically relevant consequences of chronic liver damage from developing.
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Affiliation(s)
- Lili Wang
- Gene Therapy Program, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA
| | - Peter Bell
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA
| | - Hiroki Morizono
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Health System, 111 Michigan Ave., Washington, DC 20010, USA
| | - Zhenning He
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA
| | - Elena Pumbo
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Health System, 111 Michigan Ave., Washington, DC 20010, USA
| | - Hongwei Yu
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA
| | - John White
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA
| | - Mark L Batshaw
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Health System, 111 Michigan Ave., Washington, DC 20010, USA
| | - James M Wilson
- Gene Therapy Program, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 125 S. 31st Street, Philadelphia, PA 19104, USA.
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21
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Bruinenberg VM, van der Goot E, van Vliet D, de Groot MJ, Mazzola PN, Heiner-Fokkema MR, van Faassen M, van Spronsen FJ, van der Zee EA. The Behavioral Consequence of Phenylketonuria in Mice Depends on the Genetic Background. Front Behav Neurosci 2016; 10:233. [PMID: 28066199 PMCID: PMC5167755 DOI: 10.3389/fnbeh.2016.00233] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 11/28/2016] [Indexed: 12/31/2022] Open
Abstract
To unravel the role of gene mutations in the healthy and the diseased state, countless studies have tried to link genotype with phenotype. However, over the years, it became clear that the strain of mice can influence these results. Nevertheless, identical gene mutations in different strains are often still considered equals. An example of this, is the research done in phenylketonuria (PKU), an inheritable metabolic disorder. In this field, a PKU mouse model (either on a BTBR or C57Bl/6 background) is often used to examine underlying mechanisms of the disease and/or new treatment strategies. Both strains have a point mutation in the gene coding for the enzyme phenylalanine hydroxylase which causes toxic concentrations of the amino acid phenylalanine in blood and brain, as found in PKU patients. Although the mutation is identical and therefore assumed to equally affect physiology and behavior in both strains, no studies directly compared the two genetic backgrounds to test this assumption. Therefore, this study compared the BTBR and C57Bl/6 wild-type and PKU mice on PKU-relevant amino acid- and neurotransmitter-levels and at a behavioral level. The behavioral paradigms were selected from previous literature on the PKU mouse model and address four domains, namely (1) activity levels, (2) motor performance, (3) anxiety and/or depression-like behavior, and (4) learning and memory. The results of this study showed comparable biochemical changes in phenylalanine and neurotransmitter concentrations. In contrast, clear differences in behavioral outcome between the strains in all four above-mentioned domains were found, most notably in the learning and memory domain. The outcome in this domain seem to be primarily due to factors inherent to the genetic background of the mouse and much less by differences in PKU-specific biochemical parameters in blood and brain. The difference in behavioral outcome between PKU of both strains emphasizes that the consequence of the PAH mutation is influenced by other factors than Phe levels alone. Therefore, future research should consider these differences when choosing one of the genetic strains to investigate the pathophysiological mechanism underlying PKU-related behavior, especially when combined with new treatment strategies.
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Affiliation(s)
- Vibeke M Bruinenberg
- Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Els van der Goot
- Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Danique van Vliet
- Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen Groningen, Netherlands
| | - Martijn J de Groot
- Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen Groningen, Netherlands
| | - Priscila N Mazzola
- Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of GroningenGroningen, Netherlands; Department of Pediatrics, Beatrix Children's Hospital, University Medical Center GroningenGroningen, Netherlands
| | | | - Martijn van Faassen
- Laboratory Medicine, University of Groningen, University Medical Center Groningen, Netherlands
| | - Francjan J van Spronsen
- Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen Groningen, Netherlands
| | - Eddy A van der Zee
- Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
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Abstract
Metabolic disorders comprise a large group of heterogeneous diseases ranging from very prevalent diseases such as diabetes mellitus to rare genetic disorders like Canavan Disease. Whether either of these diseases is amendable by gene therapy depends to a large degree on the knowledge of their pathomechanism, availability of the therapeutic gene, vector selection, and availability of suitable animal models. In this book chapter, we review three metabolic disorders of the central nervous system (CNS; Canavan Disease, Niemann-Pick disease and Phenylketonuria) to give examples for primary and secondary metabolic disorders of the brain and the attempts that have been made to use adeno-associated virus (AAV) based gene therapy for treatment. Finally, we highlight commonalities and obstacles in the development of gene therapy for metabolic disorders of the CNS exemplified by those three diseases.
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Affiliation(s)
- Dominic J Gessler
- University of Massachusetts Medical School, 368 Plantation Street, AS6-2049, Worcester, MA, 01605, USA
| | - Guangping Gao
- University of Massachusetts Medical School, 368 Plantation Street, AS6-2049, Worcester, MA, 01605, USA.
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23
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Kochhar JS, Chan SY, Ong PS, Kang L. Clinical therapeutics for phenylketonuria. Drug Deliv Transl Res 2015; 2:223-37. [PMID: 25787029 DOI: 10.1007/s13346-012-0067-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phenylketonuria was amongst the first of the metabolic disorders to be characterised, exhibiting an inborn error in phenylalanine metabolism due to a functional deficit of the enzyme phenylalanine hydroxylase. It affects around 700,000 people around the globe. Mutations in the gene coding for hepatic phenylalanine hydroxylase cause this deficiency resulting in elevated plasma phenylalanine concentrations, leading to cognitive impairment, neuromotor disorders and related behavioural symptoms. Inception of low phenylalanine diet in the 1950s marked a revolution in the management of phenylketonuria and has since been a vital element of all therapeutic regimens. However, compliance to dietary therapy has been found difficult and newer supplement approaches are being examined. The current development of gene therapy and enzyme replacement therapeutics may offer promising alternatives for the management of phenylketonuria. This review outlines the pathological basis of phenylketonuria, various treatment regimes, their associated challenges and the future prospects of each approach. Briefly, novel drug delivery systems which can potentially deliver therapeutic strategies in phenylketonuria have been discussed.
