1
|
Swanson MA, Jiang H, Busquet N, Carlsen J, Brindley C, Benke TA, Van Hove RA, Friederich MW, MacLean KN, Mesches MH, Van Hove JLK. Deep postnatal phenotyping of a new mouse model of nonketotic hyperglycinemia. J Inherit Metab Dis 2024. [PMID: 38840294 DOI: 10.1002/jimd.12755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/18/2024] [Accepted: 05/02/2024] [Indexed: 06/07/2024]
Abstract
Nonketotic hyperglycinemia due to deficient glycine cleavage enzyme activity causes a severe neonatal epileptic encephalopathy. Current therapies based on mitigating glycine excess have only limited impact. An animal model with postnatal phenotyping is needed to explore new therapeutic approaches. We developed a Gldc p.Ala394Val mutant model and bred it to congenic status in two colonies on C57Bl/6J (B6) and J129X1/SvJ (J129) backgrounds. Mutant mice had reduced P-protein and enzyme activity indicating a hypomorphic mutant. Glycine levels were increased in blood and brain regions, exacerbated by dietary glycine, with higher levels in female than male J129 mice. Birth defects were more prevalent in mutant B6 than J129 mice, and hydrocephalus was more frequent in B6 (40%) compared to J129 (none). The hydrocephalus rate was increased by postnatal glycine challenge in B6 mice, more so when delivered from the first neonatal week than from the fourth. Mutant mice had reduced weight gain following weaning until the eighth postnatal week, which was exacerbated by glycine loading. The electrographic spike rate was increased in mutant mice following glycine loading, but no seizures were observed. The alpha/delta band intensity ratio was decreased in the left cortex in female J129 mice, which were less active in an open field test and explored less in a Y-maze, suggesting an encephalopathic effect. Mutant mice showed no evidence of memory dysfunction. This partial recapitulation of human symptoms and biochemistry will facilitate the evaluation of new therapeutic approaches with an early postnatal time window likely most effective.
Collapse
Affiliation(s)
- Michael A Swanson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hua Jiang
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Nicolas Busquet
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jessica Carlsen
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Connie Brindley
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Tim A Benke
- Department of Pediatrics, Section of Pediatric Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Roxanne A Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Marisa W Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Kenneth N MacLean
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Michael H Mesches
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Pediatrics, Section of Pediatric Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Johan L K Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
2
|
Chambers BE, Weaver NE, Lara CM, Nguyen TK, Wingert RA. (Zebra)fishing for nephrogenesis genes. Tissue Barriers 2024; 12:2219605. [PMID: 37254823 PMCID: PMC11042071 DOI: 10.1080/21688370.2023.2219605] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/14/2023] [Indexed: 06/01/2023] Open
Abstract
Kidney disease is a devastating condition affecting millions of people worldwide, where over 100,000 patients in the United States alone remain waiting for a lifesaving organ transplant. Concomitant with a surge in personalized medicine, single-gene mutations, and polygenic risk alleles have been brought to the forefront as core causes of a spectrum of renal disorders. With the increasing prevalence of kidney disease, it is imperative to make substantial strides in the field of kidney genetics. Nephrons, the core functional units of the kidney, are epithelial tubules that act as gatekeepers of body homeostasis by absorbing and secreting ions, water, and small molecules to filter the blood. Each nephron contains a series of proximal and distal segments with explicit metabolic functions. The embryonic zebrafish provides an ideal platform to systematically dissect the genetic cues governing kidney development. Here, we review the use of zebrafish to discover nephrogenesis genes.
