1
|
Kasprzyk-Pawelec A, Tan M, Rahhal R, McIntosh A, Fernandez H, Mosaoa R, Jiang L, Pearson GW, Glasgow E, Vockley J, Albanese C, Avantaggiati ML. Loss of the mitochondrial carrier, SLC25A1, during embryogenesis induces a unique senescence program controlled by p53. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.18.549409. [PMID: 37503155 PMCID: PMC10370133 DOI: 10.1101/2023.07.18.549409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Germline inactivating mutations of the SLC25A1 gene contribute to various human developmental disorders, including combined D/L-2-hydroxyglutaric aciduria (D/L-2HGA), a severe systemic syndrome characterized by the accumulation of both enantiomers of 2-hydroxyglutaric acid (2HG). The mechanisms by which SLC25A1 deficiency leads to this disease and the role of 2HG are unclear and no therapies exist. We now show that mice lacking both Slc25a1 alleles display a spectrum of alterations that resemble human D/L-2HGA. Mechanistically, SLC25A1 loss results in a proliferation defect and activates two distinct senescence pathways, oncogene-induced senescence (OIS) and mitochondrial dysfunction-induced senescence (MiDAS), both involving the p53 tumor suppressor and driven by two discernible signals: the accumulation of 2HG, inducing OIS, and mitochondrial dysfunction, triggering MiDAS. Inhibiting these senescence programs or blocking p53 activity reverses the growth defect caused by SLC25A1 dysfunction and restores proliferation. These findings reveal novel pathogenic roles of senescence in human disorders and suggest potential strategies to correct the molecular alterations caused by SLC25A1 loss.
Collapse
|
2
|
Zara V, Assalve G, Ferramosca A. Insights into the malfunctioning of the mitochondrial citrate carrier: Implications for cell pathology. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166758. [PMID: 37209873 DOI: 10.1016/j.bbadis.2023.166758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/08/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023]
Abstract
The mitochondrial citrate carrier (CIC) is a member of the mitochondrial carrier family and is responsible for the transit of tricarboxylates and dicarboxylates across the inner membrane. By modulating the flux of these molecules, it represents the molecular link between catabolic and anabolic reactions that take place in distinct cellular sub-compartments. Therefore, this transport protein represents an important element of investigation both in physiology and in pathology. In this review we critically analyze the involvement of the mitochondrial CIC in several human pathologies, which can be divided into two subgroups, one characterized by a decrease and the other by an increase in the flux of citrate across the inner mitochondrial membrane. In particular, a decrease in the activity of the mitochondrial CIC is responsible for several congenital diseases of different severity, which are also characterized by the increase in urinary levels of L-2- and D-2-hydroxyglutaric acids. On the other hand, an increase in the activity of the mitochondrial CIC is involved, in various ways, in the onset of inflammation, autoimmune diseases, and cancer. Then, understanding the role of CIC and the mechanisms driving the flux of metabolic intermediates between mitochondria and cytosol would potentially allow for manipulation and control of metabolism in pathological conditions.
Collapse
Affiliation(s)
- Vincenzo Zara
- Department of Biological and Environmental Sciences and Technologies, University of Salento, I-73100 Lecce, Italy
| | - Graziana Assalve
- Department of Biological and Environmental Sciences and Technologies, University of Salento, I-73100 Lecce, Italy
| | - Alessandra Ferramosca
- Department of Biological and Environmental Sciences and Technologies, University of Salento, I-73100 Lecce, Italy.