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Affiliation(s)
- Jaspreet Singh Kochhar
- Department of Pharmacy, National University of Singapore, 18 Science Drive 4, Block S4 Level 2, Singapore, Singapore, 117543
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24
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Thöny B, Ding Z, Rebuffat A, Viecelli HM. Phenotypic reversion of fair hair upon gene therapy of the phenylketonuria mice. Hum Gene Ther 2015; 25:573-4. [PMID: 25029602 DOI: 10.1089/hum.2014.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Beat Thöny
- 1 Division of Metabolism, Department of Pediatrics, University of Zürich , CH-8032 Zürich, Switzerland
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25
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New Strategies for the Treatment of Phenylketonuria (PKU). Metabolites 2014; 4:1007-17. [PMID: 25375236 PMCID: PMC4279156 DOI: 10.3390/metabo4041007] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 10/27/2014] [Accepted: 10/30/2014] [Indexed: 12/19/2022] Open
Abstract
Phenylketonuria (PKU) was the first inherited metabolic disease in which dietary treatment was found to prevent the disease's clinical features. Treatment of phenylketonuria remains difficult due to progressive decrease in adherence to diet and the presence of neurocognitive defects despite therapy. This review aims to summarize the current literature on new treatment strategies. Additions to treatment include new, more palatable foods based on glycomacropeptide that contains very limited amount of aromatic amino acids, the administration of large neutral amino acids to prevent phenylalanine entry into the brain or tetrahydropterina cofactor capable of increasing residual activity of phenylalanine hydroxylase. Moreover, human trials have recently been performed with subcutaneous administration of phenylalanine ammonia-lyase, and further efforts are underway to develop an oral therapy containing phenylanine ammonia-lyase. Gene therapy also seems to be a promising approach in the near future.
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26
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A sensitive assay system to test antisense oligonucleotides for splice suppression therapy in the mouse liver. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e193. [PMID: 25226162 PMCID: PMC4222650 DOI: 10.1038/mtna.2014.44] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 07/30/2014] [Indexed: 11/22/2022]
Abstract
We have previously demonstrated the efficacy of antisense therapy for splicing defects in cellular models of metabolic diseases, suppressing the use of cryptic splice sites or pseudoexon insertions. To date, no animal models with these defects are available. Here, we propose exon skipping of the phenylalanine hydroxylase (Pah) gene expressed in liver and kidney to generate systemic hyperphenylalaninemia in mice as a sensitive in vivo assay to test splice suppression. Systemic elevation of blood L-Phe can be quantified using tandem MS/MS. Exon 11 and/or 12 skipping for the normal PAH gene was validated in hepatoma cells for comparing two oligonucleotide chemistries, morpholinos and locked nucleic acids. Subsequently, Vivo-morpholinos (VMO) were tested in wild-type and in phenotypically normal Pahenu2/+ heterozygous mice to target exon 11 and/or 12 of the murine Pah gene using different VMO dosing, mode of injection and treatment regimes. Consecutive intravenous injections of VMO resulted in transient hyperphenylalaninemia correlating with complete exon skipping and absence of PAH protein and enzyme activity. Sustained effect required repeated injection of VMOs. Our results provide not only a sensitive in vivo assay to test for splice-modulating antisense oligonucleotides, but also a simple method to generate murine models for genetic liver diseases.
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Viecelli HM, Harbottle RP, Wong SP, Schlegel A, Chuah MK, Vanden Driessche T, Harding CO, Thöny B. Treatment of phenylketonuria using minicircle-based naked-DNA gene transfer to murine liver. Hepatology 2014; 60:1035-43. [PMID: 24585515 PMCID: PMC4449723 DOI: 10.1002/hep.27104] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 02/25/2014] [Indexed: 02/03/2023]
Abstract
UNLABELLED Host immune response to viral vectors, persistence of nonintegrating vectors, and sustained transgene expression are among the major challenges in gene therapy. To overcome these hurdles, we successfully used minicircle (MC) naked-DNA vectors devoid of any viral or bacterial sequences for the long-term treatment of murine phenylketonuria, a model for a genetic liver defect. MC-DNA vectors expressed the murine phenylalanine hydroxylase (Pah) complementary DNA (cDNA) from a liver-specific promoter coupled to a de novo designed hepatocyte-specific regulatory element, designated P3, which is a cluster of evolutionary conserved transcription factor binding sites. MC-DNA vectors were subsequently delivered to the liver by a single hydrodynamic tail vein (HTV) injection. The MC-DNA vector normalized blood phenylalanine concomitant with reversion of hypopigmentation in a dose-dependent manner for more than 1 year, whereas the corresponding parental plasmid did not result in any phenylalanine clearance. MC vectors persisted in an episomal state in the liver consistent with sustained transgene expression and hepatic PAH enzyme activity without any apparent adverse effects. Moreover, 14-20% of all hepatocytes expressed transgenic PAH, and the expression was observed exclusively in the liver and predominately around pericentral areas of the hepatic lobule, while there was no transgene expression in periportal areas. CONCLUSION This study demonstrates that MC technology offers an improved safety profile and has the potential for the genetic treatment of liver diseases.
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Affiliation(s)
- Hiu Man Viecelli
- Division of Metabolism, Department of Pediatrics, University of Zurich, Zurich, Switzerland; and affiliated with the Children’s Research Center Zurich
| | - Richard P. Harbottle
- Section of Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Suet Ping Wong
- Section of Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Andrea Schlegel
- Swiss HPB and Transplant Center, Department of Surgery, University Hospital Zurich, Zurich, Switzerland
| | - Marinee K. Chuah
- Department of Gene Therapy & Regenerative Medicine, Free University of Brussels, Brussels, Belgium
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Thierry Vanden Driessche
- Department of Gene Therapy & Regenerative Medicine, Free University of Brussels, Brussels, Belgium
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Cary O. Harding
- Departments of Molecular and Medical Genetics and Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Beat Thöny
- Division of Metabolism, Department of Pediatrics, University of Zurich, Zurich, Switzerland; and affiliated with the Children’s Research Center Zurich
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Camp KM, Parisi MA, Acosta PB, Berry GT, Bilder DA, Blau N, Bodamer OA, Brosco JP, Brown CS, Burlina AB, Burton BK, Chang CS, Coates PM, Cunningham AC, Dobrowolski SF, Ferguson JH, Franklin TD, Frazier DM, Grange DK, Greene CL, Groft SC, Harding CO, Howell RR, Huntington KL, Hyatt-Knorr HD, Jevaji IP, Levy HL, Lichter-Konecki U, Lindegren ML, Lloyd-Puryear MA, Matalon K, MacDonald A, McPheeters ML, Mitchell JJ, Mofidi S, Moseley KD, Mueller CM, Mulberg AE, Nerurkar LS, Ogata BN, Pariser AR, Prasad S, Pridjian G, Rasmussen SA, Reddy UM, Rohr FJ, Singh RH, Sirrs SM, Stremer SE, Tagle DA, Thompson SM, Urv TK, Utz JR, van Spronsen F, Vockley J, Waisbren SE, Weglicki LS, White DA, Whitley CB, Wilfond BS, Yannicelli S, Young JM. Phenylketonuria Scientific Review Conference: state of the science and future research needs. Mol Genet Metab 2014; 112:87-122. [PMID: 24667081 DOI: 10.1016/j.ymgme.2014.02.013] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 01/17/2023]
Abstract
