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Vuković T, Kuek LE, Yu B, Makris G, Häberle J. The therapeutic landscape of citrin deficiency. J Inherit Metab Dis 2024. [PMID: 39021261 DOI: 10.1002/jimd.12768] [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: 02/16/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 07/20/2024]
Abstract
Citrin deficiency (CD) is a recessive, liver disease caused by sequence variants in the SLC25A13 gene encoding a mitochondrial aspartate-glutamate transporter. CD manifests as different age-dependent phenotypes and affects crucial hepatic metabolic pathways including malate-aspartate-shuttle, glycolysis, gluconeogenesis, de novo lipogenesis and the tricarboxylic acid and urea cycles. Although the exact pathophysiology of CD remains unclear, impaired use of glucose and fatty acids as energy sources due to NADH shuttle defects and PPARα downregulation, respectively, indicates evident energy deficit in CD hepatocytes. The present review summarizes current trends on available and potential treatments for CD. Baseline recommendation for CD patients is dietary management, often already present as a self-selected food preference, that includes protein and fat-rich food, and avoidance of excess carbohydrates. At present, liver transplantation remains the sole curative option for severe CD cases. Our extensive literature review indicated medium-chain triglycerides (MCT) as the most widely used CD treatment in all age groups. MCT can effectively improve symptoms across disease phenotypes by rapidly supplying energy to the liver, restoring redox balance and inducing lipogenesis. In contrast, sodium pyruvate restored glycolysis and displayed initial preclinical promise, with however limited efficacy in adult CD patients. Ursodeoxycholic acid, nitrogen scavengers and L-arginine treatments effectively address specific pathophysiological aspects such as cholestasis and hyperammonemia and are commonly administered in combination with other drugs. Finally, future possibilities including restoring redox balance, amino acid supplementation, enhancing bioenergetics, improving ureagenesis and mRNA/DNA-based gene therapy are also discussed.
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Affiliation(s)
- Toni Vuković
- University Children's Hospital Zurich and Children's Research Center, University of Zurich, Zurich, Switzerland
| | | | | | - Georgios Makris
- University Children's Hospital Zurich and Children's Research Center, University of Zurich, Zurich, Switzerland
| | - Johannes Häberle
- University Children's Hospital Zurich and Children's Research Center, University of Zurich, Zurich, Switzerland
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Inui A, Ko JS, Chongsrisawat V, Sibal A, Hardikar W, Chang MH, Treepongkaruna S, Arai K, Kim KM, Chen HL. Update on the diagnosis and management of neonatal intrahepatic cholestasis caused by citrin deficiency: Expert review on behalf of the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology, and Nutrition. J Pediatr Gastroenterol Nutr 2024; 78:178-187. [PMID: 38374571 DOI: 10.1002/jpn3.12042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/31/2023] [Accepted: 09/14/2023] [Indexed: 02/21/2024]
Abstract
Citrin deficiency is an autosomal recessive metabolic liver disease caused by mutations in the SLC25A13 gene. The disease typically presents with cholestasis, elevated liver enzymes, hyperammonemia, hypercitrullinemia, and fatty liver in young infants, resulting in a phenotype known as "neonatal intrahepatic cholestasis caused by citrin deficiency" (NICCD). The diagnosis relies on clinical manifestation, biochemical evidence of hypercitrullinemia, and identifying mutations in the SLC25A13 gene. Several common mutations have been found in patients of East Asian background. The mainstay treatment is nutritional therapy in early infancy utilizing a lactose-free and medium-chain triglyceride formula. This approach leads to the majority of patients recovering liver function by 1 year of age. Some patients may remain asymptomatic or undiagnosed, but a small proportion of cases can progress to cirrhosis and liver failure, necessitating liver transplantation. Recently, advancements in newborn screening methods have improved the age of diagnosis. Early diagnosis and timely management improve patient outcomes. Further studies are needed to elucidate the long-term follow-up of NICCD patients into adolescence and adulthood.