Collapse
Affiliation(s)
- Brooke E. Chambers
- Department of Biological Sciences, Center for Stem Cells and Regenerative Medicine, Center for Zebrafish Research, Boler-Parseghian Center for Rare and Neglected Diseases, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana (IN), USA
| | - Nicole E. Weaver
- Department of Biological Sciences, Center for Stem Cells and Regenerative Medicine, Center for Zebrafish Research, Boler-Parseghian Center for Rare and Neglected Diseases, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana (IN), USA
| | - Caroline M. Lara
- Department of Biological Sciences, Center for Stem Cells and Regenerative Medicine, Center for Zebrafish Research, Boler-Parseghian Center for Rare and Neglected Diseases, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana (IN), USA
| | - Thanh Khoa Nguyen
- Department of Biological Sciences, Center for Stem Cells and Regenerative Medicine, Center for Zebrafish Research, Boler-Parseghian Center for Rare and Neglected Diseases, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana (IN), USA
| | - Rebecca A. Wingert
- Department of Biological Sciences, Center for Stem Cells and Regenerative Medicine, Center for Zebrafish Research, Boler-Parseghian Center for Rare and Neglected Diseases, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana (IN), USA
| |
Collapse
|
3
|
Swanson MA, Jiang H, Busquet N, Carlsen J, Brindley C, Benke TA, Van Hove RA, Friederich MW, MacLean KN, Mesches MH, Van Hove JLK. Deep postnatal phenotyping of a new mouse model of nonketotic hyperglycinemia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586818. [PMID: 38586005 PMCID: PMC10996592 DOI: 10.1101/2024.03.26.586818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Nonketotic hyperglycinemia due to deficient glycine cleavage enzyme activity causes a severe neonatal epileptic encephalopathy. Current therapies based on mitigating glycine excess have only limited impact. An animal model with postnatal phenotyping is needed to explore new therapeutic approaches. We developed a Gldc p.Ala394Val mutant model and bred it to congenic status in 2 colonies on C57Bl/6J (B6) and J129X1/SvJ (J129) backgrounds. Mutant mice had reduced P-protein and enzyme activity indicating a hypomorphic mutant. Glycine levels were increased in blood and brain regions, exacerbated by dietary glycine, with higher levels in female than male J129 mice. Birth defects were more prevalent in mutant B6 than J129 mice, and hydrocephalus was more frequent in B6 (40%) compared to J129 (none). The hydrocephalus rate was increased by postnatal glycine challenge in B6 mice, more so when delivered from the first neonatal week than from the fourth. Mutant mice had reduced weight gain following weaning until the eighth postnatal week, which was exacerbated by glycine loading. The electrographic spike rate was increased in mutant mice following glycine loading, but no seizures were observed. The alpha/delta band intensity ratio was decreased in the left cortex in female J129 mice, which were less active in an open field test and explored less in a Y-maze, suggesting an encephalopathic effect. Mutant mice showed no evidence of memory dysfunction. This partial recapitulation of human symptoms and biochemistry will facilitate the evaluation of new therapeutic approaches with an early postnatal time window likely most effective. Take home message A mouse model of nonketotic hyperglycinemia is described that shows postnatal abnormalities in glycine levels, neural tube defects, body weight, electroencephalographic recordings, and in activity in young mice making it amenable for the evaluation of novel treatment interventions. Author contributions Study concept and design: JVH, MHM, NB, KNMAnimal study data: MAS, HJ, NB, MHM, JC, CBBiochemical and genetic studies: MAS, RAVH, MWFStatistical analysis: NB, JVHFirst draft writing: JVH, NB, MHMCritical rewriting: MAS, NB, MHM, TAB, JC, MWF, KNM, JVHFinal responsibility, guarantor, and communicating author: JVH. Competing interest statement The University of Colorado (JVH, MS, KNM, HJ) has the intention to file Intellectual property protection for certain biochemical treatments of NKH. Otherwise, the authors have stated that they had no interests that might be perceived as posing a conflict or bias to this subject matter. Funding support Financial support is acknowledged form the NKH Crusaders, Brodyn's Friends, Nora Jane Almany Foundation, the Dickens Family Foundation, the Lucas John Foundation, Les Petits Bourdons, Joseph's Fund, the Barnett Family, Maud & Vic Foundation, Lucy's BEElievers fund, Hope for NKH, Madi's Mission NKH fund, and from Dr. and Ms. Shaw, and the University of Colorado Foundation NKH research fund. The study was supported by a grant (CNS-X-19-103) from the University of Colorado School of Medicine and the Colorado Clinical Translational Science Institute, which is supported by NIH/NCATS Colorado CTSA Grant Number UL1 TR002535. Contents are the authors' sole responsibility and do not necessarily represent official NIH views. All funding sources had no role in the design or execution of the study, the interpretation of data, or the writing of the study. Ethics approval on Laboratory Animal Studies Mouse studies were carried out with approval from the Institutional Animal Care and Use Committee of the University of Colorado Anschutz Medical Campus (IACUC# 00413). Data sharing statement The data that support the findings of this study are available from the corresponding author upon reasonable request.