| |
Collapse
|
3
|
Phua YL, D’Annibale OM, Karunanidhi A, Mohsen AW, Kirmse B, Dobrowolski SF, Vockley J. A multiomics approach to understanding pathology of Combined D,L-2- Hydroxyglutaric Aciduria and phenylbutyrate as potential treatment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526527. [PMID: 36778323 PMCID: PMC9915603 DOI: 10.1101/2023.02.02.526527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Combined D, L-2-Hydroxyglutaric Aciduria (D,L-2HGA) is a rare genetic disorder caused by recessive mutations in the SLC25A1 gene that encodes the mitochondrial citrate carrier protein (CIC). SLC25A1 deficiency leads to a secondary increase in mitochondrial 2-ketoglutarate that, in turn, is reduced to neurotoxic 2-hydroxyglutarate. Clinical symptoms of Combined D,L-2HGA include neonatal encephalopathy, respiratory insufficiency and often with death in infancy. No current therapies exist, although replenishing cytosolic stores by citrate supplementation to replenish cytosolic stores has been proposed. In this study, we demonstrated that patient derived fibroblasts exhibited impaired cellular bioenergetics that were worsened with citrate supplementation. We hypothesized treating patient cells with phenylbutyrate, an FDA approved pharmaceutical drug, would reduce mitochondrial 2-ketoglutarate, leading to improved cellular bioenergetics including oxygen consumption and fatty acid oxidation. Metabolomic and RNA-seq analyses demonstrated a significant decrease in intracellular 2-ketoglutarate, 2-hydroxyglutarate, and in levels of mRNA coding for citrate synthase and isocitrate dehydrogenase. Consistent with the known action of phenylbutyrate, detected levels of phenylacetylglutamine was consistent with the drug acting as 2-ketoglutarate sink in patient cells. Our pre-clinical studies suggest citrate supplementation is unlikely to be an effective treatment of the disorder. However, cellular bioenergetics suggests phenylbutyrate may have interventional utility for this rare disease.
Collapse
Affiliation(s)
- Yu Leng Phua
- Department of Pediatrics, Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Pathology, Clinical Biochemical Genetics Laboratory, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York City, NY, USA
| | - Olivia M D’Annibale
- Department of Pediatrics, Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
| | - Anuradha Karunanidhi
- Department of Pediatrics, Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Al-Walid Mohsen
- Department of Pediatrics, Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
| | - Brian Kirmse
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Steven F Dobrowolski
- Department of Pathology, Clinical Biochemical Genetics Laboratory, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Jerry Vockley
- Department of Pediatrics, Division of Genetic and Genomic Medicine, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
| |
Collapse
|
4
|
Burns W, Chaudhari BP, Haffner DN. Neurogenetic and Metabolic Mimics of Common Neonatal Neurological Disorders. Semin Pediatr Neurol 2022; 42:100972. [PMID: 35868729 DOI: 10.1016/j.spen.2022.100972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
Neurogenetic and metabolic diseases often present in the neonatal period, masquerading as other disorders, most commonly as neonatal encephalopathy and seizures. Advancements in our understanding of inborn errors of metabolism are leading to an increasing number of therapeutic options. Many of these treatments can improve long-term neurodevelopment and seizure control. However, the treatments are frequently condition-specific. A high index of suspicion is required for prompt identification and treatment. When suspected, simultaneous metabolic and molecular testing are recommended along with concurrent treatment.
Collapse
Affiliation(s)
- William Burns
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH.
| | - Bimal P Chaudhari
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neonatology, Nationwide Children's Hospital, Columbus, OH; Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Darrah N Haffner
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neurology, Nationwide Children's Hospital, Columbus, OH
| |
Collapse
|
5
|
Kunji ERS, King MS, Ruprecht JJ, Thangaratnarajah C. The SLC25 Carrier Family: Important Transport Proteins in Mitochondrial Physiology and Pathology. Physiology (Bethesda) 2021; 35:302-327. [PMID: 32783608 PMCID: PMC7611780 DOI: 10.1152/physiol.00009.2020] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Members of the mitochondrial carrier family (SLC25) transport a variety of compounds across the inner membrane of mitochondria. These transport steps provide building blocks for the cell and link the pathways of the mitochondrial matrix and cytosol. An increasing number of diseases and pathologies has been associated with their dysfunction. In this review, the molecular basis of these diseases is explained based on our current understanding of their transport mechanism.
