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Martínez-Pizarro A, Picó S, López-Márquez A, Rodriguez-López C, Montalvo E, Alvarez M, Castro M, Ramón-Maiques S, Pérez B, Lucas JJ, Richard E, Desviat LR. PAH deficient pathology in humanized c.1066-11G>A phenylketonuria mice. Hum Mol Genet 2024; 33:1074-1089. [PMID: 38520741 PMCID: PMC11153335 DOI: 10.1093/hmg/ddae051] [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: 12/26/2023] [Revised: 02/12/2024] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
We have generated using CRISPR/Cas9 technology a partially humanized mouse model of the neurometabolic disease phenylketonuria (PKU), carrying the highly prevalent PAH variant c.1066-11G>A. This variant creates an alternative 3' splice site, leading to the inclusion of 9 nucleotides coding for 3 extra amino acids between Q355 and Y356 of the protein. Homozygous Pah c.1066-11A mice, with a partially humanized intron 10 sequence with the variant, accurately recapitulate the splicing defect and present almost undetectable hepatic PAH activity. They exhibit fur hypopigmentation, lower brain and body weight and reduced survival. Blood and brain phenylalanine levels are elevated, along with decreased tyrosine, tryptophan and monoamine neurotransmitter levels. They present behavioral deficits, mainly hypoactivity and diminished social interaction, locomotor deficiencies and an abnormal hind-limb clasping reflex. Changes in the morphology of glial cells, increased GFAP and Iba1 staining signals and decreased myelinization are observed. Hepatic tissue exhibits nearly absent PAH protein, reduced levels of chaperones DNAJC12 and HSP70 and increased autophagy markers LAMP1 and LC3BII, suggesting possible coaggregation of mutant PAH with chaperones and subsequent autophagy processing. This PKU mouse model with a prevalent human variant represents a useful tool for pathophysiology research and for novel therapies development.
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Affiliation(s)
- Ainhoa Martínez-Pizarro
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
| | - Sara Picó
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Arístides López-Márquez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Claudia Rodriguez-López
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Elena Montalvo
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Mar Alvarez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
| | - Margarita Castro
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
- Centro de Diagnóstico de Enfermedades Moleculares (CEDEM), Francisco Tomás y Valiente 7, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Santiago Ramón-Maiques
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Biomedicina de Valencia (IBV-CSIC), Jaume Roig, 11, 46010 València, Valencia, Spain
| | - Belén Pérez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
- Centro de Diagnóstico de Enfermedades Moleculares (CEDEM), Francisco Tomás y Valiente 7, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - José J Lucas
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Av. Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain
- Instituto Universitario de Biología Molecular, UAM, Nicolás Cabrera 1, 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, Av. Monforte de Lemos, 3-5. 28029 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital La Paz (IdiPaz), Pedro Rico, 6, 28029 Madrid, Spain
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2
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Shyam R, Sekhar Panda H, Mishra J, Jyoti Panda J, Kour A. Emerging biosensors in Phenylketonuria. Clin Chim Acta 2024; 559:119725. [PMID: 38734223 DOI: 10.1016/j.cca.2024.119725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Phenylketonuria (PKU) is an autosomal recessive metabolic disorder resulting from deficient phenylalanine hydroxylase (PAH) enzyme activity, leading to impaired phenylalanine (Phe) metabolism. This condition can lead to intellectual disability, epilepsy, and behavioural issues. Treatment typically involves strict dietary restrictions on natural protein intake, supplemented with chemically manufactured protein substitutes containing amino acids other than Phe. Various approaches, including casein glycomacropeptide (GMP), tetrahydrobiopterin (BH4), phenylalanine ammonia-lyase (PAL) therapy, large neutral amino acid (LNAA) supplementation, enzyme therapy, gene therapy, and medical therapies, aim to prevent Phe transport in the brain to potentially treat PKU. Although newborn screening programs and early dietary interventions have enhanced outcomes of the potential treatment strategies, limitations still persist in this direction. These involve potent accuracy concerns in diagnosis due to the existence of antibiotics in blood of PKU patients, affecting growth of the bacteria in the bacterial inhibition assay. Monitoring involves complex methods for instance, mass spectrometry and high-pressure liquid chromatography, which involve shortcomings such as lengthy protocols and the need for specialized equipment. To address these limitations, adaptable testing formats like bio/nano sensors are emerging with their cost-effectiveness, biodegradability, and rapid, accurate, and sensitive detection capabilities, offering promising alternatives for PKU diagnosis. This review provides insights into current treatment and diagnostic approaches, emphasizing on the potential applications of the diverse sensors intended for PKU diagnosis.
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Affiliation(s)
- Ritika Shyam
- University Institute of Pharma Sciences, Chandigarh University, Gharuan, Mohali, Punjab 140413, India
| | | | - Jibanananda Mishra
- School of Biosciences, RIMT University, Mandi Gobindgarh, Punjab 147301, India
| | - Jiban Jyoti Panda
- Institute of Nanoscience and Technology, Mohali, Punjab 140306, India.
| | - Avneet Kour
- University Institute of Pharma Sciences, Chandigarh University, Gharuan, Mohali, Punjab 140413, India.
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3
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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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4
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Deng IB, Follett J, Bu M, Farrer MJ. DNAJC12 in Monoamine Metabolism, Neurodevelopment, and Neurodegeneration. Mov Disord 2024; 39:249-258. [PMID: 38014588 DOI: 10.1002/mds.29677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/04/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
Recent studies show that pathogenic variants in DNAJC12, a co-chaperone for monoamine synthesis, may cause mild hyperphenylalaninemia with infantile dystonia, young-onset parkinsonism, developmental delay and cognitive deficits. DNAJC12 has been included in newborn screening, most revealingly in Spain, and those results highlight the importance of genetic diagnosis and early intervention in combating human disease. However, practitioners may be unaware of these advances and it is probable that many patients, especially adults, have yet to receive molecular testing for DNAJC12. Hence, this review summarizes genotype-phenotype relationships and treatment paradigms for patients with pathogenic variants in DNAJC12. It provides an overview of the structure of DNAJC12 protein, known genetic variants, domains, and binding partners, and elaborates on its role in monoamine synthesis, disease etiology, and pathogenesis. © 2023 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Isaac Bul Deng
- Department of Neurology, University of Florida, Gainesville, Florida, USA
| | - Jordan Follett
- Department of Neurology, University of Florida, Gainesville, Florida, USA
| | - Mengfei Bu
- Department of Neurology, University of Florida, Gainesville, Florida, USA
| | - Matthew J Farrer
- Department of Neurology, University of Florida, Gainesville, Florida, USA
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Rovelli V, Longo N. Phenylketonuria and the brain. Mol Genet Metab 2023; 139:107583. [PMID: 37105048 DOI: 10.1016/j.ymgme.2023.107583] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 04/14/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023]
Abstract
Classic phenylketonuria (PKU) is caused by defective activity of phenylalanine hydroxylase (PAH), the enzyme that coverts phenylalanine (Phe) to tyrosine. Toxic accumulation of phenylalanine and its metabolites, left untreated, affects brain development and function depending on the timing of exposure to elevated levels. The specific mechanisms of Phe-induced brain damage are not completely understood, but they correlate to phenylalanine levels and on the stage of brain growth. During fetal life, high levels of phenylalanine such as those seen in maternal PKU can result in microcephaly, neuronal loss and corpus callosum hypoplasia. Elevated phenylalanine levels during the first few years of life can cause acquired microcephaly, severe cognitive impairment and epilepsy, likely due to the impairment of synaptogenesis. During late childhood, elevated phenylalanine can cause alterations in neurological functioning, leading to ADHD, speech delay and mild IQ reduction. In adolescents and adults, executive function and mood are affected, with some of the abnormalities reversed by better control of phenylalanine levels. Altered brain myelination can be present at this stage. In this article, we review the current knowledge about the consequences of high phenylalanine levels in PKU patients and animal models through different stages of brain development and its effect on cognitive, behavioural and neuropsychological function.
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Affiliation(s)
- Valentina Rovelli
- Clinical Department of Pediatrics, University of Milan, ASST Santi Paolo e Carlo, San Paolo Hospital, Milan, Italy.
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
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6
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Bregalda A, Carducci C, Viscomi MT, Pierigè F, Biagiotti S, Menotta M, Biancucci F, Pascucci T, Leuzzi V, Magnani M, Rossi L. Myelin basic protein recovery during PKU mice lifespan and the potential role of microRNAs on its regulation. Neurobiol Dis 2023; 180:106093. [PMID: 36948260 DOI: 10.1016/j.nbd.2023.106093] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 03/24/2023] Open
Abstract
Untreated phenylketonuria (PKU) patients and PKU animal models show hypomyelination in the central nervous system and white matter damages, which are accompanied by myelin basic protein (MBP) impairment. Despite many assumptions, the primary explanation of the mentioned cerebral outcomes remains elusive. In this study, MBP protein and mRNA expression on brains of wild type (WT) and phenylketonuric (ENU2) mice were analyzed throughout mice lifespan (14-60-180-270-360-540 post-natal days, PND). The results confirmed the low MBP expression at first PND times, while revealed an unprecedented progressive MBP protein expression recovery in aged ENU2 mice. Unexpectedly, unaltered MBP mRNA expression between WT and ENU2 was always observed. Additionally, for the same time intervals, a significant decrease of the phenylalanine concentration in the peripheral blood and brain of ENU2 mice was detected, to date, for the first time. In this scenario, a translational hindrance of MBP during initial and late cerebral development in ENU2 mice was hypothesized, leading to the execution of a microRNA microarray analysis on 60 PND brains, which was followed by a proteomic assay on 60 and 360 PND brains in order to validate in silico miRNA-target predictions. Taken together, miR-218 - 1-3p, miR - 1231-3p and miR-217-5p were considered as the most impactful microRNAs, since a downregulation of their potential targets (MAG, CNTNAP2 and ANLN, respectively) can indirectly lead to a low MBP protein expression. These miRNAs, in addition, follow an opposite expression trend compared to MBP during adulthood, and their target proteins revealed a complete normalization in aged ENU2 mice. In conclusion, these results provide a new perspective on the PKU pathophysiology understanding and on a possible treatment, emphasizing the potential modulating role of differentially expressed microRNAs in MBP expression on PKU brains during PKU mouse lifespan.
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Affiliation(s)
- Alessandro Bregalda
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy.
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University, viale del Policlinico 155, 00161 Rome, Italy
| | - Maria Teresa Viscomi
- Department of Life Sciences and Public Health, Sect. Histology and Embryology, Università Cattolica del S. Cuore, Largo F. Vito 1, 00168 Rome, Italy; Fondazione Policlinico Universitario "Agostino Gemelli", IRCCS, 00168 Rome, Italy
| | - Francesca Pierigè
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Sara Biagiotti
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Federica Biancucci
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Tiziana Pascucci
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00142 Rome, Italy; Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University, via dei Sabelli 108, 00185 Rome, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy; EryDel SpA, via Antonio Meucci 3, 20091 Bresso, Milan, Italy
| | - Luigia Rossi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy; EryDel SpA, via Antonio Meucci 3, 20091 Bresso, Milan, Italy
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7
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Vazquez-Agra N, Fernandez-Crespo S, Marques-Afonso AT, Cruces-Sande A, Barbosa-Gouveia S, Martinez-Olmos MA, Hermida-Ameijeiras A. The correlation of lipid profile and waist circumference with phenylalanine levels in adult patients with classical phenylketonuria. Med Clin (Barc) 2023; 160:385-391. [PMID: 36628809 DOI: 10.1016/j.medcli.2022.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 01/11/2023]
Abstract
INTRODUCTION AND OBJECTIVES Some studies have pointed to a relationship between Phenyketonuria (PKU) and an increased cardiovascular risk (CVR). This study aimed to evaluate the influence of metabolic control on classical CVR factors in adult patients with PKU. MATERIAL AND METHODS It was a cross-sectional study conducted in patients older than 18 years with a diagnosis of classical PKU and under strict dietary control. Demographic, epidemiological and laboratory variables related to CVR were collected. The variables of metabolic control were some parameters related to phenylalanine (Phe) plasma levels. RESULTS A total of 47 patients were included with a mean age of 36±10 years of which 30 (64%) were women. Multivariate analysis revealed that range Phe (B=-2.211, P=0.044, 95%CI: -4.354-(-0.068)) levels were within the model for triglyceride concentrations, while minimum (B=-2.803, P=0.051, 95%CI: -5.612-0.007) and range (B=-1.515, P=0.039, 95%CI: -2.945-(-0.084)) Phe levels were within the model for high-density lipoprotein cholesterol concentrations. Median Phe levels showed a stronger correlation with waist circumference (WC) (B=1.216, P=0.002, 95%CI: 0.462-1.969) than with body mass index (B=0.355, P=0.052, 95%CI: -0.004-0.714). CONCLUSIONS High Phe levels and wide Phe fluctuations were related to weight gain, increased WC and lipid profile abnormalities. Systematic CVR assessments and comprehensive monitoring of Phe levels may be desirable to prevent or delay cardiovascular disease in PKU patients.