New developments in the treatment and management of phenylketonuria (PKU) as well as advances in molecular testing have emerged since the National Institutes of Health 2000 PKU Consensus Statement was released. An NIH State-of-the-Science Conference was convened in 2012 to address new findings, particularly the use of the medication sapropterin to treat some individuals with PKU, and to develop a research agenda. Prior to the 2012 conference, five working groups of experts and public members met over a 1-year period. The working groups addressed the following: long-term outcomes and management across the lifespan; PKU and pregnancy; diet control and management; pharmacologic interventions; and molecular testing, new technologies, and epidemiologic considerations. In a parallel and independent activity, an Evidence-based Practice Center supported by the Agency for Healthcare Research and Quality conducted a systematic review of adjuvant treatments for PKU; its conclusions were presented at the conference. The conference included the findings of the working groups, panel discussions from industry and international perspectives, and presentations on topics such as emerging treatments for PKU, transitioning to adult care, and the U.S. Food and Drug Administration regulatory perspective. Over 85 experts participated in the conference through information gathering and/or as presenters during the conference, and they reached several important conclusions. The most serious neurological impairments in PKU are preventable with current dietary treatment approaches. However, a variety of more subtle physical, cognitive, and behavioral consequences of even well-controlled PKU are now recognized. The best outcomes in maternal PKU occur when blood phenylalanine (Phe) concentrations are maintained between 120 and 360 μmol/L before and during pregnancy. The dietary management treatment goal for individuals with PKU is a blood Phe concentration between 120 and 360 μmol/L. The use of genotype information in the newborn period may yield valuable insights about the severity of the condition for infants diagnosed before maximal Phe levels are achieved. While emerging and established genotype-phenotype correlations may transform our understanding of PKU, establishing correlations with intellectual outcomes is more challenging. Regarding the use of sapropterin in PKU, there are significant gaps in predicting response to treatment; at least half of those with PKU will have either minimal or no response. A coordinated approach to PKU treatment improves long-term outcomes for those with PKU and facilitates the conduct of research to improve diagnosis and treatment. New drugs that are safe, efficacious, and impact a larger proportion of individuals with PKU are needed. However, it is imperative that treatment guidelines and the decision processes for determining access to treatments be tied to a solid evidence base with rigorous standards for robust and consistent data collection. The process that preceded the PKU State-of-the-Science Conference, the conference itself, and the identification of a research agenda have facilitated the development of clinical practice guidelines by professional organizations and serve as a model for other inborn errors of metabolism.
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Affiliation(s)
- Kathryn M Camp
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Melissa A Parisi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | | | - Gerard T Berry
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Deborah A Bilder
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84108, USA.
| | - Nenad Blau
- University Children's Hospital, Heidelberg, Germany; University Children's Hospital, Zürich, Switzerland.
| | - Olaf A Bodamer
- University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Jeffrey P Brosco
- University of Miami Mailman Center for Child Development, Miami, FL 33101, USA.
| | | | | | - Barbara K Burton
- Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA.
| | - Christine S Chang
- Agency for Healthcare Research and Quality, Rockville, MD 20850, USA.
| | - Paul M Coates
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Amy C Cunningham
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA 70112, USA.
| | | | - John H Ferguson
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | | | | | - Dorothy K Grange
- Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA.
| | - Carol L Greene
- University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Stephen C Groft
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Cary O Harding
- Oregon Health & Science University, Portland, OR 97239, USA.
| | - R Rodney Howell
- University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | | | - Henrietta D Hyatt-Knorr
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Indira P Jevaji
- Office of Research on Women's Health, National Institutes of Health, Bethesda, MD 20817, USA.
| | - Harvey L Levy
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Uta Lichter-Konecki
- George Washington University, Children's National Medical Center, Washington, DC 20010, USA.
| | | | | | | | | | - Melissa L McPheeters
- Vanderbilt Evidence-based Practice Center, Institute for Medicine and Public Health, Nashville, TN 37203, USA.
| | - John J Mitchell
- McGill University Health Center, Montreal, Quebec H3H 1P3, Canada.
| | - Shideh Mofidi
- Maria Fareri Children's Hospital of Westchester Medical Center, Valhalla, NY 10595, USA.
| | - Kathryn D Moseley
- University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA.
| | - Christine M Mueller
- Office of Orphan Products Development, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Andrew E Mulberg
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Lata S Nerurkar
- Office of Rare Diseases Research, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20982, USA.
| | - Beth N Ogata
- University of Washington, Seattle, WA 98195, USA.
| | - Anne R Pariser
- Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Suyash Prasad
- BioMarin Pharmaceutical Inc., San Rafael, CA 94901, USA.
| | - Gabriella Pridjian
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA 70112, USA.
| | | | - Uma M Reddy
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | | | | | - Sandra M Sirrs
- Vancouver General Hospital, University of British Columbia, Vancouver V5Z 1M9, Canada.
| | | | - Danilo A Tagle
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Susan M Thompson
- The Children's Hospital at Westmead, Sydney, NSW 2145, Australia.
| | - Tiina K Urv
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jeanine R Utz
- University of Minnesota, Minneapolis, MN 55455, USA.
| | - Francjan van Spronsen
- University of Groningen, University Medical Center of Groningen, Beatrix Children's Hospital, Netherlands.
| | - Jerry Vockley
- University of Pittsburgh, Pittsburgh, PA 15224, USA.
| | - Susan E Waisbren
- Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Linda S Weglicki
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Desirée A White
- Department of Psychology, Washington University, St. Louis, MO 63130, USA.
| | | | - Benjamin S Wilfond
- Seattle Children's Research Institute, University of Washington School of Medicine, Seattle, WA 98101, USA.
| | | | - Justin M Young
- The Young Face, Facial Plastic and Reconstructive Surgery, Cumming, GA 30041, USA.
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Sawin EA, Murali SG, Ney DM. Differential effects of low-phenylalanine protein sources on brain neurotransmitters and behavior in C57Bl/6-Pah(enu2) mice. Mol Genet Metab 2014; 111:452-61. [PMID: 24560888 PMCID: PMC3995025 DOI: 10.1016/j.ymgme.2014.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/30/2014] [Indexed: 11/24/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of metabolism caused by a deficiency of the enzyme phenylalanine hydroxylase, which metabolizes phenylalanine (phe) to tyrosine. A low-phe diet plus amino acid (AA) formula is necessary to prevent cognitive impairment; glycomacropeptide (GMP) contains minimal phe and provides a palatable alternative to the AA formula. Our objective was to assess neurotransmitter concentrations in the brain and the behavioral phenotype of PKU mice (Pah(enu2) on the C57Bl/6 background) and how this is affected by low-phe protein sources. Wild type (WT) and PKU mice, both male and female, were fed high-phe casein, low-phe AA, or low-phe GMP diets between 3 and 18 weeks of age. Behavioral phenotype was assessed using the open field and marble burying tests, and brain neurotransmitter concentrations were measured using HPLC with electrochemical detection system. Data were analyzed by 3-way ANOVA with genotype, sex, and diet as the main treatment effects. Brain mass and the concentrations of catecholamines and serotonin were reduced in PKU mice compared to WT mice; the low-phe AA and GMP diets improved these parameters in PKU mice. Relative brain mass was increased in female PKU mice fed the GMP diet compared to the AA diet. PKU mice exhibited hyperactivity and impaired vertical exploration compared to their WT littermates during the open field test. Regardless of genotype or diet, female mice demonstrated increased vertical activity time and increased total ambulatory and horizontal activity counts compared with male mice. PKU mice fed the high-phe casein diet buried significantly fewer marbles than WT control mice fed casein; this was normalized in PKU mice fed the low-phe AA and GMP diets. In summary, C57Bl/6-Pah(enu2) mice showed an impaired behavioral phenotype and reduced brain neurotransmitter concentrations that were improved by the low-phe AA or GMP diets. These data support lifelong adherence to a low-phe diet for PKU.