Collapse
|
4
|
Yang X, Fan G, Wang Z, Li S, Qin H, Wang Y, Ma X, Ji W, Wang Y. Study on the relationship between genetic polymorphism of reductive folic acid carrier and the risk of neural tube defects. Childs Nerv Syst 2022:10.1007/s00381-022-05805-z. [PMID: 36538104 DOI: 10.1007/s00381-022-05805-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 12/14/2022] [Indexed: 12/25/2022]
Abstract
BACKGROUND To investigate the association of folate metabolism gene polymorphism with neural tube defects (NTDs) in Chinese population. METHODS The subjects were divided into two groups, 495 children with NTDs (NTD group) and 255 healthy children (control group). RESULTS The levels of folic acid, s-adenosine methionine (SAM), and Sam/s-adenosine homocysteine (SAH) in NTD group were lower than those in control group. There were significant differences in hey, SAH, and Sam levels between two groups, but there was no significant difference in folic acid content. High fever in early pregnancy, taking antiepileptic drugs, father's exposure to organic solvents, folic acid deficiency, and mother's diabetes were the important risk factors in NTDs. MTHFR 677C > T gene was a risk factor for NTD in children, while 1298A > C gene was a protective factor. CONCLUSION Folic acid metabolism markers were different in NTD children and their mothers, and the overall trend showed that folate, SAM, and SAM/SAH levels were decreased, while Hcy and SAH levels were increased; MTHFR 677C > T gene of SNPs was a risk factor for the occurrence of NTDs, and MTHFR 1298A > C gene was a protective factor, and the environmental risk factor had a synergistic effect on occurrence of NTDs.
Collapse
Affiliation(s)
- Xusen Yang
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
- Department of Neurosurgery, Hami Hongxing Hospital, Hami, 839099, China
| | - Guofeng Fan
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Zengliang Wang
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Shaoshan Li
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Hu Qin
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Yun Wang
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Xiaohu Ma
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Wenyu Ji
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China
| | - Yongxin Wang
- Department of Neurosurgery, Xinjiang Medical University Affiliated First Hospital, Urumqi, 830054, China.
| |
Collapse
|
5
|
Weaver NE, Healy A, Wingert RA. gldc Is Essential for Renal Progenitor Patterning during Kidney Development. Biomedicines 2022; 10:biomedicines10123220. [PMID: 36551976 PMCID: PMC9776136 DOI: 10.3390/biomedicines10123220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/04/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
The glycine cleavage system (GCS) is a complex located on the mitochondrial membrane that is responsible for regulating glycine levels and contributing one-carbon units to folate metabolism. Congenital mutations in GCS components, such as glycine decarboxylase (gldc), cause an elevation in glycine levels and the rare disease, nonketotic hyperglycinemia (NKH). NKH patients suffer from pleiotropic symptoms including seizures, lethargy, mental retardation, and early death. Therefore, it is imperative to fully elucidate the pathological effects of gldc dysfunction and glycine accumulation during development. Here, we describe a zebrafish model of gldc deficiency that recapitulates phenotypes seen in humans and mice. gldc deficient embryos displayed impaired fluid homeostasis suggesting renal abnormalities, as well as aberrant craniofacial morphology and neural development defects. Whole mount in situ hybridization (WISH) revealed that gldc transcripts were highly expressed in the embryonic kidney, as seen in mouse and human repository data, and that formation of several nephron segments was disrupted in gldc deficient embryos, including proximal and distal tubule populations. These kidney defects were caused by alterations in renal progenitor populations, revealing that the proper function of Gldc is essential for the patterning of this organ. Additionally, further analysis of the urogenital tract revealed altered collecting duct and cloaca morphology in gldc deficient embryos. Finally, to gain insight into the molecular mechanisms underlying these disruptions, we examined the effects of exogenous glycine treatment and observed analogous renal and cloacal defects. Taken together, these studies indicate for the first time that gldc function serves an essential role in regulating renal progenitor development by modulating glycine levels.