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Affiliation(s)
- Nestor Vazquez-Agra
- Department of Internal Medicine, University Hospital of Santiago de Compostela, A Coruña, Spain.
| | | | | | - Anton Cruces-Sande
- Laboratory of Neurochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Santiago de Compostela, A Coruña, Spain
| | - Sofia Barbosa-Gouveia
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, University Hospital of Santiago de Compostela, A Coruña, Spain
| | - Miguel-Angel Martinez-Olmos
- Division of Endocrinology and Nutrition, University Hospital of Santiago de Compostela, A Coruña, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Carlos III Health Institute, Madrid, Spain
| | - Alvaro Hermida-Ameijeiras
- Department of Internal Medicine, University Hospital of Santiago de Compostela, A Coruña, Spain; UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, A Coruña, Spain
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Elhawary NA, AlJahdali IA, Abumansour IS, Elhawary EN, Gaboon N, Dandini M, Madkhali A, Alosaimi W, Alzahrani A, Aljohani F, Melibary EM, Kensara OA. Genetic etiology and clinical challenges of phenylketonuria. Hum Genomics 2022; 16:22. [PMID: 35854334 PMCID: PMC9295449 DOI: 10.1186/s40246-022-00398-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/08/2022] [Indexed: 02/08/2023] Open
Abstract
This review discusses the epidemiology, pathophysiology, genetic etiology, and management of phenylketonuria (PKU). PKU, an autosomal recessive disease, is an inborn error of phenylalanine (Phe) metabolism caused by pathogenic variants in the phenylalanine hydroxylase (PAH) gene. The prevalence of PKU varies widely among ethnicities and geographic regions, affecting approximately 1 in 24,000 individuals worldwide. Deficiency in the PAH enzyme or, in rare cases, the cofactor tetrahydrobiopterin results in high blood Phe concentrations, causing brain dysfunction. Untreated PKU, also known as PAH deficiency, results in severe and irreversible intellectual disability, epilepsy, behavioral disorders, and clinical features such as acquired microcephaly, seizures, psychological signs, and generalized hypopigmentation of skin (including hair and eyes). Severe phenotypes are classic PKU, and less severe forms of PAH deficiency are moderate PKU, mild PKU, mild hyperphenylalaninaemia (HPA), or benign HPA. Early diagnosis and intervention must start shortly after birth to prevent major cognitive and neurological effects. Dietary treatment, including natural protein restriction and Phe-free supplements, must be used to maintain blood Phe concentrations of 120-360 μmol/L throughout the life span. Additional treatments include the casein glycomacropeptide (GMP), which contains very limited aromatic amino acids and may improve immunological function, and large neutral amino acid (LNAA) supplementation to prevent plasma Phe transport into the brain. The synthetic BH4 analog, sapropterin hydrochloride (i.e., Kuvan®, BioMarin), is another potential treatment that activates residual PAH, thus decreasing Phe concentrations in the blood of PKU patients. Moreover, daily subcutaneous injection of pegylated Phe ammonia-lyase (i.e., pegvaliase; PALYNZIQ®, BioMarin) has promised gene therapy in recent clinical trials, and mRNA approaches are also being studied.
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Affiliation(s)
- Nasser A. Elhawary
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Imad A. AlJahdali
- grid.412832.e0000 0000 9137 6644Department of Community Medicine, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Iman S. Abumansour
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Ezzeldin N. Elhawary
- grid.123047.30000000103590315Faculty of Medicine, MS Genomic Medicine Program, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Nagwa Gaboon
- grid.7269.a0000 0004 0621 1570Department of Clinical Genetics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mohammed Dandini
- Department of Laboratory and Blood Bank, Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Abdulelah Madkhali
- grid.415254.30000 0004 1790 7311Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Wafaa Alosaimi
- Department of Hematology, Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Abdulmajeed Alzahrani
- Department of Laboratory and Blood Bank at Maternity and Children Hospital, Mecca, Saudi Arabia
| | - Fawzia Aljohani
- Department of Pediatric Clinics, Maternity and Children Hospital, King Salman Medical City, Madinah, Saudi Arabia
| | - Ehab M. Melibary
- grid.412832.e0000 0000 9137 6644Department of Medical Genetics, College of Medicine, Umm Al-Qura University, P.O. Box 57543, Mecca, 21955 Saudi Arabia
| | - Osama A. Kensara
- grid.412832.e0000 0000 9137 6644Department of Clinical Nutrition, Faculty of Applied Medical Sciences, Umm Al-Qura University, Jeddah, Saudi Arabia
- Department of Biochemistry, Batterjee Medical College, Jeddah, Saudi Arabia
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9
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Dobrowolski SF, Phua YL, Vockley J, Goetzman E, Blair HC. Phenylketonuria oxidative stress and energy dysregulation: Emerging pathophysiological elements provide interventional opportunity. Mol Genet Metab 2022; 136:111-117. [PMID: 35379539 PMCID: PMC9832337 DOI: 10.1016/j.ymgme.2022.03.012] [Citation(s) in RCA: 8] [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: 04/02/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 01/13/2023]
Abstract
Phenylalanine hydroxylase (PAH) deficient phenylketonuria (PKU) is rightfully considered the paradigm treatable metabolic disease. Dietary substrate restriction (i.e. phenylalanine (Phe) restriction) was applied >60 years ago and remains the primary PKU management means. The traditional model of PKU neuropathophysiology dictates blood Phe over-representation directs asymmetric blood:brain barrier amino acid transport through the LAT1 transporter with subsequent increased cerebral Phe concentration and low concentrations of tyrosine (Tyr), tryptophan (Trp), leucine (Leu), valine (Val), and isoleucine (Ile). Low Tyr and Trp concentrations generate secondary serotonergic and dopaminergic neurotransmitter paucities, widely attributed as drivers of PKU neurologic phenotypes. White matter disease, a central PKU characteristic, is ascribed to Phe-mediated tissue toxicity. Impaired cerebral protein synthesis, by reduced concentrations of non-Phe large neutral amino acids, is another cited pathological mechanism. The PKU amino acid transport model suggests Phe management should be more efficacious than is realized, as even early identified, continuously treated patients that retain therapy compliance into adulthood, demonstrate neurologic disease elements. Reduced cerebral metabolism was an early-recognized element of PKU pathology. Legacy data (late 1960's to mid-1970's) determined the Phe catabolite phenylpyruvate inhibits mitochondrial pyruvate transport. Respirometry of Pahenu2 cerebral mitochondria have attenuated respiratory chain complex 1 induction in response to pyruvate substrate, indicating reduced energy metabolism. Oxidative stress is intrinsic to PKU and Pahenu2 brain tissue presents increased reactive oxygen species. Phenylpyruvate inhibits glucose-6-phosphate dehydrogenase that generates reduced niacinamide adenine dinucleotide phosphate the obligatory cofactor of glutathione reductase. Pahenu2 brain tissue metabolomics identified increased oxidized glutathione and glutathione disulfide. Over-represented glutathione disulfide argues for reduced glutathione reductase activity secondary to reduced NADPH. Herein, we review evidence of energy and oxidative stress involvement in PKU pathology. Data suggests energy deficit and oxidative stress are features of PKU pathophysiology, providing intervention-amenable therapeutic targets to ameliorate disease elements refractory to standard of care.
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Affiliation(s)
- Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America.
| | - Yu Leng Phua
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Eric Goetzman
- Division of Medical Genetics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, United States of America
| | - Harry C Blair
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States of America; Veteran's Affairs Medical Center, Pittsburgh, PA, United States of America
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10
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Winn SR, Dudley S, Scherer T, Rimann N, Thöny B, Boutros S, Krenik D, Raber J, Harding CO. Modeling the cognitive effects of diet discontinuation in adults with phenylketonuria (PKU) using pegvaliase therapy in PAH-deficient mice. Mol Genet Metab 2022; 136:46-64. [PMID: 35339387 PMCID: PMC9106909 DOI: 10.1016/j.ymgme.2022.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 10/18/2022]
Abstract
Existing phenylalanine hydroxylase (PAH)-deficient mice strains are useful models of untreated or late-treated human phenylketonuria (PKU), as most contemporary therapies can only be initiated after weaning and the pups have already suffered irreversible consequences of chronic hyperphenylalaninemia (HPA) during early brain development. Therefore, we sought to evaluate whether enzyme substitution therapy with pegvaliase initiated near birth and administered repetitively to C57Bl/6-Pahenu2/enu2 mice would prevent HPA-related behavioral and cognitive deficits and form a model for early-treated PKU. The main results of three reported experiments are: 1) lifelong weekly pegvaliase treatment prevented the cognitive deficits associated with HPA in contrast to persisting deficits in mice treated with pegvaliase only as adults. 2) Cognitive deficits reappear in mice treated with weekly pegvaliase from birth but in which pegvaliase is discontinued at 3 months age. 3) Twice weekly pegvaliase injection also prevented cognitive deficits but again cognitive deficits emerged in early-treated animals following discontinuation of pegvaliase treatment during adulthood, particularly in females. In all studies, pegvaliase treatment was associated with complete correction of brain monoamine neurotransmitter content and with improved overall growth of the mice as measured by body weight. Mean total brain weight however remained low in all PAH deficient mice regardless of treatment. Application of enzyme substitution therapy with pegvaliase, initiated near birth and continued into adulthood, to PAH-deficient Pahenu2/enu2 mice models contemporary early-treated human PKU. This model will be useful for exploring the differential pathophysiologic effects of HPA at different developmental stages of the murine brain.
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Affiliation(s)
- Shelley R Winn
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Sandra Dudley
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Tanja Scherer
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Nicole Rimann
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Beat Thöny
- Department of Pediatrics, University of Zurich, Steinwiessstrasse 75, Zurich CH-8032, Switzerland
| | - Sydney Boutros
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Destine Krenik
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA; Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA
| | - Cary O Harding
- Department of Medical and Molecular Genetics, Oregon Health & Science University, Mailstop L-103, 3181 Sam Jackson Park Rd., Portland, OR 97239, USA.
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11
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Borges AC, Broersen K, Leandro P, Fernandes TG. Engineering Organoids for in vitro Modeling of Phenylketonuria. Front Mol Neurosci 2022; 14:787242. [PMID: 35082602 PMCID: PMC8784555 DOI: 10.3389/fnmol.2021.787242] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022] Open
Abstract
Phenylketonuria is a recessive genetic disorder of amino-acid metabolism, where impaired phenylalanine hydroxylase function leads to the accumulation of neurotoxic phenylalanine levels in the brain. Severe cognitive and neuronal impairment are observed in untreated/late-diagnosed patients, and even early treated ones are not safe from life-long sequelae. Despite the wealth of knowledge acquired from available disease models, the chronic effect of Phenylketonuria in the brain is still poorly understood and the consequences to the aging brain remain an open question. Thus, there is the need for better predictive models, able to recapitulate specific mechanisms of this disease. Human induced pluripotent stem cells (hiPSCs), with their ability to differentiate and self-organize in multiple tissues, might provide a new exciting in vitro platform to model specific PKU-derived neuronal impairment. In this review, we gather what is known about the impact of phenylalanine in the brain of patients and highlight where hiPSC-derived organoids could contribute to the understanding of this disease.