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Affiliation(s)
- Emily A Sawin
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Denise M Ney
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
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Abstract
Phenylketonuria (PKU) is an inborn error of metabolism of the amino acid phenylalanine. It is an autosomal recessive disorder with a rate of incidence of 1 in 10,000 in Caucasian populations. Mutations in the phenylalanine hydroxylase (PAH) gene are the major cause of PKU, due to the loss of the catalytic activity of the enzyme product PAH. Newborn screening for PKU allows early intervention, avoiding irreparable neurological damage and intellectual disability that would arise from untreated PKU. The current primary treatment of PKU is the limitation of dietary protein intake, which in the long term may be associated with poor compliance in some cases and other health problems due to malnutrition. The only alternative therapy currently approved is the supplementation of BH4, the requisite co-factor of PAH, in the orally-available form of sapropterin dihydrochloride. This treatment is not universally available, and is only effective for a proportion (estimated 30%) of PKU patients. Research into novel therapies for PKU has taken many different approaches to address the lack of PAH activity at the core of this disorder: enzyme replacement via virus-mediated gene transfer, transplantation of donor liver and recombinant PAH protein, enzyme substitution using phenylalanine ammonia lyase (PAL) to provide an alternative pathway for the metabolism of phenylalanine, and restoration of native PAH activity using chemical chaperones and nonsense read-through agents. It is hoped that continuing efforts into these studies will translate into a significant improvement in the physical outcome, as well as quality of life, for patients with PKU.
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Affiliation(s)
- Gladys Ho
- 1 Genetic Metabolic Disorders Research Unit; 2 Disciplines of Paediatrics and Child Health and 3 Genetic Medicine, University of Sydney, Sydney, NSW, Australia ; 4 Genetic Metabolic Disorders Service, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, NSW, Australia
| | - John Christodoulou
- 1 Genetic Metabolic Disorders Research Unit; 2 Disciplines of Paediatrics and Child Health and 3 Genetic Medicine, University of Sydney, Sydney, NSW, Australia ; 4 Genetic Metabolic Disorders Service, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, NSW, Australia
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Sarkissian CN, Ying M, Scherer T, Thöny B, Martinez A. The mechanism of BH4 -responsive hyperphenylalaninemia--as it occurs in the ENU1/2 genetic mouse model. Hum Mutat 2012; 33:1464-73. [PMID: 22644647 DOI: 10.1002/humu.22128] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 05/15/2012] [Indexed: 01/07/2023]
Abstract
The Pah(enu1/enu2) (ENU1/2) mouse is a heteroallelic orthologous model displaying blood phenylalanine (Phe) concentrations characteristic of mild hyperphenylalaninemia. ENU1/2 mice also have reduced liver phenylalanine hydroxylase (PAH) protein content (∼20% normal) and activity (∼2.5% normal). The mutant PAH protein is highly ubiquitinated, which is likely associated with its increased misfolding and instability. The administration of a single subcutaneous injection of l-Phe (1.1 mg l-Phe/g body weight) leads to an approximately twofold to threefold increase of blood Phe and phenylalanine/tyrosine (Phe/Tyr) ratio, and a 1.6-fold increase of both nonubiquitinated PAH protein content and PAH activity. It also results in elevated concentrations of liver 6R-l-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)), potentially through the influence of Phe on GTP cyclohydrolase I and its feedback regulatory protein. The increased BH(4) content seems to stabilize PAH. Supplementing ENU1/2 mice with BH(4) (50 mg/kg/day for 10 days) reduces the blood Phe/Tyr ratio within the mild hyperphenylalaninemic range; however, PAH content and activity were not elevated. It therefore appears that BH(4) supplementation of ENU1/2 mice increases Phe hydroxylation levels through a kinetic rather than a chaperone stabilizing effect. By boosting blood Phe concentrations, and by BH(4) supplementation, we have revealed novel insights into the processing and regulation of the ENU1/2-mutant PAH.
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Affiliation(s)
- Christineh N Sarkissian
- Department of Human Genetics, McGill University-Montreal Children's Hospital Research Institute, Montreal, Quebec, Canada
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Underhaug J, Aubi O, Martinez A. Phenylalanine hydroxylase misfolding and pharmacological chaperones. Curr Top Med Chem 2012; 12:2534-45. [PMID: 23339306 PMCID: PMC3664513 DOI: 10.2174/1568026611212220008] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 12/15/2022]
Abstract
Phenylketonuria (PKU) is a loss-of-function inborn error of metabolism. As many other inherited diseases the main pathologic mechanism in PKU is an enhanced tendency of the mutant phenylalanine hydroxylase (PAH) to misfold and undergo ubiquitin-dependent degradation. Recent alternative approaches with therapeutic potential for PKU aim at correcting the PAH misfolding, and in this respect pharmacological chaperones are the focus of increasing interest. These compounds, which often resemble the natural ligands and show mild competitive inhibition, can rescue the misfolded proteins by stimulating their renaturation in vivo. For PKU, a few studies have proven the stabilization of PKU-mutants in vitro, in cells, and in mice by pharmacological chaperones, which have been found either by using the tetrahydrobiopterin (BH(4)) cofactor as query structure for shape-focused virtual screening or by high-throughput screening of small compound libraries. Both approaches have revealed a number of compounds, most of which bind at the iron-binding site, competitively with respect to BH(4). Furthermore, PAH shares a number of ligands, such as BH(4), amino acid substrates and inhibitors, with the other aromatic amino acid hydroxylases: the neuronal/neuroendocrine enzymes tyrosine hydroxylase (TH) and the tryptophan hydroxylases (TPHs). Recent results indicate that the PAH-targeted pharmacological chaperones should also be tested on TH and the TPHs, and eventually be derivatized to avoid unwanted interactions with these other enzymes. After derivatization and validation in animal models, the PAH-chaperoning compounds represent novel possibilities in the treatment of PKU.
