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Topbaş M, Canbay E, Sezer E, Canda E, Kalkan Uçar S, Çoker M, Yıldırım Sözmen E. Development, optimization and validation of LC-MS/MS method for the determination of DBS GALT enzyme activity. Anal Biochem 2023; 678:115284. [PMID: 37572839 DOI: 10.1016/j.ab.2023.115284] [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: 07/21/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
Galactosemia is a carbohydrate metabolism disorder often caused by galactose-1-phosphate uridyl transferase (GALT) deficiency. Detecting GALT deficiency involves measuring intra-erythrocyte enzyme activity. We aimed to create a robust liquid chromatography-mass spectrometry (LC-MS/MS) method to assess GALT activity in dried blood spot (DBS) samples. We validated this method and compared it to the fluorometric approach. We investigated the impact of K2EDTA and lithium heparin tubes on enzyme activity to identify the best sample collection tube. We also assessed the reaction-stopping method. The developed approach employed [13C6]-galactose-1-phosphate as a substrate and UDP-N-acetylglycosamine as an internal standard (IS). The mean ± SD value for GALT activity of DBS samples was determined as 6.37 ± 1.96 μmol/gHb/hour. The linear range was 0.4-50 μM (2.4-310% of normal) in the DBS method. The % coefficient of variation (%CV) values were less than 15 for intra-day and inter-day repeatability studies. Over 90% recovery was achieved in recovery studies, and no ion suppression from matrix was detected. DBS samples were quite stable for 31 days under different storage conditions. Enzyme activity results reported as <3.5 U/g Hb by fluorometric method, were quantitatively determined for even very low concentrations by LC-MS/MS method.
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Affiliation(s)
- Muhammet Topbaş
- Department of Medical Biochemistry, Faculty of Medicine, Ege University, Bornova, Izmir, 35100, Turkey
| | - Erhan Canbay
- Department of Medical Biochemistry, Faculty of Medicine, Ege University, Bornova, Izmir, 35100, Turkey.
| | - Ebru Sezer
- Department of Medical Biochemistry, Faculty of Medicine, Ege University, Bornova, Izmir, 35100, Turkey
| | - Ebru Canda
- Department of Pediatric Metabolic Disease, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey
| | - Sema Kalkan Uçar
- Department of Pediatric Metabolic Disease, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey
| | - Mahmut Çoker
- Department of Pediatric Metabolic Disease, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey
| | - Eser Yıldırım Sözmen
- Department of Medical Biochemistry, Faculty of Medicine, Ege University, Bornova, Izmir, 35100, Turkey
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2
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Yuzyuk T, Wilson AR, Mao R, Pasquali M. Galactose-1-Phosphate Uridyltransferase Activities in Different Genotypes: A Retrospective Analysis of 927 Samples. J Appl Lab Med 2019; 3:222-230. [DOI: 10.1373/jalm.2017.025536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/29/2018] [Indexed: 11/06/2022]
Abstract
Abstract
Background
Classic galactosemia is an inherited disorder of galactose metabolism caused by the impaired activity of galactose-1-phosphate uridyltransferase (GALT). Untreated galactosemia is life-threatening; however, early dietary intervention prevents mortality and reduces morbidity associated with this disease. The diagnosis of galactosemia includes the measurement of GALT activity in red blood cells (RBC) and GALT gene analysis. In this study, we evaluate GALT activity in different genotypes using the results of combined biochemical and molecular testing in 927 samples.
Methods
GALT activity in RBC was measured by LC-MS/MS. The analysis of the GALT gene was performed by targeted gene analysis and/or full gene sequencing. Samples were assigned based on the presence of pathogenic (G) or Duarte 2 (D) variants, or their absence (Neg), to G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes. Finite mixture models were applied to investigate distributions of GALT activities in these genotypes. The reference ranges were determined using the central 95% of values of GALT activities.
Results
The ranges of GALT activity in G/G, D/G, G/Neg, D/D, D/Neg, and Neg/Neg genotypes are 0.0 to 0.7 μmol·h−1 gHb−1, 3.1 to 7.8 μmol·h−1 gHb−1, 6.5 to 16.2 μmol·h−1 gHb−1, 6.4 to 16.5 μmol·h−1 gHb−1, 12.0 to 24.0 μmol·h−1 gHb−1, and 19.4 to 33.4 μmol·h−1 gHb−1, respectively.
