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Gowda VK, Reddy VS, Krishnanada V, Srinivasan VM. Drug Resistant Epilepsy (DRE) Secondary to 3-Hydroxy Acyl-CoA Dehydrogenase Deficiency (HADH) in Siblings. Indian J Pediatr 2024; 91:523. [PMID: 38085414 DOI: 10.1007/s12098-023-04978-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/04/2023] [Indexed: 04/19/2024]
Affiliation(s)
- Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Near NIMHANS, Bengaluru, 560029, Karnataka, India.
| | - Viveka-Santhosh Reddy
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Near NIMHANS, Bengaluru, 560029, Karnataka, India
| | - Vikas Krishnanada
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Near NIMHANS, Bengaluru, 560029, Karnataka, India
| | - Varunvenkat M Srinivasan
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Near NIMHANS, Bengaluru, 560029, Karnataka, India
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De Leon DD, Arnoux JB, Banerjee I, Bergada I, Bhatti T, Conwell LS, Fu J, Flanagan SE, Gillis D, Meissner T, Mohnike K, Pasquini TL, Shah P, Stanley CA, Vella A, Yorifuji T, Thornton PS. International Guidelines for the Diagnosis and Management of Hyperinsulinism. Horm Res Paediatr 2023; 97:279-298. [PMID: 37454648 PMCID: PMC11124746 DOI: 10.1159/000531766] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 05/16/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Hyperinsulinism (HI) due to dysregulation of pancreatic beta-cell insulin secretion is the most common and most severe cause of persistent hypoglycemia in infants and children. In the 65 years since HI in children was first described, there has been a dramatic advancement in the diagnostic tools available, including new genetic techniques and novel radiologic imaging for focal HI; however, there have been almost no new therapeutic modalities since the development of diazoxide. SUMMARY Recent advances in neonatal research and genetics have improved our understanding of the pathophysiology of both transient and persistent forms of neonatal hyperinsulinism. Rapid turnaround of genetic test results combined with advanced radiologic imaging can permit identification and localization of surgically-curable focal lesions in a large proportion of children with congenital forms of HI, but are only available in certain centers in "developed" countries. Diazoxide, the only drug currently approved for treating HI, was recently designated as an "essential medicine" by the World Health Organization but has been approved in only 16% of Latin American countries and remains unavailable in many under-developed areas of the world. Novel treatments for HI are emerging, but they await completion of safety and efficacy trials before being considered for clinical use. KEY MESSAGES This international consensus statement on diagnosis and management of HI was developed in order to assist specialists, general pediatricians, and neonatologists in early recognition and treatment of HI with the ultimate aim of reducing the prevalence of brain injury caused by hypoglycemia. A previous statement on diagnosis and management of HI in Japan was published in 2017. The current document provides an updated guideline for management of infants and children with HI and includes potential accommodations for less-developed regions of the world where resources may be limited.
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Affiliation(s)
- Diva D. De Leon
- Congenital Hyperinsulinism Center and Division of Endocrinology and Diabetes, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Jean Baptiste Arnoux
- Reference Center for Inherited Metabolic Diseases, Necker-Enfants Malades Hospital, AP-HP, University of Paris-Cité, Paris, France
| | - Indraneel Banerjee
- Paediatric Endocrinology, Royal Manchester Children’s Hospital, University of Manchester, Manchester, UK
| | - Ignacio Bergada
- Centro de Investigaciones Endocrinológicas “Dr. César Bergadá” (CONICET – FEI), Division de Endrocrinología, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Tricia Bhatti
- Department of Clinical Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Louise S. Conwell
- Australia and Children’s Health Queensland Clinical Unit, Department of Endocrinology and Diabetes, Queensland Children’s Hospital, Children’s Health Queensland, Greater Brisbane Clinical School, Medical School, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Junfen Fu
- National Clinical Research Center for Child Health, Department of Endocrinology, The Children’s Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Sarah E. Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - David Gillis
- Hadassah Medical Center, Department of Pediatrics, Ein-Kerem, Jerusalem and Faculty of Medicine, Hebrew-University, Jerusalem, Israel
| | - Thomas Meissner
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children’s Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Klaus Mohnike
- Department of General Pediatrics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Tai L.S. Pasquini
- Research and Policy Director, Congenital Hyperinsulinism International, Glen Ridge, NJ, USA
| | - Pratik Shah
- Pediatric Endocrinology, The Royal London Children’s Hospital, Queen Mary University of London, London, UK
| | - Charles A. Stanley
- Congenital Hyperinsulinism Center and Division of Endocrinology and Diabetes, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Adrian Vella
- Division of Diabetes, Endocrinology and Metabolism, Mayo Clinic, Rochester, MN, USA
| | - Tohru Yorifuji
- Pediatric Endocrinology and Metabolism, Children’s Medical Center, Osaka City General Hospital, Osaka, Japan
| | - Paul S. Thornton
- Congenital Hyperinsulinism Center, Cook Children’s Medical Center and Texas Christian University Burnett School of Medicine, Fort Worth, TX, USA
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3
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Praveena R, Balasankar A, Aruchamy K, Oh T, Polisetti V, Ramasundaram S, Anbazhakan K. Structural Activity and HAD Inhibition Efficiency of Pelargonidin and Its Glucoside-A Theoretical Approach. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27228016. [PMID: 36432125 PMCID: PMC9696994 DOI: 10.3390/molecules27228016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022]
Abstract
Anthocyanins are an important pharmaceutical ingredient possessing diet regulatory, antioxidant, anticancer, antidiabetic, anti-obesity, antimicrobial, and anti-inflammatory properties. Pelargonidin is an important anthocyanin-based orange-red flavonoid compound used in drugs for treating hypoglycemia, retinopathy, skeletal myopathy, etc. The main sources of pelargonidin are strawberries and food products with red pigmentation. There is a lack of evidence for supporting its use as an independent supplement. In the present study, pelargonidin and pelargonidin-3-O-glucoside are studied for their structural properties using quantum chemical calculations based on density functional theory. The results confirmed that the parent compound and its glycosylated derivative acted as good electron donors. Electrostatic potential, frontier molecular orbitals, and molecular descriptor analyses also substantiated their electron donating properties. Furthermore, based on the probability, a target prediction was performed for pelargonidin and pelargonidin-3-O-glucoside. Hydroxyacyl-coenzyme A dehydrogenase was chosen as an enzymatic target of interest, since the presence work focuses on glucuronidated compounds and their efficacy over diabetes. Possible interactions between these compounds and a target with nominable binding energies were also evaluated. Further, the structural stability of these two compounds were also analyzed using a molecular dynamics simulation.
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Affiliation(s)
- Rangasamy Praveena
- Department of Chemistry, Bannari Amman Institute of Technology, Sathyamangalam 638401, India
| | | | - Kanakaraj Aruchamy
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Taehwan Oh
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Veerababu Polisetti
- Wallenberg Wood Science Center, Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
- Correspondence: (V.P.); (S.R.); (K.A.)
| | - Subramaniyan Ramasundaram
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
- Correspondence: (V.P.); (S.R.); (K.A.)
| | - Kandasamy Anbazhakan
- Department of Physics, Gobi Arts & Science College, Gobichettipalayam 638453, India
- Correspondence: (V.P.); (S.R.); (K.A.)
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4
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Fang H, Li H, Zhang H, Wang S, Xu S, Chang L, Yang Y, Cui R. Short-chain L-3-hydroxyacyl-CoA dehydrogenase: A novel vital oncogene or tumor suppressor gene in cancers. Front Pharmacol 2022; 13:1019312. [PMID: 36313354 PMCID: PMC9614034 DOI: 10.3389/fphar.2022.1019312] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/23/2022] [Indexed: 08/22/2023] Open
Abstract
The reprogramming of cellular metabolism is frequently linked to tumorigenesis. Glucose, fatty acids, and amino acids are the specific substrates involved in how an organism maintains metabolic equilibrium. The HADH gene codes for the short-chain L-3-hydroxyacyl-CoA dehydrogenase (HADH), a crucial enzyme in fatty acid oxidation that catalyzes the third phase of fatty acid oxidation in mitochondria. Increasing data suggest that HADH is differentially expressed in various types of malignancies and is linked to cancer development and progression. The significance of HADH expression in tumors and its potential mechanisms of action in the onset and progression of certain cancers are summarized in this article. The possible roles of HADH as a target and/or biomarker for the detection and treatment of various malignancies is also described here.
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Affiliation(s)
- He Fang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Hanyang Li
- Department of Thyroid Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Hang Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Shu Wang
- Department of Radiotherapy, The Second Hospital of Jilin University, Changchun, China
| | - Shuang Xu
- Department of Anesthesiology, The Second Hospital of Jilin University, Changchun, China
| | - Li Chang
- Department of Pathology, The Second Hospital of Jilin University, Changchun, China
| | - Yongsheng Yang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Ranji Cui
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
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5
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Functional analysis of HADH c.99C>G shows that the variant causes the proliferation of pancreatic islets and leu-sensitive hyperinsulinaemia. J Genet 2022. [DOI: 10.1007/s12041-022-01381-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Zheng Y, Wang Y, Zheng M, Wang G, Zhao H. Exposed to Sulfamethoxazole induced hepatic lipid metabolism disorder and intestinal microbiota changes on zebrafish (Danio rerio). Comp Biochem Physiol C Toxicol Pharmacol 2022; 253:109245. [PMID: 34801728 DOI: 10.1016/j.cbpc.2021.109245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/07/2021] [Accepted: 11/14/2021] [Indexed: 11/30/2022]
Abstract
Antibiotics are widely used around the world. Pollution of Sulfamethoxazole (SMX) in water poses a great threat to aquatic life. In this study, the toxic effects of SMX on the liver were assessed through RNA sequencing analysis and 16S rRNA sequencing analysis was conducted to determine the influence of SMX on gut microbiota of zebrafish (Danio rerio). Adult male zebrafish were exposed to 0, 5, 90 and 450 μg/L of environmentally relevant concentrations of SMX for 21 days respectively. The results showed that the liver had severe histopathological damages including pyknotic nuclei, cytoplasmic hyalinization and vacuolization and deformed hepatocytes with loose cell-to-cell contact. Transcriptomic analysis revealed that liver function was seriously affected by SMX exposure. Meanwhile, SMX exposure significantly inhibited the expression of genes associated with fatty acid synthesis, oxidation and transport. Besides, exfoliated and dissolved epithelial cells were observed in the gut after SMX treatment. Although there was no significant change on richness and species diversity of intestinal microbial community, the relative abundance of phylum and genus of SMX treatments were significantly different from that of control group. The present study implied that SMX may cause potential health risks to fish through inducing histopathological damages, genetic expression alterations, disorder of fatty acid metabolism and intestinal microbiota dysbiosis.