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Affiliation(s)
| | | | - Aurora Martinez
- Department of Biomedicine, and K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
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Abstract
Phenylalanine hydroxylase deficiency is an autosomal recessive disorder that results in intolerance to the dietary intake of the essential amino acid phenylalanine. It occurs in approximately 1:15,000 individuals. Deficiency of this enzyme produces a spectrum of disorders including classic phenylketonuria, mild phenylketonuria, and mild hyperphenylalaninemia. Classic phenylketonuria is caused by a complete or near-complete deficiency of phenylalanine hydroxylase activity and without dietary restriction of phenylalanine most children will develop profound and irreversible intellectual disability. Mild phenylketonuria and mild hyperphenylalaninemia are associated with lower risk of impaired cognitive development in the absence of treatment. Phenylalanine hydroxylase deficiency can be diagnosed by newborn screening based on detection of the presence of hyperphenylalaninemia using the Guthrie microbial inhibition assay or other assays on a blood spot obtained from a heel prick. Since the introduction of newborn screening, the major neurologic consequences of hyperphenylalaninemia have been largely eradicated. Affected individuals can lead normal lives. However, recent data suggest that homeostasis is not fully restored with current therapy. Treated individuals have a higher incidence of neuropsychological problems. The mainstay of treatment for hyperphenylalaninemia involves a low-protein diet and use of a phenylalanine-free medical formula. This treatment must commence as soon as possible after birth and should continue for life. Regular monitoring of plasma phenylalanine and tyrosine concentrations is necessary. Targets of plasma phenylalanine of 120-360 μmol/L (2-6 mg/dL) in the first decade of life are essential for optimal outcome. Phenylalanine targets in adolescence and adulthood are less clear. A significant proportion of patients with phenylketonuria may benefit from adjuvant therapy with 6R-tetrahydrobiopterin stereoisomer. Special consideration must be given to adult women with hyperphenylalaninemia because of the teratogenic effects of phenylalanine. Women with phenylalanine hydroxylase deficiency considering pregnancy should follow special guidelines and assure adequate energy intake with the proper proportion of protein, fat, and carbohydrates to minimize risks to the developing fetus. Molecular genetic testing of the phenylalanine hydroxylase gene is available for genetic counseling purposes to determine carrier status of at-risk relatives and for prenatal testing.
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Bélanger-Quintana A, Burlina A, Harding CO, Muntau AC. Up to date knowledge on different treatment strategies for phenylketonuria. Mol Genet Metab 2011; 104 Suppl:S19-25. [PMID: 21967857 PMCID: PMC4437510 DOI: 10.1016/j.ymgme.2011.08.009] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 07/23/2011] [Accepted: 08/05/2011] [Indexed: 11/18/2022]
Abstract
Dietary management for phenylketonuria was established over half a century ago, and has rendered an immense success in the prevention of the severe mental retardation associated with the accumulation of phenylalanine. However, the strict low-phenylalanine diet has several shortcomings, not the least of which is the burden it imposes on the patients and their families consequently frequent dietary non-compliance. Imperfect neurological outcome of patients in comparison to non-PKU individuals and nutritional deficiencies associated to the PKU diet are other important reasons to seek alternative therapies. In the last decade there has been an impressive effort in the investigation of other ways to treat PKU that might improve the outcome and quality of life of these patients. These studies have lead to the commercialization of sapropterin dihydrochloride, but there are still many questions regarding which patients to challenge with sapropterin what is the best challenge protocol and what could be the implications of this treatment in the long-term. Current human trials of PEGylated phenylalanine ammonia lyase are underway, which might render an alternative to diet for those patients non-responsive to sapropterin dihydrochloride. Preclinical investigation of gene and cell therapies for PKU is ongoing. In this manuscript, we will review the current knowledge on novel pharmacologic approaches to the treatment of phenylketonuria.
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Affiliation(s)
- Amaya Bélanger-Quintana
- Division of Metabolic Diseases, Pediatrics Department, Ramon y Cajal Hospital, Madrid, Spain.
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Yagi H, Ogura T, Mizukami H, Urabe M, Hamada H, Yoshikawa H, Ozawa K, Kume A. Complete restoration of phenylalanine oxidation in phenylketonuria mouse by a self-complementary adeno-associated virus vector. J Gene Med 2011; 13:114-22. [PMID: 21322099 DOI: 10.1002/jgm.1543] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Classical phenylketonuria (PKU) arises from a deficiency of phenylalanine hydroxylase (PAH) that catalyses phenylalanine oxidation in the liver. Lack of PAH activity causes massive hyperphenylalaninemia and consequently severe brain damage. Preclinical studies showed that conventional adeno-associated virus (AAV) vectors could correct hyperphenylalaninemia in a mouse model of PKU, although limitations such as very large dose requirement and relative inefficiency in female animals were recognized. METHOD An AAV8-pseudotyped vector was constructed with a self-complementary AAV (scAAV) genome for efficient liver transduction and expression. Following vector injection to PKU mice, blood Phe was periodically measured by an enzymatic fluorometric assay. In vivo Phe oxidation was evaluated by a non-invasive breath test using [1-(13) C]Phe. Vector copy number in the host tissues was determined by quantitative polymerase chain reaction. RESULTS A single injection of 1 × 10(11) -1 × 10(12) particles of the scAAV8 vector resulted in a reduction of blood Phe to normal or near-normal levels for more than 1 year in both genders. The treated animals showed normal level of in vivo Phe oxidation. The presence of > 1 copy of vector DNA per diploid genome in the liver was associated with normal blood Phe in the AAV-treated PKU mice. CONCLUSIONS Complete phenotypic correction of PKU mice was achieved by the scAAV8 vector for the longest duration reported to date. The vector overcame the female-specific disadvantage in AAV-mediated liver transduction; thus, it offers a promising platform of long-lasting gene therapy for PKU.
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Affiliation(s)
- Hiroya Yagi
- Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Japan
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Kotchey NM, Adachi K, Zahid M, Inagaki K, Charan R, Parker RS, Nakai H. A potential role of distinctively delayed blood clearance of recombinant adeno-associated virus serotype 9 in robust cardiac transduction. Mol Ther 2011; 19:1079-89. [PMID: 21364543 DOI: 10.1038/mt.2011.3] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Recombinant adeno-associated virus serotype 9 (rAAV9) vectors show robust in vivo transduction by a systemic approach. It has been proposed that rAAV9 has enhanced ability to cross the vascular endothelial barriers. However, the scientific basis of systemic administration of rAAV9 and its transduction mechanisms have not been fully established. Here, we show indirect evidence suggesting that capillary walls still remain as a significant barrier to rAAV9 in cardiac transduction but not so in hepatic transduction in mice, and the distinctively delayed blood clearance of rAAV9 plays an important role in overcoming this barrier, contributing to robust cardiac transduction. We find that transvascular transport of rAAV9 in the heart is a capacity-limited slow process and occurs in the absence of caveolin-1, the major component of caveolae that mediate endothelial transcytosis. In addition, a reverse genetic study identifies the outer region of the icosahedral threefold capsid protrusions as a potential culprit for rAAV9's delayed blood clearance. These results support a model in which the delayed blood clearance of rAAV9 sustains the capacity-limited slow transvascular vector transport and plays a role in mediating robust cardiac transduction, and provide important implications in AAV capsid engineering to create new rAAV variants with more desirable properties.