Conclusions
The GALT activity ranges established in this study are in agreement with the expected impact of the genotype on the enzymatic activity. Molecular findings should be interpreted in view of biochemical results to confirm genotype–phenotype correlation.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
| | - Andrew R Wilson
- School of Nursing, University of Utah Health Sciences Center, Salt Lake City, UT
| | - Rong Mao
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT
- ARUP Laboratories, Salt Lake City, UT
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3
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Demirbas D, Huang X, Daesety V, Feenstra S, Haskovic M, Qi W, Gubbels CS, Hecht L, Levy HL, Waisbren SE, Berry GT. The ability of an LC-MS/MS-based erythrocyte GALT enzyme assay to predict the phenotype in subjects with GALT deficiency. Mol Genet Metab 2019; 126:368-376. [PMID: 30718057 DOI: 10.1016/j.ymgme.2019.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/20/2019] [Accepted: 01/21/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND GALT deficiency is a rare genetic disorder of carbohydrate metabolism. Due to the decreased activity or absence of the enzyme galactose-1-phosphate uridylyltransferase (GALT), cells from affected individuals are unable to metabolize galactose normally. Lactose consumption in the newborn period could potentially lead to a lethal disease process with multi-organ involvement. In contrast to the newborn-stage disease, however, a galactose-restricted diet does not prevent long-term complications such as central nervous system (CNS) dysfunction with speech defects, learning disability and neurological disease in addition to hypergonadotropic hypogonadism or primary ovarian insufficiency (POI) in females. As the literature suggests an association between GALT enzyme activity and the long-term complications, it is of importance to have a highly sensitive assay to quantify the GALT enzyme activity. To that end, we had developed a sensitive and accurate LC-MS/MS method to measure GALT enzyme activity. Its ability to predict outcome is the subject of this report. MATERIALS AND METHODS The GALT enzyme activity in erythrocytes from 160 individuals, in which 135 with classic, clinical variant or biochemical variant galactosemia, was quantified by LC-MS/MS. Individuals with GALT deficiency were evaluated for the long-term complications of speech defects, dysarthria, ataxia, dystonia, tremor, POI, as well as intellectual functioning (full scale IQ). The LC-MS/MS results were compared to a variety of assays: radioactive, [14C]-galactose-1-phosphate, paper chromatography with scintillation counting, enzyme-coupled assays with spectrophotometric or fluorometric readout or high-pressure liquid chromatography with UV detection of UDP-galactose. RESULTS The LC-MS/MS method measured GALT activity as low as 0.2%, whereas other methods showed no detectable activity. Largely due to GALT activities that were over 1%, the LC-MS/MS measurements were not significantly different than values obtained in other laboratories using other methodologies. Severe long-term complications were less frequently noted in subjects with >1% activity. Patients with a p.Q188R/p.Q188R genotype have no residual enzyme activity in erythrocytes. CONCLUSION Our LC-MS/MS assay may be necessary to accurately quantify residual GALT activities below 5%. The data suggest that patients with >1% residual activity are less likely to develop diet-independent long-term complications. However, much larger sample sizes are needed to properly assess the clinical phenotype in patients with residual enzyme activities between 0.1 and 5%.
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Affiliation(s)
- Didem Demirbas
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Xiaoping Huang
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Vikram Daesety
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Susan Feenstra
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Minela Haskovic
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Wanshu Qi
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Cynthia S Gubbels
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Leah Hecht
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Harvey L Levy
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Susan E Waisbren
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Gerard T Berry
- Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.