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Affiliation(s)
- Alice C. Borges
- Department of Bioengineering and iBB – Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Kerensa Broersen
- Department of Applied Stem Cell Technologies, Faculty of Science and Technology, Technical Medical Centre, University of Twente, Enschede, Netherlands
| | - Paula Leandro
- Faculty of Pharmacy, iMed.ULisboa - Research Institute for Medicines, Universidade de Lisboa, Lisbon, Portugal
| | - Tiago G. Fernandes
- Department of Bioengineering and iBB – Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- *Correspondence: Tiago G. Fernandes,
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12
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Manek R, Zhang YV, Berthelette P, Hossain M, Cornell CS, Gans J, Anarat-Cappillino G, Geller S, Jackson R, Yu D, Singh K, Ryan S, Bangari DS, Xu EY, Kyostio-Moore SRM. Blood phenylalanine reduction reverses gene expression changes observed in a mouse model of phenylketonuria. Sci Rep 2021; 11:22886. [PMID: 34819582 PMCID: PMC8613214 DOI: 10.1038/s41598-021-02267-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/09/2021] [Indexed: 12/02/2022] Open
Abstract
Phenylketonuria (PKU) is a genetic deficiency of phenylalanine hydroxylase (PAH) in liver resulting in blood phenylalanine (Phe) elevation and neurotoxicity. A pegylated phenylalanine ammonia lyase (PEG-PAL) metabolizing Phe into cinnamic acid was recently approved as treatment for PKU patients. A potentially one-time rAAV-based delivery of PAH gene into liver to convert Phe into tyrosine (Tyr), a normal way of Phe metabolism, has now also entered the clinic. To understand differences between these two Phe lowering strategies, we evaluated PAH and PAL expression in livers of PAHenu2 mice on brain and liver functions. Both lowered brain Phe and increased neurotransmitter levels and corrected animal behavior. However, PAL delivery required dose optimization, did not elevate brain Tyr levels and resulted in an immune response. The effect of hyperphenylalanemia on liver functions in PKU mice was assessed by transcriptome and proteomic analyses. We observed an elevation in Cyp4a10/14 proteins involved in lipid metabolism and upregulation of genes involved in cholesterol biosynthesis. Majority of the gene expression changes were corrected by PAH and PAL delivery though the role of these changes in PKU pathology is currently unclear. Taken together, here we show that blood Phe lowering strategy using PAH or PAL corrects both brain pathology as well as previously unknown lipid metabolism associated pathway changes in liver.
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Affiliation(s)
- Rachna Manek
- Genomic Medicine Unit, Sanofi, Framingham, MA, USA.
| | - Yao V Zhang
- Genomic Medicine Unit, Sanofi, Framingham, MA, USA
| | | | | | | | - Joseph Gans
- Translational Sciences, Sanofi, Framingham, MA, USA
| | | | - Sarah Geller
- Pre-Development Sciences NA, Analytical R&D, Sanofi, Framingham, MA, USA
| | | | - Dan Yu
- Genomic Medicine Unit, Sanofi, Framingham, MA, USA
| | - Kuldeep Singh
- Global Discovery Pathology, Sanofi, Framingham, MA, USA
| | - Sue Ryan
- Global Discovery Pathology, Sanofi, Framingham, MA, USA
| | | | - Ethan Y Xu
- Translational Sciences, Sanofi, Framingham, MA, USA
- Excision BioTherapeutics, Cambridge, MA, USA
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13
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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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14
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Joly JH, Chew BTL, Graham NA. The landscape of metabolic pathway dependencies in cancer cell lines. PLoS Comput Biol 2021; 17:e1008942. [PMID: 33872312 PMCID: PMC8084347 DOI: 10.1371/journal.pcbi.1008942] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 04/29/2021] [Accepted: 04/06/2021] [Indexed: 01/22/2023] Open
Abstract
The metabolic reprogramming of cancer cells creates metabolic vulnerabilities that can be therapeutically targeted. However, our understanding of metabolic dependencies and the pathway crosstalk that creates these vulnerabilities in cancer cells remains incomplete. Here, by integrating gene expression data with genetic loss-of-function and pharmacological screening data from hundreds of cancer cell lines, we identified metabolic vulnerabilities at the level of pathways rather than individual genes. This approach revealed that metabolic pathway dependencies are highly context-specific such that cancer cells are vulnerable to inhibition of one metabolic pathway only when activity of another metabolic pathway is altered. Notably, we also found that the no single metabolic pathway was universally essential, suggesting that cancer cells are not invariably dependent on any metabolic pathway. In addition, we confirmed that cell culture medium is a major confounding factor for the analysis of metabolic pathway vulnerabilities. Nevertheless, we found robust associations between metabolic pathway activity and sensitivity to clinically approved drugs that were independent of cell culture medium. Lastly, we used parallel integration of pharmacological and genetic dependency data to confidently identify metabolic pathway vulnerabilities. Taken together, this study serves as a comprehensive characterization of the landscape of metabolic pathway vulnerabilities in cancer cell lines.
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Affiliation(s)
- James H Joly
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California, United States of America
| | - Brandon T L Chew
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California, United States of America
| | - Nicholas A Graham
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California, United States of America.,Norris Comprehensive Cancer Center, University of Southern California, University of Southern California, Los Angeles, California, United States of America.,Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, United States of America
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15
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Singh K, Cornell CS, Jackson R, Kabiri M, Phipps M, Desai M, Fogle R, Ying X, Anarat-Cappillino G, Geller S, Johnson J, Roberts E, Malley K, Devlin T, DeRiso M, Berthelette P, Zhang YV, Ryan S, Rao S, Thurberg BL, Bangari DS, Kyostio-Moore S. CRISPR/Cas9 generated knockout mice lacking phenylalanine hydroxylase protein as a novel preclinical model for human phenylketonuria. Sci Rep 2021; 11:7254. [PMID: 33790381 PMCID: PMC8012645 DOI: 10.1038/s41598-021-86663-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 03/18/2021] [Indexed: 02/01/2023] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessive inborn error of L-phenylalanine (Phe) metabolism. It is caused by a partial or complete deficiency of the enzyme phenylalanine hydroxylase (PAH), which is necessary for conversion of Phe to tyrosine (Tyr). This metabolic error results in buildup of Phe and reduction of Tyr concentration in blood and in the brain, leading to neurological disease and intellectual deficits. Patients exhibit retarded body growth, hypopigmentation, hypocholesterolemia and low levels of neurotransmitters. Here we report first attempt at creating a homozygous Pah knock-out (KO) (Hom) mouse model, which was developed in the C57BL/6 J strain using CRISPR/Cas9 where codon 7 (GAG) in Pah gene was changed to a stop codon TAG. We investigated 2 to 6-month-old, male, Hom mice using comprehensive behavioral and biochemical assays, MRI and histopathology. Age and sex-matched heterozygous Pah-KO (Het) mice were used as control mice, as they exhibit enough PAH enzyme activity to provide Phe and Tyr levels comparable to the wild-type mice. Overall, our findings demonstrate that 6-month-old, male Hom mice completely lack PAH enzyme, exhibit significantly higher blood and brain Phe levels, lower levels of brain Tyr and neurotransmitters along with lower myelin content and have significant behavioral deficit. These mice exhibit phenotypes that closely resemble PKU patients such as retarded body growth, cutaneous hypopigmentation, and hypocholesterolemia when compared to the age- and sex-matched Het mice. Altogether, biochemical, behavioral, and pathologic features of this novel mouse model suggest that it can be used as a reliable translational tool for PKU preclinical research and drug development.
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Affiliation(s)
- Kuldeep Singh
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA ,Present Address: WuXi AppTec Inc., 8th Floor, 55 Cambridge Parkway, Cambridge, MA 02142 USA
| | - Cathleen S. Cornell
- grid.417555.70000 0000 8814 392XGenomic Medicine Unit, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
| | - Robert Jackson
- grid.417555.70000 0000 8814 392XGenomic Medicine Unit, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
| | - Mostafa Kabiri
- grid.420214.1Transgenic Model and Technology, Translational In-Vivo Research Platform, Industrie Park Hoechst, Sanofi, Frankfurt, Germany
| | - Michael Phipps
- grid.417555.70000 0000 8814 392XTransgenic Model and Technology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Mitul Desai
- grid.417555.70000 0000 8814 392XGlobal Bioimaging, Translational In-Vivo Models Research Platform, Sanofi, Framingham, MA 01701 USA
| | - Robert Fogle
- grid.417555.70000 0000 8814 392XGlobal Bioimaging, Translational In-Vivo Models Research Platform, Sanofi, Framingham, MA 01701 USA
| | - Xiaoyou Ying
- grid.417555.70000 0000 8814 392XGlobal Bioimaging, Translational In-Vivo Models Research Platform, Sanofi, Framingham, MA 01701 USA
| | - Gulbenk Anarat-Cappillino
- grid.417555.70000 0000 8814 392XPre-Development Sciences NA, Analytical R&D, Sanofi, Framingham, MA 01701 USA
| | - Sarah Geller
- grid.417555.70000 0000 8814 392XPre-Development Sciences NA, Analytical R&D, Sanofi, Framingham, MA 01701 USA
| | - Jennifer Johnson
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Errin Roberts
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Katie Malley
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Tim Devlin
- grid.417555.70000 0000 8814 392XTransgenic Model and Technology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Matthew DeRiso
- grid.417555.70000 0000 8814 392XTransgenic Model and Technology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Patricia Berthelette
- grid.417555.70000 0000 8814 392XGenomic Medicine Unit, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
| | - Yao V. Zhang
- grid.417555.70000 0000 8814 392XGenomic Medicine Unit, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
| | - Susan Ryan
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Srinivas Rao
- grid.417555.70000 0000 8814 392XTranslational In-Vivo Models Research Platform, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
| | - Beth L. Thurberg
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Dinesh S. Bangari
- grid.417555.70000 0000 8814 392XGlobal Discovery Pathology, Translational In-Vivo Models Research Platform, Sanofi, 5 The Mountain Road, Framingham, MA 01701 USA
| | - Sirkka Kyostio-Moore
- grid.417555.70000 0000 8814 392XGenomic Medicine Unit, Sanofi, 49 New York Avenue, Framingham, MA 01701 USA
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16
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Turton N, Rutherford T, Thijssen D, Hargreaves IP. Putative adjunct therapies to target mitochondrial dysfunction and oxidative stress in phenylketonuria, lysosomal storage disorders and peroxisomal disorders. Expert Opin Orphan Drugs 2020. [DOI: 10.1080/21678707.2020.1850254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Affiliation(s)
- Nadia Turton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Tricia Rutherford
- Department of research and development, Vitaflo International Ltd, Liverpool, UK
| | - Dick Thijssen
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Iain P Hargreaves
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
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17
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Ferreira BK, Rodrigues MT, Streck EL, Ferreira GC, Schuck PF. White matter disturbances in phenylketonuria: Possible underlying mechanisms. J Neurosci Res 2020; 99:349-360. [PMID: 32141105 DOI: 10.1002/jnr.24598] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/09/2020] [Accepted: 02/04/2020] [Indexed: 12/24/2022]
Abstract
White matter pathologies, as well as intellectual disability, microcephaly, and other central nervous system injuries, are clinical traits commonly ascribed to classic phenylketonuria (PKU). PKU is an inherited metabolic disease elicited by the deficiency of phenylalanine hydroxylase. Accumulation of l-phenylalanine (Phe) and its metabolites is found in tissues and body fluids in phenylketonuric patients. In order to mitigate the clinical findings, rigorous dietary Phe restriction constitutes the core of therapeutic management in PKU. Myelination is the process whereby the oligodendrocytes wrap myelin sheaths around the axons, supporting the conduction of action potentials. White matter injuries are implicated in the brain damage related to PKU, especially in untreated or poorly treated patients. The present review summarizes evidence toward putative mechanisms driving the white matter pathology in PKU patients.