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Affiliation(s)
- Nicole M Kotchey
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15219, USA
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Thöny B. Long-term correction of murine phenylketonuria by viral gene transfer: liver versus muscle. J Inherit Metab Dis 2010; 33:677-80. [PMID: 20151201 DOI: 10.1007/s10545-010-9044-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 12/22/2009] [Accepted: 12/23/2009] [Indexed: 01/23/2023]
Abstract
Current therapy for phenylketonuria (PKU) consists of life-long dietary restriction of phenylalanine (Phe), which presents problems of adherence for patients. Alternative therapies under investigation include, among others, the use of gene therapy to provide copies of wild-type, non-mutant, phenylalanine hydroxylase (PAH) enzyme. Expression of PAH in both liver (the usual metabolic source of this enzyme) and skeletal muscle is under investigation. Liver gene therapy, using a viral vector based on the adeno-associated viruses (AAVs), provided effective clearance of serum Phe that was sustained for 1 year in some mice. In order for PAH expression to be effective in skeletal muscle, the essential metabolic cofactor, tetrahydrobiopterin (BH(4)), must also be provided, either by supplementation or gene therapy. Both these approaches were effective. When transgenic PKU mice that constitutively expressed PAH in muscle were given intraperitoneal supplementation with BH(4), this produced (transient) effective clearance of Phe to normal levels. In addition, use of an AAV vector containing the genes for PAH, and for two key synthetic enzymes for BH(4), provided substantial and long-lasting correction (more than 1 year) of blood Phe levels when injected into skeletal muscle of PKU mice. These two strategies provide promising treatment alternatives for the management of PKU in patients.
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Affiliation(s)
- Beat Thöny
- Division of Clinical Chemistry and Biochemistry, Department of Paediatrics, University of Zürich, Steinwiesstrasse 75, 8032 Zürich, Switzerland.
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Abstract
Phenylketonuria is the most prevalent inherited defect in amino acid metabolism. Owing to mutations in the gene encoding the enzyme phenylalanine hydroxylase, the essential amino acid phenylalanine cannot be hydroxylated to tyrosine and blood and tissue concentrations of phenylalanine increase. Untreated, phenylketonuria causes severe mental retardation, epilepsy and behavioral problems. The combined effect of neonatal screening and treatment has, however, meant that phenylketonuria is now a biochemical rather than a clinical diagnosis. Treatment consists of stringent dietary restriction of natural protein intake and supplementation of amino acids other than phenylalanine by a chemically manufactured protein substitute. Although clinical outcome on a phenylalanine-restricted diet is good, neuropsychological deficits are now known to exist in dietary-treated patients with phenylketonuria, and quality of life, nutritional condition and psychosocial outcome could probably also be improved. The need for new therapeutic approaches is being met by supplementation with tetrahydrobiopterin or large neutral amino acids, whilst development of the use of phenylalanine ammonia lyase, and, in the longer term, gene therapy and chaperone treatment holds promise. This Review provides an overview of the history of phenylketonuria, the challenges of treatment today and the treatment possibilities in the near future.
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Affiliation(s)
- Francjan J van Spronsen
- Beatrix Children's Hospital, University Medical Center of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands.
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Rebuffat A, Harding CO, Ding Z, Thöny B. Comparison of adeno-associated virus pseudotype 1, 2, and 8 vectors administered by intramuscular injection in the treatment of murine phenylketonuria. Hum Gene Ther 2010; 21:463-77. [PMID: 19916803 PMCID: PMC2865356 DOI: 10.1089/hum.2009.127] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 11/15/2009] [Indexed: 12/20/2022] Open
Abstract
Phenylketonuria (PKU) is caused by hepatic phenylalanine hydroxylase (PAH) deficiency and is associated with systemic accumulation of phenylalanine (Phe). Previously we demonstrated correction of murine PKU after intravenous injection of a recombinant type 2 adeno-associated viral vector pseudotyped with type 8 capsid (rAAV2/8), which successfully directed hepatic transduction and Pah gene expression. Here, we report that liver PAH activity and phenylalanine clearance were also restored in PAH-deficient mice after simple intramuscular injection of either AAV2 pseudotype 1 (rAAV2/1) or rAAV2/8 vectors. Serotype 2 AAV vector (rAAV2/2) was also investigated, but long-term phenylalanine clearance has been observed only for pseudotypes 1 and 8. Therapeutic correction was shown in both male and female mice, albeit more effectively in males, in which correction lasted for the entire period of the experiment (>1 year). Although phenylalanine levels began to rise in female mice at about 8-10 months after rAAV2/8 injection they remained only mildly hyperphenylalaninemic thereafter and subsequent supplementation with synthetic tetrahydrobiopterin resulted in a transient decrease in blood phenylalanine. Alternatively, subsequent administration of a second vector with a different AAV pseudotype to avoid immunity against the previously administrated vector was also successful for long-term treatment of female PKU mice. Overall, this relatively less invasive gene transfer approach completes our previous studies and allows comparison of complementary strategies in the development of efficient PKU gene therapy protocols.
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Affiliation(s)
- Alexandre Rebuffat
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zürich, CH-8032 Zürich, Switzerland
| | - Cary O. Harding
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR 97201, USA
| | - Zhaobing Ding
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zürich, CH-8032 Zürich, Switzerland
- Present address: Institute of Bioengineering and Nanotechnology, The Nanos, 138669, Singapore
| | - Beat Thöny
- Division of Clinical Chemistry and Biochemistry, Department of Pediatrics, University of Zürich, CH-8032 Zürich, Switzerland
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Intensive pharmacological immunosuppression allows for repetitive liver gene transfer with recombinant adenovirus in nonhuman primates. Mol Ther 2010; 18:754-65. [PMID: 20087317 DOI: 10.1038/mt.2009.312] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Repeated administration of gene therapies is hampered by host immunity toward vectors and transgenes. Attempts to circumvent antivector immunity include pharmacological immunosuppression or alternating different vectors and vector serotypes with the same transgene. Our studies show that B-cell depletion with anti-CD20 monoclonal antibody and concomitant T-cell inhibition with clinically available drugs permits repeated liver gene transfer to a limited number of nonhuman primates with recombinant adenovirus. Adenoviral vector-mediated transfer of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene was visualized in vivo with a semiquantitative transgene-specific positron emission tomography (PET) technique, liver immunohistochemistry, and immunoblot for the reporter transgene in needle biopsies. Neutralizing antibody and T cell-mediated responses toward the viral capsids were sequentially monitored and found to be repressed by the drug combinations tested. Repeated liver transfer of the HSV1-tk reporter gene with the same recombinant adenoviral vector was achieved in macaques undergoing a clinically feasible immunosuppressive treatment that ablated humoral and cellular immune responses. This strategy allows measurable gene retransfer to the liver as late as 15 months following the first adenoviral exposure in a macaque, which has undergone a total of four treatments with the same adenoviral vector.