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Affiliation(s)
- Ying Zheng
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Yufei Wang
- AP Center Changzhou Senior High School of Jiangsu Province, Changzhou, China
| | - Mutang Zheng
- AP Center Changzhou Senior High School of Jiangsu Province, Changzhou, China
| | - Gang Wang
- AP Center Changzhou Senior High School of Jiangsu Province, Changzhou, China
| | - Hongfeng Zhao
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
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7
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Zhang W, Sang YM. Genetic pathogenesis, diagnosis, and treatment of short-chain 3-hydroxyacyl-coenzyme A dehydrogenase hyperinsulinism. Orphanet J Rare Dis 2021; 16:467. [PMID: 34736508 PMCID: PMC8567654 DOI: 10.1186/s13023-021-02088-6] [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: 09/08/2021] [Accepted: 10/17/2021] [Indexed: 11/27/2022] Open
Abstract
Congenital hyperinsulinism (CHI), a major cause of persistent and recurrent hypoglycemia in infancy and childhood. Numerous pathogenic genes have been associated with 14 known genetic subtypes of CHI. Adenosine triphosphate-sensitive potassium channel hyperinsulinism (KATP-HI) is the most common and most severe subtype, accounting for 40–50% of CHI cases. Short-chain 3-hydroxyacyl-coenzyme A dehydrogenase hyperinsulinism (SCHAD-HI) is a rare subtype that accounts for less than 1% of all CHI cases that are caused by homozygous mutations in the hydroxyacyl-coenzyme A dehydrogenase (HADH) gene. This review provided a systematic description of the genetic pathogenesis and current progress in the diagnosis and treatment of SCHAD-HI to improve our understanding of this disease.
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Affiliation(s)
- Wei Zhang
- Medizinische Klinik and Poliklinik IV, Klinikum der Universität München, LMU München, Munich, Germany
| | - Yan-Mei Sang
- Department of Pediatric Endocrinology, Genetic and Metabolism, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
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8
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Xu YW, Lin P, Zheng SF, Huang W, Lin ZY, Shang-Guan HC, Lin YX, Yao PS, Kang DZ. Acetylation Profiles in the Metabolic Process of Glioma-Associated Seizures. Front Neurol 2021; 12:713293. [PMID: 34664012 PMCID: PMC8519730 DOI: 10.3389/fneur.2021.713293] [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: 05/22/2021] [Accepted: 08/13/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: We test the hypothesis that lysine acetylation is involved in the metabolic process of glioma-associated seizures (GAS). Methods: We used label-free mass spectrometry-based quantitative proteomics to quantify dynamic changes of protein acetylation between gliomas with seizure (CA1 group) and gliomas without seizure (CA2 group). Furthermore, differences of acetyltransferase and deacetylase expression between CA1 and CA2 groups were performed by a quantitative proteomic study. We further classified acetylated proteins into groups according to cell component, molecular function, and biological process. In addition, metabolic pathways and protein interaction networks were analyzed. Regulated acetyltransferases and acetylated profiles were validated by PRM and Western blot. Results: We detected 169 downregulated lysine acetylation sites of 134 proteins and 39 upregulated lysine acetylation sites of 35 proteins in glioma with seizures based on acetylome. We detected 407 regulated proteins by proteomics, from which ACAT2 and ACAA2 were the differentially regulated enzymes in the acetylation of GAS. According to the KEGG analysis, the upregulated acetylated proteins within the PPIs were mapped to pathways involved in the TCA cycle, oxidative phosphorylation, biosynthesis of amino acids, and carbon metabolism. The downregulated acetylated proteins within the PPIs were mapped to pathways involved in fatty acid metabolism, oxidative phosphorylation, TCA cycle, and necroptosis. Regulated ACAT2 expression and acetylated profiles were validated by PRM and Western blot. Conclusions: The data support the hypothesis that regulated protein acetylation is involved in the metabolic process of GAS, which may be induced by acetyl-CoA acetyltransferases.
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Affiliation(s)
- Ya-Wen Xu
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Peng Lin
- Department of Pain, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Shu-Fa Zheng
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Wen Huang
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Zhang-Ya Lin
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Huang-Cheng Shang-Guan
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Yuan-Xiang Lin
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Precision Medicine for Cancer, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Pei-Sen Yao
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - De-Zhi Kang
- Department of Neurosurgery, Neurosurgical Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Fujian Key Laboratory of Precision Medicine for Cancer, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China.,Key Laboratory of Radiation Biology of Fujian Higher Education Institutions, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
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9
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Velasco K, St-Louis JL, Hovland HN, Thompson N, Ottesen Å, Choi MH, Pedersen L, Njølstad PR, Arnesen T, Fjeld K, Aukrust I, Myklebust LM, Molven A. Functional evaluation of 16 SCHAD missense variants: Only amino acid substitutions causing congenital hyperinsulinism of infancy lead to loss-of-function phenotypes in vitro. J Inherit Metab Dis 2021; 44:240-252. [PMID: 32876354 DOI: 10.1002/jimd.12309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 08/24/2020] [Accepted: 08/28/2020] [Indexed: 12/26/2022]
Abstract
Short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), encoded by the HADH gene, is a ubiquitously expressed mitochondrial enzyme involved in fatty acid oxidation. This protein also plays a role in insulin secretion as recessive HADH mutations cause congenital hyperinsulinism of infancy (CHI) via loss of an inhibitory interaction with glutamate dehydrogenase (GDH). Here, we present a functional evaluation of 16 SCHAD missense variants identified either in CHI patients or by high-throughput sequencing projects in various populations. To avoid interactions with endogenously produced SCHAD protein, we assessed protein stability, subcellular localization, and GDH interaction in a SCHAD knockout HEK293 cell line constructed by CRISPR-Cas9 methodology. We also established methods for efficient SCHAD expression and purification in E. coli, and tested enzymatic activity of the variants. Our analyses showed that rare variants of unknown significance identified in populations generally had similar properties as normal SCHAD. However, the CHI-associated variants p.Gly34Arg, p.Ile184Phe, p.Pro258Leu, and p.Gly303Ser were unstable with low protein levels detectable when expressed in HEK293 cells. Moreover, CHI variants p.Lys136Glu, p.His170Arg, and p.Met188Val presented normal protein levels but displayed clearly impaired enzymatic activity in vitro, and their interaction with GDH appeared reduced. Our results suggest that pathogenic missense variants of SCHAD either make the protein target of a post-translational quality control system or can impair the function of SCHAD without influencing its steady-state protein level. We did not find any evidence that rare SCHAD missense variants observed only in the general population and not in CHI patients are functionally affected.
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Affiliation(s)
- Kelly Velasco
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Johanna L St-Louis
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Henrikke N Hovland
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Nels Thompson
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Åsta Ottesen
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Man Hung Choi
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Pathology, Haukeland University Hospital, Bergen, Norway
| | - Line Pedersen
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Pål R Njølstad
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Pediatrics and Adolescent Medicine, Haukeland University Hospital, Bergen, Norway
| | - Thomas Arnesen
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Department of Surgery, Haukeland University Hospital, Bergen, Norway
| | - Karianne Fjeld
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Ingvild Aukrust
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Line M Myklebust
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Anders Molven
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Pathology, Haukeland University Hospital, Bergen, Norway
- Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
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10
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Gϋemes M, Rahman SA, Kapoor RR, Flanagan S, Houghton JAL, Misra S, Oliver N, Dattani MT, Shah P. Hyperinsulinemic hypoglycemia in children and adolescents: Recent advances in understanding of pathophysiology and management. Rev Endocr Metab Disord 2020; 21:577-597. [PMID: 32185602 PMCID: PMC7560934 DOI: 10.1007/s11154-020-09548-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hyperinsulinemic hypoglycemia (HH) is characterized by unregulated insulin release, leading to persistently low blood glucose concentrations with lack of alternative fuels, which increases the risk of neurological damage in these patients. It is the most common cause of persistent and recurrent hypoglycemia in the neonatal period. HH may be primary, Congenital HH (CHH), when it is associated with variants in a number of genes implicated in pancreatic development and function. Alterations in fifteen genes have been recognized to date, being some of the most recently identified mutations in genes HK1, PGM1, PMM2, CACNA1D, FOXA2 and EIF2S3. Alternatively, HH can be secondary when associated with syndromes, intra-uterine growth restriction, maternal diabetes, birth asphyxia, following gastrointestinal surgery, amongst other causes. CHH can be histologically characterized into three groups: diffuse, focal or atypical. Diffuse and focal forms can be determined by scanning using fluorine-18 dihydroxyphenylalanine-positron emission tomography. Newer and improved isotopes are currently in development to provide increased diagnostic accuracy in identifying lesions and performing successful surgical resection with the ultimate aim of curing the condition. Rapid diagnostics and innovative methods of management, including a wider range of treatment options, have resulted in a reduction in co-morbidities associated with HH with improved quality of life and long-term outcomes. Potential future developments in the management of this condition as well as pathways to transition of the care of these highly vulnerable children into adulthood will also be discussed.