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4
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Haskovic M, Derks B, van der Ploeg L, Trommelen J, Nyakayiru J, van Loon LJC, Mackinnon S, Yue WW, Peake RWA, Zha L, Demirbas D, Qi W, Huang X, Berry GT, Achten J, Bierau J, Rubio-Gozalbo ME, Coelho AI. Arginine does not rescue p.Q188R mutation deleterious effect in classic galactosemia. Orphanet J Rare Dis 2018; 13:212. [PMID: 30477550 PMCID: PMC6260575 DOI: 10.1186/s13023-018-0954-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022] Open
Abstract
Background Classic galactosemia is a rare genetic metabolic disease with an unmet treatment need. Current standard of care fails to prevent chronically-debilitating brain and gonadal complications. Many mutations in the GALT gene responsible for classic galactosemia have been described to give rise to variants with conformational abnormalities. This pathogenic mechanism is highly amenable to a therapeutic strategy based on chemical/pharmacological chaperones. Arginine, a chemical chaperone, has shown beneficial effect in other inherited metabolic disorders, as well as in a prokaryotic model of classic galactosemia. The p.Q188R mutation presents a high prevalence in the Caucasian population, making it a very clinically relevant mutation. This mutation gives rise to a protein with lower conformational stability and lower catalytic activity. The aim of this study is to assess the potential therapeutic role of arginine for this mutation. Methods Arginine aspartate administration to four patients with the p.Q188R/p.Q188R mutation, in vitro studies with three fibroblast cell lines derived from classic galactosemia patients as well as recombinant protein experiments were used to evaluate the effect of arginine in galactose metabolism. This study has been registered at https://clinicaltrials.gov (NCT03580122) on 09 July 2018. Retrospectively registered. Results Following a month of arginine administration, patients did not show a significant improvement of whole-body galactose oxidative capacity (p = 0.22), erythrocyte GALT activity (p = 0.87), urinary galactose (p = 0.52) and urinary galactitol levels (p = 0.41). Patients’ fibroblasts exposed to arginine did not show changes in GALT activity. Thermal shift analysis of recombinant p.Q188R GALT protein in the presence of arginine did not exhibit a positive effect. Conclusions This short pilot study in four patients homozygous for the p.Q188R/p.Q188R mutation reveals that arginine has no potential therapeutic role for galactosemia patients homozygous for the p.Q188R mutation. Electronic supplementary material The online version of this article (10.1186/s13023-018-0954-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Minela Haskovic
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands.,Department of Pediatrics, Maastricht University Medical Center +, Maastricht, The Netherlands.,GROW-School for Oncology and Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Britt Derks
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands.,Department of Pediatrics, Maastricht University Medical Center +, Maastricht, The Netherlands.,GROW-School for Oncology and Developmental Biology, University of Maastricht, Maastricht, The Netherlands
| | - Liesbeth van der Ploeg
- Department of Dietetics, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - Jorn Trommelen
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - Jean Nyakayiru
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - Sabrina Mackinnon
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Roy W A Peake
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Li Zha
- Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Didem Demirbas
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Wanshu Qi
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Xiaoping Huang
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gerard T Berry
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jelle Achten
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - Jörgen Bierau
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands
| | - M Estela Rubio-Gozalbo
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands. .,Department of Pediatrics, Maastricht University Medical Center +, Maastricht, The Netherlands. .,GROW-School for Oncology and Developmental Biology, University of Maastricht, Maastricht, The Netherlands.
| | - Ana I Coelho
- Department of Clinical Genetics, Maastricht University Medical Center +, Maastricht, The Netherlands.,Department of Pediatrics, Maastricht University Medical Center +, Maastricht, The Netherlands.,GROW-School for Oncology and Developmental Biology, University of Maastricht, Maastricht, The Netherlands
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5
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Yuzyuk T, Balakrishnan B, Schwarz EL, De Biase I, Hobert J, Longo N, Mao R, Lai K, Pasquali M. Effect of genotype on galactose-1-phosphate in classic galactosemia patients. Mol Genet Metab 2018; 125:258-265. [PMID: 30172461 DOI: 10.1016/j.ymgme.2018.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 11/27/2022]
Abstract
Impaired activity of galactose-1-phosphate uridyltransferase (GALT) causes classic galactosemia (OMIM 230400), characterized by the accumulation of galactose-1-phosphate (GAL1P) in patients' red blood cells (RBCs). Our recent study demonstrated a correlation between RBC GAL1P and long-term outcomes in galactosemia patients. Here, we analyze biochemical and molecular results in 77 classic galactosemia patients to evaluate the association between GALT genotypes and GAL1P concentration in RBCs. Experimental data from model organisms were also included to assess the correlation between GAL1P and predicted residual activity of each genotype. Although all individuals in this study showed markedly reduced RBC GALT activity, we observed significant differences in RBC GAL1P concentrations among galactosemia genotypes. While levels of GAL1P on treatment did not correlate with RBC GALT activities (p = 0.166), there was a negative nonlinear correlation between mean GAL1P concentrations and predicted residual enzyme activity of genotype (p = 0.004). These studies suggest that GAL1P levels in RBCs on treatment likely reflect the overall functional impairment of GALT in patients with galactosemia.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA.
