1
|
Pillai NR, Amin H, Gijavanekar C, Liu N, Issaq N, Broniowska KA, Bertuch AA, Sutton VR, Elsea SH, Scaglia F. Hematologic presentation and the role of untargeted metabolomics analysis in monitoring treatment for riboflavin transporter deficiency. Am J Med Genet A 2020; 182:2781-2787. [PMID: 32909658 DOI: 10.1002/ajmg.a.61851] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/02/2020] [Accepted: 08/15/2020] [Indexed: 12/21/2022]
Abstract
Riboflavin transporter deficiency (RTD) (MIM #614707) is a neurogenetic disorder with its most common manifestations including sensorineural hearing loss, peripheral neuropathy, respiratory insufficiency, and bulbar palsy. Here, we present a 2-year-old boy whose initial presentation was severe macrocytic anemia necessitating multiple blood transfusions and intermittent neutropenia; he subsequently developed ataxia and dysarthria. Trio-exome sequencing detected compound heterozygous variants in SLC52A2 that were classified as pathogenic and a variant of uncertain significance. Bone marrow evaluation demonstrated megaloblastic changes. Notably, his anemia and neutropenia resolved after treatment with oral riboflavin, thus expanding the clinical phenotype of this disorder. We reiterate the importance of starting riboflavin supplementation in a young child who presents with macrocytic anemia and neurological features while awaiting biochemical and genetic work up. We detected multiple biochemical abnormalities with the help of untargeted metabolomics analysis associated with abnormal flavin adenine nucleotide function which normalized after treatment, emphasizing the reversible pathomechanisms involved in this disorder. The utility of untargeted metabolomics analysis to monitor the effects of riboflavin supplementation in RTD has not been previously reported.
Collapse
Affiliation(s)
- Nishitha R Pillai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Hitha Amin
- Texas Children's Hospital, Houston, Texas, USA.,Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Ning Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Niveen Issaq
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas, USA
| | | | - Alison A Bertuch
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Hematology/Oncology, Baylor College of Medicine, Houston, Texas, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA.,Joint BCM-CUHK Center of Medical Genetics, Prince of Wales Hospital, Shatin, Hong Kong SAR
| |
Collapse
|
2
|
Sun Y, Zhou Q, Li J, Zhao C, Yu Z, Zhu Q. LncRNA RP11-422N16.3 Inhibits Cell Proliferation and EMT, and Induces Apoptosis in Hepatocellular Carcinoma Cells by Sponging miR-23b-3p. Onco Targets Ther 2019; 12:10943-10961. [PMID: 31849497 PMCID: PMC6913766 DOI: 10.2147/ott.s232243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/26/2019] [Indexed: 12/26/2022] Open
Abstract
Objective This study investigated the mechanism of RP11-422N16.3 sponging miR-23b-3p in cell proliferation, apoptosis and epithelial-mesenchymal transition (EMT) in liver cancer. Methods Expressions of RP11-422N16.3, miR-23b-3p and dimethylglycine dehydrogenase (DMGDH) were determined in liver cancer tissues, adjacent normal tissues, hepatocellular carcinoma cell lines and normal liver epithelial cell line. Up-regulation of RP11-422N16.3 and down-regulation of miR-23b-3p were conducted in hepatocellular carcinoma cells. Bioinformatics analysis, luciferase reporter assay and RNA-pull down assay were performed to verify the relationship among miR-23b-3p, DMGDH, as well as RP11-422N16.3. Cell proliferation and cell apoptosis were determined by CCK-8 and Flow Cytometry analysis, respectively. Results Expressions of RP11-422N16.3 and DMGDH were down-regulated while that of miR-23b-3p were up-regulated in hepatocellular carcinoma cancer tissues and cells. RP11-422N16.3 localized in cytoplasm and competitively bound to miR-23b-3p. Up-regulation of RP11-422N16.3 and down-regulation of miR-23b-3p contributed to increased expressions of DMGDH and E-cadherin, and decreased expressions of miR-23b-3p, ZEB1, Snail and Vimentin, resulting in inhibiting cell proliferation and promoting cell apoptosis. Inhibition of RP11-422N16.3 or overexpression of miR-23b-3p accelerated cell proliferation and slowed down cell apoptosis. miR-23b-3p inhibited the expression of DMGDH. Conclusion Our data suggested that LncRNA RP11-422N16.3, by competitively binding to miR-23b-3p, promoted DMGDH expression, contributing to inhibit cell proliferation and EMT, and induce cell apoptosis in hepatocellular carcinoma cells.
Collapse
Affiliation(s)
- Yunpeng Sun
- Departments of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| | - Qingqing Zhou
- Departments of Nursing, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| | - Junjian Li
- Departments of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| | - Chang Zhao
- Departments of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| | - Zhengping Yu
- Departments of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| | - Qiandong Zhu
- Departments of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, People's Republic of China
| |
Collapse
|
3
|
Augustin P, Hromic A, Pavkov-Keller T, Gruber K, Macheroux P. Structure and biochemical properties of recombinant human dimethylglycine dehydrogenase and comparison to the disease-related H109R variant. FEBS J 2016; 283:3587-3603. [PMID: 27486859 PMCID: PMC5082570 DOI: 10.1111/febs.13828] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/25/2016] [Accepted: 08/01/2016] [Indexed: 12/14/2022]
Abstract
The human dimethylglycine dehydrogenase (hDMGDH) is a flavin adenine dinucleotide (FAD)- and tetrahydrofolate (THF)-dependent, mitochondrial matrix enzyme taking part in choline degradation, one-carbon metabolism and electron transfer to the respiratory chain. The rare natural variant H109R causes dimethylglycine dehydrogenase deficiency leading to increased blood and urinary dimethylglycine concentrations. A detailed biochemical and structural characterization of hDMGDH was thus far hampered by insufficient heterologous expression of the protein. In the present study, we report the development of an intracellular, heterologous expression system in Komagataella phaffii (formerly known as Pichia pastoris) providing the opportunity to determine kinetic parameters, spectroscopic properties, thermostability, and the redox potential of hDMGDH. Moreover, we have successfully crystallized the wild-type enzyme and determined the structure to 3.1-Å resolution. The structure-based analysis of our biochemical data provided new insights into the kinetic properties of the enzyme in particular with respect to oxygen reactivity. A comparative study with the H109R variant demonstrated that the variant suffers from decreased protein stability, cofactor saturation, and substrate affinity. DATABASE Structural data are available in the PDB database under the accession number 5L46.