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Affiliation(s)
- Maria Gϋemes
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, Great Ormond Street, London, WC1N 3JH, UK
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children, London, UK
- Endocrinology Service, Hospital Infantil Universitario Niño Jesús, Madrid, Spain
| | - Sofia Asim Rahman
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, Great Ormond Street, London, WC1N 3JH, UK
| | - Ritika R Kapoor
- Pediatric Diabetes and Endocrinology, King's College Hospital NHS Trust, Denmark Hill, London, UK
| | - Sarah Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
| | - Jayne A L Houghton
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK
- Royal Devon and Exeter Foundation Trust, Exeter, UK
| | - Shivani Misra
- Department of Diabetes, Endocrinology and Metabolic Medicine, Faculty of Medicine, Imperial College Healthcare NHS Trust, London, UK
| | - Nick Oliver
- Department of Diabetes, Endocrinology and Metabolic Medicine, Faculty of Medicine, Imperial College Healthcare NHS Trust, London, UK
| | - Mehul Tulsidas Dattani
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, Great Ormond Street, London, WC1N 3JH, UK
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children, London, UK
| | - Pratik Shah
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, Great Ormond Street, London, WC1N 3JH, UK.
- Department of Pediatric Endocrinology, Great Ormond Street Hospital for Children, London, UK.
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Casertano A, Frisso G, Montefusco G, Mazzaccara C, Villani GR, Mozzillo E, Ruoppolo M, Franzese A. A new case of M/SCHAD deficiency: the contribution of metabolic findings in directing the definitive genetic diagnosis for an optimal management. GAZZETTA MEDICA ITALIANA ARCHIVIO PER LE SCIENZE MEDICHE 2019. [DOI: 10.23736/s0393-3660.18.03884-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Severe clinical manifestation of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase deficiency associated with two novel mutations: a case report. BMC Pediatr 2019; 19:344. [PMID: 31597564 PMCID: PMC6784346 DOI: 10.1186/s12887-019-1747-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/24/2019] [Indexed: 11/29/2022] Open
Abstract
Background Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (mHS) deficiency is an autosomal recessive inborn error of metabolism, which will give rise to failure of ketogenesis in liver during illness or fasting. It is a very rare disease with only a few patients reported worldwide, most of which had a good prognosis after proper therapies. Case presentation We report a 9-month-old boy with mHS deficiency presenting with unusually severe and persistent acidosis after diarrhea and reduced oral food intake. The metabolic acidosis persisted even after supplementation with sugar and alkaline solution. Blood purification and assisted respiration alleviated symptoms, but a second onset induced by respiratory infection several days later led to multiple organ failure and death. Urine organic acid analysis during the acute episode revealed a complex pattern of ketogenic dicarboxylic and 3-hydroxydicarboxylic aciduria with prominent elevation of glutaric acid and adipic acid, which seem to be specific to mHS deficiency. Plasma acylcarnitine analysis revealed elevated 3-hydroxybutyrylcarnitine and acetylcarnitine. This is the first report of elevated 3-hydroxybutyrylcarnitine in mHS deficiency. Whole exome sequencing revealed a novel compound heterozygous mutation in HMGCS2 (c.100C > T and c.1465delA). Conclusion This severe case suggests the need for patients with mHS deficiency to avoid recurrent illness because it can induce severe metabolic crisis, possibly leading to death. Such patients may also require special treatment, such as blood purification. Urine organic acid profile during the acute episode may give a hint to the disease.
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Kostopoulou E, Shah P. Hyperinsulinaemic hypoglycaemia-an overview of a complex clinical condition. Eur J Pediatr 2019; 178:1151-1160. [PMID: 31243576 DOI: 10.1007/s00431-019-03414-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/18/2022]
Abstract
Hyperinsulinaemic hypoglycaemia (HH) is a major cause of hypoglycaemia in the neonatal period, infancy and childhood. It is caused by unsuppressed insulin secretion in the setting of hypoglycaemia and carries a high risk of significant neurological sequelae, such as cognitive impairment. Genetic mutations have been implicated in the pathogenesis of the condition. Other causes include intra-uterine growth retardation, perinatal asphyxia, maternal diabetes mellitus and syndromes, such as Beckwith-Wiedemann. Based on the aetiology, the clinical presentation can range from absence of symptoms to the typical adrenergic symptoms and coma and even death. The diagnosis is based on biochemical findings and the gold-standard imaging technique is 18F-DOPA PET/CT scanning. Treatment options involve medications, such as diazoxide, nifedipine, glucagon and octreotide, as well as surgery. Novel treatment, such as long-acting octreotide, lanreotide and sirolimus, may be used as an alternative to pancreatectomy. Potential future medical treatments include exendin, a GLP-1 receptor antagonist, and glucagon infusion via a pump.Conclusion: Advances in the fields of genetic testing, imaging techniques and medical treatment are beginning to provide novel insights into earlier detection, less invasive treatment approaches and fewer complications associated with the complex entity of hyperinsulinaemic hypoglycaemia. What is Known: • HH is caused by dysregulated insulin release from the β cell due to genetic mutations and carries a risk for complications, such as neurocognitive impairment. 18F-DOPA PET/CT scanning is presented as the gold-standard imaging technique currently in children with hyperinsulinaemic hypoglycaemia. • Clinical presentation is heterogeneous and treatment options include medical therapy and pancreatectomy. What is New: • 18F-DOPA PET/CT is indicated in suspected focal CHI due to paternal transmitted mutations in ABCC8 or KCNJ11. • Novel treatment options have been introduced, such as long-acting octreotide, lanreotide, sirolimus and selective nonpeptide somatostatin receptor subtype 5 (SSTR5) agonists. Future medical treatments include exendin, a GLP-1 antagonist, and glucagon infusion via a pump. However, all these options are off-label at present.
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Affiliation(s)
- Eirini Kostopoulou
- Research Laboratory of the Division of Paediatric Endocrinology and Diabetes, Department of Paediatrics, School of Medicine, University of Patras, 26500, Patras, Greece.
| | - Pratik Shah
- Endocrinology Department, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.,Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
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14
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Galcheva S, Demirbilek H, Al-Khawaga S, Hussain K. The Genetic and Molecular Mechanisms of Congenital Hyperinsulinism. Front Endocrinol (Lausanne) 2019; 10:111. [PMID: 30873120 PMCID: PMC6401612 DOI: 10.3389/fendo.2019.00111] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/06/2019] [Indexed: 12/13/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is a heterogenous and complex disorder in which the unregulated insulin secretion from pancreatic beta-cells leads to hyperinsulinaemic hypoglycaemia. The severity of hypoglycaemia varies depending on the underlying molecular mechanism and genetic defects. The genetic and molecular causes of CHI include defects in pivotal pathways regulating the secretion of insulin from the beta-cell. Broadly these genetic defects leading to unregulated insulin secretion can be grouped into four main categories. The first group consists of defects in the pancreatic KATP channel genes (ABCC8 and KCNJ11). The second and third categories of conditions are enzymatic defects (such as GDH, GCK, HADH) and defects in transcription factors (for example HNF1α, HNF4α) leading to changes in nutrient flux into metabolic pathways which converge on insulin secretion. Lastly, a large number of genetic syndromes are now linked to hyperinsulinaemic hypoglycaemia. As the molecular and genetic basis of CHI has expanded over the last few years, this review aims to provide an up-to-date knowledge on the genetic causes of CHI.
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Affiliation(s)
- Sonya Galcheva
- Department of Paediatrics, University Hospital St. Marina, Varna Medical University, Varna, Bulgaria
| | - Hüseyin Demirbilek
- Department of Paediatric Endocrinology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Sara Al-Khawaga
- Division of Endocrinology, Department of Paediatric Medicine, Sidra Medicine, Doha, Qatar
| | - Khalid Hussain
- Division of Endocrinology, Department of Paediatric Medicine, Sidra Medicine, Doha, Qatar
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15
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Merritt JL, Norris M, Kanungo S. Fatty acid oxidation disorders. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:473. [PMID: 30740404 DOI: 10.21037/atm.2018.10.57] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fatty acid oxidation disorders (FAODs) are inborn errors of metabolism due to disruption of either mitochondrial β-oxidation or the fatty acid transport using the carnitine transport pathway. The presentation of a FAOD will depend upon the specific disorder, but common elements may be seen, and ultimately require a similar treatment. Initial presentations of the FAODs in the neonatal period with severe symptoms include cardiomyopathy, while during infancy and childhood liver dysfunction and hypoketotic hypoglycemia are common. Episodic rhabdomyolysis is frequently the initial presentation during or after adolescence; although, these symptoms may develop at any age for most of the FAODs The treatment of all FAOD's include avoidance of fasting, aggressive treatment during illness, and supplementation of carnitine, if necessary. The long-chain FAODs differ by requiring a fat-restricted diet and supplementation of medium chain triglyceride oil and often docosahexaenoic acid (DHA)-an essential fatty acid, crucial for brain, visual, and immune functions and prevention of fat soluble vitamin deficiencies. The FAOD are a group of autosomal recessive disorders associated with significant morbidity and mortality, but early diagnosis on newborn screening (NBS) and early initiation of treatment are improving outcomes. There is a need for clinical studies including randomized, controlled, therapeutic trials to continue to evaluate current understanding and to implement future therapies.
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Affiliation(s)
- J Lawrence Merritt
- Department of Pediatrics, University of Washington, Seattle, WA, USA.,Biochemial Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | - Marie Norris
- Biochemial Genetics, Seattle Children's Hospital, Seattle, WA, USA
| | - Shibani Kanungo
- Department of Pediatrics and Adolescent Medicine, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
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16
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Wilson DF, Cember ATJ, Matschinsky FM. Glutamate dehydrogenase: role in regulating metabolism and insulin release in pancreatic β-cells. J Appl Physiol (1985) 2018; 125:419-428. [PMID: 29648519 DOI: 10.1152/japplphysiol.01077.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Regulation of insulin release and glucose homeostasis by pancreatic β-cells is dependent on the metabolism of glucose by glucokinase (GK) and the influence of that activity on oxidative phosphorylation. Genetic alterations that result in hyperactivity of mitochondrial glutamate dehydrogenase (GDH-1) can cause hypoglycemia-hyperammonemia following high protein meals, but the role of GDH-1 remains poorly understood. GDH-1 activity is strongly inhibited by GTP, to near zero in the absence of ADP, and cooperatively activated ( n = 2.3) by ADP. The dissociation constant for ADP is near 200 µM in vivo, but leucine and its nonmetabolized analog 2-amino-2-norbornane-carboxylic acid (BCH) can activate GDH-1 by increasing the affinity for ADP. Under physiological conditions, as [ADP] increases GDH-1 activity remains very low until ~35 µM (threshold) and then increases rapidly. A model for GDH-1 and its regulation has been combined with a previously published model for glucose sensing that coupled GK activity and oxidative phosphorylation. The combined model (GK-GDH-core) shows that GK activity determines the energy state ([ATP]/[ADP][Pi]) in β-cells for glucose concentrations > 5 mM ([ADP] < 35 µM). As glucose falls < 5 mM the [ADP]-dependent increase in GDH-1 activity prevents [ADP] from rising above ~70 µM. Thus, GDH-1 dynamically buffers β-cell energy metabolism during hypoglycemia, maintaining the energy state and the basal rate of insulin release. GDH-1 hyperactivity suppresses the normal increase in [ADP] in hypoglycemia. This leads to hypoglycemia following a high protein meal by increasing the basal rate of insulin release (β-cells) and decreasing glucagon release (α-cells). NEW & NOTEWORTHY A model of β-cell metabolism and regulation of insulin release is presented. The model integrates regulation of oxidative phosphorylation, glucokinase (GK), and glutamate dehydrogenase (GDH-1). GDH-1 is near equilibrium under physiological conditions, but the activity is inhibited by GTP. In hypoglycemia, however, GK activity is low and [ADP], a potent activator of GDH-1, increases. Reducing equivalents from GDH dynamically buffers the intramitochondrial [NADH]/[NAD+], and thereby the energy state, preventing hypoglycemia-induced substrate deprivation.
