1
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Ding J, Li H, Liu Y, Xie Y, Yu J, Sun H, Xiao D, Zhou Y, Bao L, Wang H, Gao C. OXCT1 Enhances Gemcitabine Resistance Through NF-κB Pathway in Pancreatic Ductal Adenocarcinoma. Front Oncol 2021; 11:698302. [PMID: 34804914 PMCID: PMC8602561 DOI: 10.3389/fonc.2021.698302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 10/18/2021] [Indexed: 12/15/2022] Open
Abstract
Background Pancreatic ductal adenocarcinoma (PDAC) is a type of malignant tumor with a five-year survival rate of less than 10%. Gemcitabine (GEM) is the most commonly used drug for PDAC chemotherapy. However, a vast majority of patients with PDAC develop resistance after GEM treatment. Methods We screened for GEM resistance genes through bioinformatics analysis. We used immunohistochemistry to analyze 3-oxoacid CoA-transferase 1 (OXCT1) expression in PDAC tissues. The survival data were analyzed using the Kaplan–Meier curve. The expression levels of the genes related to OXCT1 and the NF-κB signaling pathway were quantified using real−time quantitative PCR and western blot analyses. We performed flow cytometry to detect the apoptosis rate. Colony formation assay was performed to measure the cell proliferation levels. The cytotoxicity assays of cells were conducted using RTCA. The downstream pathway of OXCT1 was identified via the Gene Set Enrichment Analysis. Tumor growth response to GEM in vivo was also determined in mouse models. Results Bioinformatics analysis revealed that OXCT1 is the key gene leading to GEM resistance. Patients with high OXCT1 expression exhibited short relapse-free survival under GEM treatment. OXCT1 overexpression in PDAC cell lines exerted inhibitory effect on apoptosis after GEM treatment. However, the down-regulation of OXCT1 showed the opposite effect. Blocking the NF-κB signaling pathway also reduced GEM resistance of PDAC cells. Tumor growth inhibition induced by GEM in vivo reduced after OXCT1 overexpression. Moreover, the effect of OXCT1 on GEM refractoriness in PDAC cell lines was reversed through using an NF-κB inhibitor. Conclusion OXCT1 promoted GEM resistance in PDAC via the NF-κB signaling pathway both in vivo and in vitro. Our results suggest that OXCT1 could be used as a potential therapeutic target for patients with PDAC.
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Affiliation(s)
- Jinsheng Ding
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China.,The Graduate School, Tianjin Medical University, Tianjin, China.,Key Laboratory of Cancer Prevention and Therapy, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Hui Li
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China.,The Graduate School, Tianjin Medical University, Tianjin, China
| | - Yang Liu
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China.,The Graduate School, Tianjin Medical University, Tianjin, China
| | - Yongjie Xie
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China.,The Graduate School, Tianjin Medical University, Tianjin, China
| | - Jie Yu
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Huizhi Sun
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China.,The Graduate School, Tianjin Medical University, Tianjin, China
| | - Di Xiao
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Yizhang Zhou
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Li Bao
- Key Laboratory of Cancer Prevention and Therapy, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Hongwei Wang
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Chuntao Gao
- Department of Pancreatic Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
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2
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Grünert SC, Foster W, Schumann A, Lund A, Pontes C, Roloff S, Weinhold N, Yue WW, AlAsmari A, Obaid OA, Faqeih EA, Stübbe L, Yamamoto R, Gemperle-Britschgi C, Walter M, Spiekerkoetter U, Mackinnon S, Sass JO. Succinyl-CoA:3-oxoacid coenzyme A transferase (SCOT) deficiency: A rare and potentially fatal metabolic disease. Biochimie 2021; 183:55-62. [PMID: 33596448 DOI: 10.1016/j.biochi.2021.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 02/03/2021] [Accepted: 02/03/2021] [Indexed: 12/23/2022]
Abstract
Succinyl-CoA:3-oxoacid coenzyme A transferase deficiency (SCOTD) is a rare autosomal recessive disorder of ketone body utilization caused by mutations in OXCT1. We performed a systematic literature search and evaluated clinical, biochemical and genetic data on 34 previously published and 10 novel patients with SCOTD. Structural mapping and in silico analysis of protein variants is also presented. All patients presented with severe ketoacidotic episodes. Age at first symptoms ranged from 36 h to 3 years (median 7 months). About 70% of patients manifested in the first year of life, approximately one quarter already within the neonatal period. Two patients died, while the remainder (95%) were alive at the time of the report. Almost all the surviving patients (92%) showed normal psychomotor development and no neurologic abnormalities. A total of 29 missense mutations are reported. Analysis of the published crystal structure of the human SCOT enzyme, paired with both sequence-based and structure-based methods to predict variant pathogenicity, provides insight into the biochemical consequences of the reported variants. Pathogenic variants cluster in SCOT protein regions that affect certain structures of the protein. The described pathogenic variants can be viewed in an interactive map of the SCOT protein at https://michelanglo.sgc.ox.ac.uk/r/oxct. This comprehensive data analysis provides a systematic overview of all cases of SCOTD published to date. Although SCOTD is a rather benign disorder with often favourable outcome, metabolic crises can be life-threatening or even fatal. As the diagnosis can only be made by enzyme studies or mutation analyses, SCOTD may be underdiagnosed.