| | - Bijina Balakrishnan
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | | | - Irene De Biase
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Judith Hobert
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Nicola Longo
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA; Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Rong Mao
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | - Kent Lai
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
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6
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Yuzyuk T, Viau K, Andrews A, Pasquali M, Longo N. Biochemical changes and clinical outcomes in 34 patients with classic galactosemia. J Inherit Metab Dis 2018; 41:197-208. [PMID: 29350350 DOI: 10.1007/s10545-018-0136-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/19/2017] [Accepted: 01/02/2018] [Indexed: 10/18/2022]
Abstract
Impaired activity of galactose-1-phosphate uridyltransferase (GALT) causes galactosemia, an autosomal recessive disorder of galactose metabolism. Early initiation of a galactose-restricted diet can prevent or resolve neonatal complications. Despite therapy, patients often experience long-term complications including speech impairment, learning disabilities, and premature ovarian insufficiency in females. This study evaluates clinical outcomes in 34 galactosemia patients with markedly reduced GALT activity and compares outcomes between patients with different levels of mean galactose-1-phosphate in red blood cells (GAL1P) using logistic regression: group 1 (n = 13) GAL1P ≤1.7 mg/dL vs. group 2 (n = 21) GAL1P ≥ 2 mg/dL. Acute symptoms at birth were comparable between groups (p = 0.30) with approximately 50% of patients presenting with jaundice, liver failure, and failure-to-thrive. However, group 2 patients had significantly higher prevalence of negative long-term outcomes compared to group 1 patients (p = 0.01). Only one of 11 patients >3 yo in group 1 developed neurological and severe behavioral problems of unclear etiology. In contrast, 17 of 20 patients >3 yo in group 2 presented with one or more long-term complications associated with galactosemia. The majority of females ≥15 yo in this group also had impaired ovarian function with markedly reduced levels of anti-Müllerian hormone. These findings suggest that galactosemia patients with higher GAL1P levels are more likely to have negative long-term outcome. Therefore, evaluation of GAL1P levels on a galactose-restricted diet might be helpful in providing a prognosis for galactosemia patients with rare or novel genotypes whose clinical presentations are not well known.
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Affiliation(s)
- Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA.
| | - Krista Viau
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
- Boston Children's Hospital, Boston, MA, USA
| | - Ashley Andrews
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Marzia Pasquali
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Nicola Longo
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, 500 Chipeta Way, Salt Lake City, UT, 84108, USA
- Division of Medical Genetics/Pediatrics, University of Utah, Salt Lake City, UT, USA
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7
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Vanoevelen JM, van Erven B, Bierau J, Huang X, Berry GT, Vos R, Coelho AI, Rubio-Gozalbo ME. Impaired fertility and motor function in a zebrafish model for classic galactosemia. J Inherit Metab Dis 2018; 41:117-127. [PMID: 28913702 PMCID: PMC5786655 DOI: 10.1007/s10545-017-0071-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/16/2017] [Accepted: 07/03/2017] [Indexed: 01/28/2023]
Abstract
Classic galactosemia is a genetic disorder of galactose metabolism, caused by severe deficiency of galactose-1-phosphate uridylyltransferase (GALT) enzyme activity due to mutations of the GALT gene. Its pathogenesis is still not fully elucidated, and a therapy that prevents chronic impairments is lacking. In order to move research forward, there is a high need for a novel animal model, which allows organ studies throughout development and high-throughput screening of pharmacologic compounds. Here, we describe the generation of a galt knockout zebrafish model and present its phenotypical characterization. Using a TALEN approach, a galt knockout line was successfully created. Accordingly, biochemical assays confirm essentially undetectable galt enzyme activity in homozygotes. Analogous to humans, galt knockout fish accumulate galactose-1-phosphate upon exposure to exogenous galactose. Furthermore, without prior exposure to exogenous galactose, they exhibit reduced motor activity and impaired fertility (lower egg quantity per mating, higher number of unsuccessful crossings), resembling the human phenotype(s) of neurological sequelae and subfertility. In conclusion, our galt knockout zebrafish model for classic galactosemia mimics the human phenotype(s) at biochemical and clinical levels. Future studies in our model will contribute to improved understanding and management of this disorder.