Collapse
Affiliation(s)
- Edmund R S Kunji
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Martin S King
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Jonathan J Ruprecht
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Chancievan Thangaratnarajah
- Groningen Biomolecular Sciences and Biotechnology Institute, Membrane Enzymology, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
6
|
The Mitochondrial Citrate Carrier SLC25A1/CIC and the Fundamental Role of Citrate in Cancer, Inflammation and Beyond. Biomolecules 2021; 11:biom11020141. [PMID: 33499062 PMCID: PMC7912299 DOI: 10.3390/biom11020141] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 12/18/2022] Open
Abstract
The mitochondrial citrate/isocitrate carrier, CIC, has been shown to play an important role in a growing list of human diseases. CIC belongs to a large family of nuclear-encoded mitochondrial transporters that serve the fundamental function of allowing the transit of ions and metabolites through the impermeable mitochondrial membrane. Citrate is central to mitochondrial metabolism and respiration and plays fundamental activities in the cytosol, serving as a metabolic substrate, an allosteric enzymatic regulator and, as the source of Acetyl-Coenzyme A, also as an epigenetic modifier. In this review, we highlight the complexity of the mechanisms of action of this transporter, describing its involvement in human diseases and the therapeutic opportunities for targeting its activity in several pathological conditions.
Collapse
|
7
|
Advances into Understanding the Vital Role of the Mitochondrial Citrate Carrier (CIC) in Metabolic Diseases. Pharmacol Res 2020; 161:105132. [DOI: 10.1016/j.phrs.2020.105132] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/24/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023]
|
8
|
Li W, Zhang M, Zhang L, Shi Y, Zhao L, Wu B, Li X, Zhou S. A case report of an intermediate phenotype between congenital myasthenic syndrome and D-2- and L-2-hydroxyglutaric aciduria due to novel SLC25A1 variants. BMC Neurol 2020; 20:278. [PMID: 32660532 PMCID: PMC7359281 DOI: 10.1186/s12883-020-01854-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/02/2020] [Indexed: 12/04/2022] Open
Abstract
Background Variants in the SLC25A1 gene are associated with a severe neurometabolic disease, D-2- and L-2-hydroxyglutaric aciduria (D/L-2-HGA). A report in 2014 presented the first account of congenital myasthenic syndrome (CMS) with mild intellectual disability (ID) caused by SLC25A1. To date, only two missense variants in SLC25A1 have been linked to CMS. Case presentations A Chinese boy presented fatigable muscular weakness, myasthenic crisis, epilepsy and developmental delay along with mild elevation of urinary 2-ketoglutarate (2-KG) and lactic acid levels. He showed a partial response to pyridostigmine. Genetic analysis using trio whole-exome sequencing (WES), Sanger sequencing, and cosegregation analyses revealed two novel pathogenic variants of SLC25A1 (c.628C > T, p.R210X; c.145G > A, p.V49M). Conclusions We report a boy who carries novel compound heterozygous variants of SLC25A1 and presents a phenotype intermediate between CMS and D/L-2-HGA. This case expands the range of known phenotypes and genotypes associated with SLC25A1.
Collapse
Affiliation(s)
- Wenhui Li
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Min Zhang
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Linmei Zhang
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Yiyun Shi
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Lei Zhao
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Bingbing Wu
- Center for Molecular Medicine, Children's Hospital of Fudan University, Shanghai, China.,Key Laboratory of Birth Defects, Pediatrics Research Institute, Children's Hospital of Fudan University, Shanghai, China
| | - Xihua Li
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China
| | - Shuizhen Zhou
- Department of Neurology, Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, China.