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Affiliation(s)
- Sarah C Grünert
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.
| | - William Foster
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Anke Schumann
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Allan Lund
- Department of Paediatrics, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Christina Pontes
- Centre for Paediatrics and Adolescent Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Sylvia Roloff
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Center for Chronically Sick Children, Berlin, Germany
| | - Natalie Weinhold
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Center for Chronically Sick Children, Berlin, Germany
| | - Wyatt W Yue
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ali AlAsmari
- Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Osama A Obaid
- Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Eissa Ali Faqeih
- Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Lisa Stübbe
- MVZ Dr. Eberhard & Partner Dortmund GbR (ÜBAG), Dortmund, Germany
| | - Raina Yamamoto
- MVZ Dr. Eberhard & Partner Dortmund GbR (ÜBAG), Dortmund, Germany
| | - Corinne Gemperle-Britschgi
- University Children's Hospital, Clinical Chemistry & Biochemistry and Children's Research Center, Zürich, Switzerland
| | - Melanie Walter
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Ute Spiekerkoetter
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Sabrina Mackinnon
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.
| | - Jörn Oliver Sass
- Research Group Inborn Errors of Metabolism, Department of Natural Sciences & Institute for Functional Gene Analytics (IFGA), Bonn-Rhein-Sieg University of Applied Sciences, Rheinbach, Germany.
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3
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Sasai H, Aoyama Y, Otsuka H, Abdelkreem E, Naiki Y, Kubota M, Sekine Y, Itoh M, Nakama M, Ohnishi H, Fujiki R, Ohara O, Fukao T. Heterozygous carriers of succinyl-CoA:3-oxoacid CoA transferase deficiency can develop severe ketoacidosis. J Inherit Metab Dis 2017; 40:845-852. [PMID: 28695376 DOI: 10.1007/s10545-017-0065-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 02/05/2023]
Abstract
Succinyl-CoA:3-oxoacid CoA transferase (SCOT, gene symbol OXCT1) deficiency is an autosomal recessive disorder in ketone body utilization that results in severe recurrent ketoacidotic episodes in infancy, including neonatal periods. More than 30 patients with this disorder have been reported and to our knowledge, their heterozygous parents and siblings have had no apparent ketoacidotic episodes. Over 5 years (2008-2012), we investigated several patients that presented with severe ketoacidosis and identified a heterozygous OXCT1 mutation in four of these cases (Case1 p.R281C, Case2 p.T435N, Case3 p.W213*, Case4 c.493delG). To confirm their heterozygous state, we performed a multiplex ligation-dependent probe amplification analysis on the OXCT1 gene which excluded the presence of large deletions or insertions in another allele. A sequencing analysis of subcloned full-length SCOT cDNA showed that wild-type cDNA clones were present at reasonable rates to mutant cDNA clones. Over the following 2 years (2013-2014), we analyzed OXCT1 mutations in six more patients presenting with severe ketoacidosis (blood pH ≦7.25 and total ketone body ≧10 mmol/L) with non-specific urinary organic acid profiles. Of these, a heterozygous OXCT1 mutation was found in two cases (Case5 p.G391D, Case6 p.R281C). Moreover, transient expression analysis revealed R281C and T435N mutants to be temperature-sensitive. This characteristic may be important because most patients developed ketoacidosis during infections. Our data indicate that heterozygous carriers of OXCT1 mutations can develop severe ketoacidotic episodes in conjunction with ketogenic stresses.