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Affiliation(s)
- Jo M Vanoevelen
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, P.O. Box 616, box 16, 6200 MD, Maastricht, The Netherlands.
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands.
| | - Britt van Erven
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, P.O. Box 616, box 16, 6200 MD, Maastricht, The Netherlands
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Jörgen Bierau
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, P.O. Box 616, box 16, 6200 MD, Maastricht, The Netherlands
| | - Xiaoping Huang
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gerard T Berry
- The Manton Center for Orphan Disease Research, Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Rein Vos
- Department of Methodology and Statistics, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, The Netherlands
| | - Ana I Coelho
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, P.O. Box 616, box 16, 6200 MD, Maastricht, The Netherlands
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Pediatrics, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - M Estela Rubio-Gozalbo
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, P.O. Box 616, box 16, 6200 MD, Maastricht, The Netherlands.
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands.
- Department of Pediatrics, Maastricht University Medical Centre, Maastricht, The Netherlands.
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8
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Campos CG, Veras HCT, de Aquino Ribeiro JA, Costa PPKG, Araújo KP, Rodrigues CM, de Almeida JRM, Abdelnur PV. New Protocol Based on UHPLC-MS/MS for Quantitation of Metabolites in Xylose-Fermenting Yeasts. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2646-2657. [PMID: 28879550 DOI: 10.1007/s13361-017-1786-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/14/2017] [Indexed: 06/07/2023]
Abstract
Xylose fermentation is a bottleneck in second-generation ethanol production. As such, a comprehensive understanding of xylose metabolism in naturally xylose-fermenting yeasts is essential for prospection and construction of recombinant yeast strains. The objective of the current study was to establish a reliable metabolomics protocol for quantification of key metabolites of xylose catabolism pathways in yeast, and to apply this protocol to Spathaspora arborariae. Ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was used to quantify metabolites, and afterwards, sample preparation was optimized to examine yeast intracellular metabolites. S. arborariae was cultivated using xylose as a carbon source under aerobic and oxygen-limited conditions. Ion pair chromatography (IPC) and hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) were shown to efficiently quantify 14 and 5 metabolites, respectively, in a more rapid chromatographic protocol than previously described. Thirteen and eleven metabolites were quantified in S. arborariae under aerobic and oxygen-limited conditions, respectively. This targeted metabolomics protocol is shown here to quantify a total of 19 metabolites, including sugars, phosphates, coenzymes, monosaccharides, and alcohols, from xylose catabolism pathways (glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle) in yeast. Furthermore, to our knowledge, this is the first time that intracellular metabolites have been quantified in S. arborariae after xylose consumption. The results indicated that fine control of oxygen levels during fermentation is necessary to optimize ethanol production by S. arborariae. The protocol presented here may be applied to other yeast species and could support yeast genetic engineering to improve second generation ethanol production. Graphical Abstract ᅟ.
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Affiliation(s)
- Christiane Gonçalves Campos
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil
- Chemistry Institute, Federal University of Goiás, Campus Samambaia, Goiânia, GO, 74690-900, Brazil
| | - Henrique César Teixeira Veras
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil
- Postgraduate Program in Molecular Biology, Department of Cellular Biology, University of Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil
| | | | | | - Katiúscia Pereira Araújo
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil
| | - Clenilson Martins Rodrigues
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil
| | - João Ricardo Moreira de Almeida
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil
- Postgraduate Program in Chemical and Biological Technologies, Institute of Chemistry, University of Brasília, Campus Darcy Ribeiro, Brasília, DF, Brazil
| | - Patrícia Verardi Abdelnur
- Brazilian Agricultural Research Corporation, Embrapa Agroenergy, W3 Norte, PqEB, Brasília, DF, 70770-901, Brazil.
- Chemistry Institute, Federal University of Goiás, Campus Samambaia, Goiânia, GO, 74690-900, Brazil.