Collapse
|
6
|
Wendling O, Hentsch D, Jacobs H, Lemercier N, Taubert S, Pertuy F, Vonesch JL, Sorg T, Di Michele M, Le Cam L, Rosahl T, Carballo-Jane E, Liu M, Mu J, Mark M, Herault Y. High Resolution Episcopic Microscopy for Qualitative and Quantitative Data in Phenotyping Altered Embryos and Adult Mice Using the New "Histo3D" System. Biomedicines 2021; 9:767. [PMID: 34356832 PMCID: PMC8301480 DOI: 10.3390/biomedicines9070767] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 12/27/2022] Open
Abstract
3D imaging in animal models, during development or in adults, facilitates the identification of structural morphological changes that cannot be achieved with traditional 2D histological staining. Through the reconstruction of whole embryos or a region-of-interest, specific changes are better delimited and can be easily quantified. We focused here on high-resolution episcopic microscopy (HREM), and its potential for visualizing and quantifying the organ systems of normal and genetically altered embryos and adult organisms. Although the technique is based on episcopic images, these are of high resolution and are close to histological quality. The images reflect the tissue structure and densities revealed by histology, albeit in a grayscale color map. HREM technology permits researchers to take advantage of serial 2D aligned stacks of images to perform 3D reconstructions. Three-dimensional visualization allows for an appreciation of topology and morphology that is difficult to achieve with classical histological studies. The nature of the data lends itself to novel forms of computational analysis that permit the accurate quantitation and comparison of individual embryos in a manner that is impossible with histology. Here, we have developed a new HREM prototype consisting of the assembly of a Leica Biosystems Nanocut rotary microtome with optics and a camera. We describe some examples of applications in the prenatal and adult lifestage of the mouse to show the added value of HREM for phenotyping experimental cohorts to compare and quantify structure volumes. At prenatal stages, segmentations and 3D reconstructions allowed the quantification of neural tissue and ventricular system volumes of normal brains at E14.5 and E16.5 stages. 3D representations of normal cranial and peripheric nerves at E15.5 and of the normal urogenital system from stages E11.5 to E14.5 were also performed. We also present a methodology to quantify the volume of the atherosclerotic plaques of ApoEtm1Unc/tm1Unc mutant mice and illustrate a 3D reconstruction of knee ligaments in adult mice.
Collapse
Affiliation(s)
- Olivia Wendling
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Didier Hentsch
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Hugues Jacobs
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | | | - Serge Taubert
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Fabien Pertuy
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | - Jean-Luc Vonesch
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Tania Sorg
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | - Michela Di Michele
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Université Montpellier, 34298 Montpellier, France; (M.D.M.); (L.L.C.)
- Institut Régional du Cancer de Montpellier (ICM), Université Montpellier, 34298 Montpellier, France
| | - Laurent Le Cam
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Université Montpellier, 34298 Montpellier, France; (M.D.M.); (L.L.C.)