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Affiliation(s)
- David F Wilson
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Abigail T J Cember
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Franz M Matschinsky
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
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17
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Vajravelu ME, Chai J, Krock B, Baker S, Langdon D, Alter C, De León DD. Congenital Hyperinsulinism and Hypopituitarism Attributable to a Mutation in FOXA2. J Clin Endocrinol Metab 2018; 103:1042-1047. [PMID: 29329447 PMCID: PMC6276717 DOI: 10.1210/jc.2017-02157] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/05/2018] [Indexed: 12/14/2022]
Abstract
CONTEXT Persistent hypoglycemia in the newborn period most commonly occurs as a result of hyperinsulinism. The phenotype of hypoketotic hypoglycemia can also result from pituitary hormone deficiencies, including growth hormone and adrenocorticotropic hormone deficiency. Forkhead box A2 (Foxa2) is a transcription factor shown in mouse models to influence insulin secretion by pancreatic β cells. In addition, Foxa2 is involved in regulation of pituitary development, and deletions of FOXA2 have been linked to panhypopituitarism. OBJECTIVE To describe an infant with congenital hyperinsulinism and hypopituitarism as a result of a mutation in FOXA2 and to determine the functional impact of the identified mutation. MAIN OUTCOME MEASURE Difference in wild-type (WT) vs mutant Foxa2 transactivation of target genes that are critical for β cell function (ABCC8, KNCJ11, HADH) and pituitary development (GLI2, NKX2-2, SHH). RESULTS Transactivation by mutant Foxa2 of all genes studied was substantially decreased compared with WT. CONCLUSIONS We report a mutation in FOXA2 leading to congenital hyperinsulinism and hypopituitarism and provide functional evidence of the molecular mechanism responsible for this phenotype.
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Affiliation(s)
- Mary Ellen Vajravelu
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
| | - Jinghua Chai
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
| | - Bryan Krock
- Division of Genomic Diagnostics, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
| | - Samuel Baker
- Division of Genomic Diagnostics, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
| | - David Langdon
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
- Department of Pediatrics, Children’s Hospital of Philadelphia and Perelman
School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Craig Alter
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
- Department of Pediatrics, Children’s Hospital of Philadelphia and Perelman
School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Diva D De León
- Division of Endocrinology and Diabetes, Children’s Hospital of Philadelphia,
Philadelphia, Pennsylvania
- Department of Pediatrics, Children’s Hospital of Philadelphia and Perelman
School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
- Correspondence and Reprint Requests: Diva D. De León, MD, Division of Endocrinology and Diabetes, Children’s Hospital
of Philadelphia, 3615 Civic Center Boulevard, Ambramson Research Center, Room 802A,
Philadelphia, Pennsylvania 19104. E-mail:
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18
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Lu M, Li C. Nutrient sensing in pancreatic islets: lessons from congenital hyperinsulinism and monogenic diabetes. Ann N Y Acad Sci 2017; 1411:65-82. [PMID: 29044608 DOI: 10.1111/nyas.13448] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/05/2017] [Accepted: 07/14/2017] [Indexed: 12/14/2022]
Abstract
Pancreatic beta cells sense changes in nutrients during the cycles of fasting and feeding and release insulin accordingly to maintain glucose homeostasis. Abnormal beta cell nutrient sensing resulting from gene mutations leads to hypoglycemia or diabetes. Glucokinase (GCK) plays a key role in beta cell glucose sensing. As one form of congenital hyperinsulinism (CHI), activating mutations of GCK result in a decreased threshold for glucose-stimulated insulin secretion and hypoglycemia. In contrast, inactivating mutations of GCK result in diabetes, including a mild form (MODY2) and a severe form (permanent neonatal diabetes mellitus (PNDM)). Mutations of beta cell ion channels involved in insulin secretion regulation also alter glucose sensing. Activating or inactivating mutations of ATP-dependent potassium (KATP ) channel genes result in severe but completely opposite clinical phenotypes, including PNDM and CHI. Mutations of the other ion channels, including voltage-gated potassium channels (Kv 7.1) and voltage-gated calcium channels, also lead to abnormal glucose sensing and CHI. Furthermore, amino acids can stimulate insulin secretion in a glucose-independent manner in some forms of CHI, including activating mutations of the glutamate dehydrogenase gene, HDAH deficiency, and inactivating mutations of KATP channel genes. These genetic defects have provided insight into a better understanding of the complicated nature of beta cell fuel-sensing mechanisms.
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Affiliation(s)
- Ming Lu
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics & Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
| | - Changhong Li
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics & Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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19
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Multiple Forms of Glutamate Dehydrogenase in Animals: Structural Determinants and Physiological Implications. BIOLOGY 2016; 5:biology5040053. [PMID: 27983623 PMCID: PMC5192433 DOI: 10.3390/biology5040053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 11/26/2016] [Accepted: 12/07/2016] [Indexed: 11/17/2022]
Abstract
Glutamate dehydrogenase (GDH) of animal cells is usually considered to be a mitochondrial enzyme. However, this enzyme has recently been reported to be also present in nucleus, endoplasmic reticulum and lysosomes. These extramitochondrial localizations are associated with moonlighting functions of GDH, which include acting as a serine protease or an ATP-dependent tubulin-binding protein. Here, we review the published data on kinetics and localization of multiple forms of animal GDH taking into account the splice variants, post-translational modifications and GDH isoenzymes, found in humans and apes. The kinetic properties of human GLUD1 and GLUD2 isoenzymes are shown to be similar to those published for GDH1 and GDH2 from bovine brain. Increased functional diversity and specific regulation of GDH isoforms due to alternative splicing and post-translational modifications are also considered. In particular, these structural differences may affect the well-known regulation of GDH by nucleotides which is related to recent identification of thiamine derivatives as novel GDH modulators. The thiamine-dependent regulation of GDH is in good agreement with the fact that the non-coenzyme forms of thiamine, i.e., thiamine triphosphate and its adenylated form are generated in response to amino acid and carbon starvation.
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20
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Babiker O, Flanagan SE, Ellard S, Al Girim H, Hussain K, Senniappan S. Protein-induced hyperinsulinaemic hypoglycaemia due to a homozygous HADH mutation in three siblings of a Saudi family. J Pediatr Endocrinol Metab 2015; 28:1073-7. [PMID: 25915078 DOI: 10.1515/jpem-2015-0033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/30/2015] [Indexed: 11/15/2022]
Abstract
Hyperinsulinaemic hypoglycaemia (HH) is caused by mutations in the key genes involved in regulation of insulin secretion from the pancreatic β-cells and mutations in ABCC8 and KCNJ11 are the most common causes of HH. Mutations in HADH (which encodes the enzyme 3-hydroxyacyl-CoA dehydrogenase) are a rare cause of HH. We report three siblings (21, 9, and 7 years old) from a consanguineous Saudi family with HH due to a homozygous mutation in HADH. All three siblings presented with HH in the 1st year of life. HH responded well to medical therapy (diazoxide/octreotide) although the 1st sibling suffered neurological damage. The protein load test revealed protein sensitivity in the 21-year-old proband, the oldest reported patient with HH secondary to a HADH mutation. Genetic analysis revealed a homozygous HADH splicing mutation (c.133-1G>A) in all three siblings. HADH mutations can present in later infancy or childhood with severe HH that is usually diazoxide responsive. Severe neurological complications such as epilepsy and developmental delay can be associated with HADH mutations. This is the 1st report of HH due to HADH mutation in an adult suggesting that HH could persist into adulthood possibly becoming milder over the years.
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21
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Senniappan S, Sadeghizadeh A, Flanagan SE, Ellard S, Hashemipour M, Hosseinzadeh M, Salehi M, Hussain K. Genotype and phenotype correlations in Iranian patients with hyperinsulinaemic hypoglycaemia. BMC Res Notes 2015; 8:350. [PMID: 26268944 PMCID: PMC4535259 DOI: 10.1186/s13104-015-1319-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 08/04/2015] [Indexed: 01/19/2023] Open
Abstract
Background Hyperinsulinaemic hypoglycaemia (HH) is a group of clinically and genetically heterogeneous disorders characterized by unregulated insulin secretion. Abnormalities in nine different genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A, UCP2 and HNF1A) have been reported in HH, the most common being ABCC8 and KCNJ11. We describe the genetic aetiology and phenotype of Iranian patients with HH. Methods Retrospective clinical, biochemical and genetic information was collected on 23 patients with biochemically confirmed HH. Mutation analysis was carried out for the ATP-sensitive potassium (KATP) channel genes (ABCC8 and KCNJ11), GLUD1, GCK, HADH and HNF4A. Results 78 % of the patients were identified to have a genetic cause for HH. 48 % of patients had mutation in HADH, whilst ABCC8/KCNJ11 mutations were identified in 30 % of patients. Among the diazoxide-responsive patients (18/23), mutations were identified in 72 %. These include two novel homozygous ABCC8 mutations. Of the five patients with diazoxide-unresponsive HH, three had homozygous ABCC8 mutation, one had heterozygous ABCC8 mutation inherited from an unaffected father and one had homozygous KCNJ11 mutation. 52 % of children in our cohort were born to consanguineous parents. Patients with ABCC8/KCNJ11 mutations were noted to be significantly heavier than those with HADH mutation (p = 0.002). Our results revealed neurodevelopmental deficits in 30 % and epilepsy in 52 % of all patients. Conclusions To the best of our knowledge, this is the first study of its kind in Iran. We found disease-causing mutations in 78 % of HH patients. The predominance of HADH mutation might be due to a high incidence of consanguineous marriage in this population. Further research involving a larger cohort of HH patients is required in Iranian population.