| |
Collapse
|
9
|
Palmieri F, Scarcia P, Monné M. Diseases Caused by Mutations in Mitochondrial Carrier Genes SLC25: A Review. Biomolecules 2020; 10:biom10040655. [PMID: 32340404 PMCID: PMC7226361 DOI: 10.3390/biom10040655] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
In the 1980s, after the mitochondrial DNA (mtDNA) had been sequenced, several diseases resulting from mtDNA mutations emerged. Later, numerous disorders caused by mutations in the nuclear genes encoding mitochondrial proteins were found. A group of these diseases are due to defects of mitochondrial carriers, a family of proteins named solute carrier family 25 (SLC25), that transport a variety of solutes such as the reagents of ATP synthase (ATP, ADP, and phosphate), tricarboxylic acid cycle intermediates, cofactors, amino acids, and carnitine esters of fatty acids. The disease-causing mutations disclosed in mitochondrial carriers range from point mutations, which are often localized in the substrate translocation pore of the carrier, to large deletions and insertions. The biochemical consequences of deficient transport are the compartmentalized accumulation of the substrates and dysfunctional mitochondrial and cellular metabolism, which frequently develop into various forms of myopathy, encephalopathy, or neuropathy. Examples of diseases, due to mitochondrial carrier mutations are: combined D-2- and L-2-hydroxyglutaric aciduria, carnitine-acylcarnitine carrier deficiency, hyperornithinemia-hyperammonemia-homocitrillinuria (HHH) syndrome, early infantile epileptic encephalopathy type 3, Amish microcephaly, aspartate/glutamate isoform 1 deficiency, congenital sideroblastic anemia, Fontaine progeroid syndrome, and citrullinemia type II. Here, we review all the mitochondrial carrier-related diseases known until now, focusing on the connections between the molecular basis, altered metabolism, and phenotypes of these inherited disorders.
Collapse
Affiliation(s)
- Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, Laboratory of Biochemistry and Molecular Biology, University of Bari Aldo Moro, via E. Orabona 4, 70125 Bari, Italy;
- Correspondence: (F.P.); (M.M.); Tel.: +39-0805443323 (F.P.)
| | - Pasquale Scarcia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, Laboratory of Biochemistry and Molecular Biology, University of Bari Aldo Moro, via E. Orabona 4, 70125 Bari, Italy;
| | - Magnus Monné
- Department of Biosciences, Biotechnologies and Biopharmaceutics, Laboratory of Biochemistry and Molecular Biology, University of Bari Aldo Moro, via E. Orabona 4, 70125 Bari, Italy;
- Department of Sciences, University of Basilicata, via Ateneo Lucano 10, 85100 Potenza, Italy
- Correspondence: (F.P.); (M.M.); Tel.: +39-0805443323 (F.P.)
| |
Collapse
|
10
|
Congenital myasthenic syndrome with mild intellectual disability caused by a recurrent SLC25A1 variant. Eur J Hum Genet 2019; 28:373-377. [PMID: 31527857 PMCID: PMC7029005 DOI: 10.1038/s41431-019-0506-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/26/2019] [Accepted: 08/29/2019] [Indexed: 11/10/2022] Open
Abstract
Congenital myasthenic syndromes (CMS) are a clinically and genetically heterogeneous group of disorders caused by mutations which lead to impaired neuromuscular transmission. SLC25A1 encodes a mitochondrial citrate carrier, associated mainly with the severe neurometabolic disease combined D-2- and L-2-hydroxyglutaric aciduria (D/L-2-HGA). We previously reported a single family with a homozygous missense variant in SLC25A1 with a phenotype restricted to relatively mild CMS with intellectual disability, but to date no additional cases of this CMS subtype had been reported. Here, we performed whole exome sequencing (WES) in three additional and unrelated families presenting with CMS and mild intellectual disability to identify the underlying causative gene. The WES analysis revealed the presence of a homozygous c.740G>A; p.(Arg247Gln) missense SLC25A1 variant, the same SLC25A1 variant as identified in the original family with this phenotype. Electron microscopy of muscle from two cases revealed enlarged and accumulated mitochondria. Haplotype analysis performed in two unrelated families suggested that this variant is a result of recurrent mutation and not a founder effect. This suggests that p.(Arg247Gln) is associated with a relatively mild CMS phenotype with subtle mitochondrial abnormalities, while other variants in this gene cause more severe neurometabolic disease. In conclusion, the p.(Arg247Gln) SLC25A1 variant should be considered in patients presenting with a presynaptic CMS phenotype, particularly with accompanying intellectual disability.