- Institut Régional du Cancer de Montpellier (ICM), Université Montpellier, 34298 Montpellier, France
| | - Thomas Rosahl
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Ester Carballo-Jane
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Mindy Liu
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - James Mu
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Manuel Mark
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
- Service de Biologie de la Reproduction, Hôpitaux Universitaires de Strasbourg (HUS), CEDEX, 67091 Strasbourg, France
| | - Yann Herault
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| |
Collapse
|
7
|
Leung KY, De Castro SCP, Galea GL, Copp AJ, Greene NDE. Glycine Cleavage System H Protein Is Essential for Embryonic Viability, Implying Additional Function Beyond the Glycine Cleavage System. Front Genet 2021; 12:625120. [PMID: 33569080 PMCID: PMC7868403 DOI: 10.3389/fgene.2021.625120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/04/2021] [Indexed: 12/03/2022] Open
Abstract
Glycine cleavage system H protein (GCSH) is a component of the glycine cleavage system (GCS), a conserved protein complex that acts to decarboxylate glycine. Mutation of AMT or GLDC, encoding the GCS components aminomethyltransferase and glycine decarboxylase, can cause malformations of the developing CNS (neural tube defects (NTDs) and ventriculomegaly) as well as a post-natal life-limiting neurometabolic disorder, Non-Ketotic Hyperglycinemia. In contrast, it is unclear whether mutation of GCSH contributes to these conditions and we therefore investigated GCSH loss of function in mice. Mice that were heterozygous for a Gcsh null allele were viable and did not exhibit elevated plasma glycine. Moreover, heterozygous mutation of Gcsh did not increase the frequency of NTDs in Gldc mutant embryos. Homozygous Gcsh null mice were not recovered at post-natal stages. Analysis of litters at E8.5-10.5, revealed the presence of homozygous null embryos which were much smaller than littermates and had failed to develop beyond early post-implantation stages with no visible somites or head-folds. Hence, unlike null mutations of Gldc or Amt, which are compatible with embryonic survival despite the presence of NTDs, loss of Gcsh causes embryonic death prior to mid-gestation. Maternal supplementation with formate did not restore embryonic development beyond E7.5, suggesting that the primary cause of lethality was not loss of glycine cleavage activity or suppression of folate one-carbon metabolism. These findings suggest that GCSH has additional roles beyond function in the glycine cleavage system. We hypothesize that GCSH potentially acts in lipoylation of 2-oxoacid dehydrogenase proteins, as reported in bacteria.
Collapse
Affiliation(s)
- Kit-Yi Leung
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Sandra C P De Castro
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Gabriel L Galea
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Andrew J Copp
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Nicholas D E Greene
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| |
Collapse
|
8
|
Santos C, Pai YJ, Mahmood MR, Leung KY, Savery D, Waddington SN, Copp AJ, Greene NDE. Impaired folate 1-carbon metabolism causes formate-preventable hydrocephalus in glycine decarboxylase-deficient mice. J Clin Invest 2020; 130:1446-1452. [PMID: 31794432 PMCID: PMC7269562 DOI: 10.1172/jci132360] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/20/2019] [Indexed: 12/16/2022] Open
Abstract
Ventriculomegaly and hydrocephalus are associated with loss of function of glycine decarboxylase (Gldc) in mice and in humans suffering from non-ketotic hyperglycinemia (NKH), a neurometabolic disorder characterized by accumulation of excess glycine. Here, we showed that ventriculomegaly in Gldc-deficient mice is preceded by stenosis of the Sylvian aqueduct and malformation or absence of the subcommissural organ and pineal gland. Gldc functions in the glycine cleavage system, a mitochondrial component of folate metabolism, whose malfunction results in accumulation of glycine and diminished supply of glycine-derived 1-carbon units to the folate cycle. We showed that inadequate 1-carbon supply, as opposed to excess glycine, is the cause of hydrocephalus associated with loss of function of the glycine cleavage system. Maternal supplementation with formate prevented both ventriculomegaly, as assessed at prenatal stages, and postnatal development of hydrocephalus in Gldc-deficient mice. Furthermore, ventriculomegaly was rescued by genetic ablation of 5,10-methylene tetrahydrofolate reductase (Mthfr), which results in retention of 1-carbon groups in the folate cycle at the expense of transfer to the methylation cycle. In conclusion, a defect in folate metabolism can lead to prenatal aqueduct stenosis and resultant hydrocephalus. These defects are preventable by maternal supplementation with formate, which acts as a 1-carbon donor.