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Affiliation(s)
| | - Atefeh Sadeghizadeh
- Department of Pediatrics, Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Sarah E Flanagan
- Institute Biomedical and Clinical Science, University of Exeter Medical School, Exeter, EX2 5DW, UK.
| | - Sian Ellard
- Institute Biomedical and Clinical Science, University of Exeter Medical School, Exeter, EX2 5DW, UK.
| | - Mahin Hashemipour
- Endocrinology and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Majid Hosseinzadeh
- Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Mansour Salehi
- Pediatric Inherited Disease Research Center (PIDRC), Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Khalid Hussain
- Developmental Endocrinology Research Group, Clinical and Molecular Genetics Unit, Institute of Child Health, University College London, London, UK. .,Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children, London, UK.
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22
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Abstract
In hyperinsulinemic hypoglycemia (HH) there is dysregulation of insulin secretion from pancreatic β-cells. Insulin secretion becomes inappropriate for the level of blood glucose leading to severe hypoglycemia. HH is associated with a high risk of brain injury because insulin inhibits lipolysis and ketogenesis thus preventing the generation of alternative brain substrates (such as ketone bodies). Hence HH must be diagnosed as soon as possible and the management instituted appropriately to prevent brain damage. This article reviews the mechanisms of glucose physiology in the newborn, the mechanisms of insulin secretion, the etiologic types of HH, and its management.
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Affiliation(s)
- Maria Güemes
- Developmental Endocrinology Research Group, Molecular Genetics Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - Khalid Hussain
- Developmental Endocrinology Research Group, Molecular Genetics Unit, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
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23
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Çamtosun E, Flanagan SE, Ellard S, Şıklar Z, Hussain K, Kocaay P, Berberoğlu M. A Deep Intronic HADH Splicing Mutation (c.636+471G>T) in a Congenital Hyperinsulinemic Hypoglycemia Case: Long Term Clinical Course. J Clin Res Pediatr Endocrinol 2015; 7:144-7. [PMID: 26316438 PMCID: PMC4563187 DOI: 10.4274/jcrpe.1963] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Unlike other congenital fatty acid oxidation defects, short-chain L-3-hydroxyacyl-CoA (SCHAD, HADH) deficiency is characterised by hypoglycemia with hyperinsulinism in the neonatal or infancy periods. The long-term and detailed clinical progression of the disease is largely unknown with almost 40 patients reported and only a few patients described clinically. We present clinical and laboratory findings together with the long-term clinical course of a case with a deep intronic HADH splicing mutation (c.636+471G>T) causing neonatal-onset hyperinsulinemic hypoglycemia with mild progression.
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Affiliation(s)
- Emine Çamtosun
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Sarah E. Flanagan
- Exeter University Faculty of Medicine, Institute of Biomedical and Clinical Science, Exeter, UK
| | - Sian Ellard
- Exeter University Faculty of Medicine, Institute of Biomedical and Clinical Science, Exeter, UK
| | - Zeynep Şıklar
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey Phone: +90 312 595 66 35 E-mail:
| | - Khalid Hussain
- UCL Institute of Child Health, Genetics and Epigenetics in Health and Disease Genetics and Genomic Medicine Programme, London, UK
,
Great Ormond Street Hospital for Children, Clinic of Pediatric Endocrinology, London, UK
| | - Pınar Kocaay
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Merih Berberoğlu
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
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24
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Wang Z, Zhang Y, Shi R, Zhou Z, Wang F, Strappe P. A novel gene network analysis in liver tissues of diabetic rats in response to resistant starch treatment. SPRINGERPLUS 2015; 4:110. [PMID: 25789210 PMCID: PMC4356702 DOI: 10.1186/s40064-015-0873-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/04/2015] [Indexed: 01/03/2023]
Abstract
In this study, we investigated the genome-wide gene expression profiles in the liver tissue of diabetic rats before and after RS treatment. The microarray-based analysis revealed that a total of 173 genes were up-regulated and 197 genes were down-regulated in response to RS treatment. These genes were mainly related to glucose metabolism (e.g., hexokinase, pyruvate kinase and phosphotransferase etc.), and lipid metabolism (e.g., carnitine palmitoyl transfer 1, fatty acid transporter, beta hydroxyl butyric dehydrogenase etc.). Cluster analysis results showed that the up/down-regulated genes were highly responsive to RS treatment, and were considered to be directly or indirectly associated with reducing plasma glucose and body fat. To interpret the mechanism of RS regulation at the molecular level, a novel gene network was constructed based on 370 up/down-regulated genes coupled with 718 known diabetes-related genes. The topology of the network showed the characteristics of small-world and scale-free network, with some pathways demonstrating a high degree. Forkhead class A signaling pathway, with a degree of 8, was analyzed and was found to have an effect mainly on glucose and lipid metabolism processes. The results indicate that RS can suppress the development of type 2 diabetes in the STZ rat model through modulating the expression of multiple genes involved in glucose and lipid metabolism. The potential application of this novel gene network is also discussed.
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Affiliation(s)
- Zhiwei Wang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457 China ; School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Yinghui Zhang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457 China ; School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Runge Shi
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457 China ; School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Zhongkai Zhou
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457 China ; School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Fang Wang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457 China ; School of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Padraig Strappe
- School of Biomedical Sciences, Charles Sturt University, WaggaWagga, NSW 2678 Australia
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Kao YT, Chang BL, Liang JJ, Tsai HJ, Lee YL, Lin RJ, Lin YL. Japanese encephalitis virus nonstructural protein NS5 interacts with mitochondrial trifunctional protein and impairs fatty acid β-oxidation. PLoS Pathog 2015; 11:e1004750. [PMID: 25816318 PMCID: PMC4376648 DOI: 10.1371/journal.ppat.1004750] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/17/2015] [Indexed: 01/16/2023] Open
Abstract
Infection with Japanese encephalitis virus (JEV) can induce the expression of pro-inflammatory cytokines and cause acute encephalitis in humans. β-oxidation breaks down fatty acids for ATP production in mitochondria, and impaired β-oxidation can induce pro-inflammatory cytokine expression. To address the role of fatty-acid β-oxidation in JEV infection, we measured the oxygen consumption rate of mock- and JEV-infected cells cultured with or without long chain fatty acid (LCFA) palmitate. Cells with JEV infection showed impaired LCFA β-oxidation and increased interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) expression. JEV nonstructural protein 5 (NS5) interacted with hydroxyacyl-CoA dehydrogenase α and β subunits, two components of the mitochondrial trifunctional protein (MTP) involved in LCFA β-oxidation, and NS5 proteins were detected in mitochondria and co-localized with MTP. LCFA β-oxidation was impaired and higher cytokines were induced in cells overexpressing NS5 protein as compared with control cells. Deletion and mutation studies showed that the N-terminus of NS5 was involved in the MTP association, and a single point mutation of NS5 residue 19 from methionine to alanine (NS5-M19A) reduced its binding ability with MTP. The recombinant JEV with NS5-M19A mutation (JEV-NS5-M19A) was less able to block LCFA β-oxidation and induced lower levels of IL-6 and TNF-α than wild-type JEV. Moreover, mice challenged with JEV-NS5-M19A showed less neurovirulence and neuroinvasiveness. We identified a novel function of JEV NS5 in viral pathogenesis by impairing LCFA β-oxidation and inducing cytokine expression by association with MTP.
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Affiliation(s)
- Yu-Ting Kao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Bi-Lan Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jian-Jong Liang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hang-Jen Tsai
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Ling Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ren-Jye Lin
- Department of General Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Primary Care Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yi-Ling Lin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
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26
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Kalaivanan P, Arya VB, Shah P, Datta V, Flanagan SE, Mackay DJG, Ellard S, Senniappan S, Hussain K. Chromosome 6q24 transient neonatal diabetes mellitus and protein sensitive hyperinsulinaemic hypoglycaemia. J Pediatr Endocrinol Metab 2014; 27:1065-9. [PMID: 24859512 DOI: 10.1515/jpem-2014-0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/23/2014] [Indexed: 11/15/2022]
Abstract
AIM We describe the novel clinical observation of protein induced hyperinsulinaemic hypoglycaemia following remission of transient neonatal diabetes mellitus (TNDM) in a patient with 6q24 methylation defect. METHODS A male infant of non-consanguineous Caucasian parents, born at 40 weeks of gestation with a birth weight of 3330 g (-0.55 standard deviation score) presented with hyperglycaemia in the first week of life and was diagnosed with 6q24 TNDM. At 22 months of age, he developed recurrent hypoglycaemic episodes. Controlled diagnostic fast, oral glucose tolerance test, protein loading test and mixed meal tolerance test were undertaken. Sequencing of ABCC8, KCNJ11, GLUD1 and HADH were performed. RESULTS Investigations suggested a diagnosis of protein sensitive hyperinsulinaemic hypoglycaemia with normal serum ammonia, acylcarnitine profile and urine organic acids. Sequencing of ABCC8, KCNJ11, GLUD1 and HADH did not identify a pathogenic mutation to explain his hyperinsulinaemic hypoglycaemia. CONCLUSION This clinical case demonstrates the novel observation of protein sensitive hyperinsulinaemic hypoglycaemia in a patient with 6q24 TNDM. Long-term follow-up of patients with chromosome 6q24 TNDM is warranted following remission.