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Affiliation(s)
- Ayano Inui
- Department of Pediatric Hepatology and Gastroenterology, Saiseikai Yokohamshi Tobu Hospital, Yokohama, Japan
| | - Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Voranush Chongsrisawat
- Department of Pediatrics, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | | | - Winita Hardikar
- Department of Gastroenterology, Royal Children's Hospital, Melbourne, Australia
| | - Mei-Hwei Chang
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Suporn Treepongkaruna
- Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Katsuhiro Arai
- Division of Gastroenterology, National Center for Child Health and Development, Tokyo, Japan
| | - Kyung Mo Kim
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Huey-Ling Chen
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
- Department and Graduate Institute of Medical Education and Bioethics, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
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Holeček M. Aspartic Acid in Health and Disease. Nutrients 2023; 15:4023. [PMID: 37764806 PMCID: PMC10536334 DOI: 10.3390/nu15184023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/12/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Aspartic acid exists in L- and D-isoforms (L-Asp and D-Asp). Most L-Asp is synthesized by mitochondrial aspartate aminotransferase from oxaloacetate and glutamate acquired by glutamine deamidation, particularly in the liver and tumor cells, and transamination of branched-chain amino acids (BCAAs), particularly in muscles. The main source of D-Asp is the racemization of L-Asp. L-Asp transported via aspartate-glutamate carrier to the cytosol is used in protein and nucleotide synthesis, gluconeogenesis, urea, and purine-nucleotide cycles, and neurotransmission and via the malate-aspartate shuttle maintains NADH delivery to mitochondria and redox balance. L-Asp released from neurons connects with the glutamate-glutamine cycle and ensures glycolysis and ammonia detoxification in astrocytes. D-Asp has a role in brain development and hypothalamus regulation. The hereditary disorders in L-Asp metabolism include citrullinemia, asparagine synthetase deficiency, Canavan disease, and dicarboxylic aminoaciduria. L-Asp plays a role in the pathogenesis of psychiatric and neurologic disorders and alterations in BCAA levels in diabetes and hyperammonemia. Further research is needed to examine the targeting of L-Asp metabolism as a strategy to fight cancer, the use of L-Asp as a dietary supplement, and the risks of increased L-Asp consumption. The role of D-Asp in the brain warrants studies on its therapeutic potential in psychiatric and neurologic disorders.
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Affiliation(s)
- Milan Holeček
- Department of Physiology, Faculty of Medicine in Hradec Králové, Charles University, Šimkova 870, 500 03 Hradec Králové, Czech Republic
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Holeček M. Aspartate-glutamate carrier 2 (citrin): a role in glucose and amino acid metabolism in the liver. BMB Rep 2023; 56:385-391. [PMID: 37254569 PMCID: PMC10390287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/19/2023] [Accepted: 05/29/2023] [Indexed: 06/01/2023] Open
Abstract
Aspartate-glutamate carrier 2 (AGC2, citrin) is a mitochondrial carrier expressed in the liver that transports aspartate from mitochondria into the cytosol in exchange for glutamate. The AGC2 is the main component of the malate-aspartate shuttle (MAS) that ensures indirect transport of NADH produced in the cytosol during glycolysis, lactate oxidation to pyruvate, and ethanol oxidation to acetaldehyde into mitochondria. Through MAS, AGC2 is necessary to maintain intracellular redox balance, mitochondrial respiration, and ATP synthesis. Through elevated cytosolic Ca2+ level, the AGC2 is stimulated by catecholamines and glucagon during starvation, exercise, and muscle wasting disorders. In these conditions, AGC2 increases aspartate input to the urea cycle, where aspartate is a source of one of two nitrogen atoms in the urea molecule (the other is ammonia), and a substrate for the synthesis of fumarate that is gradually converted to oxaloacetate, the starting substrate for gluconeogenesis. Furthermore, aspartate is a substrate for the synthesis of asparagine, nucleotides, and proteins. It is concluded that AGC2 plays a fundamental role in the compartmentalization of aspartate and glutamate metabolism and linkage of the reactions of MAS, glycolysis, gluconeogenesis, amino acid catabolism, urea cycle, protein synthesis, and cell proliferation. Targeting of AGC genes may represent a new therapeutic strategy to fight cancer. [BMB Reports 2023; 56(7): 385-391].