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Santillan DA, Santillan MK, Hunter SK. Cell encapsulation as a potential nondietary therapy for maternal phenylketonuria. Am J Obstet Gynecol 2009; 201:289.e1-6. [PMID: 19631922 DOI: 10.1016/j.ajog.2009.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/27/2009] [Accepted: 05/20/2009] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The objective of this work was to determine whether cells overexpressing phenylalanine (Phe) hydroxylase (PAH) can significantly reduce Phe in vitro for potential use as a therapy for preventing maternal phenylketonuria. STUDY DESIGN Human 293T and WRL68 cell lines were transiently and stably transfected to overexpress PAH. Cells were encapsulated within microspheres of sodium alginate. Timed measurements of Phe in media were performed using tandem mass spectrometry. RESULTS Both nonencapsulated and encapsulated transiently transfected cells overexpressing PAH significantly reduced the Phe concentration in media by approximately 50% in comparison to mock-transfected cells. Cell line clones stably expressing PAH significantly decreased the Phe concentration in the media by up to 85% compared with media alone. CONCLUSION Both unencapsulated and encapsulated cells overexpressing PAH significantly reduce Phe in vitro. Studies using phenylketonuria model mice will be important in determining the ability of our therapy to prevent the teratogenic effects of elevated maternal Phe in maternal phenylketonuria.
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Cunningham SC, Spinoulas A, Carpenter KH, Wilcken B, Kuchel PW, Alexander IE. AAV2/8-mediated correction of OTC deficiency is robust in adult but not neonatal Spf(ash) mice. Mol Ther 2009; 17:1340-6. [PMID: 19384294 PMCID: PMC2835243 DOI: 10.1038/mt.2009.88] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Accepted: 03/30/2009] [Indexed: 11/08/2022] Open
Abstract
Ornithine transcarbamylase (OTC) deficiency, the most common urea cycle disorder, is associated with severe hyperammonemia accompanied by a high risk of neurological damage and death in patients presenting with the neonatal-onset form. Contemporary therapies, including liver transplantation, remain inadequate with considerable morbidity, justifying vigorous investigation of alternate therapies. Clinical evidence suggests that as little as 3% normal enzyme activity is sufficient to ameliorate the severe neonatal phenotype, making OTC deficiency an ideal model for the development of liver-targeted gene therapy. In this study, we investigated metabolic correction in neonatal and adult male OTC-deficient Spf(ash) mice following adeno-associated virus (AAV)2/8-mediated delivery of the murine OTC complementary DNA under the transcriptional control of a liver-specific promoter. Substantially supraphysiological levels of OTC enzymatic activity were readily achieved in both adult and neonatal mice following a single intraperitoneal (i.p.) injection, with metabolic correction in adults being robust and life-long. In the neonates, however, full metabolic correction was transient, although modest levels of OTC expression persisted into adulthood. Although not directly testable in Spf(ash) mice, these levels were theoretically sufficient to prevent hyperammonemia in a null phenotype. This loss of expression in the neonatal liver is the consequence of hepatocellular proliferation and presents an added challenge to human therapy.
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Affiliation(s)
- Sharon C Cunningham
- Gene Therapy Research Unit, Children's Medical Research Institute and The Children's Hospital at Westmead, Wentworthville, New South Wales, Australia
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Giannandrea M, Pierce RH, Crispe IN. Indirect action of tumor necrosis factor-alpha in liver injury during the CD8+ T cell response to an adeno-associated virus vector in mice. Hepatology 2009; 49:2010-20. [PMID: 19291774 PMCID: PMC2871665 DOI: 10.1002/hep.22869] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
UNLABELLED CD8+ T cells can cause hepatocellular injury by two distinct mechanisms. In addition to their direct cytotoxic effect, there is also collateral liver injury, which occurs when cells are killed in an antigen-independent manner. Whereas immune effector cytokines interferon-gamma (IFNgamma) and tumor necrosis factor-alpha (TNFalpha) have both been implicated in various forms of hepatitis, their respective roles in direct and/or collateral liver damage remains unclear. In order to investigate these elements of liver injury, we developed a new experimental model of CD8+ T-cell-mediated hepatitis based on an adeno-associated virus-based gene therapy vector. This vector is used to deliver antigen to hepatocytes, and CD8+ T cells specific for the vector-encoded transgene are adoptively transferred to produce liver immunopathology. In this experimental model, CD8+ T-cell IFNgamma acts on Kupffer cells, inducing TNFalpha secretion and liver injury. Both IFNgamma and TNFalpha are important in this injury process, but TNFalpha acts as an autocrine amplifier of Kupffer cell function, rather than as a direct effector of hepatocellular damage. CONCLUSIONS TNFalpha indirectly promotes liver damage and is not a direct hepatotoxic agent. IFNgamma also indirectly contributes to liver injury through Kupffer cell activation while, in parallel, directly promoting hepatitis through induction of hepatocyte major histocompatability complex class I. In principle, it may be possible to ameliorate this immunopathologic indirect mechanism by developing therapies that target Kupffer cells, without impairing CD8+ T-cell-mediated antiviral immunity. This would have great therapeutic potential in chronic viral hepatitis.
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Affiliation(s)
- Matthew Giannandrea
- David H. Smith Center for Vaccine Biology and Immunology, Aab Institute for Biomedical Research, University of Rochester Medical Center, Rochester NY 14642-8609, USA.
| | - Robert H. Pierce
- Schering-Plough Biopharma, 901 California Ave, Palo Alto, CA 94304, USA.
| | - Ian Nicholas Crispe
- The Seattle Biomedical Research Institute, 307 North Westlake Avenue, Seattle, WA 98019
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Skvorak KJ, Paul HS, Dorko K, Marongiu F, Ellis E, Chace D, Ferguson C, Gibson KM, Homanics GE, Strom SC. Hepatocyte transplantation improves phenotype and extends survival in a murine model of intermediate maple syrup urine disease. Mol Ther 2009; 17:1266-73. [PMID: 19436271 DOI: 10.1038/mt.2009.99] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Maple syrup urine disease (MSUD; OMIM 248600) is an inborn error of metabolism of the branched chain alpha-ketoacid dehydrogenase (BCKDH) complex that is treated primarily by dietary manipulation of branched-chain amino acids (BCAA). Dietary restriction is lifelong and compliance is difficult. Liver transplantation significantly improves outcomes; however, alternative therapies are needed. To test novel therapies such as hepatocyte transplantation (HTx), we previously created a murine model of intermediate MSUD (iMSUD), which closely mimics human iMSUD. LacZ-positive murine donor hepatocytes were harvested and directly injected (10(5) cells/50 microl) into liver of iMSUD mice (two injections at 1-10 days of age). Donor hepatocytes engrafted into iMSUD recipient liver, increased liver BCKDH activity, improved blood total BCAA/alanine ratio, increased body weight at weaning, and extended the lifespan of HTx-treated iMSUD mice compared to phosphate-buffered saline (PBS)-treated and untreated iMSUD mice. Based on these data demonstrating partial metabolic correction of iMSUD in a murine model, coupled to the fact that multiple transplants are possible to enhance these results, we suggest that HTx represents a promising therapeutic intervention for MSUD that warrants further investigation.