Collapse
Affiliation(s)
- Peter Augustin
- Institute of Biochemistry, Graz University of Technology, Austria
| | - Altijana Hromic
- Institute of Molecular Biosciences, University of Graz, Austria
| | | | - Karl Gruber
- Institute of Molecular Biosciences, University of Graz, Austria
| | - Peter Macheroux
- Institute of Biochemistry, Graz University of Technology, Austria.
| |
Collapse
|
4
|
Luka Z, Pakhomova S, Loukachevitch LV, Newcomer ME, Wagner C. Folate in demethylation: the crystal structure of the rat dimethylglycine dehydrogenase complexed with tetrahydrofolate. Biochem Biophys Res Commun 2014; 449:392-8. [PMID: 24858690 PMCID: PMC4113215 DOI: 10.1016/j.bbrc.2014.05.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 05/15/2014] [Indexed: 11/23/2022]
Abstract
Dimethylglycine dehydrogenase (DMGDH) is a mammalian mitochondrial enzyme which plays an important role in the utilization of methyl groups derived from choline. DMGDH is a flavin containing enzyme which catalyzes the oxidative demethylation of dimethylglycine in vitro with the formation of sarcosine (N-methylglycine), hydrogen peroxide and formaldehyde. DMGDH binds tetrahydrofolate (THF) in vivo, which serves as an acceptor of formaldehyde and in the cell the product of the reaction is 5,10-methylenetetrahydrofolate instead of formaldehyde. To gain insight into the mechanism of the reaction we solved the crystal structures of the recombinant mature and precursor forms of rat DMGDH and DMGDH-THF complexes. Both forms of DMGDH reveal similar kinetic parameters and have the same tertiary structure fold with two domains formed by N- and C-terminal halves of the protein. The active center is located in the N-terminal domain while the THF binding site is located in the C-terminal domain about 40Å from the isoalloxazine ring of FAD. The folate binding site is connected with the enzyme active center via an intramolecular channel. This suggests the possible transfer of the intermediate imine of dimethylglycine from the active center to the bound THF where they could react producing a 5,10-methylenetetrahydrofolate. Based on the homology of the rat and human DMGDH the structural basis for the mechanism of inactivation of the human DMGDH by naturally occurring His109Arg mutation is proposed.
Collapse
Affiliation(s)
- Zigmund Luka
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Svetlana Pakhomova
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | | | - Marcia E Newcomer
- Louisiana State University, Department of Biological Sciences, Baton Rouge, LA 70803, USA
| | - Conrad Wagner
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| |
Collapse
|
6
|
Lienhart WD, Gudipati V, Macheroux P. The human flavoproteome. Arch Biochem Biophys 2013; 535:150-62. [PMID: 23500531 PMCID: PMC3684772 DOI: 10.1016/j.abb.2013.02.015] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/21/2013] [Accepted: 02/23/2013] [Indexed: 11/26/2022]
Abstract
Vitamin B2 (riboflavin) is an essential dietary compound used for the enzymatic biosynthesis of FMN and FAD. The human genome contains 90 genes encoding for flavin-dependent proteins, six for riboflavin uptake and transformation into the active coenzymes FMN and FAD as well as two for the reduction to the dihydroflavin form. Flavoproteins utilize either FMN (16%) or FAD (84%) while five human flavoenzymes have a requirement for both FMN and FAD. The majority of flavin-dependent enzymes catalyze oxidation-reduction processes in primary metabolic pathways such as the citric acid cycle, β-oxidation and degradation of amino acids. Ten flavoproteins occur as isozymes and assume special functions in the human organism. Two thirds of flavin-dependent proteins are associated with disorders caused by allelic variants affecting protein function. Flavin-dependent proteins also play an important role in the biosynthesis of other essential cofactors and hormones such as coenzyme A, coenzyme Q, heme, pyridoxal 5'-phosphate, steroids and thyroxine. Moreover, they are important for the regulation of folate metabolites by using tetrahydrofolate as cosubstrate in choline degradation, reduction of N-5.10-methylenetetrahydrofolate to N-5-methyltetrahydrofolate and maintenance of the catalytically competent form of methionine synthase. These flavoenzymes are discussed in detail to highlight their role in health and disease.
Collapse
Affiliation(s)
| | | | - Peter Macheroux
- Graz University of Technology, Institute of Biochemistry, Petersgasse 12, A-8010 Graz, Austria
| |
Collapse
|
7
|
Affiliation(s)
- Katarzyna Swiderek
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology , Zeromskiego 116, 90-924 Lodz, Poland
| | | |
Collapse
|