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MESH Headings
- Chromosomes, Human, Pair 6/genetics
- DNA Methylation
- Diabetes Mellitus/genetics
- Diabetes Mellitus/metabolism
- Diabetes Mellitus/pathology
- Glucose Tolerance Test
- Humans
- Hyperinsulinism/complications
- Hyperinsulinism/genetics
- Hyperinsulinism/metabolism
- Hypoglycemia/complications
- Hypoglycemia/genetics
- Hypoglycemia/metabolism
- Infant, Newborn
- Infant, Newborn, Diseases/genetics
- Infant, Newborn, Diseases/metabolism
- Infant, Newborn, Diseases/pathology
- Male
- Mutation/genetics
- Potassium Channels, Inwardly Rectifying/genetics
- Prognosis
- Proteins/chemistry
- Sulfonylurea Receptors/genetics
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27
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Demirbilek H, Arya VB, Ozbek MN, Akinci A, Dogan M, Demirel F, Houghton J, Kaba S, Guzel F, Baran RT, Unal S, Tekkes S, Flanagan SE, Ellard S, Hussain K. Clinical characteristics and phenotype-genotype analysis in Turkish patients with congenital hyperinsulinism; predominance of recessive KATP channel mutations. Eur J Endocrinol 2014; 170:885-92. [PMID: 24686051 DOI: 10.1530/eje-14-0045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Congenital hyperinsulinism (CHI) is the commonest cause of hyperinsulinaemic hypoglycaemia in the neonatal, infancy and childhood periods. Its clinical presentation, histology and underlying molecular biology are extremely heterogeneous. The aim of this study was to describe the clinical characteristics, analyse the genotype-phenotype correlations and describe the treatment outcome of Turkish CHI patients. DESIGN AND METHODS A total of 35 patients with CHI were retrospectively recruited from four large paediatric endocrine centres in Turkey. Detailed clinical, biochemical and genotype information was collected. RESULTS Diazoxide unresponsiveness was observed in nearly half of the patients (n=17; 48.5%). Among diazoxide-unresponsive patients, mutations in ABCC8/KCNJ11 were identified in 16 (94%) patients. Among diazoxide-responsive patients (n=18), mutations were identified in two patients (11%). Genotype-phenotype correlation revealed that mutations in ABCC8/KCNJ11 were associated with an increased birth weight and early age of presentation. Five patients had p.L1171fs (c.3512del) ABCC8 mutations, suggestive of a founder effect. The rate of detection of a pathogenic mutation was higher in consanguineous families compared with non-consanguineous families (87.5 vs 21%; P<0.0001).Among the diazoxide-unresponsive group, ten patients were medically managed with octreotide therapy and carbohydrate-rich feeds and six patients underwent subtotal pancreatectomy. There was a high incidence of developmental delay and cerebral palsy among diazoxide-unresponsive patients. CONCLUSIONS This is the largest study to report genotype-phenotype correlations among Turkish patients with CHI. Mutations in ABCC8 and KCNJ11 are the commonest causes of CHI in Turkish patients (48.6%). There is a higher likelihood of genetic diagnosis in patients with early age of presentation, higher birth weight and from consanguineous pedigrees.
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Affiliation(s)
- Huseyin Demirbilek
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, TurkeyDepartments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, TurkeyDepartments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Trainin
| | - Ved Bhushan Arya
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, TurkeyDepartments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Mehmet Nuri Ozbek
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Aysehan Akinci
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Murat Dogan
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Fatma Demirel
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Jayne Houghton
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Sultan Kaba
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Fatma Guzel
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Riza Taner Baran
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Sevim Unal
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Selahattin Tekkes
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Sarah E Flanagan
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Sian Ellard
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
| | - Khalid Hussain
- Departments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, TurkeyDepartments of NeonatologyPaediatric EndocrinologyGreat Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UKDevelopmental Endocrinology Research GroupMolecular Genetics Unit, The Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UKDepartments of Paediatric EndocrinologyAnkara Children's Hematology and Oncology Training Hospital, Ankara, TurkeyDepartments of Paediatric EndocrinologyChildren State Hospital, Diyarbakır, TurkeyDepartments of Paediatric EndocrinologyInönü University, Malatya, TurkeyDepartments of Paediatric EndocrinologyYüzüncü Yıl University, Van, TurkeyInstitute of Biomedical and Clinical ScienceUniversity of Exeter Medical School, Exeter EX2 5DW, UKDepartment of Medical Biology and GeneticsDicle University, Diyarbakır, Turkey
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28
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Abstract
Hypoglycemia in the pediatric population is a common finding important to recognize and manage to prevent brain injury. Recent advances in molecular genetics have provided new insight into its biochemical and physiologic basis and have led to more appropriate and specific treatment. Although a major cause of brain injury in pediatrics, the ability to predict the long-term outcome in these patients remains difficult. Identification of these at-risk individuals is important. The physiologic adaptations associated with transition from fetal to neonatal life are now better understood thus allowing for improved surveillance and management. Despite these advances, analytical limitations of point-of-care testing instruments at low glucose concentration continue to persist, This review aims to address these questions and provide an overview of pediatric hypoglycemia and the molecular pathways involved.
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29
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Xu Y, Li H, Jin YH, Fan J, Sun F. Dimerization interface of 3-hydroxyacyl-CoA dehydrogenase tunes the formation of its catalytic intermediate. PLoS One 2014; 9:e95965. [PMID: 24763278 PMCID: PMC3999109 DOI: 10.1371/journal.pone.0095965] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/02/2014] [Indexed: 12/13/2022] Open
Abstract
3-hydroxyacyl-CoA dehydrogenase (HAD, EC 1.1.1.35) is a homodimeric enzyme localized in the mitochondrial matrix, which catalyzes the third step in fatty acid β-oxidation. The crystal structures of human HAD and subsequent complexes with cofactor/substrate enabled better understanding of HAD catalytic mechanism. However, numerous human diseases were found related to mutations at HAD dimerization interface that is away from the catalytic pocket. The role of HAD dimerization in its catalytic activity needs to be elucidated. Here, we solved the crystal structure of Caenorhabditis elegans HAD (cHAD) that is highly conserved to human HAD. Even though the cHAD mutants (R204A, Y209A and R204A/Y209A) with attenuated interactions on the dimerization interface still maintain a dimerization form, their enzymatic activities significantly decrease compared to that of the wild type. Such reduced activities are in consistency with the reduced ratios of the catalytic intermediate formation. Further molecular dynamics simulations results reveal that the alteration of the dimerization interface will increase the fluctuation of a distal region (a.a. 60–80) that plays an important role in the substrate binding. The increased fluctuation decreases the stability of the catalytic intermediate formation, and therefore the enzymatic activity is attenuated. Our study reveals the molecular mechanism about the essential role of the HAD dimerization interface in its catalytic activity via allosteric effects.
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Affiliation(s)
- Yingzhi Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - He Li
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, Jilin University, Changchun, China
| | - Ying-Hua Jin
- Key Laboratory for Molecular Enzymology & Engineering of the Ministry of Education, Jilin University, Changchun, China
| | - Jun Fan
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, China
- * E-mail: (FS); (JF)
| | - Fei Sun
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- * E-mail: (FS); (JF)
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30
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Li M, Li C, Allen A, Stanley CA, Smith TJ. Glutamate dehydrogenase: structure, allosteric regulation, and role in insulin homeostasis. Neurochem Res 2013; 39:433-45. [PMID: 24122080 DOI: 10.1007/s11064-013-1173-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/26/2013] [Accepted: 10/03/2013] [Indexed: 02/02/2023]
Abstract
Glutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of L-glutamate to 2-oxoglutarate. Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine and inhibitors include GTP, palmitoyl CoA, and ATP. Spontaneous mutations in the GTP inhibitory site that lead to the hyperinsulinism/hyperammonemia (HHS) syndrome have shed light as to why mammalian GDH is so tightly regulated. Patients with HHS exhibit hypersecretion of insulin upon consumption of protein and concomitantly extremely high levels of ammonium in the serum. The atomic structures of four new inhibitors complexed with GDH complexes have identified three different allosteric binding sites. Using a transgenic mouse model expressing the human HHS form of GDH, at least three of these compounds blocked the dysregulated form of GDH in pancreatic tissue. EGCG from green tea prevented the hyper-response to amino acids in whole animals and improved basal serum glucose levels. The atomic structure of the ECG-GDH complex and mutagenesis studies is directing structure-based drug design using these polyphenols as a base scaffold. In addition, all of these allosteric inhibitors are elucidating the atomic mechanisms of allostery in this complex enzyme.
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Affiliation(s)
- Ming Li
- Donald Danforth Plant Science Center, 975 North Warson Road, Saint Louis, MO, 63132, USA
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31
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Kapoor RR, Flanagan SE, Arya VB, Shield JP, Ellard S, Hussain K. Clinical and molecular characterisation of 300 patients with congenital hyperinsulinism. Eur J Endocrinol 2013; 168:557-64. [PMID: 23345197 PMCID: PMC3599069 DOI: 10.1530/eje-12-0673] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Congenital hyperinsulinism (CHI) is a clinically heterogeneous condition. Mutations in eight genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A and HNF1A) are known to cause CHI. AIM To characterise the clinical and molecular aspects of a large cohort of patients with CHI. METHODOLOGY Three hundred patients were recruited and clinical information was collected before genotyping. ABCC8 and KCNJ11 genes were analysed in all patients. Mutations in GLUD1, HADH, GCK and HNF4A genes were sought in patients with diazoxide-responsive CHI with hyperammonaemia (GLUD1), raised 3-hydroxybutyrylcarnitine and/or consanguinity (HADH), positive family history (GCK) or when CHI was diagnosed within the first week of life (HNF4A). RESULTS Mutations were identified in 136/300 patients (45.3%). Mutations in ABCC8/KCNJ11 were the commonest genetic cause identified (n=109, 36.3%). Among diazoxide-unresponsive patients (n=105), mutations in ABCC8/KCNJ11 were identified in 92 (87.6%) patients, of whom 63 patients had recessively inherited mutations while four patients had dominantly inherited mutations. A paternal mutation in the ABCC8/KCNJ11 genes was identified in 23 diazoxide-unresponsive patients, of whom six had diffuse disease. Among the diazoxide-responsive patients (n=183), mutations were identified in 41 patients (22.4%). These include mutations in ABCC8/KCNJ11 (n=15), HNF4A (n=7), GLUD1 (n=16) and HADH (n=3). CONCLUSIONS A genetic diagnosis was made for 45.3% of patients in this large series. Mutations in the ABCC8 gene were the commonest identifiable cause. The vast majority of patients with diazoxide-responsive CHI (77.6%) had no identifiable mutations, suggesting other genetic and/or environmental mechanisms.