Collapse
Affiliation(s)
- Chloe Santos
- UCL Great Ormond Street Institute of Child Health and
| | - Yun Jin Pai
- UCL Great Ormond Street Institute of Child Health and
| | | | - Kit-Yi Leung
- UCL Great Ormond Street Institute of Child Health and
| | - Dawn Savery
- UCL Great Ormond Street Institute of Child Health and
| | - Simon N Waddington
- EGA Institute for Women's Health, University College London, London, United Kingdom.,MRC Antiviral Gene Therapy Research Unit, Faculty of Health Science, University of the Witswatersrand, Johannesburg, South Africa
| | - Andrew J Copp
- UCL Great Ormond Street Institute of Child Health and
| | | |
Collapse
|
9
|
Autuori MC, Pai YJ, Stuckey DJ, Savery D, Marconi AM, Massa V, Lythgoe MF, Copp AJ, David AL, Greene NDE. Use of high-frequency ultrasound to study the prenatal development of cranial neural tube defects and hydrocephalus in Gldc-deficient mice. Prenat Diagn 2017; 37:273-281. [PMID: 28056489 PMCID: PMC5347903 DOI: 10.1002/pd.5004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/16/2016] [Accepted: 12/29/2016] [Indexed: 12/05/2022]
Abstract
Objective We used non‐invasive high‐frequency ultrasound (HFUS) imaging to investigate embryonic brain development in a mouse model for neural tube defects (NTDs) and non‐ketotic hyperglycinemia (NKH). Method Using HFUS, we imaged embryos carrying loss of function alleles of Gldc encoding glycine decarboxylase, a component of the glycine cleavage system in mitochondrial folate metabolism, which is known to be associated with cranial NTDs and NKH in humans. We serially examined the same litter during the second half of embryonic development and quantified cerebral structures. Genotype was confirmed using PCR. Histology was used to confirm ultrasound findings. Results High‐frequency ultrasound allowed in utero detection of two major brain abnormalities in Gldc‐deficient mouse embryos, cranial NTDs (exencephaly) and ventriculomegaly (corresponding with the previous finding of post‐natal hydrocephalus). Serial ultrasound allowed individual embryos to be analysed at successive gestational time points. From embryonic day 16.5 to 18.5, the lateral ventricle volume reduced in wild‐type and heterozygous embryos but increased in homozygous Gldc‐deficient embryos. Conclusion Exencephaly and ventriculomegaly were detectable by HFUS in homozygous Gldc‐deficient mouse embryos indicating this to be an effective tool to study CNS development. Longitudinal analysis of the same embryo allowed the prenatal onset and progression of ventricle enlargement in Gldc‐deficient mice to be determined. © 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. What's already known about this topic?High‐frequency ultrasound (HFUS) has been used to non‐invasively monitor in utero mouse central nervous system (CNS) development during mid‐gestation (embryonic day 10.5–14.5); later gestational ages are yet to be studied. Missense mutations of the glycine decarboxylase gene (Gldc) are associated clinically with a metabolic disorder, Non‐ketotic hyperglycinemia (NKH) and neural tube defects (NTDs) such as exencephaly.
What does this study add?We extended HFUS imaging of the mouse CNS into late gestation embryonic day 18.5 in a genetic mouse mutant lacking Gldc in which NTDs, such as exencephaly, and hydrocephalus are prevalent. Serial HFUS can determine the age of onset of ventricle dilation that precedes hydrocephalus in this model.
Collapse
Affiliation(s)
- Maria C Autuori
- Newlife Birth Defects Research Centre and Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, UK.,Department of Obstetrics and Gynaecology, San Paolo Hospital, Milan, Italy
| | - Yun J Pai
- Newlife Birth Defects Research Centre and Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Daniel J Stuckey
- Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - Dawn Savery
- Newlife Birth Defects Research Centre and Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Anna M Marconi
- Department of Obstetrics and Gynaecology, San Paolo Hospital, Milan, Italy
| | - Valentina Massa
- Department of Health Science, San Paolo Hospital, Milan, Italy
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - Andrew J Copp
- Newlife Birth Defects Research Centre and Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Anna L David
- Maternal and Fetal Medicine, Institute for Women's Health, University College London, London, UK
| | - Nicholas D E Greene
- Newlife Birth Defects Research Centre and Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, UK
| |
Collapse
|