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Affiliation(s)
- Bruna Klippel Ferreira
- Laboratório de Neuroenergética e Erros Inatos do Metabolismo, Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Porto Alegre, Brazil
| | - Melissa Torres Rodrigues
- Laboratório de Erros Inatos do Metabolismo, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-graduação em Biologia Celular e Molecular, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Emilio Luiz Streck
- Laboratório de Neurologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, Brazil
| | - Gustavo Costa Ferreira
- Laboratório de Neuroenergética e Erros Inatos do Metabolismo, Programa de Bioquímica e Biofísica Celular, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Porto Alegre, Brazil
| | - Patricia Fernanda Schuck
- Laboratório de Erros Inatos do Metabolismo, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-graduação em Biologia Celular e Molecular, Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
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18
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Vardy ERLC, MacDonald A, Ford S, Hofman DL. Phenylketonuria, co-morbidity, and ageing: A review. J Inherit Metab Dis 2020; 43:167-178. [PMID: 31675115 DOI: 10.1002/jimd.12186] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/27/2019] [Accepted: 10/28/2019] [Indexed: 12/17/2022]
Abstract
Phenylketonuria (PKU) is a metabolic condition which, left untreated, results in severe and irreversible brain damage. Newborn screening and the development of the low phenylalanine (Phe) diet have transformed the outcomes for people with PKU. Those who have benefited from early treatment are now approaching their fifth and sixth decade. It is therefore timely to consider multi-morbidity in PKU and the effects of ageing, in parallel with the wider benefits of emerging treatment options in addition to dietary relaxation. We have conducted the first literature review of co-morbidity and ageing in the context of PKU. Avenues explored have emerged from limited study of multi-morbidity to date and the knowledge and critical enquiry of the authors. Findings suggest PKU to have a wider impact than brain development, and result in several intriguing questions that require investigation to attain the best outcomes for people with PKU in adulthood moving through to older age. We recognise the difficulty in studying longitudinal outcomes in rare diseases and emphasise the necessity to develop PKU registries and cohorts that facilitate well-designed studies to answer some of the questions raised in this review. Whilst awaiting new information in these areas we propose that clinicians engage with patients to make personalised and well-informed decisions around Phe control and assessment for co-morbidity.
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Affiliation(s)
- Emma R L C Vardy
- Department of Ageing and Complex Medicine, Salford Royal NHS Foundation Trust, Salford Care Organisation, Part of Northern Care Alliance NHS Group, Salford, UK
| | - Anita MacDonald
- Department of dietetics, Birmingham Women's and Children's NHS Trust, Birmingham, UK
| | - Suzanne Ford
- National Society for Phenylketonuria, Preston, UK
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Cannet C, Pilotto A, Rocha JC, Schäfer H, Spraul M, Berg D, Nawroth P, Kasperk C, Gramer G, Haas D, Piel D, Kölker S, Hoffmann G, Freisinger P, Trefz F. Lower plasma cholesterol, LDL-cholesterol and LDL-lipoprotein subclasses in adult phenylketonuria (PKU) patients compared to healthy controls: results of NMR metabolomics investigation. Orphanet J Rare Dis 2020; 15:61. [PMID: 32106880 PMCID: PMC7047385 DOI: 10.1186/s13023-020-1329-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/07/2020] [Indexed: 12/22/2022] Open
Abstract
Background Phenylketonuria (PKU; OMIM#261600) is a rare metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene resulting in high phenylalanine (Phe) in blood and brain. If not treated early this results in intellectual disability, behavioral and psychiatric problems, microcephaly, motor deficits, eczematous rash, autism, seizures, and developmental problems. There is a controversial discussion of whether patients with PKU have an additional risk for atherosclerosis due to interference of Phe with cholesterol synthesis and LDL-cholesterol regulation. Since cholesterol also plays a role in membrane structure and myelination, better insight into the clinical significance of the impact of Phe on lipoprotein metabolism is desirable. In 22 treated PKU patients (mean age 38.7 years) and 14 healthy controls (mean age 35.2 years), we investigated plasma with NMR spectroscopy and quantified 105 lipoprotein parameters (including lipoprotein subclasses) and 24 low molecular weight parameters. Analysis was performed on a 600 MHz Bruker AVANCE IVDr spectrometer as previously described. Results Concurrent plasma Phe in PKU patients showed a wide range with a mean of 899 μmol/L (50–1318 μmol/L). Total cholesterol and LDL-cholesterol were significantly lower in PKU patients versus controls: 179.4 versus 200.9 mg/dL (p < 0.02) and 79.5 versus 104.1 mg/dL (p < 0.0038), respectively. PKU patients also had lower levels of 22 LDL subclasses with the greatest differences in LDL2 Apo-B, LDL2 Particle Number, LDL2-phospholipids, and LDL2-cholesterol (p < 0.0001). There was a slight negative correlation of total cholesterol and LDL-cholesterol with concurrent Phe level. VLDL5-free cholesterol, VLDL5-cholesterol, VLDL5-phospholipids, and VLDL4-free cholesterol showed a significant (p < 0.05) negative correlation with concurrent Phe level. There was no difference in HDL and their subclasses between PKU patients and controls. Tyrosine, glutamine, and creatinine were significantly lower in PKU patients compared to controls, while citric and glutamic acids were significantly higher. Conclusions Using NMR spectroscopy, a unique lipoprotein profile in PKU patients can be demonstrated which mimics a non-atherogenic profile as seen in patients treated by statins.
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Affiliation(s)
| | - Andrea Pilotto
- Department of Neurodegeneration, Hertie Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Parkinson's Disease Rehabilitation Centre, FERB ONLUS S, Isidoro Hospital, Trescore Balneario, Italy
| | - Júlio César Rocha
- Center for Health Technology and Services Research (CINTESIS), Porto, Portugal.,Nutrition & Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | | | | | - Daniela Berg
- Department of Neurology, University-Hospital-Schleswig-Holstein, Christian-Albrechts-University, Kiel, Germany
| | - Peter Nawroth
- Department of Endocrinology and Metabolism, University Hospital, Heidelberg, Germany
| | - Christian Kasperk
- Department of Endocrinology and Metabolism, University Hospital, Heidelberg, Germany
| | - Gwendolyn Gramer
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - Dorothea Haas
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - David Piel
- Pediatrics, Reutlingen Hospital, Reutlingen, Germany
| | - Stefan Kölker
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | - Georg Hoffmann
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany
| | | | - Friedrich Trefz
- Department of Pediatrics, Centre for Pediatric and Adolescent Medicine, Division of Neuropaediatrics and Metabolic Medicine, University Hospital, Heidelberg, Germany. .,Metabolic Consulting, Reutlingen, Germany.
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Ashe K, Kelso W, Farrand S, Panetta J, Fazio T, De Jong G, Walterfang M. Psychiatric and Cognitive Aspects of Phenylketonuria: The Limitations of Diet and Promise of New Treatments. Front Psychiatry 2019; 10:561. [PMID: 31551819 PMCID: PMC6748028 DOI: 10.3389/fpsyt.2019.00561] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 07/17/2019] [Indexed: 12/30/2022] Open
Abstract
Phenylketonuria (PKU) is a recessive disorder of phenylalanine metabolism due to mutations in the gene for phenylalanine hydroxylase (PAH). Reduced PAH activity results in significant hyperphenylalaninemia, which leads to alterations in cerebral myelin and protein synthesis, as well as reduced levels of serotonin, dopamine, and noradrenaline in the brain. When untreated, brain development is grossly disrupted and significant intellectual impairment and behavioral disturbance occur. The advent of neonatal heel prick screening has allowed for diagnosis at birth, and the institution of a phenylalanine restricted diet. Dietary treatment, particularly when maintained across neurodevelopment and well into adulthood, has resulted in markedly improved outcomes at a cognitive and psychiatric level for individuals with PKU. However, few individuals can maintain full dietary control lifelong, and even with good control, an elevated risk remains of-in particular-mood, anxiety, and attentional disorders across the lifespan. Increasingly, dietary recommendations focus on maintaining continuous dietary treatment lifelong to optimize psychiatric and cognitive outcomes, although the effect of long-term protein restricted diets on brain function remains unknown. While psychiatric illness is very common in adult PKU populations, very little data exist to guide clinicians on optimal treatment. The advent of new treatments that do not require restrictive dietary management, such as the enzyme therapy Pegvaliase, holds the promise of allowing patients a relatively normal diet alongside optimized mental health and cognitive functioning.
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Affiliation(s)
- Killian Ashe
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Wendy Kelso
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Sarah Farrand
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Julie Panetta
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Tim Fazio
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia
| | - Gerard De Jong
- Statewide Adult Metabolic Service, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia
| | - Mark Walterfang
- Neuropsychiatry Unit, Royal Melbourne Hospital, Melbourne, VIC, Australia.,Melbourne Neuropsychiatry Centre, University of Melbourne and North-Western Mental Health, Melbourne, VIC, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
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21
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Montoya Parra GA, Singh RH, Cetinyurek-Yavuz A, Kuhn M, MacDonald A. Status of nutrients important in brain function in phenylketonuria: a systematic review and meta-analysis. Orphanet J Rare Dis 2018; 13:101. [PMID: 29941009 PMCID: PMC6020171 DOI: 10.1186/s13023-018-0839-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/05/2018] [Indexed: 01/08/2023] Open
Abstract
Background Despite early and ongoing dietary management with a phe-restricted diet, suboptimal neuropsychological function has been observed in PKU. The restrictive nature of the PKU diet may expose patients to sub-optimal nutritional intake and deficiencies which may impact normal brain function. A systematic review of the published literature was carried out, where possible with meta-analysis, to compare the status of nutrients (Nutrients: DHA, EPA phospholipids, selenium, vitamins B6, B12, E, C, A, D, folic acid, choline, uridine, calcium, magnesium, zinc, iron, iodine and cholesterol) known to be important for brain development and functioning between individuals with PKU and healthy controls. Results Of 1534 publications identified, 65 studies met the entry criteria. Significantly lower levels of DHA, EPA and cholesterol were found for PKU patients compared to healthy controls. No significant differences in zinc, vitamins B12, E and D, calcium, iron and magnesium were found between PKU patients and controls. Because of considerable heterogeneity, the meta-analyses findings for folate and selenium were not reported. Due to an insufficient number of publications (< 4) no meta-analysis was undertaken for vitamins A, C and B6, choline, uridine, iodine and phospholipids. Conclusions The current data show that PKU patients have lower availability of DHA, EPA and cholesterol. Compliance with the phe-restricted diet including the micronutrient fortified protein substitute (PS) is essential to ensure adequate micronutrient status. Given the complexity of the diet, patients’ micronutrient and fatty acid status should be continuously monitored, with a particular focus on patients who are non-compliant or poorly compliant with their PS. Given their key role in brain function, assessment of the status of nutrients where limited data was found (e.g. choline, iodine) should be undertaken. Standardised reporting of studies in PKU would strengthen the output of meta-analysis and so better inform best practice for this rare condition. Electronic supplementary material The online version of this article (10.1186/s13023-018-0839-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gina A Montoya Parra
- Danone Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, The Netherlands.
| | - Rani H Singh
- Metabolic Genetics and Nutrition Program, Emory University, Atlanta, GA, USA
| | | | - Mirjam Kuhn
- Danone Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, The Netherlands
| | - Anita MacDonald
- Department of Metabolic Diseases, Birmingham Children's Hospital, Birmingham, UK
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22
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Pascucci T, Rossi L, Colamartino M, Gabucci C, Carducci C, Valzania A, Sasso V, Bigini N, Pierigè F, Viscomi MT, Ventura R, Cabib S, Magnani M, Puglisi-Allegra S, Leuzzi V. A new therapy prevents intellectual disability in mouse with phenylketonuria. Mol Genet Metab 2018; 124:39-49. [PMID: 29661557 DOI: 10.1016/j.ymgme.2018.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 01/20/2023]
Abstract
Untreated phenylketonuria (PKU) results in severe neurodevelopmental disorders, which can be partially prevented by an early and rigorous limitation of phenylalanine (Phe) intake. Enzyme substitution therapy with recombinant Anabaena variabilis Phe Ammonia Lyase (rAvPAL) proved to be effective in reducing blood Phe levels in preclinical and clinical studies of adults with PKU. Aims of present study were: a) to gather proofs of clinical efficacy of rAvPAL treatment in preventing neurological impairment in an early treated murine model of PKU; b) to test the advantages of an alternative delivering system for rAvPAL such as autologous erythrocytes. BTBR-Pahenu2-/- mice were treated from 15 to 64 post-natal days with weekly infusions of erythrocytes loaded with rAvPAL. Behavioral, neurochemical, and brain histological markers denoting untreated PKU were examined in early treated adult mice in comparison with untreated and wild type animals. rAvPAL therapy normalized blood and brain Phe; prevented cognitive developmental failure, brain depletion of serotonin, dendritic spine abnormalities, and myelin basic protein reduction. No adverse events or inactivating immune reaction were observed. In conclusion present study testifies the clinical efficacy of rAvPAL treatment in a preclinical model of PKU and the advantages of erythrocytes as carrier of the enzyme in term of frequency of the administrations and prevention of immunological reactions.