Collapse
|
11
|
Laboratory analysis of organic acids, 2018 update: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2018. [DOI: 10.1038/gim.2018.45] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
|
12
|
Pop A, Williams M, Struys EA, Monné M, Jansen EEW, De Grassi A, Kanhai WA, Scarcia P, Ojeda MRF, Porcelli V, van Dooren SJM, Lennertz P, Nota B, Abdenur JE, Coman D, Das AM, El-Gharbawy A, Nuoffer JM, Polic B, Santer R, Weinhold N, Zuccarelli B, Palmieri F, Palmieri L, Salomons GS. An overview of combined D-2- and L-2-hydroxyglutaric aciduria: functional analysis of CIC variants. J Inherit Metab Dis 2018; 41:169-180. [PMID: 29238895 PMCID: PMC5830478 DOI: 10.1007/s10545-017-0106-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/15/2017] [Accepted: 10/18/2017] [Indexed: 11/13/2022]
Abstract
Combined D-2- and L-2-hydroxyglutaric aciduria (D/L-2-HGA) is a devastating neurometabolic disorder, usually lethal in the first years of life. Autosomal recessive mutations in the SLC25A1 gene, which encodes the mitochondrial citrate carrier (CIC), were previously detected in patients affected with combined D/L-2-HGA. We showed that transfection of deficient fibroblasts with wild-type SLC25A1 restored citrate efflux and decreased intracellular 2-hydroxyglutarate levels, confirming that deficient CIC is the cause of D/L-2-HGA. We developed and implemented a functional assay and applied it to all 17 missense variants detected in a total of 26 CIC-deficient patients, including eight novel cases, showing reduced activities of varying degrees. In addition, we analyzed the importance of residues affected by these missense variants using our existing scoring system. This allowed not only a clinical and biochemical overview of the D/L-2-HGA patients but also phenotype-genotype correlation studies.
Collapse
Affiliation(s)
- Ana Pop
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Monique Williams
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Eduard A Struys
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Magnus Monné
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Erwin E W Jansen
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Anna De Grassi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Warsha A Kanhai
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Pasquale Scarcia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Matilde R Fernandez Ojeda
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Vito Porcelli
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Silvy J M van Dooren
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Pascal Lennertz
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Benjamin Nota
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands
| | - Jose E Abdenur
- Division of Metabolic Disorders, CHOC Children's, Orange, CA, USA
- Department of Pediatrics, University of California at Irvine, Irvine, CA, USA
| | - David Coman
- Department of Metabolic Medicine, Lady Cilento Children's Hospital, Brisbane, Australia
- School of Medicine, University of Queensland Brisbane, Griffith University Gold Coast, Gold Coast, Australia
| | - Anibh Martin Das
- Clinic for Pediatric Kidney-, Liver- and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Areeg El-Gharbawy
- Department of Pediatrics and Division of Medical Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jean-Marc Nuoffer
- Division of Pediatric Endocrinology, Diabetology and Metabolism and University Institute of Clinical Chemistry, Inselspital, University Hospital, University of Bern, Bern, Switzerland
| | - Branka Polic
- Department of Pediatrics, PICU, University Hospital Centre, Split, Croatia
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Natalie Weinhold
- Sozialpädiatrisches Zentrum, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnology, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Luigi Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnology, Consiglio Nazionale delle Ricerche, Bari, Italy.
| | - Gajja S Salomons
- Metabolic Laboratory, Department of Clinical Chemistry, Amsterdam Neuroscience, VU Medical Center Metabolic Unit PK 1X009, Postbus 7057, 1007 MB, Amsterdam, The Netherlands.