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Affiliation(s)
- Kristen J Skvorak
- Department of Human Genetics, University of Pittsburgh, Pennsylvania, USA.
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Suckau L, Fechner H, Chemaly E, Krohn S, Hadri L, Kockskämper J, Westermann D, Bisping E, Ly H, Wang X, Kawase Y, Chen J, Liang L, Sipo I, Vetter R, Weger S, Kurreck J, Erdmann V, Tschope C, Pieske B, Lebeche D, Schultheiss HP, Hajjar RJ, Poller WC. Long-term cardiac-targeted RNA interference for the treatment of heart failure restores cardiac function and reduces pathological hypertrophy. Circulation 2009; 119:1241-52. [PMID: 19237664 DOI: 10.1161/circulationaha.108.783852] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND RNA interference (RNAi) has the potential to be a novel therapeutic strategy in diverse areas of medicine. Here, we report on targeted RNAi for the treatment of heart failure, an important disorder in humans that results from multiple causes. Successful treatment of heart failure is demonstrated in a rat model of transaortic banding by RNAi targeting of phospholamban, a key regulator of cardiac Ca(2+) homeostasis. Whereas gene therapy rests on recombinant protein expression as its basic principle, RNAi therapy uses regulatory RNAs to achieve its effect. METHODS AND RESULTS We describe structural requirements to obtain high RNAi activity from adenoviral and adeno-associated virus (AAV9) vectors and show that an adenoviral short hairpin RNA vector (AdV-shRNA) silenced phospholamban in cardiomyocytes (primary neonatal rat cardiomyocytes) and improved hemodynamics in heart-failure rats 1 month after aortic root injection. For simplified long-term therapy, we developed a dimeric cardiotropic adeno-associated virus vector (rAAV9-shPLB) to deliver RNAi activity to the heart via intravenous injection. Cardiac phospholamban protein was reduced to 25%, and suppression of sacroplasmic reticulum Ca(2+) ATPase in the HF groups was rescued. In contrast to traditional vectors, rAAV9 showed high affinity for myocardium but low affinity for liver and other organs. rAAV9-shPLB therapy restored diastolic (left ventricular end-diastolic pressure, dp/dt(min), and tau) and systolic (fractional shortening) functional parameters to normal ranges. The massive cardiac dilation was normalized, and cardiac hypertrophy, cardiomyocyte diameter, and cardiac fibrosis were reduced significantly. Importantly, no evidence was found of microRNA deregulation or hepatotoxicity during these RNAi therapies. CONCLUSIONS Our data show for the first time the high efficacy of an RNAi therapeutic strategy in a cardiac disease.
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Affiliation(s)
- Lennart Suckau
- Department of Cardiology and Pneumology, Charité-University Medicine Berlin, Germany
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Sarkissian CN, Gámez A, Scriver CR. What we know that could influence future treatment of phenylketonuria. J Inherit Metab Dis 2009; 32:3-9. [PMID: 18668342 DOI: 10.1007/s10545-008-0917-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 06/10/2008] [Accepted: 06/11/2008] [Indexed: 11/25/2022]
Abstract
Phenylketonuria (PKU), a Mendelian autosomal recessive phenotype (OMIM 261600), is an inborn error of metabolism that can result in impaired postnatal cognitive development. The phenotypic outcome is multifactorial in origin, based both in nature, the mutations in the gene encoding the L-phenylalanine hydroxylase enzyme, and nurture, the nutritional experience introducing L-phenylalanine into the diet. The PKU story contains many messages including a framework to appreciate the complexity of this disease where phenotype reflects both locus-specific and genomic components. This knowledge is now being applied in the development of patient-specific therapies.
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Affiliation(s)
- C N Sarkissian
- Department of Biology, Human Genetics and Pediatrics, McGill University, Quebec, Canada.
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Jung SC, Park JW, Oh HJ, Choi JO, Seo KI, Park ES, Park HY. Protective effect of recombinant adeno-associated virus 2/8-mediated gene therapy from the maternal hyperphenylalaninemia in offsprings of a mouse model of phenylketonuria. J Korean Med Sci 2008; 23:877-83. [PMID: 18955797 PMCID: PMC2580016 DOI: 10.3346/jkms.2008.23.5.877] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessively inherited metabolic disorder caused by a deficiency of phenylalanine hydroxylase (PAH). The accumulation of phenylalanine leads to severe mental and psychomotor retardation, and the fetus of an uncontrolled pregnant female patient presents with maternal PKU syndrome. We have reported previously on the cognitive outcome of biochemical and phenotypic reversal of PKU in a mouse model, Pahenu2, by the AAV serotype 2-mediated gene delivery of a human PAH transgene. However, the therapeutic efficacy had been limited to only male PKU mice. In this study, we generated a pseudotyped recombinant AAV2/8-hPAH vector and infused it into female PKU mice through the hepatic portal vein or tail vein. Two weeks after injection, complete fur color change to black was observed in female PKU, as in males. The PAH activity in the liver increased to 65-70% of the wild-type activity in female PKU mice and to 90% in male PKU mice. Plasma phenylalanine concentration in female PKU mice decreased to the normal value. In addition, the offsprings of the treated female PKU mice can rescue from the harmful effect of maternal hyperphenylalaninemia. These results indicate that recombinant AAV2/8-mediated gene therapy is a potential therapeutic strategy for PKU.
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Affiliation(s)
- Sung-Chul Jung
- Department of Biochemistry, School of Medicine, Ewha Womans University, Seoul, Korea.
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Systemic AAV6 Delivery Mediating RNA Interference Against SOD1: Neuromuscular Transduction Does Not Alter Disease Progression in fALS Mice. Mol Ther 2008; 16:1018-25. [DOI: 10.1038/mt.2008.73] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Cunningham SC, Dane AP, Spinoulas A, Alexander IE. Gene Delivery to the Juvenile Mouse Liver Using AAV2/8 Vectors. Mol Ther 2008; 16:1081-1088. [DOI: 10.1038/mt.2008.72] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 03/14/2008] [Indexed: 11/09/2022] Open
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