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Affiliation(s)
- Tiziana Pascucci
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Luigia Rossi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino (PU), Italy; EryDel SpA, via Sasso 36, 61029 Urbino (PU), Italy
| | - Marco Colamartino
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Claudia Gabucci
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino (PU), Italy
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University, viale del Policlinico 155, 00161 Rome, Italy
| | - Alessandro Valzania
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Valeria Sasso
- Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Noemi Bigini
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino (PU), Italy
| | - Francesca Pierigè
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino (PU), Italy
| | | | - Rossella Ventura
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Simona Cabib
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino (PU), Italy; EryDel SpA, via Sasso 36, 61029 Urbino (PU), Italy
| | - Stefano Puglisi-Allegra
- Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy; Fondazione Santa Lucia, IRCCS, via Ardeatina 306, 00142 Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, via dei Sabelli 108, 00185 Rome, Italy.
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23
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Stepien KM, Heaton R, Rankin S, Murphy A, Bentley J, Sexton D, Hargreaves IP. Evidence of Oxidative Stress and Secondary Mitochondrial Dysfunction in Metabolic and Non-Metabolic Disorders. J Clin Med 2017; 6:E71. [PMID: 28753922 PMCID: PMC5532579 DOI: 10.3390/jcm6070071] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/07/2017] [Accepted: 07/14/2017] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial dysfunction and oxidative stress have been implicated in the pathogenesis of a number of diseases and conditions. Oxidative stress occurs once the antioxidant defenses of the body become overwhelmed and are no longer able to detoxify reactive oxygen species (ROS). The ROS can then go unchallenged and are able to cause oxidative damage to cellular lipids, DNA and proteins, which will eventually result in cellular and organ dysfunction. Although not always the primary cause of disease, mitochondrial dysfunction as a secondary consequence disease of pathophysiology can result in increased ROS generation together with an impairment in cellular energy status. Mitochondrial dysfunction may result from either free radical-induced oxidative damage or direct impairment by the toxic metabolites which accumulate in certain metabolic diseases. In view of the importance of cellular antioxidant status, a number of therapeutic strategies have been employed in disorders associated with oxidative stress with a view to neutralising the ROS and reactive nitrogen species implicated in disease pathophysiology. Although successful in some cases, these adjunct therapies have yet to be incorporated into the clinical management of patients. The purpose of this review is to highlight the emerging evidence of oxidative stress, secondary mitochondrial dysfunction and antioxidant treatment efficacy in metabolic and non-metabolic diseases in which there is a current interest in these parameters.
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Affiliation(s)
- Karolina M Stepien
- The Mark Holland Metabolic Unit Salford Royal NHS Foundation Trust Stott Lane, Salford M6 8HD, UK.
| | - Robert Heaton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Scott Rankin
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Alex Murphy
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - James Bentley
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Darren Sexton
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
| | - Iain P Hargreaves
- School of Pharmacy, Liverpool John Moore University, Byrom Street, Liverpool L3 3AF, UK.
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24
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Abstract
Cerebral neurotransmitter (NT) deficiency has been suggested as a contributing factor in the pathophysiology of brain dysfunction in phenylketonuria (PKU), even in early-treated phenylketonuric patients. The study aimed to review dopamine and serotonin status in PKU, and the effect of the impaired neurotransmission. Several mechanisms are involved in the pathophysiology of PKU, primarily characterized by impaired dopamine and serotonin synthesis. These deficits are related to executive dysfunctions and social-emotional problems, respectively, in early treated patients. Blood phenylalanine is the main biomarker for treatment compliance follow-up, but further investigations and validation of peripheral biomarkers may be performed to monitor NT status. The development of new therapies is needed not only for decreasing blood and brain phenylalanine levels but also to improve NT syntheses.
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25
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van Vliet D, Bruinenberg VM, Mazzola PN, van Faassen MHJR, de Blaauw P, Kema IP, Heiner-Fokkema MR, van Anholt RD, van der Zee EA, van Spronsen FJ. Large Neutral Amino Acid Supplementation Exerts Its Effect through Three Synergistic Mechanisms: Proof of Principle in Phenylketonuria Mice. PLoS One 2015; 10:e0143833. [PMID: 26624009 PMCID: PMC4666635 DOI: 10.1371/journal.pone.0143833] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/10/2015] [Indexed: 11/19/2022] Open
Abstract
Background Phenylketonuria (PKU) was the first disorder in which severe neurocognitive dysfunction could be prevented by dietary treatment. However, despite this effect, neuropsychological outcome in PKU still remains suboptimal and the phenylalanine-restricted diet is very demanding. To improve neuropsychological outcome and relieve the dietary restrictions for PKU patients, supplementation of large neutral amino acids (LNAA) is suggested as alternative treatment strategy that might correct all brain biochemical disturbances caused by high blood phenylalanine, and thereby improve neurocognitive functioning. Objective As a proof-of-principle, this study aimed to investigate all hypothesized biochemical treatment objectives of LNAA supplementation (normalizing brain phenylalanine, non-phenylalanine LNAA, and monoaminergic neurotransmitter concentrations) in PKU mice. Methods C57Bl/6 Pah-enu2 (PKU) mice and wild-type mice received a LNAA supplemented diet, an isonitrogenic/isocaloric high-protein control diet, or normal chow. After six weeks of dietary treatment, blood and brain amino acid and monoaminergic neurotransmitter concentrations were assessed. Results In PKU mice, the investigated LNAA supplementation regimen significantly reduced blood and brain phenylalanine concentrations by 33% and 26%, respectively, compared to normal chow (p<0.01), while alleviating brain deficiencies of some but not all supplemented LNAA. Moreover, LNAA supplementation in PKU mice significantly increased brain serotonin and norepinephrine concentrations from 35% to 71% and from 57% to 86% of wild-type concentrations (p<0.01), respectively, but not brain dopamine concentrations (p = 0.307). Conclusions This study shows that LNAA supplementation without dietary phenylalanine restriction in PKU mice improves brain biochemistry through all three hypothesized biochemical mechanisms. Thereby, these data provide proof-of-concept for LNAA supplementation as a valuable alternative dietary treatment strategy in PKU. Based on these results, LNAA treatment should be further optimized for clinical application with regard to the composition and dose of the LNAA supplement, taking into account all three working mechanisms of LNAA treatment.
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Affiliation(s)
- Danique van Vliet
- University of Groningen, University Medical Center Groningen, Beatrix Children’s Hospital, Groningen, The Netherlands
- University of Groningen, Center of Behavior and Neurosciences, Department of Molecular Neurobiology, Groningen, The Netherlands
| | - Vibeke M. Bruinenberg
- University of Groningen, Center of Behavior and Neurosciences, Department of Molecular Neurobiology, Groningen, The Netherlands
| | - Priscila N. Mazzola
- University of Groningen, University Medical Center Groningen, Beatrix Children’s Hospital, Groningen, The Netherlands
- University of Groningen, Center of Behavior and Neurosciences, Department of Molecular Neurobiology, Groningen, The Netherlands
| | - Martijn H. J. R. van Faassen
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen, The Netherlands
| | - Pim de Blaauw
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen, The Netherlands
| | - Ido P. Kema
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen, The Netherlands
| | - M. Rebecca Heiner-Fokkema
- University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen, The Netherlands
| | | | - Eddy A. van der Zee
- University of Groningen, Center of Behavior and Neurosciences, Department of Molecular Neurobiology, Groningen, The Netherlands
| | - Francjan J. van Spronsen
- University of Groningen, University Medical Center Groningen, Beatrix Children’s Hospital, Groningen, The Netherlands
- * E-mail:
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Schuck PF, Malgarin F, Cararo JH, Cardoso F, Streck EL, Ferreira GC. Phenylketonuria Pathophysiology: on the Role of Metabolic Alterations. Aging Dis 2015; 6:390-9. [PMID: 26425393 DOI: 10.14336/ad.2015.0827] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/27/2015] [Indexed: 11/01/2022] Open
Abstract
Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism caused by the deficiency of phenylalanine hydroxylase. This deficiency leads to the accumulation of Phe and its metabolites in tissues and body fluids of PKU patients. The main signs and symptoms are found in the brain but the pathophysiology of this disease is not well understood. In this context, metabolic alterations such as oxidative stress, mitochondrial dysfunction, and impaired protein and neurotransmitters synthesis have been described both in animal models and patients. This review aims to discuss the main metabolic disturbances reported in PKU and relate them with the pathophysiology of this disease. The elucidation of the pathophysiology of brain damage found in PKU patients will help to develop better therapeutic strategies to improve quality of life of patients affected by this condition.
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Affiliation(s)
- Patrícia Fernanda Schuck
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Fernanda Malgarin
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - José Henrique Cararo
- 1 Laboratório de Erros Inatos do Metabolismo, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Fabiola Cardoso
- 2 Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Emilio Luiz Streck
- 3 Laboratório de Bioenergética, Unidade Acadêmica de Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Gustavo Costa Ferreira
- 2 Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Changes of lipoproteins in phenylalanine hydroxylase-deficient children during the first year of life. Clin Chim Acta 2014; 433:1-4. [PMID: 24607329 DOI: 10.1016/j.cca.2014.02.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/27/2014] [Accepted: 02/24/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND Influence of hyperphenylalaninemia on lipoproteins in early life remains unclear. METHODS We enrolled 24 phenylalanine hydroxylase (PAH)-deficient children who were classified into a phenylketonuria (PKU) group (n=12) lacking PAH activity and a benign hyperphenylalaninemia (HPA) group (n=12) having partial PAH activity, and their 11 non-affected siblings. We measured serum total-cholesterol, low-density lipoprotein (LDL)-cholesterol, and high-density lipoprotein (HDL)-cholesterol levels together with apolipoproteins for the first year of life, and compared them with those of 30 age-matched healthy controls. RESULTS The affected groups invariably had lower cholesterol levels than non-affected groups. At birth, HDL-cholesterol decrease was greatest and predominated over the LDL-cholesterol decrease: total cholesterol, 28/36% decrease to the control level in HPA/PKU; HDL-cholesterol, 33/51%; LDL-cholesterol, 20/28%. At 3months, the opposite changes were observed: total cholesterol, 16/28%; HDL-cholesterol, 13/23%; LDL-cholesterol, 16/33%. At 12months, LDL were still significantly lower in both groups (8/18%, p<.05 and .001), although HDL was significantly decreased only in the PKU group (15%, p<.05). Apolipoprotein A-I/A-II and B changed respectively in accordance with HDL-cholesterol and LDL-cholesterol changes. Despite similar phenylalanine levels, the PKU group invariably had lower cholesterol concentrations than the HPA group had. CONCLUSION Irrespective of phenylalanine concentrations, lipoprotein synthesis in PAH-deficient children, particularly in PKU children, was suppressed in early life.