| |
Collapse
|
13
|
Majd H, King MS, Smith AC, Kunji ERS. Pathogenic mutations of the human mitochondrial citrate carrier SLC25A1 lead to impaired citrate export required for lipid, dolichol, ubiquinone and sterol synthesis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2018; 1859:1-7. [PMID: 29031613 DOI: 10.1016/j.bbabio.2017.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 10/03/2017] [Accepted: 10/09/2017] [Indexed: 11/22/2022]
Abstract
Missense mutations of the human mitochondrial citrate carrier, encoded by the SLC25A1 gene, lead to an autosomal recessive neurometabolic disorder characterised by neonatal-onset encephalopathy with severe muscular weakness, intractable seizures, respiratory distress, and lack of psychomotor development, often resulting in early death. Here, we have measured the effect of all twelve known pathogenic mutations on the transport activity. The results show that nine mutations abolish transport of citrate completely, whereas the other three reduce the transport rate by >70%, indicating that impaired citrate transport is the most likely primary cause of the disease. Some mutations may be detrimental to the structure of the carrier, whereas others may impair key functional elements, such as the substrate binding site and the salt bridge network on the matrix side of the carrier. To understand the consequences of impaired citrate transport on metabolism, the substrate specificity was also determined, showing that the human citrate carrier predominantly transports citrate, isocitrate, cis-aconitate, phosphoenolpyruvate and malate. Although D-2- and L-2 hydroxyglutaric aciduria is a metabolic hallmark of the disease, it is unlikely that the citrate carrier plays a significant role in the removal of hydroxyglutarate from the cytosol for oxidation to oxoglutarate in the mitochondrial matrix. In contrast, computer simulations of central metabolism predict that the export of citrate from the mitochondrion cannot be fully compensated by other pathways, restricting the cytosolic production of acetyl-CoA that is required for the synthesis of lipids, sterols, dolichols and ubiquinone, which in turn explains the severe disease phenotypes.
Collapse
Affiliation(s)
- Homa Majd
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Martin S King
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Anthony C Smith
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Edmund R S Kunji
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK.
| |
Collapse
|
14
|
Eguchi M, Ozaki E, Yamauchi T, Ohta M, Higaki T, Masuda K, Imoto I, Ishii E, Eguchi-Ishimae M. Manifestation of recessive combined D-2-, L-2-hydroxyglutaric aciduria in combination with 22q11.2 deletion syndrome. Am J Med Genet A 2017; 176:351-358. [PMID: 29265763 DOI: 10.1002/ajmg.a.38578] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 10/13/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022]
Abstract
22q11.2 deletion syndrome is one of the most common human microdeletion syndromes. The clinical phenotype of 22q11.2 deletion syndrome is variable, ranging from mild to life-threatening symptoms, depending mainly on the extent of the deleted region. Brain malformations described in association with 22q11.2 deletion syndrome include polymicrogyria, cerebellar hypoplasia, megacisterna magna, and agenesis of the corpus callosum (ACC), although these are rare. We report here for the first time a patient who manifested combined D-2- and L-2-hydroxyglutaric aciduria as a result of a hemizygous mutation in SLC25A1 in combination with 22q11.2 deletion. The girl was diagnosed to have ACC shortly after birth and a deletion of 22q11.2 was identified by genetic analysis. Although the patient showed cardiac anomalies, which is one of the typical symptoms of 22q11.2 deletion syndrome, her rather severe phenotype and atypical face prompted us to search for additional pathogenic mutations. Three genes present in the deleted 22q11.2 region, SLC25A1, TUBA8, and SNAP29, which have been reported to be associated with brain malformation, were analyzed for the presence of pathogenic mutations. A frameshift mutation, c.18_24dup (p.Ala9Profs*82), was identified in the first exon of the remaining SLC25A1 allele, resulting in the complete loss of normal SLC25A1 function in the patient's cells. Our results support the notion that the existence of another genetic abnormality involving the retained allele on 22q11.2 should be considered when atypical or rare phenotypes are observed.