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Laboratory diagnosis of galactosemia: a technical standard and guideline of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2017; 20:3-11. [PMID: 29261178 DOI: 10.1038/gim.2017.172] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 11/09/2022] Open
Abstract
Disclaimer: These ACMG Standards and Guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these Standards and Guidelines is voluntary and does not necessarily assure a successful medical outcome. These Standards and Guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient's record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these Standards and Guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Galactosemias are inherited disorders of galactose metabolism due to deficiency in one of the three enzymes involved in the Leloir pathway: galactose-1-phosphate uridyltransferase, galactokinase, and uridine diphosphate (UDP)-galactose-4'-epimerase. Galactose-1-phosphate uridyltransferase deficiency, or classic galactosemia, is the most frequent and the most severe of the three enzyme deficiencies; it is characterized by failure to thrive, liver failure, susceptibility to sepsis, and death, if untreated. Newborn screening for classic galactosemia has been implemented in all of the United States, while screening for galactokinase deficiency and UDP-galactose-4'-epimerase deficiency is not universal. Early identification and treatment of galactosemia leads to improved outcome. This document reviews the laboratory methods and best practices for the diagnosis of galactosemia.
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Zhang J, Xiang Y, Novak DE, Hoganson GE, Zhu J, Lu Y. Using a Personal Glucose Meter and Alkaline Phosphatase for Point-of-Care Quantification of Galactose-1-Phosphate Uridyltransferase in Clinical Galactosemia Diagnosis. Chem Asian J 2015; 10:2221-7. [DOI: 10.1002/asia.201500642] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Indexed: 12/11/2022]
Affiliation(s)
- Jingjing Zhang
- Department of Chemistry; University of Illinois at Urbana-Champaign; Urbana IL 61801 USA
| | - Yu Xiang
- Department of Chemistry; University of Illinois at Urbana-Champaign; Urbana IL 61801 USA
| | - Donna E. Novak
- Division of Genetics; University of Illinois at Chicago; 840 S Wood St, CSB Chicago IL 60612 USA
| | - George E. Hoganson
- Division of Genetics; University of Illinois at Chicago; 840 S Wood St, CSB Chicago IL 60612 USA
| | - Junjie Zhu
- School of Chemistry and Chemical Engineering; Nanjing University; Nanjing 210093 P. R. China
| | - Yi Lu
- Department of Chemistry; University of Illinois at Urbana-Champaign; Urbana IL 61801 USA
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Lacombe C, Untereiner V, Gobinet C, Zater M, Sockalingum GD, Garnotel R. Rapid screening of classic galactosemia patients: a proof-of-concept study using high-throughput FTIR analysis of plasma. Analyst 2015; 140:2280-6. [DOI: 10.1039/c4an01942c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
FTIR as a new approach to screen a rare disease.
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Affiliation(s)
- Caroline Lacombe
- Université de Reims Champagne-Ardenne
- Equipe MéDIAN
- Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51096 Reims
| | - Valérie Untereiner
- Université de Reims Champagne-Ardenne
- Equipe MéDIAN
- Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51096 Reims
| | - Cyril Gobinet
- Université de Reims Champagne-Ardenne
- Equipe MéDIAN
- Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51096 Reims
| | - Mokhtar Zater
- Biochimie – Hôpital de Bicêtre
- Hôpitaux Universitaires Paris-Sud
- France
| | - Ganesh D. Sockalingum
- Université de Reims Champagne-Ardenne
- Equipe MéDIAN
- Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51096 Reims
| | - Roselyne Garnotel
- Université de Reims Champagne-Ardenne
- Equipe MéDIAN
- Biophotonique et Technologies pour la Santé
- UFR de Pharmacie
- 51096 Reims
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Chen J, Meyers GAD, Bennett MJ. An interference-free two-step enzyme assay with UPLC-tandem mass spectrometric product measurement for the clinical diagnosis of uridine diphosphate galactose-4-epimerase deficiency. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 959:5-9. [PMID: 24732214 DOI: 10.1016/j.jchromb.2014.03.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 02/04/2014] [Accepted: 03/21/2014] [Indexed: 11/30/2022]
Abstract
We present a robust clinical assay for the measurement of red blood cell uridine diphosphate galactose-4-epimerase enzyme activity for the diagnostic confirmation of patients positive for a newborn screen for inherited galactosemia in whom galactose-1-phosphate uridyltransferase activity is normal. Previous assays required the use of ion-pairing reagents and frequent need for system maintenance that was not appropriate for heavy clinical use where patient results should be quickly available. We have designed a two-step enzyme assay which converts stable-isotope-labeled UDP-galactose to isotope-labeled-UDP-glucose which is converted in the second reaction to the final product of [(13)C6]-UDP-glucuronic acid. Measurement conditions t remove potential interference from endogenous UDP-glucose and UDP-galactose. We also report a significant ion suppression effect of the red cell preparation for which we have optimized assay sample volume to minimize this effect.