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Mazzola PN, Karikas GA, Schulpis KH, Dutra-Filho CS. Antioxidant treatment strategies for hyperphenylalaninemia. Metab Brain Dis 2013; 28:541-50. [PMID: 23657560 DOI: 10.1007/s11011-013-9414-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/01/2013] [Indexed: 12/12/2022]
Abstract
Hyperphenylalaninemia (HPA) leads to increased oxidative stress in patients with phenylketonuria (PKU) and in animal models of PKU. Early diagnosis and immediate adherence to a phenylalanine-restricted diet prevents HPA and, consequently, severe brain damage. However, treated adolescent and adult PKU patients have difficulties complying with the diet, leading to an oscillation of phenylalanine levels and associated oxidative stress. The brain is especially susceptible to reactive species, and oxidative stress might add to the impaired cognitive function found in these patients. The restricted PKU diet has a very limited nutrient content from natural foods and almost no animal protein, which reduces the intake of important compounds. These specific compounds can act as scavengers of reactive species and can be co-factors of antioxidant enzymes. Supplementation with nutrients, vitamins, and tetrahydropterin has given quite promising results in patients and animal models. Antioxidant supplementation has been studied in HPA, however there is no consensus about its always beneficial effects. In this way, regular exercise could be a beneficial addition on antioxidant status in PKU patients. A deeper understanding of PKU molecular biochemistry, and genetics, as well as the need for improved targeted treatment options, could lead to the development of new therapeutic strategies.
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Affiliation(s)
- Priscila Nicolao Mazzola
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica. Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, CEP 90035-003, Porto Alegre, RS, Brazil,
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Okano Y, Nagasaka H. Optimal serum phenylalanine for adult patients with phenylketonuria. Mol Genet Metab 2013; 110:424-30. [PMID: 24094552 DOI: 10.1016/j.ymgme.2013.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 09/12/2013] [Accepted: 09/12/2013] [Indexed: 11/28/2022]
Abstract
High serum phenylalanine in adult patients with phenylketonuria (PKU) causes neuropsychological and psychosocial problems that can be resolved by phenylalanine-restricted diet. Therefore, PKU patients must continue to adhere to phenylalanine-restricted diet for life, although the optimal serum phenylalanine level in later life has yet to be established. The purpose of this review was to establish the optimal serum phenylalanine level in later life of PKU patients. We evaluated oxidative stress status, nitric oxide metabolism, cholesterol-derived oxysterols, vitamin D and bone status, and magnetic resonance imaging (MRI) in adult PKU patients according to serum phenylalanine level. Oxidative stress increased markedly at serum phenylalanine of 700-800 μmol/L. Serum phenylalanine higher than 700-850 μmol/L correlated with the disturbance of nitric oxide regulatory system. Adult PKU patients had poor vitamin D status and exhibited predominance of bone resorption over bone formation. In the brain, the levels of 24S-hydroxycholesterol, a marker of brain cholesterol elimination, were low at serum phenylalanine levels exceeding 650 μmol/L. MRI studies showed high signal intensity in deep white matter on T2-weighted and FLAIR images of PKU patients with serum phenylalanine greater than 500 μmol/L, with decreased apparent diffusion coefficients. Changes in most parameters covering the entire body organs in adult PKU were almost acceptable below 700-800 μmol/L of phenylalanine level. However, the optimal serum phenylalanine level should be 500 μmol/L or less in later life for the brain to be safe.
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Affiliation(s)
- Yoshiyuki Okano
- Department of Genetics, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan
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Nagasaka H, Okano Y, Kimura A, Mizuochi T, Sanayama Y, Takatani T, Nakagawa S, Hasegawa E, Hirano KI, Mochizuki H, Ohura T, Ishige-Wada M, Usui H, Yorifuji T, Tsukahara H, Hirayama S, Ohtake A, Yamato S, Miida T. Oxysterol changes along with cholesterol and vitamin D changes in adult phenylketonuric patients diagnosed by newborn mass-screening. Clin Chim Acta 2012; 416:54-9. [PMID: 23168022 DOI: 10.1016/j.cca.2012.10.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND Phenylketonuria (PKU) possibly leads to hypocholesterolemia and lowered vitamin D (VD) status. Metabolism of oxysterols linking with those of cholesterol and VD has never been examined in PKU. METHODS Blood oxysterols along with blood phenylalanine, lipids and VD were examined for 33 PKU adults aged 21-38 years and 20 age-matched healthy controls. RESULTS Total- and low-density cholesterols, and 25-hydroxy VD(3) were decreased significantly in the PKU group (cholesterols, 10% decrease; 25-hydroxy VD(3) 35% decrease vs. the control group). 24S-hydroxycholesterol (24S-OHC) eliminating brain cholesterol, and 27-OHC and 7α-hydroxycholesterol (7α-OHC) representing peripheral and hepatic cholesterol elimination, respectively, were significantly decreased in PKU group: 24S-OHC, 25% decrease, p<.01; 27-OHC and 7α-OHC, 35-40% decrease, p<.001. 7β-Hydroxycholesterol (7β-OHC) reflecting oxidative stress was increased significantly in PKU group (p<.05). 7α-OHC and 27-OHC levels in PKU group always showed similar values, regardless of other parameters while the 24S-OHC and 7β-OHC levels decreased and increased, respectively, showing significant correlations with phenylalanine level (p<.005). 27-OHC level showed a significant positive correlation with the 25-hydroxy VD(3) level in this group (p<.001). CONCLUSION Blood oxysterol changes predominate over blood cholesterol changes and influence on VD status in adult PKU patients.
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Affiliation(s)
- Hironori Nagasaka
- Department of Pediatrics, Takarazuka City Hospital, Takarazuka, Japan.
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31
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Mütze U, Beblo S, Kortz L, Matthies C, Koletzko B, Bruegel M, Rohde C, Thiery J, Kiess W, Ceglarek U. Metabolomics of dietary fatty acid restriction in patients with phenylketonuria. PLoS One 2012; 7:e43021. [PMID: 22912778 PMCID: PMC3418234 DOI: 10.1371/journal.pone.0043021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 07/17/2012] [Indexed: 11/20/2022] Open
Abstract
Background Patients with phenylketonuria (PKU) have to follow a lifelong phenylalanine restricted diet. This type of diet markedly reduces the intake of saturated and unsaturated fatty acids especially long chain polyunsaturated fatty acids (LC-PUFA). Long-chain saturated fatty acids are substrates of mitochondrial fatty acid oxidation for acetyl-CoA production. LC-PUFA are discussed to affect inflammatory and haemostaseological processes in health and disease. The influence of the long term PKU diet on fatty acid metabolism with a special focus on platelet eicosanoid metabolism has been investigated in the study presented here. Methodology/Principal Findings 12 children with PKU under good metabolic control and 8 healthy controls were included. Activated fatty acids (acylcarnitines C6–C18) in dried blood and the cholesterol metabolism in serum were analyzed by liquid chromatographic tandem mass spectrometry (LC-MS/MS). Fatty acid composition of plasma glycerophospholipids was determined by gas chromatography. LC-PUFA metabolites were analyzed in supernatants by LC-MS/MS before and after platelet activation and aggregation using a standardized protocol. Patients with PKU had significantly lower free carnitine and lower activated fatty acids in dried blood compared to controls. Phytosterols as marker of cholesterol (re-) absorption were not influenced by the dietary fatty acid restriction. Fatty acid composition in glycerophospholipids was comparable to that of healthy controls. However, patients with PKU showed significantly increased concentrations of y-linolenic acid (C18:3n-6) a precursor of arachidonic acid. In the PKU patients significantly higher platelet counts were observed. After activation with collagen platelet aggregation and thromboxane B2 and thromboxane B3 release did not differ from that of healthy controls. Conclusion/Significance Long-term dietary fatty acid restriction influenced the intermediates of mitochondrial beta-oxidation. No functional influence on unsaturated fatty acid metabolism and platelet aggregation in patients with PKU was detected.
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Affiliation(s)
- Ulrike Mütze
- Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, University of Leipzig, Leipzig, Germany.
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32
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Nagasaka H, Tsukahara H, Takatani T, Sanayama Y, Takayanagi M, Ohura T, Sakamoto O, Ito T, Wada M, Yoshino M, Ohtake A, Yorifuji T, Hirayama S, Miida T, Fujimoto H, Mochizuki H, Hattori T, Okano Y. Cross-sectional study of bone metabolism with nutrition in adult classical phenylketonuric patients diagnosed by neonatal screening. J Bone Miner Metab 2011; 29:737-43. [PMID: 21594581 DOI: 10.1007/s00774-011-0276-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 04/20/2011] [Indexed: 10/18/2022]
Abstract
The mechanism underlying the development of osteopenia or osteoporosis in longstanding phenylketonuria (PKU) remains to be clarified. We investigated the details of bone metabolism in 21 female and 13 male classical PKU patients aged 20-35 years. Vitamin D (VD), parathyroid hormone (PTH), bone turnover markers, and daily nutrient intake were examined. The patients had lower daily energy and protein intake than did the age-matched controls (22 women, 14 men), but their respective fat, VD, and calcium intake did not differ. Serum 1,25-dihydroxy VD and 25-hydroxy VD levels in female and male patient groups were significantly higher and lower than those in respective control groups (females, P < 0.001; males, P < 0.05 and P < 0.01, respectively). Serum intact PTH levels were significantly higher in the female patient group (P < 0.05). Urinary calcium levels in the patient groups were significantly higher than those of the control subjects (females, P < 0.001; males, P < 0.05). Bone resorption markers were significantly higher in patients than in controls, although bone formation markers were not different. Patient serum levels of osteoprotegerin-inhibiting bone resorption were significantly lower (females, P < 0.001; males, P < 0.01). None of the bone parameters correlated significantly with serum phenylalanine or nutrient intake. PKU patients exhibited lower VD status and more rapid bone resorption despite normal calcium-VD intakes.
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Affiliation(s)
- Hironori Nagasaka
- Department of Pediatrics, Takarazuka City Hospital, 4-5-1 Kohama Cho, Takarazuka 665-0827, Japan.
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33
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Protein substitution to produce a processed cheese with high branched-chain amino acids of medical and genetic importance. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2010. [DOI: 10.1016/j.ejmhg.2010.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Abstract
Phenylketonuria is the most prevalent disorder caused by an inborn error in aminoacid metabolism. It results from mutations in the phenylalanine hydroxylase gene. Phenotypes can vary from a very mild increase in blood phenylalanine concentrations to a severe classic phenotype with pronounced hyperphenylalaninaemia, which, if untreated, results in profound and irreversible mental disability. Neonatal screening programmes identify individuals with phenylketonuria. The initiation of a phenylalanine-restricted diet very soon after birth prevents most of the neuropsychological complications. However, the diet is difficult to maintain and compliance is often poor, especially in adolescents, young adults, and pregnant women. Tetrahydrobiopterin stimulates phenylalanine hydroxylase activity in about 20% of patients, and in those patients serves as a useful adjunct to the phenylalanine-restricted diet because it increases phenylalanine tolerance and allows some dietary freedom. Possible future treatments include enzyme substitution with phenylalanine ammonia lyase, which degrades phenylalanine, and gene therapy to restore phenylalanine hydroxylase activity.
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Affiliation(s)
- Nenad Blau
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital, Zurich, Switzerland.
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35
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Feillet F, van Spronsen FJ, MacDonald A, Trefz FK, Demirkol M, Giovannini M, Bélanger-Quintana A, Blau N. Challenges and pitfalls in the management of phenylketonuria. Pediatrics 2010; 126:333-41. [PMID: 20624808 DOI: 10.1542/peds.2009-3584] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Despite recent advances in the management of phenylketonuria and hyperphenylalaninemia, important questions on the management of this disorder remain unanswered. Consensus exists on the need for neonatal screening and early treatment, yet disagreement persists over threshold levels of blood phenylalanine for starting treatment, target blood phenylalanine levels, and the management of older patient groups. The mainstay of treatment is a phenylalanine-restricted diet, but its application varies between and within countries. Beyond diet treatment, there is a lack of consensus on the use of newer treatments such as tetrahydrobiopterin. Although neonatal screening and early treatment has meant that most well-treated children grow up with near-normal IQ scores, the effect of relaxing metabolic control on cognitive and executive function later in life is still not fully understood. Although it is clear from the available literature that the active control of blood phenylalanine levels is of vital importance, there are other treatment-related factors that affect outcome. A uniform and firmly evidence-based approach to the management of phenylketonuria is required.