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Affiliation(s)
| | - Sarah E Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical SchoolExeter, EX2 5DWUK
| | | | - Julian P Shield
- Department of Child Health, Bristol Royal Hospital for ChildrenBristol, BS2 8BJUK
| | - Sian Ellard
- Institute of Biomedical and Clinical Science, University of Exeter Medical SchoolExeter, EX2 5DWUK
| | - Khalid Hussain
- (Correspondence should be addressed to K Hussain who is now at Molecular Genetics Unit, Developmental Endocrinology Research Group, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK; )
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Flanagan S, Xie W, Caswell R, Damhuis A, Vianey-Saban C, Akcay T, Darendeliler F, Bas F, Guven A, Siklar Z, Ocal G, Berberoglu M, Murphy N, O’Sullivan M, Green A, Clayton P, Banerjee I, Clayton P, Hussain K, Weedon M, Ellard S. Next-generation sequencing reveals deep intronic cryptic ABCC8 and HADH splicing founder mutations causing hyperinsulinism by pseudoexon activation. Am J Hum Genet 2013; 92:131-6. [PMID: 23273570 PMCID: PMC3542457 DOI: 10.1016/j.ajhg.2012.11.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/30/2012] [Accepted: 11/20/2012] [Indexed: 02/01/2023] Open
Abstract
Next-generation sequencing (NGS) enables analysis of the human genome on a scale previously unachievable by Sanger sequencing. Exome sequencing of the coding regions and conserved splice sites has been very successful in the identification of disease-causing mutations, and targeting of these regions has extended clinical diagnostic testing from analysis of fewer than ten genes per phenotype to more than 100. Noncoding mutations have been less extensively studied despite evidence from mRNA analysis for the existence of deep intronic mutations in >20 genes. We investigated individuals with hyperinsulinaemic hypoglycaemia and biochemical or genetic evidence to suggest noncoding mutations by using NGS to analyze the entire genomic regions of ABCC8 (117 kb) and HADH (94 kb) from overlapping ~10 kb PCR amplicons. Two deep intronic mutations, c.1333-1013A>G in ABCC8 and c.636+471G>T HADH, were identified. Both are predicted to create a cryptic splice donor site and an out-of-frame pseudoexon. Sequence analysis of mRNA from affected individuals' fibroblasts or lymphoblastoid cells confirmed mutant transcripts with pseudoexon inclusion and premature termination codons. Testing of additional individuals showed that these are founder mutations in the Irish and Turkish populations, accounting for 14% of focal hyperinsulinism cases and 32% of subjects with HADH mutations in our cohort. The identification of deep intronic mutations has previously focused on the detection of aberrant mRNA transcripts in a subset of disorders for which RNA is readily obtained from the target tissue or ectopically expressed at sufficient levels. Our approach of using NGS to analyze the entire genomic DNA sequence is applicable to any disease.
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Affiliation(s)
- Sarah E. Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| | - Weijia Xie
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| | - Richard Caswell
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| | - Annet Damhuis
- Department of Molecular Genetics, Royal Devon and Exeter National Health Service Foundation Trust, Exeter EX2 5AD, UK
| | - Christine Vianey-Saban
- Service Maladies Héréditaires du Métabolisme et Dépistage Néonatal, Centre de Biologie et de Pathologie Est, Centre Hospitalier Universitaire, Lyon 69677, France
| | - Teoman Akcay
- Department of Pediatric Endocrinology, Sisli Etfal Educational and Research Hospital, Sisli, Istanbul 34377, Turkey
| | - Feyza Darendeliler
- Pediatric Endocrinology Unit, Istanbul Faculty of Medicine, Istanbul University, Istanbul 34394, Turkey
| | - Firdevs Bas
- Pediatric Endocrinology Unit, Istanbul Faculty of Medicine, Istanbul University, Istanbul 34394, Turkey
| | - Ayla Guven
- Department of Pediatric Endocrinology, Göztepe Educational and Research Hospital, Kadiköy, Istanbul 34730, Turkey
| | - Zeynep Siklar
- Department of Pediatric Endocrinology, Ankara University School of Medicine, Ankara 06100, Turkey
| | - Gonul Ocal
- Department of Pediatric Endocrinology, Ankara University School of Medicine, Ankara 06100, Turkey
| | - Merih Berberoglu
- Department of Pediatric Endocrinology, Ankara University School of Medicine, Ankara 06100, Turkey
| | - Nuala Murphy
- Department of Endocrinology, Children’s University Hospital, Temple Street, Dublin 12, Ireland
| | - Maureen O’Sullivan
- Our Lady’s Children’s Hospital, Crumlin, Dublin 12, Ireland
- University of Dublin, Trinity College, Dublin 12, Ireland
| | - Andrew Green
- National Centre for Medical Genetics, Our Lady’s Children’s Hospital, Crumlin, Dublin 12, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin 12, Ireland
| | - Peter E. Clayton
- Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9WL, UK
| | - Indraneel Banerjee
- Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9WL, UK
- Department of Paediatric Endocrinology, Royal Manchester Children’s Hospital, Manchester M13 9WL, UK
| | - Peter T. Clayton
- Clinical and Molecular Genetics Unit, University College London Institute of Child Health, in partnership with the Great Ormond Street Hospital for Children National Health Service Trust, London WC1N 1EH, UK
| | - Khalid Hussain
- London Centre for Paediatric Endocrinology and Metabolism, in partnership with the Great Ormond Street Hospital for Children National Health Service Trust, London WC1N 1EH, UK
- Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Michael N. Weedon
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| | - Sian Ellard
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
- Department of Molecular Genetics, Royal Devon and Exeter National Health Service Foundation Trust, Exeter EX2 5AD, UK
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Zhang T, Li C. Mechanisms of amino acid-stimulated insulin secretion in congenital hyperinsulinism. Acta Biochim Biophys Sin (Shanghai) 2013; 45:36-43. [PMID: 23212075 DOI: 10.1093/abbs/gms107] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The role of amino acids in the regulation of insulin secretion in pancreatic beta-cells is highlighted in three forms of congenital hyperinsulinism (HI), namely gain-of-function mutations of glutamate dehydrogenase (GDH), loss-of-function mutations of ATP-dependent potassium channels, and a deficiency of short-chain 3-hydroxyacyl-CoA dehydrogenase. Studies on disease mouse models of HI suggest that amino acid oxidation and signaling effects are the major mechanisms of amino acid-stimulated insulin secretion. Amino acid oxidation via GDH produces ATP and triggers insulin secretion. The signaling effect of amino acids amplifies insulin release after beta-cell depolarization and elevation of cytosolic calcium.
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Affiliation(s)
- Tingting Zhang
- Division of Endocrinology, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Vilarinho L, Marques JS, Rocha H, Ramos A, Lopes L, Narayan SB, Bennett MJ. Diagnosis of a patient with a kinetic variant of medium and short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency by newborn screening. Mol Genet Metab 2012; 106:277-80. [PMID: 22579592 DOI: 10.1016/j.ymgme.2012.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/07/2012] [Accepted: 04/07/2012] [Indexed: 11/28/2022]
Abstract
Medium and short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency is a rare cause of impaired mitochondrial fatty acid oxidation. We present a case report of a patient with hyperinsulinism and homozygosity for a novel mutation causing a kinetic variant of the enzyme. The diagnosis was initially inferred by abnormal newborn screening acylcarnitine analysis with elevated C4-hydroxyacylcarnitine.
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Affiliation(s)
- Laura Vilarinho
- Newborn Screening Unit, National Institute of Health, Porto, Portugal.
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Senniappan S, Shanti B, James C, Hussain K. Hyperinsulinaemic hypoglycaemia: genetic mechanisms, diagnosis and management. J Inherit Metab Dis 2012; 35:589-601. [PMID: 22231386 DOI: 10.1007/s10545-011-9441-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/06/2011] [Accepted: 12/13/2011] [Indexed: 10/14/2022]
Abstract
Hyperinsulinaemic hypoglycaemia (HH) is due to the unregulated secretion of insulin from pancreatic β-cells. A rapid diagnosis and appropriate management of these patients is essential to prevent the potentially associated complications like epilepsy, cerebral palsy and neurological impairment. The molecular basis of HH involves defects in key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF4A and UCP2) which regulate insulin secretion. The most severe forms of HH are due to loss of function mutations in ABCC8/KCNJ11 which encode the SUR1 and KIR6.2 components respectively of the pancreatic β-cell K(ATP) channel. At a histological level there are two major forms (diffuse and focal) each with a different genetic aetiology. The diffuse form is inherited in an autosomal recessive (or dominant) manner whereas the focal form is sporadic in inheritance and is localised to a small region of the pancreas. The focal form can now be accurately localised pre-operatively using a specialised positron emission tomography scan with the isotope Fluroine-18L-3, 4-dihydroxyphenyalanine (18F-DOPA-PET). Focal lesionectomy can provide cure from the hypoglycaemia. However the diffuse form is managed medically or by near total pancreatectomy (with high risk of diabetes mellitus). Recent advances in molecular genetics, imaging with 18F-DOPA-PET/CT and novel surgical techniques have changed the clinical approach to patients with HH.