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Affiliation(s)
- Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan
| | - Yuka Aoyama
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan
- Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Japan
| | - Hiroki Otsuka
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan
| | - Elsayed Abdelkreem
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan
- Department of Pediatrics, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Yasuhiro Naiki
- Division of Endocrinology and Metabolism, National Center for Child Health and Development, Tokyo, Japan
| | - Mitsuru Kubota
- Department of General Pediatrics and Interdisciplinary Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Yuji Sekine
- Department of General Pediatrics, Shizuoka Children's Hospital, Shizuoka, Japan
| | - Masatsune Itoh
- Department of Pediatrics, Kanazawa Medical University, Kanazawa, Japan
| | - Mina Nakama
- Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan
| | - Hidenori Ohnishi
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan
| | - Ryoji Fujiki
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Osamu Ohara
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu City, Gifu, 501-1194, Japan.
- Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan.
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4
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Zheng DJ, Hooper M, Spencer-Manzon M, Pierce RW. A Case of Succinyl-CoA:3-Oxoacid CoA Transferase Deficiency Presenting with Severe Acidosis in a 14-Month-Old Female: Evidence for Pathogenicity of a Point Mutation in the OXCT1 Gene. J Pediatr Intensive Care 2017; 7:62-66. [PMID: 31073471 DOI: 10.1055/s-0037-1604270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 06/12/2017] [Indexed: 10/19/2022] Open
Abstract
We describe a case of succinyl-CoA:3-oxoacid CoA transferase (SCOT) deficiency in an otherwise healthy 14 month-old female. She presented with lethargy, tachypnea, and hyperpnea with hypoglycemia and a severe anion gap metabolic acidosis. Early management included correction of the acidosis and metabolic support with dextrose and insulin. Inborn errors of metabolism are rare outside the neonatal period. However, SCOT deficiency may present at older ages. Maintaining a high index of suspicion, immediate transfer to a pediatric intensive care unit, and prompt metabolic support are key to achieving a favorable outcome.
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Affiliation(s)
- Daniel J Zheng
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut, United States
| | - Michael Hooper
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut, United States
| | - Michele Spencer-Manzon
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut, United States.,Department of Genetics, Yale School of Medicine, New Haven, Connecticut, United States
| | - Richard W Pierce
- Department of Pediatrics, Yale School of Medicine, New Haven, Connecticut, United States
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5
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Erdol S, Ture M, Yakut T, Saglam H, Sasai H, Abdelkreem E, Otsuka H, Fukao T. A Turkish Patient With Succinyl-CoA:3-Oxoacid CoA Transferase Deficiency Mimicking Diabetic Ketoacidosis. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2016. [DOI: 10.1177/2326409816651281] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Sahin Erdol
- Division of Metabolism, Department of Pediatrics, Uludağ University Faculty of Medicine, Görükle, Bursa, Turkey
| | - Mehmet Ture
- Department of Medical Genetics, Uludağ University, Görükle, Bursa, Turkey
| | - Tahsin Yakut
- Department of Medical Genetics, Uludağ University, Görükle, Bursa, Turkey
| | - Halil Saglam
- Division of Metabolism, Department of Pediatrics, Uludağ University Faculty of Medicine, Görükle, Bursa, Turkey
| | - Hideo Sasai
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Elsayed Abdelkreem
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Hiroki Otsuka
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
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6
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Hori T, Yamaguchi S, Shinkaku H, Horikawa R, Shigematsu Y, Takayanagi M, Fukao T. Inborn errors of ketone body utilization. Pediatr Int 2015; 57:41-8. [PMID: 25559898 DOI: 10.1111/ped.12585] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 12/01/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency and mitochondrial acetoacetyl-CoA thiolase (beta-ketothiolase or T2) deficiency are classified as autosomal recessive disorders of ketone body utilization characterized by intermittent ketoacidosis. Patients with mutations retaining no residual activity on analysis of expression of mutant cDNA are designated as severe genotype, and patients with at least one mutation retaining significant residual activity, as mild genotype. Permanent ketosis is a pathognomonic characteristic of SCOT-deficient patients with severe genotype. Patients with mild genotype, however, may not have permanent ketosis, although they may develop severe ketoacidotic episodes similar to patients with severe genotype. Permanent ketosis has not been reported in T2 deficiency. In T2-deficient patients with severe genotype, biochemical diagnosis is done on urinary organic acid analysis and blood acylcarnitine analysis to observe characteristic findings during both ketoacidosis and non-episodic conditions. In Japan, however, it was found that T2-deficient patients with mild genotype are common, and typical profiles were not identified on these analyses. Based on a clinical study of ketone body utilization disorders both in Japan and worldwide, we have developed guidelines for disease diagnosis and treatment. These diseases are treatable by avoiding fasting and by providing early infusion of glucose, which enable the patients to grow without sequelae.