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Affiliation(s)
- François Feillet
- Service de Médecine Infantile 1, Centre de Référence des Maladies Héréditaires du Métabolisme, INSERM U 954, CHU Brabois Enfants, Vandoeuvre les Nancy, France
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36
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Schoemans R, Aigrot MS, Wu C, Marée R, Hong P, Belachew S, Josse C, Lubetzki C, Bours V. Oligodendrocyte development and myelinogenesis are not impaired by high concentrations of phenylalanine or its metabolites. J Inherit Metab Dis 2010; 33:113-20. [PMID: 20151197 PMCID: PMC3071566 DOI: 10.1007/s10545-010-9052-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 01/11/2010] [Accepted: 01/13/2010] [Indexed: 10/19/2022]
Abstract
Phenylketonuria (PKU) is a metabolic genetic disease characterized by deficient phenylalanine hydroxylase (PAH) enzymatic activity. Brain hypomyelination has been reported in untreated patients, but its mechanism remains unclear. We therefore investigated the influence of phenylalanine (Phe), phenylpyruvate (PP), and phenylacetate (PA) on oligodendrocytes. We first showed in a mouse model of PKU that the number of oligodendrocytes is not different in corpus callosum sections from adult mutants or from control brains. Then, using enriched oligodendroglial cultures, we detected no cytotoxic effect of high concentrations of Phe, PP, or PA. Finally, we analyzed the impact of Phe, PP, and PA on the myelination process in myelinating cocultures using both an in vitro index of myelination, based on activation of the myelin basic protein (MBP) promoter, and the direct quantification of myelin sheaths by both optical measurement and a bioinformatics method. None of these parameters was affected by the increased levels of Phe or its derivatives. Taken together, our data demonstrate that high levels of Phe, such as in PKU, are unlikely to directly induce brain hypomyelination, suggesting involvement of alternative mechanisms in this myelination defect.
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Affiliation(s)
- Renaud Schoemans
- Human Genetics, GIGA-Research, University of Liège, Liège, Belgium
| | | | - Chaohong Wu
- Michtom School of Computer Science, Volen Center for Complex Systems, Room 261, Brandeis University, Waltham, MA 02454, USA
| | - Raphaël Marée
- Bioinformatics platform, GIGA-Research, University of Liège, Liège, Belgium
| | - Pengyu Hong
- Michtom School of Computer Science, Volen Center for Complex Systems, Room 261, Brandeis University, Waltham, MA 02454, USA
| | | | - Claire Josse
- Human Genetics, GIGA-Research, University of Liège, Liège, Belgium
| | | | - Vincent Bours
- Human Genetics, GIGA-Research, University of Liège, Liège, Belgium
- Genetics Center, CHU Liège, Liège, Belgium
- Department of Genetics, CHU Liège, Université de Liège B34, Avenue de l’hôpital 1, 4000 Liège, Belgique, Belgium
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37
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Li D, Gu X, Lu L, Liang L. Effects of phenylalanine on the survival and neurite outgrowth of rat cortical neurons in primary cultures: possible involvement of brain-derived neurotrophic factor. Mol Cell Biochem 2010; 339:1-7. [PMID: 20101519 DOI: 10.1007/s11010-009-0364-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/16/2009] [Indexed: 12/15/2022]
Abstract
Phenylketonuria (PKU) is characterized by elevated levels of phenylalanine (Phe) in plasma and cerebrospinal fluid of PKU patients, leading to mental retardation. The developmental delay in the cerebral cortex is one of the characteristic pathologic changes in untreated phenylketonuria patients. This is thought to be due to the toxic effects of Phe and/or its metabolites; however, the underlying mechanisms are as yet unknown. In this study, using a model system in which cultured cortical neurons were induced with Phe, we observed that Phe inhibited the longest neurite outgrowth and induced the neuronal death. We further demonstrated that the expression of BDNF mRNA and protein was significantly decreased by Phe, together with a decrease in extracellular signal-regulated kinase (ERK) and Akt phosphorylation activity. There was no change in expression of TrkB mRNA and protein. Considering the important role of BDNF in normal brain development and function, these L: -Phe-induced changes in BDNF in PKU brain may be a critical element of the neurological symptoms of PKU.
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Affiliation(s)
- Duan Li
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Institute for Pediatric Research, 1665 Kong Jiang Rd, Shanghai 200092, China.
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38
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Experimental Evidence that Phenylalanine Provokes Oxidative Stress in Hippocampus and Cerebral Cortex of Developing Rats. Cell Mol Neurobiol 2009; 30:317-26. [DOI: 10.1007/s10571-009-9455-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 09/03/2009] [Indexed: 12/12/2022]
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39
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Kyprianou N, Murphy E, Lee P, Hargreaves I. Assessment of mitochondrial respiratory chain function in hyperphenylalaninaemia. J Inherit Metab Dis 2009; 32:289-96. [PMID: 19277893 DOI: 10.1007/s10545-009-1080-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Revised: 01/12/2009] [Accepted: 01/14/2009] [Indexed: 11/30/2022]
Abstract
Phenylketonuria (PKU) is an autosomal recessive disorder resulting in neurological and intellectual disability when untreated. However, even in treated patients there may be residual neurological impairment such as tremor. It has been suggested that the hyperphenylalaninaemia in patients with PKU reduces complex I (NADH:ubiquinone reductase) activity of the mitochondrial respiratory chain (MRC) and/or biosynthesis of coenzyme Q(10) (CoQ(10)), which acts as an electron carrier in the MRC, leading to impaired energy metabolism in the brain of patients with PKU and hence the neurological pathology. The aim of this study was to elucidate the mechanism of phenylalanine (Phe) toxicity on the MRC. We compared mean plasma and blood-spot Phe and mononuclear CoQ(10) levels in 17 patients with PKU and a tremor compared to 22 patients without tremor. Human 1321N1 astrocytoma cells were exposed to hyperphenylalaninaemia by the addition of 300 or 900 micromol/L of Phe to the cell culture medium. Following 96 h of culture we measured complex I and citrate synthase activities and CoQ(10) level. Results showed no significant difference in Phe or CoQ(10) levels in patients with tremor compared to those without tremor. Further, hyperphenylalaninaemia did not cause a significant reduction in complex I activity or CoQ(10) biosynthesis, even when taking into account the mitochondrial enrichment of the cell samples by expressing complex I and CoQ(10) as a ratio to citrate synthase. In conclusion, the results of this study suggest that hyperphenylalaninaemia does not contribute to the pathophysiology of PKU by causing a decrease in MRC complex I activity and/or CoQ(10) biosynthesis.
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40
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van Spronsen FJ, Hoeksma M, Reijngoud DJ. Brain dysfunction in phenylketonuria: is phenylalanine toxicity the only possible cause? J Inherit Metab Dis 2009; 32:46-51. [PMID: 19191004 DOI: 10.1007/s10545-008-0946-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 10/16/2008] [Accepted: 11/20/2008] [Indexed: 11/25/2022]
Abstract
In phenylketonuria, mental retardation is prevented by a diet that severely restricts natural protein and is supplemented with a phenylalanine-free amino acid mixture. The result is an almost normal outcome, although some neuropsychological disturbances remain. The pathology underlying cognitive dysfunction in phenylketonuria is unknown, although it is clear that the high plasma concentrations of phenylalanine influence the blood-brain barrier transport of large neutral amino acids. The high plasma phenylalanine concentrations increase phenylalanine entry into brain and restrict the entry of other large neutral amino acids. In the literature, emphasis has been on high brain phenylalanine as the pathological substrate that causes mental retardation. Phenylalanine was found to interfere with different cerebral enzyme systems. However, apart from the neurotoxicity of phenylalanine, a deficiency of the other large neutral amino acids in brain may also be an important factor affecting cognitive function in phenylketonuria. Cerebral protein synthesis was found to be disturbed in a mouse model of phenylketonuria and could be caused by shortage of large neutral amino acids instead of high levels of phenylalanine. Therefore, in this review we emphasize the possibility of a different idea about the pathogenesis of mental dysfunction in phenylketonuria patients and the aim of treatment strategies. The aim of treatment in phenylketonuria might be to normalize cerebral concentrations of all large neutral amino acids rather than prevent high cerebral phenylalanine concentrations alone. In-depth studies are necessary to investigate the role of large neutral amino acid deficiencies in brain.
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Affiliation(s)
- F J van Spronsen
- Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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41
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Kölker S, Sauer SW, Hoffmann GF, Müller I, Morath MA, Okun JG. Pathogenesis of CNS involvement in disorders of amino and organic acid metabolism. J Inherit Metab Dis 2008; 31:194-204. [PMID: 18392748 DOI: 10.1007/s10545-008-0823-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 02/12/2008] [Accepted: 02/14/2008] [Indexed: 12/21/2022]
Abstract
Inherited disorders of amino and organic acid metabolism have a high cumulative frequency, and despite heterogeneous aetiology and varying clinical presentation, the manifestation of neurological disease is common. It has been demonstrated for some of these diseases that accumulating pathological metabolites are directly involved in the manifestation of neurological disease. Various pathomechanisms have been suggested in different in vitro and in vivo models including an impairment of brain energy metabolism, an imbalance of excitatory and inhibitory neurotransmission, altered transport across the blood-brain barrier and between glial cells and neurons, impairment of myelination and disturbed neuronal efflux of metabolic water. This review summarizes recent knowledge on pathomechanisms involved in phenylketonuria, glutaric aciduria type I, succinic semialdehyde dehydrogenase deficiency and aspartoacylase deficiency with examples, highlighting general as well as disease-specific concepts and their putative impact on treatment.
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Affiliation(s)
- S Kölker
- Department of General Pediatrics, Division of Inherited Metabolic Disease, University Children’s Hospital Heidelberg, Heidelberg, Germany.
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42
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Koch R, Verma S, Gilles FH. Neuropathology of a 4-month-old infant born to a woman with phenylketonuria. Dev Med Child Neurol 2008; 50:230-3. [PMID: 18201217 DOI: 10.1111/j.1469-8749.2008.02028.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We evaluated the brain of a 4-month-old male infant whose mother had inadequately controlled maternal phenylketonuria (MPKU). At autopsy his brain was normally developed but underweight. We found ventriculomegaly, hypoplastic cerebral white matter, and delay of myelination in late myelinating tracts without white matter astrocytosis and without chronic lesions in any gray matter structure. We compared the development of the infant's white matter tracts with published data on infant myelination. Congenital heart disease complicated the case. Abnormalities in developmental white matter may account for neurological abnormalities in infants with MPKU.
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Affiliation(s)
- Richard Koch
- Department of Genetics, Children's Hospital Los Angeles, 4650 Sunset Boulevard, Los Angeles, CA 90027, USA
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43
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Hargreaves IP. Coenzyme Q10 in phenylketonuria and mevalonic aciduria. Mitochondrion 2007; 7 Suppl:S175-80. [PMID: 17442628 DOI: 10.1016/j.mito.2007.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 02/01/2007] [Accepted: 02/18/2007] [Indexed: 10/23/2022]
Abstract
Mevalonic aciduria (MVA) and phenylketonuria (PKU) are inborn errors of metabolism caused by deficiencies in the enzymes mevalonate kinase and phenylalanine 4-hydroxylase, respectively. Despite numerous studies the factors responsible for the pathogenicity of these disorders remain to be fully characterised. In common with MVA, a deficit in coenzyme Q10 (CoQ10) concentration has been implicated in the pathophysiology of PKU. In MVA the decrease in CoQ10 concentration may be attributed to a deficiency in mevalonate kinase, an enzyme common to both CoQ10 and cholesterol synthesis. However, although dietary sources of cholesterol cannot be excluded, the low/normal cholesterol levels in MVA patients suggests that some other factor may also be contributing to the decrease in CoQ10.The main factor associated with the low CoQ10 level of PKU patients is purported to be the elevated phenylalanine level. Phenylalanine has been shown to inhibit the activities of both 3-hydroxy-3-methylglutaryl-CoA reductase and mevalonate-5-pyrophosphate decarboxylase, enzymes common to both cholesterol and CoQ10 biosynthesis. Although evidence of a lowered plasma/serum CoQ10 level has been reported in MVA and PKU, few studies have assessed the intracellular CoQ10 concentration of patients. Plasma/serum CoQ10 is influenced by dietary intake as well as its lipoprotein content and therefore may be limited as a means of assessing intracellular CoQ10 concentration. Whether the pathogenesis of MVA and PKU are related to a loss of CoQ10 has yet to be established and further studies are required to assess the intracellular CoQ10 concentration of patients before this relationship can be confirmed or refuted.