Collapse
Affiliation(s)
- Mariko Eguchi
- Department of Pediatrics, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.,Division of Medical Genetics, Ehime University Hospital, Toon, Ehime, Japan
| | - Erina Ozaki
- Division of Medical Genetics, Ehime University Hospital, Toon, Ehime, Japan.,Department of Total Medical Support Center, Ehime University Hospital, Toon, Ehime, Japan
| | - Toshifumi Yamauchi
- Department of Neonatology, Maternity & Perinatal Care Unit, Ehime University Hospital, Toon, Ehime, Japan
| | - Masaaki Ohta
- Department of Neonatology, Maternity & Perinatal Care Unit, Ehime University Hospital, Toon, Ehime, Japan
| | - Takashi Higaki
- Department of Regional Pediatrics and Perinatology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan
| | - Kiyoshi Masuda
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Issei Imoto
- Department of Human Genetics, Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Eiichi Ishii
- Department of Pediatrics, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.,Division of Medical Genetics, Ehime University Hospital, Toon, Ehime, Japan
| | | |
Collapse
|
15
|
Cohen I, Staretz-Chacham O, Wormser O, Perez Y, Saada A, Kadir R, Birk OS. A novel homozygous SLC25A1 mutation with impaired mitochondrial complex V: Possible phenotypic expansion. Am J Med Genet A 2017; 176:330-336. [PMID: 29226520 DOI: 10.1002/ajmg.a.38574] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 11/13/2017] [Accepted: 11/16/2017] [Indexed: 11/08/2022]
Abstract
SLC25A1 mutations are associated with combined D,L-2-hydroxyglutaric aciduria (DL- 2HGA; OMIM #615182), characterized by muscular hypotonia, severe neurodevelopmental dysfunction and intractable seizures. SLC25A1 encodes the mitochondrial citrate carrier (CIC), which mediates efflux of the mitochondrial tricarboxylic acid (TCA) cycle intermediates citrate and isocitrate in exchange for cytosolic malate. Only a single family with an SLC25A1 mutation has been described in which mitochondrial respiratory chain dysfunction was documented, specifically in complex IV. Five infants of two consanguineous Bedouin families of the same tribe presented with small head circumference and neonatal-onset encephalopathy with severe muscular weakness, intractable seizures, respiratory distress, and lack of psychomotor development culminating in early death. Ventricular septal defects (VSD) were demonstrated in three patients. Blood and CSF lactate were elevated with normal levels of plasma amino acids and free carnitine and increased 2-OH-glutaric acid urinary exertion. EEG was compatible with white matter disorder. Brain MRI revealed ventriculomegaly, thin corpus callosum with increased lactate peak on spectroscopy. Mitochondrial complex V deficiency was demonstrated in skeletal muscle biopsy of one infant. Homozygosity mapping and sequencing ruled out homozygosity of affected individuals in all known complex V-associated genes. Whole exome sequencing identified a novel homozygous SLC25A1 c.713A>G (p.Asn238Ser) mutation, segregating as expected in the affected kindred and not found in 220 control alleles. Thus, SLC25A1 mutations might be associated with mitochondrial complex V deficiency and should be considered in the differential diagnosis of mitochondrial respiratory chain defects.
Collapse
Affiliation(s)
- Idan Cohen
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Orna Staretz-Chacham
- Metabolic unit, Division of Pediatrics, Soroka Medical Center, Ben Gurion University, Beer Sheva, Israel
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Yonatan Perez
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and The Department of Genetic Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Rotem Kadir
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel.,Genetics Institute, Soroka Medical Center, Beer-Sheva, Israel
| |
Collapse
|
16
|
Plasma Membrane Na⁺-Coupled Citrate Transporter (SLC13A5) and Neonatal Epileptic Encephalopathy. Molecules 2017; 22:molecules22030378. [PMID: 28264506 PMCID: PMC6155422 DOI: 10.3390/molecules22030378] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/24/2017] [Accepted: 02/25/2017] [Indexed: 12/30/2022] Open
Abstract