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Affiliation(s)
- Tomohiro Hori
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Japan
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7
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Fukao T, Mitchell G, Sass JO, Hori T, Orii K, Aoyama Y. Ketone body metabolism and its defects. J Inherit Metab Dis 2014; 37:541-51. [PMID: 24706027 DOI: 10.1007/s10545-014-9704-9] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/01/2014] [Accepted: 03/10/2014] [Indexed: 12/17/2022]
Abstract
Acetoacetate (AcAc) and 3-hydroxybutyrate (3HB), the two main ketone bodies of humans, are important vectors of energy transport from the liver to extrahepatic tissues, especially during fasting, when glucose supply is low. Blood total ketone body (TKB) levels should be evaluated in the context of clinical history, such as fasting time and ketogenic stresses. Blood TKB should also be evaluated in parallel with blood glucose and free fatty acids (FFA). The FFA/TKB ratio is especially useful for evaluation of ketone body metabolism. Defects in ketogenesis include mitochondrial HMG-CoA synthase (mHS) deficiency and HMG-CoA lyase (HL) deficiency. mHS deficiency should be considered in non-ketotic hypoglycemia if a fatty acid beta-oxidation defect is suspected, but cannot be confirmed. Patients with HL deficiency can develop hypoglycemic crises and neurological symptoms even in adolescents and adults. Succinyl-CoA-3-oxoacid CoA transferase (SCOT) deficiency and beta-ketothiolase (T2) deficiency are two defects in ketolysis. Permanent ketosis is pathognomonic for SCOT deficiency. However, patients with "mild" SCOT mutations may have nonketotic periods. T2-deficient patients with "mild" mutations may have normal blood acylcarnitine profiles even in ketoacidotic crises. T2 deficient patients cannot be detected in a reliable manner by newborn screening using acylcarnitines. We review recent data on clinical presentation, metabolite profiles and the course of these diseases in adults, including in pregnancy.
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Affiliation(s)
- Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1194, Japan,
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8
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Shafqat N, Kavanagh KL, Sass JO, Christensen E, Fukao T, Lee WH, Oppermann U, Yue WW. A structural mapping of mutations causing succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency. J Inherit Metab Dis 2013; 36:983-7. [PMID: 23420214 PMCID: PMC3825524 DOI: 10.1007/s10545-013-9589-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 11/08/2022]
Abstract
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency is a rare inherited metabolic disorder of ketone metabolism, characterized by ketoacidotic episodes and often permanent ketosis. To date there are ~20 disease-associated alleles on the OXCT1 gene that encodes the mitochondrial enzyme SCOT. SCOT catalyzes the first, rate-limiting step of ketone body utilization in peripheral tissues, by transferring a CoA moiety from succinyl-CoA to form acetoacetyl-CoA, for entry into the tricarboxylic acid cycle for energy production. We have determined the crystal structure of human SCOT, providing a molecular understanding of the reported mutations based on their potential structural effects. An interactive version of this manuscript (which may contain additional mutations appended after acceptance of this manuscript) may be found on the web address: http://www.thesgc.org/jimd/SCOT .