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Affiliation(s)
- Iain P Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
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44
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Sitta A, Barschak AG, Deon M, Terroso T, Pires R, Giugliani R, Dutra-Filho CS, Wajner M, Vargas CR. Investigation of oxidative stress parameters in treated phenylketonuric patients. Metab Brain Dis 2006; 21:287-96. [PMID: 17146735 DOI: 10.1007/s11011-006-9035-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 05/17/2006] [Indexed: 11/27/2022]
Abstract
Phenylketonuria (PKU) is the most frequent disturbance of amino acid metabolism being caused by severe deficiency of phenylalanine hydroxylase activity. Untreated PKU patients present severe mental retardation whose pathophysiology is not completely estabilished. Despite the low-Phe diet, a considerable number of phenylketonuric patients present a mild to moderate psychomotor delay and decreased cognitive functions. In the present study we evaluated various parameters of oxidative stress namely thiobarbituric acid-reactive species (TBA-RS), total antioxidant reactivity (TAR) and activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in two groups of treated PKU patients, one with well controlled and the other with high Phe blood levels in order to investigate whether blood Phe concentrations could be correlated with the extend of oxidative stress. We initially verified a marked increase of TBA-RS, and a decrease of TAR in plasma, as well as a reduction of erythrocyte GSH-Px activity which were similar in both groups of PKU patients, when compared to controls of similar ages. In contrast, CAT and SOD activities were not altered in PKU patients. These results show that oxidative stress occurs in PKU patients and that this pathogenic process is probably not directly correlated to Phe blood levels.
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Affiliation(s)
- A Sitta
- Serviço de Genética Médica, HCPA, Rua Ramiro Barcelos, 2350 CEP, 90.035-903, Porto Alegre, RS, Brasil
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45
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Pérez-Dueñas B, Pujol J, Soriano-Mas C, Ortiz H, Artuch R, Vilaseca MA, Campistol J. Global and regional volume changes in the brains of patients with phenylketonuria. Neurology 2006; 66:1074-8. [PMID: 16606920 DOI: 10.1212/01.wnl.0000204415.39853.4a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Although phenylketonuria is a treatable disease, patients with late or nonoptimal phenylalanine-restricted diet may experience brain damage. The authors used tridimensional MRI and a voxelwise analysis method to investigate possible volume changes in the brain parenchyma of patients with phenylketonuria.Methods: The authors assessed 27 treated patients (mean age ± SD, 20 ± 7 years) and 27 matched control subjects. Global tissue volumes were compared, and statistical parametric maps of between-group regional volume differences were obtained for gray and white matter. Anatomic data were correlated with relevant clinical and biochemical variables.Results: Patients with phenylketonuria showed smaller gray matter volumes that were associated with lower IQ and older age at diagnosis. Voxel-based maps revealed that significant gray matter volume reduction occurred in motor and premotor cortex and thalamus. A relative increase in gray matter volume was observed in the ventral part of the striatum. The authors found no group differences for global white matter measurements. Higher recent phenylalanine levels, however, were associated with larger global white matter volume in early-treated patients. Voxel-based maps showed a relative volume reduction in periventricular white matter and a relative increase in the region of the internal capsule, extending to the adjacent thalamus and striatum.Conclusions: Treated patients may show significant gray and white matter volume changes related to the duration and strict observation of dietary treatment. Further studies are needed to investigate whether the presence of neurologic symptoms may be explained by specific anatomic alterations.
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Affiliation(s)
- B Pérez-Dueñas
- Department of Neurology, Hospital Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain
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46
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Abstract
To have more insight into the mechanism of neuronal injury in phenylketonuria (PKU) patients, gene expression profiles were studied in cell culture of embryonic rat cortical neurons induced by phenylalanine. Randomly chose cortical cultured for 3 days were treated by 0.9-mM phenylalanine for 12 h. Control group of the same batch was treated with the same volume of medium. Total RNA was extracted and hybridized with the Affymetrix gene chip U34 according to the protocol provided by the Affymetrix Company. Real-time PCR was used to further confirm the result. We found that the hybridization signals of 167 genes were increased among the total 1323 probes plotted on the chip. The 167 increased genes could be functionally categorized into signal transduction, neuron related, cytoskeleton, metabolism, ion channels, transcription factors, cytokines, and apoptosis related. Signals of seven probes were decreased, which accounted to 0.5% of the total number. A series of genes that were not reported previously were upregulated by phenylalanine, including Ca2+/calmodulin-dependent protein kinase, Brain type II (CaMK II), ras, P38, L-voltage dependent calcium channel, some genes related to vesicle formation and transmitter release, some glutamate receptor subunits and glutamate transporters. According to the gene expression profiles, it is likely that multiprocesses are involved in the neuronal injury induced by phenylalanine, such as the activation on of the NMDR-Ca2+-CaMK II-Ras-P38 axis, the abnormality in neurotransmitter release. Our study also suggests that the excitatory neurotransmitter glutamate may play a role in the neural pathology of PKU.
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Affiliation(s)
- Huiwen Zhang
- Department of Endocrinology and Genetic Metabolism, Xin Hua Hospital, Shanghai Institute for Pediatric Research, Shanghai Second Medical University, Shanghai 200092, People's Republic of China
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47
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Poupot M, Fournié JJ. Non-peptide antigens activating human Vγ9/Vδ2 T lymphocytes. Immunol Lett 2004; 95:129-38. [PMID: 15388252 DOI: 10.1016/j.imlet.2004.06.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 06/25/2004] [Accepted: 06/29/2004] [Indexed: 11/29/2022]
Abstract
Various non-peptidic ligands which specifically activate most of circulating human Vgamma9/Vdelta2 T lymphocytes are now known. Most of these are so-called phosphoantigens and directly trigger the Vgamma9/Vdelta2 TCR expressing cells, without need for MHC-restricted presentation molecules. Although some potent phosphoantigens currently involved in clinical trials are chemically-synthesized molecules, most of the natural antigens were isolated from microbial cultures. The structures and biosynthesis of phosphoantigens are reviewed here and the possible physiological significance of their recognition by gammadelta T lymphocytes is discussed.
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Affiliation(s)
- Mary Poupot
- département Oncogénèse and Signalisation dans les Cellules Hématopoiétiques, Unité 563 de l'Institut National de la Santé Et de la Recherche Médicale, Centre de Physiopathologie de Toulouse Purpan, BP3028, 31024 Toulouse, France
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48
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Artuch R, Colomé C, Sierra C, Brandi N, Lambruschini N, Campistol J, Ugarte D, Vilaseca MA. A longitudinal study of antioxidant status in phenylketonuric patients. Clin Biochem 2004; 37:198-203. [PMID: 14972641 DOI: 10.1016/j.clinbiochem.2003.10.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2003] [Revised: 10/28/2003] [Accepted: 10/31/2003] [Indexed: 11/23/2022]
Abstract
OBJECTIVES To investigate the implications of the three main factors of the antioxidant system reported in relation to oxidative damage in phenylketonuric patients: selenium, ubiquinone-10 (Q10) and antioxidant enzymes over 3 years of metabolic follow-up. DESIGN AND METHODS Longitudinal study of 46 phenylketonuric patients (age range: 6 months-34 years). Antioxidants were measured by atomic absorption spectrophotometric, chromatographic and spectrophotometric procedures. RESULTS Plasma selenium concentrations in phenylketonuria (PKU) were not different from those of a healthy population. Decreased plasma Q10 concentrations were mainly related to the dietary control and the age of patients. Erythrocyte catalase activity was significantly decreased in PKU while the other enzyme activities were not different from those of a healthy population. CONCLUSION Selenium status is not impaired in phenylketonuric patients under dietary treatment. Q10 values tend to decrease with increased patient age. Catalase activity was negatively associated with plasma phenylalanine values.
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Affiliation(s)
- Rafael Artuch
- Serveis de Bioquímica, Hospital Sant Joan de Deu, Esplugues, Barcelona, Spain.
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49
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Abstract
Phenylketonuria is caused by specific mutations in the phenylalanine hydroxylase gene and is characterized by elevated blood phenylalanine levels, hypomyelination in forebrain structures, reduced dopamine levels, and cognitive difficulties. To determine whether brain tyrosine levels and/or myelination play a role in the up-regulation of dopamine, phenylketonuric mice were placed on a low phenylalanine diet for 4 weeks and as blood phenylalanine levels dropped to normal, the relationships between phenylalanine, tyrosine, dopamine, myelin proteins, and axonal proteins in frontal cortex and striatum were determined using gas chromatography mass spectrometry, histology, and western blotting techniques. Blood phenylalanine rapidly decreased from an eight-fold elevation to near control levels, and blood tyrosine gradually rose from about 50% to near normal values. In frontal cortex and striatum, phenylalanine levels dropped to 2- and 1.5-fold elevations above control, respectively, and tyrosine levels increased but remained less than 70% of control in both structures. In frontal cortex, increases in dopamine and myelin basic protein occurred in a similar biphasic pattern, reaching near normal levels by week 4. In striatum, dopamine and MBP dramatically increased to near normal levels in the first week. Myelination was confirmed histologically and by western blot quantification of phosphorylated neurofilaments. In summary, our results showed: (i) an increase in dopamine despite low brain tyrosine levels and (ii) similar recovery patterns for myelination and dopamine. Since myelin/axonal interactions trigger signaling pathways that result in axonal maturation, we speculate that this interaction also may trigger signals that up-regulate neurotransmitter synthesis.
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Affiliation(s)
- Bernadin Joseph
- Department of Neurology, The University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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50
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Colomé C, Artuch R, Vilaseca MA, Sierra C, Brandi N, Lambruschini N, Cambra FJ, Campistol J. Lipophilic antioxidants in patients with phenylketonuria. Am J Clin Nutr 2003; 77:185-8. [PMID: 12499340 DOI: 10.1093/ajcn/77.1.185] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Low serum ubiquinone-10 concentrations have been described in phenylketonuric patients fed natural-protein-restricted diets. Such low concentrations may be related to increased free radical damage. OBJECTIVE We evaluated the relation between low serum ubiquinone-10 concentrations and other lipophilic antioxidants (tocopherol and retinol), selenium, glutathione peroxidase activity, and malondialdehyde concentrations as a marker of lipid peroxidation. DESIGN This was a cross-sectional study of 58 patients with phenylketonuria (aged 2-36 y; median: 13 y) under dietary treatment, 58 age-matched control subjects, and 30 children with moderate hyperphenylalaninemia fed unrestricted diets (aged 3-17 y; median: 7.5 y). Serum ubiquinone-10 concentrations were analyzed by HPLC with electrochemical detection. Serum retinol, serum tocopherol, and plasma malondialdehyde were analyzed by HPLC with ultraviolet detection. RESULTS A significant positive correlation was observed between ubiquinone-10 and tocopherol (r = 0.510, P < 0.001) in the patients with phenylketonuria. After the patients were stratified into 2 groups according to ubiquinone-10 values, significantly lower concentrations of tocopherol were observed in group 1 (low ubiquinone values) than in group 2 (normal ubiquinone values), the hyperphenylalaninemic children, and the control group. Plasma malondialdehyde concentrations were significantly higher in group 1 than in the other groups. No significant differences between groups 1 and 2 were observed in daily intakes of selenium, ascorbate, tocopherol, or retinol. CONCLUSIONS Plasma lipid peroxidation seems to be increased in phenylketonuria. Low concentrations of ubiquinone-10 could be associated with either excessive tocopherol consumption or high malondialdehyde concentrations in patients with phenylketonuria.
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Affiliation(s)
- Catrina Colomé
- Serveis de Bioquímica, Hospital Sant Joan de Déu, Universitat de Barcelona, Spain
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