SLC13A5 is a Na+-coupled transporter for citrate that is expressed in the plasma membrane of specific cell types in the liver, testis, and brain. It is an electrogenic transporter with a Na+:citrate3− stoichiometry of 4:1. In humans, the Michaelis constant for SLC13A5 to transport citrate is ~600 μM, which is physiologically relevant given that the normal concentration of citrate in plasma is in the range of 150–200 μM. Li+ stimulates the transport function of human SLC13A5 at concentrations that are in the therapeutic range in patients on lithium therapy. Human SLC13A5 differs from rodent Slc13a5 in two important aspects: the affinity of the human transporter for citrate is ~30-fold less than that of the rodent transporter, thus making human SLC13A5 a low-affinity/high-capacity transporter and the rodent Slc13a5 a high-affinity/low-capacity transporter. In the liver, SLC13A5 is expressed exclusively in the sinusoidal membrane of the hepatocytes, where it plays a role in the uptake of circulating citrate from the sinusoidal blood for metabolic use. In the testis, the transporter is expressed only in spermatozoa, which is also only in the mid piece where mitochondria are located; the likely function of the transporter in spermatozoa is to mediate the uptake of citrate present at high levels in the seminal fluid for subsequent metabolism in the sperm mitochondria to generate biological energy, thereby supporting sperm motility. In the brain, the transporter is expressed mostly in neurons. As astrocytes secrete citrate into extracellular medium, the potential function of SLC13A5 in neurons is to mediate the uptake of circulating citrate and astrocyte-released citrate for subsequent metabolism. Slc13a5-knockout mice have been generated; these mice do not have any overt phenotype but are resistant to experimentally induced metabolic syndrome. Recently however, loss-of-function mutations in human SLC13A5 have been found to cause severe epilepsy and encephalopathy early in life. Interestingly, there is no evidence of epilepsy or encephalopathy in Slc13a5-knockout mice, underlining the significant differences in clinical consequences of the loss of function of this transporter between humans and mice. The markedly different biochemical features of human SLC13A5 and mouse Slc13a5 likely contribute to these differences between humans and mice with regard to the metabolic consequences of the transporter deficiency. The exact molecular mechanisms by which the functional deficiency of the citrate transporter causes epilepsy and impairs neuronal development and function remain to be elucidated, but available literature implicate both dysfunction of GABA (γ-aminobutyrate) signaling and hyperfunction of NMDA (N-methyl-d-aspartate) receptor signaling. Plausible synaptic mechanisms linking loss-of-function mutations in SLC13A5 to epilepsy are discussed.
Collapse
|
17
|
Quantitative metabolic flux analysis reveals an unconventional pathway of fatty acid synthesis in cancer cells deficient for the mitochondrial citrate transport protein. Metab Eng 2016; 43:198-207. [PMID: 27856334 DOI: 10.1016/j.ymben.2016.11.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/13/2016] [Accepted: 11/07/2016] [Indexed: 11/23/2022]
Abstract
The mitochondrial citrate transport protein (CTP), encoded by SLC25A1, accommodates bidirectional trafficking of citrate between the mitochondria and cytosol, supporting lipid biosynthesis and redox homeostasis. Genetic CTP deficiency causes a fatal neurodevelopmental syndrome associated with the accumulation of L- and D-2-hydroxyglutaric acid, and elevated CTP expression is associated with poor prognosis in several types of cancer, emphasizing the importance of this transporter in multiple human pathologies. Here we describe the metabolic consequences of CTP deficiency in cancer cells. As expected from the phenotype of CTP-deficient humans, somatic CTP loss in cancer cells induces broad dysregulation of mitochondrial metabolism, resulting in accumulation of lactate and of the L- and D- enantiomers of 2-hydroxyglutarate (2HG) and depletion of TCA cycle intermediates. It also eliminates mitochondrial import of citrate from the cytosol. To quantify the impact of CTP deficiency on metabolic flux, cells were cultured with a set of 13C-glucose and 13C-glutamine tracers with resulting data integrated by metabolic flux analysis (MFA). CTP-deficient cells displayed a major restructuring of central carbon metabolism, including suppression of pyruvate dehydrogenase (PDH) and induction of glucose-dependent anaplerosis through pyruvate carboxylase (PC). We also observed an unusual lipogenic pathway in which carbon from glucose supplies mitochondrial production of alpha-ketoglutarate (AKG), which is then trafficked to the cytosol and used to supply reductive carboxylation by isocitrate dehydrogenase 1 (IDH1). The resulting citrate is cleaved to produce lipogenic acetyl-CoA, thereby completing a novel pathway of glucose-dependent reductive carboxylation. In CTP deficient cells, IDH1 inhibition suppresses lipogenesis from either glucose or glutamine, implicating IDH1 as a required component of fatty acid synthesis in states of CTP deficiency.
Collapse
|