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Affiliation(s)
- Naeem Shafqat
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ UK
| | - Kate L. Kavanagh
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ UK
| | - Jörn Oliver Sass
- Zentrum für Kinder- und Jugendmedizin, Universitätsklinikum Freiburg, 79106 Freiburg, Germany
- Klinische Chemie & Biochemie, Universitäts-Kinderspital, 8032 Zürich, Switzerland
| | - Ernst Christensen
- Department of Clinical Genetics, Juliane Marie Centre, 2100 Copenhagen, Denmark
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, 501-1194 Japan
- Medical information Sciences Division, United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, 501-1194 Japan
| | - Wen Hwa Lee
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ UK
| | - Udo Oppermann
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ UK
- Botnar Research Centre, Oxford Biomedical Research Unit, OX3 7LD Oxford, UK
| | - Wyatt W. Yue
- Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ UK
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9
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Hori T, Fukao T, Murase K, Sakaguchi N, Harding CO, Kondo N. Molecular basis of two-exon skipping (exons 12 and 13) by c.1248+5g>a in OXCT1 gene: study on intermediates of OXCT1 transcripts in fibroblasts. Hum Mutat 2013; 34:473-80. [PMID: 23281106 DOI: 10.1002/humu.22258] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 11/30/2012] [Indexed: 11/09/2022]
Abstract
The molecular basis of simultaneous two-exon skipping induced by a splice-site mutation has yet to be completely explained. The splice donor site mutation c.1248+5g>a (IVS13) of the OXCT1 gene resulted predominantly in skipping of exons 12 and 13 in fibroblasts from a patient (GS23) with succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency. We compared heteronuclear RNA (hnRNA) intermediates between controls' and GS23's fibroblasts. Our strategy was to use RT-PCR of hnRNA to detect the presence or absence of spliced exon clusters in RNA intermediates (SECRIs) comprising sequential exons. Our initial hypothesis was that a SECRI comprising exons 12 and 13 was formed first followed by skipping of this SECRI in GS23 cells. However, such a pathway was revealed to be not a major one. Hence, we compared the intron removal of SCOT transcript between controls and GS23. In controls, intron 11 was the last intron to be spliced and the removal of intron 12 was also rather slow and occurred after the removal of intron 13 in a major pathway. However, the mutation in GS23 cells resulted in retention of intron 13, thus causing the retention of introns 12 and 11. This "splicing paralysis" may be solved by skipping the whole intron 11-exon 12-intron 12-exon 13-mutated intron 13, resulting in skipping of exons 12 and 13.
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Affiliation(s)
- Tomohiro Hori
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu, Gifu, Japan
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10
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Clinical and molecular characterization of five patients with succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency. Biochim Biophys Acta Mol Basis Dis 2011; 1812:619-24. [PMID: 21296660 DOI: 10.1016/j.bbadis.2011.01.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/26/2011] [Accepted: 01/28/2011] [Indexed: 11/21/2022]
Abstract
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency is an inborn error of ketone body metabolism and causes episodic ketoacidosis. We report clinical and molecular analyses of 5 patients with SCOT deficiency. Patients GS07, GS13, and GS14 are homozygotes of S405P, L327P, and R468C, respectively. GS17 and GS18 are compound heterozygotes for S226N and A215V, and V404F and E273X, respectively. These mutations have not been reported previously. Missense mutations were further characterized by transient expression analysis of mutant cDNAs. Among 6 missense mutations, mutants L327P, R468C, and A215V retained some residual activities and their mutant proteins were detected in immunoblot analysis following expression at 37°C. They were more stable at 30°C than 37°C, indicating their temperature sensitive character. The R468C mutant is a distinct temperature sensitive mutant which retained 12% and 51% of wild-type residual activities at 37 and 30°C, respectively. The S226N mutant protein was detected but retained no residual activity. Effects of missense mutations were predicted from the tertiary structure of the SCOT molecule. Main effects of these mutations were destabilization of SCOT molecules, and some of them also affected catalytic activity. Among 5 patients, GS07 and GS18 had null mutations in both alleles and the other three patients retained some residual SCOT activities. All 5 developed a first severe ketoacidotic crisis with blood gas pH <7.1, and experienced multiple ketoacidotic decompensations (two of them had seven such episodes). In general, the outcome was good even following multiple ketoacidotic events. Permanent ketosis or ketonuria is considered a pathognomonic feature of SCOT deficiency. However, this condition depends not only on residual activity but also on environmental factors.
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