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Affiliation(s)
- Milan Holeček
- Department of Physiology, Faculty of Medicine, Charles University, Hradec Králové 500 03, Czech Republic
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Holeček M. Aspartate-glutamate carrier 2 (citrin): a role in glucose and amino acid metabolism in the liver. BMB Rep 2023; 56:385-391. [PMID: 37254569 PMCID: PMC10390287 DOI: 10.5483/bmbrep.2023-0052] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/19/2023] [Accepted: 05/29/2023] [Indexed: 09/29/2023] Open
Abstract
Aspartate-glutamate carrier 2 (AGC2, citrin) is a mitochondrial carrier expressed in the liver that transports aspartate from mitochondria into the cytosol in exchange for glutamate. The AGC2 is the main component of the malate-aspartate shuttle (MAS) that ensures indirect transport of NADH produced in the cytosol during glycolysis, lactate oxidation to pyruvate, and ethanol oxidation to acetaldehyde into mitochondria. Through MAS, AGC2 is necessary to maintain intracellular redox balance, mitochondrial respiration, and ATP synthesis. Through elevated cytosolic Ca2+ level, the AGC2 is stimulated by catecholamines and glucagon during starvation, exercise, and muscle wasting disorders. In these conditions, AGC2 increases aspartate input to the urea cycle, where aspartate is a source of one of two nitrogen atoms in the urea molecule (the other is ammonia), and a substrate for the synthesis of fumarate that is gradually converted to oxaloacetate, the starting substrate for gluconeogenesis. Furthermore, aspartate is a substrate for the synthesis of asparagine, nucleotides, and proteins. It is concluded that AGC2 plays a fundamental role in the compartmentalization of aspartate and glutamate metabolism and linkage of the reactions of MAS, glycolysis, gluconeogenesis, amino acid catabolism, urea cycle, protein synthesis, and cell proliferation. Targeting of AGC genes may represent a new therapeutic strategy to fight cancer. [BMB Reports 2023; 56(7): 385-391].
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Affiliation(s)
- Milan Holeček
- Department of Physiology, Faculty of Medicine, Charles University, Hradec Králové 500 03, Czech Republic
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Zhang S, Du Y, Cai L, Chen M, Song Y, He L, Gong N, Lin Q. Obstacles to home-based dietary management for caregivers of children with citrin deficiency: a qualitative study. Orphanet J Rare Dis 2022; 17:256. [PMID: 35804387 PMCID: PMC9264664 DOI: 10.1186/s13023-022-02437-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background Dietary management is the most important and effective treatment for citrin deficiency, as well as a decisive factor in the clinical outcome of patients. However, the dietary management ability of caregivers of children with citrin deficiency is generally poor, especially in East Asia where carbohydrate-based diets are predominant. The aim of this study was to identify the difficulties that caregivers encounter in the process of home-based dietary management, and the reasons responsible for these challenges. Results A total of 26 caregivers of children with citrin deficiency were recruited, including 24 mothers, one father, and one grandmother. Grounded theory was employed to identify three themes (covering 12 sub-themes) related to the dilemma of dietary management: dietary management that is difficult to implement; conflicts with traditional concepts; and the notion that children are only a part of family life. The first theme describes the objective difficulties that caregivers encounter in the process of dietary management; the second theme describes the underlying reasons responsible for the non-adherent behavior of caregivers; the third theme further reveals the self-compromise by caregivers in the face of multiple difficulties. Conclusions This study reflects the adverse effects of multi-dimensional contradictions on the adherence of caregivers to dietary management. These findings reveal that the dietary management of citrin deficiency is not only a rational process, rather it is deeply embedded in family, social, and dietary traditions.
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Affiliation(s)
- Shuxian Zhang
- School of Nursing, Jinan University, Guangzhou City, 510632, Guangdong Prov., China
| | - Yun Du
- The First Affiliated Hospital of Jinan University, Guangzhou City, 510630, Guangdong Prov., China
| | - Lingli Cai
- School of Nursing, Jinan University, Guangzhou City, 510632, Guangdong Prov., China
| | - Meixue Chen
- School of Nursing, Jinan University, Guangzhou City, 510632, Guangdong Prov., China
| | - Yuanzong Song
- The First Affiliated Hospital of Jinan University, Guangzhou City, 510630, Guangdong Prov., China
| | - Lilan He
- The First Affiliated Hospital of Jinan University, Guangzhou City, 510630, Guangdong Prov., China
| | - Ni Gong
- School of Nursing, Jinan University, Guangzhou City, 510632, Guangdong Prov., China.
| | - Qingran Lin
- School of Nursing, Jinan University, Guangzhou City, 510632, Guangdong Prov., China. .,The First Affiliated Hospital of Jinan University, Guangzhou City, 510630, Guangdong Prov., China.