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Affiliation(s)
- Jie Chen
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Gail A Ditewig Meyers
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Michael J Bennett
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, United States.
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Li Y, Huang X, Harmonay L, Liu Y, Kellogg MD, Fridovich-Keil JL, Berry GT. Liquid chromatography-tandem mass spectrometry enzyme assay for UDP-galactose 4'-epimerase: use of fragment intensity ratio in differentiation of structural isomers. Clin Chem 2014; 60:783-90. [PMID: 24578239 DOI: 10.1373/clinchem.2013.219931] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Distinction between asymptomatic and potentially clinically significant forms of galactosemia due to UDP-galactose 4'-epimerase (GALE) deficiency requires enzyme measurement in erythrocytes and other cells. We sought to develop a GALE assay using a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method. METHODS The reversible GALE assay was conducted with UDPGal as a substrate. The coeluting reaction product, uridine diphosphate glucose (UDPGlc), and its isomeric substrate, uridine diphosphate galactose (UDPGal), were detected by MS/MS at mass transitions 565 > 280, 565 > 241 and 565 > 403. The UDPGal was enriched in mass transition 565 > 403 compared with UDPGlc, whereas the UDPGlc was enriched in the mass transition 565 > 241 compared with UDPGal. The percentage of UDPGal in the reaction mixture was calculated by use of the ratio of ion intensities of the 2 daughter ions and a fourth-order polynomial calibrator curve. RESULTS The method yielded a mean (SD) GALE activity of 9.8 (2.2) μmol · g(-1) hemoglobin · h(-1) in erythrocyte extracts from 27 controls. The apparent Km of the substrate, UDPGal, was 0.05 mmol/L. The GALE activity ranged from 433 to 993 μmol · g(-1) protein · h(-1) in control lymphoblast extracts. In a blinded test of 22 subjects suspected of GALE deficiency, we identified 6 individuals whose residual activities were below the range of controls, compatible with intermediate GALE deficiency. CONCLUSIONS This assay can be used to distinguish the different forms of GALE deficiency. From an analytical standpoint, differentiating isomers on the basis of fragment intensity ratios should also prove useful for analogous enzymatic studies involving substrates and products that are structural isomers.
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Affiliation(s)
- Yijun Li
- The Manton Center for Orphan Disease Research, Division of Genetics, Department of Pediatrics
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Subfertility and growth restriction in a new galactose-1 phosphate uridylyltransferase (GALT) - deficient mouse model. Eur J Hum Genet 2014; 22:1172-9. [PMID: 24549051 DOI: 10.1038/ejhg.2014.12] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 01/03/2014] [Accepted: 01/15/2014] [Indexed: 12/27/2022] Open
Abstract
The first GalT gene knockout (KO) mouse model for Classic Galactosemia (OMIM 230400) accumulated some galactose and its metabolites upon galactose challenge, but was seemingly fertile and symptom free. Here we constructed a new GalT gene-trapped mouse model by injecting GalT gene-trapped mouse embryonic stem cells into blastocysts, which were later implanted into pseudo-pregnant females. High percentage GalT gene-trapped chimera obtained were used to generate heterozygous and subsequently, homozygous GalT gene-trapped mice. Biochemical assays confirmed total absence of galactose-1 phosphate uridylyltransferase (GALT) activity in the homozygotes. Although the homozygous GalT gene-trapped females could conceive and give birth when fed with normal chow, they had smaller litter size (P=0.02) and longer time-to-pregnancy (P=0.013) than their wild-type littermates. Follicle-stimulating hormone levels of the mutant female mice were not significantly different from the age-matched, wild-type females, but histological examination of the ovaries revealed fewer follicles in the homozygous mutants (P=0.007). Administration of a high-galactose (40% w/w) diet to lactating homozygous GalT gene-trapped females led to lethality in over 70% of the homozygous GalT gene-trapped pups before weaning. Cerebral edema, abnormal changes in the Purkinje and the outer granular cell layers of the cerebellum, as well as lower blood GSH/GSSG ratio were identified in the galactose-intoxicated pups. Finally, reduced growth was observed in GalT gene-trapped pups fed with normal chow and all pups fed with high-galactose (20% w/w) diet. This new mouse model presents several of the complications of Classic Galactosemia and will be useful to investigate pathogenesis and new therapies.
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