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Kido J, Häberle J, Sugawara K, Tanaka T, Nagao M, Sawada T, Wada Y, Numakura C, Murayama K, Watanabe Y, Kojima-Ishii K, Sasai H, Kosugiyama K, Nakamura K. Clinical manifestation and long-term outcome of citrin deficiency: Report from a nationwide study in Japan. J Inherit Metab Dis 2022; 45:431-444. [PMID: 35142380 DOI: 10.1002/jimd.12483] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 02/08/2022] [Indexed: 11/05/2022]
Abstract
Citrin deficiency is an autosomal recessive disorder caused by mutations in the SLC25A13 gene. The disease can present with age-dependent clinical manifestations: neonatal intrahepatic cholestasis by citrin deficiency (NICCD), failure to thrive, and dyslipidemia by citrin deficiency (FTTDCD), and adult-onset type II citrullinemia (CTLN2). As a nationwide study to investigate the clinical manifestations, medical therapy, and long-term outcome in Japanese patients with citrin deficiency, we collected clinical data of 222 patients diagnosed and/or treated at various different institutions between January 2000 and December 2019. In the entire cohort, 218 patients were alive while 4 patients (1 FTTDCD and 3 CTLN2) had died. All patients <20 years were alive. Patients with citrin deficiency had an increased risk for low weight and length at birth, and CTLN2 patients had an increased risk for growth impairment during adolescence. Liver transplantation has been performed in only 4 patients (1 NICCD, 3 CTLN2) with a good response thereafter. This study reports the diagnosis and clinical course in a large cohort of patients with citrin deficiency and suggests that early intervention including a low carbohydrate diet and MCT supplementation can be associated with improved clinical course and long-term outcome.
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Affiliation(s)
- Jun Kido
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Department of Pediatrics, Kumamoto University Hospital, Kumamoto, Japan
| | - Johannes Häberle
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Keishin Sugawara
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Toju Tanaka
- Department of Pediatrics, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan
| | - Masayoshi Nagao
- Department of Pediatrics, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan
| | - Takaaki Sawada
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Department of Pediatrics, Kumamoto University Hospital, Kumamoto, Japan
| | - Yoichi Wada
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Chikahiko Numakura
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan
| | - Kei Murayama
- Department of Metabolism, Center for Medical Genetics, Chiba Children's Hospital, Chiba, Japan
| | - Yoriko Watanabe
- Research Institute of Medical Mass Spectrometry, Kurume University School of Medicine, Kurume, Japan
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Japan
| | - Kanako Kojima-Ishii
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | | | - Kimitoshi Nakamura
- Department of Pediatrics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Department of Pediatrics, Kumamoto University Hospital, Kumamoto, Japan
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Suzuki T, Wada Y, Mikami-Saito Y, Kikuchi A, Kure S. Usefulness of serum BUN or BUN/creatinine ratio as markers for citrin deficiency in positive cases of newborn screening. Mol Genet Metab Rep 2022; 30:100834. [PMID: 35242568 PMCID: PMC8856906 DOI: 10.1016/j.ymgmr.2021.100834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 10/25/2022] Open
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张 妮, 张 占, 林 伟, 张 萌, 李 冰. Physical and neuropsychological development of children with Citrin deficiency. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2021; 23:1262-1266. [PMID: 34911610 PMCID: PMC8690716 DOI: 10.7499/j.issn.1008-8830.2108115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/01/2021] [Indexed: 01/24/2023]
Abstract
OBJECTIVES To study the physical and neuropsychological development of children with Citrin deficiency (CD). METHODS A total of 93 children, aged 1.9-59.8 months, who were diagnosed with CD by SLC25A13 gene analysis in the First Affiliated Hospital of Jinan University from August 2010 to August 2015, were enrolled as subjects. A retrospective analysis was performed for their birth condition and physical growth and neuropsychological development indices. Among these children, 7 underwent physical measurement and neuropsychological development assessment within 1 year old and after 1 year old, and therefore, a total of 100 cases were included for analysis. RESULTS For the 93 children with CD, the incidence rate of failure to thrive was 25% (23 children) and the proportion of small for gestational age was 47% (44 children). For the 100 cases of CD, the incidence rates of growth retardation, underweight, emaciation, overweight, and microcephalus were 23% (23 cases), 14% (14 cases), 4% (4 cases), 8% (8 cases), and 9% (9 cases), respectively. The incidence rate of neuropsychological developmental delay was 25% (25 cases), and the incidence rates of development delay in the five domains of adaptability, gross motor, fine motor, language, and social ability were 7% (7 cases), 15% (15 cases), 7% (7 cases), 9% (9 cases), and 7% (7 cases), respectively. CONCLUSIONS Physical and neuropsychological developmental delay can be observed in children with CD, and physical and neuropsychological development should be regularly assessed.
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