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Affiliation(s)
- Senthil Senniappan
- Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children NHS Trust WC1N 3JH and Institute of Child Health, University College London, London, WC1N 1EH, UK
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Heslegrave AJ, Kapoor RR, Eaton S, Chadefaux B, Akcay T, Simsek E, Flanagan SE, Ellard S, Hussain K. Leucine-sensitive hyperinsulinaemic hypoglycaemia in patients with loss of function mutations in 3-Hydroxyacyl-CoA Dehydrogenase. Orphanet J Rare Dis 2012; 7:25. [PMID: 22583614 PMCID: PMC3433310 DOI: 10.1186/1750-1172-7-25] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 05/14/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Loss of function mutations in 3-Hydroxyacyl-CoA Dehydrogenase (HADH) cause protein sensitive hyperinsulinaemic hypoglycaemia (HH). HADH encodes short chain 3-hydroxacyl-CoA dehydrogenase, an enzyme that catalyses the penultimate reaction in mitochondrial β-oxidation of fatty acids. Mutations in GLUD1 encoding glutamate dehydrogenase, also cause protein sensitive HH (due to leucine sensitivity). Reports suggest a protein-protein interaction between HADH and GDH. This study was undertaken in order to understand the mechanism of protein sensitivity in patients with HADH mutations. METHODS An oral leucine tolerance test was conducted in controls and nine patients with HADH mutations. Basal GDH activity and the effect of GTP were determined in lymphoblast homogenates from 4 patients and 3 controls. Immunoprecipitation was conducted in patient and control lymphoblasts to investigate protein interactions. RESULTS Patients demonstrated severe HH (glucose range 1.7-3.2 mmol/l; insulin range 4.8-63.8 mU/l) in response to the oral leucine load, this HH was not observed in control patients subjected to the same leucine load. Basal GDH activity and half maximal inhibitory concentration of GTP was similar in patients and controls. HADH protein could be co-immunoprecipitated with GDH protein in control samples but not in patient samples. CONCLUSIONS We conclude that GDH and HADH have a direct protein-protein interaction, which is lost in patients with HADH mutations causing leucine induced HH. This is not associated with loss of inhibitory effect of GTP on GDH (as in patients with GLUD1 mutations).
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Affiliation(s)
- Amanda J Heslegrave
- The Institute of Child Health, University College London, London, WC1N 1EH, UK
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Short-chain 3-hydroxyacyl-coenzyme A dehydrogenase associates with a protein super-complex integrating multiple metabolic pathways. PLoS One 2012; 7:e35048. [PMID: 22496890 PMCID: PMC3322157 DOI: 10.1371/journal.pone.0035048] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 03/10/2012] [Indexed: 11/29/2022] Open
Abstract
Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD) and glutamate dehydrogenase (GDH) explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways. As an example, in murine liver, we find SCHAD interaction with aspartate transaminase (AST) and GDH from amino acid metabolic pathways, carbamoyl phosphate synthase I (CPS-1) from ureagenesis, other fatty acid oxidation and ketogenesis enzymes and fructose-bisphosphate aldolase, an extra-mitochondrial enzyme of the glycolytic pathway. Most of the interactions appear to be independent of SCHAD's role in the penultimate step of fatty acid oxidation suggesting an organizational, structural or non-enzymatic role for the SCHAD protein.
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Li M, Li C, Allen A, Stanley CA, Smith TJ. The structure and allosteric regulation of mammalian glutamate dehydrogenase. Arch Biochem Biophys 2011; 519:69-80. [PMID: 22079166 DOI: 10.1016/j.abb.2011.10.015] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 10/19/2011] [Accepted: 10/25/2011] [Indexed: 01/10/2023]
Abstract
Glutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of l-glutamate to 2-oxoglutarate. Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine, while the most important inhibitors include GTP, palmitoyl CoA, and ATP. Recently, spontaneous mutations in the GTP inhibitory site that lead to the hyperinsulinism/hyperammonemia (HHS) syndrome have shed light as to why mammalian GDH is so tightly regulated. Patients with HHS exhibit hypersecretion of insulin upon consumption of protein and concomitantly extremely high levels of ammonium in the serum. The atomic structures of four new inhibitors complexed with GDH complexes have identified three different allosteric binding sites. Using a transgenic mouse model expressing the human HHS form of GDH, at least three of these compounds were found to block the dysregulated form of GDH in pancreatic tissue. EGCG from green tea prevented the hyper-response to amino acids in whole animals and improved basal serum glucose levels. The atomic structure of the ECG-GDH complex and mutagenesis studies is directing structure-based drug design using these polyphenols as a base scaffold. In addition, all of these allosteric inhibitors are elucidating the atomic mechanisms of allostery in this complex enzyme.
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Affiliation(s)
- Ming Li
- Donald Danforth Plant Science Center, 975 North Warson Road, Saint Louis, MO 63132, USA
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Popa FI, Perlini S, Teofoli F, Degani D, Funghini S, La Marca G, Rinaldo P, Vincenzi M, Antoniazzi F, Boner A, Camilot M. 3-hydroxyacyl-coenzyme a dehydrogenase deficiency: identification of a new mutation causing hyperinsulinemic hypoketotic hypoglycemia, altered organic acids and acylcarnitines concentrations. JIMD Rep 2011; 2:71-7. [PMID: 23430856 DOI: 10.1007/8904_2011_50] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 03/03/2011] [Accepted: 03/04/2011] [Indexed: 12/24/2022] Open
Abstract
The human HADH gene encodes the short-chain-L-3-hydroxyacyl-CoA dehydrogenase, the enzyme which catalyzes the third step of the β-oxidation of the fatty acids in the mitochondrial matrix. Loss-of-function mutations in the HADH gene lead to short-chain-L-3-hydroxyacyl-CoA dehydrogenase deficiency, an autosomal recessive genetic defect of unknown prevalence with a wide spectrum of phenotypic variability. As in other metabolic diseases, the diagnostic relevance of the biochemical evaluations, plasma acylcarnitines, and urinary organic acids, are crucially dependent on the clinical conditions of the patient during specimen collection.This paper describes the eighth patient carrying a HADH gene mutation, a new homozygous deletion c.565delG leading to an early stop codon (p.V116Wfs124X), in an infant with hyperinsulininemic hypoglycemia, displaying abnormal patterns of plasma acylcarnitines and urinary organic acids. We conclude that, when the residual catalytic activity of the mutated enzyme is seriously reduced, the biochemical hallmarks of the disease, namely plasma 3-hydroxybutyrylcarnitine and urinary 3-hydroxyglutaric acid, are invariably present.
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Affiliation(s)
- Florina Ion Popa
- Department of Life Sciences and Reproduction, Division of Pediatrics, University of Verona, P.le L.A. Scuro 10, 37134, Verona, Italy
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Martins E, Cardoso ML, Rodrigues E, Barbot C, Ramos A, Bennett MJ, Teles EL, Vilarinho L. Short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency: the clinical relevance of an early diagnosis and report of four new cases. J Inherit Metab Dis 2011; 34:835-42. [PMID: 21347589 DOI: 10.1007/s10545-011-9287-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 01/22/2011] [Accepted: 01/25/2011] [Indexed: 02/07/2023]
Abstract
Short-chain 3-hydroxyacyl-CoA dehydrogenase (HADH, SCHAD) deficiency (OMIM #231530) represents a recently described disorder of mitochondrial fatty acid beta-oxidation, with less than ten cases described worldwide. The main clinical presentation of this metabolic disease is different from other inherited defects of fatty acid β-oxidation as the hypoglycemia is associated with hyperinsulinism. We present the clinical, biochemical and molecular findings of four new Caucasian patients with HADH deficiency. These new cases contribute to a more comprehensive description of the phenotype, diagnostic biomarkers and treatment options for this poorly defined disease.
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Affiliation(s)
- Esmeralda Martins
- Unidade de Doenças Metabólicas, Hospital de Crianças Maria Pia, Rua da Boavista, 827, 4050-111 Porto, Portugal.
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Flanagan SE, Patch AM, Locke JM, Akcay T, Simsek E, Alaei M, Yekta Z, Desai M, Kapoor RR, Hussain K, Ellard S. Genome-wide homozygosity analysis reveals HADH mutations as a common cause of diazoxide-responsive hyperinsulinemic-hypoglycemia in consanguineous pedigrees. J Clin Endocrinol Metab 2011; 96:E498-502. [PMID: 21252247 PMCID: PMC3100671 DOI: 10.1210/jc.2010-1906] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CONTEXT AND OBJECTIVE Recessive mutations in the hydroxyacyl-CoA dehydrogenase (HADH) gene encoding the enzyme 3-hydroxyacyl-CoA dehydrogenase are a rare cause of diazoxide-responsive hyperinsulinemic hypoglycemia (HH) with just five probands reported to date. HADH deficiency in the first three identified patients was associated with detectable urinary 3-hydroxyglutarate and raised plasma 3-hydroxybutyryl-carnitine levels, but two recent cases did not have abnormal urine organic acids or acylcarnitines. RESEARCH DESIGN AND METHODS We studied 115 patients with diazoxide-responsive HH in whom the common genetic causes of HH had been excluded. No patients were reported to have abnormal acylcarnitines or urinary organic acids. Homozygosity mapping was undertaken in probands from 13 consanguineous pedigrees to search for regions harboring mutations that are identical by descent. RESULTS HADH sequencing was performed after genome-wide single nucleotide polymorphism analysis revealed a large shared region of homozygosity spanning the HADH locus in six unrelated probands. Homozygous mutations were identified in three of these patients and in a further two probands from consanguineous families. HADH analysis in the remainder of the cohort identified mutations in a further six probands for whom consanguinity was not reported, but who originated from countries with high rates of consanguinity. Six different HADH mutations were identified in 11/115 (10%) patients tested. CONCLUSION HADH mutations are a relatively common cause of diazoxide-responsive HH with a frequency similar to that of GLUD1 and HNF4A mutations. We recommend that HADH sequence analysis is considered in all patients with diazoxide-responsive HH when recessive inheritance is suspected.
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Affiliation(s)
- Sarah E Flanagan
- Institute of Biomedical and Clinical Science, Peninsula Medical School, Barrack Road, Exeter, EX2 5DW, United Kingdom
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Marquard J, Palladino AA, Stanley CA, Mayatepek E, Meissner T. Rare forms of congenital hyperinsulinism. Semin Pediatr Surg 2011; 20:38-44. [PMID: 21186003 DOI: 10.1053/j.sempedsurg.2010.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Rare forms of congenital hyperinsulinism (CHI) are caused by mutations in GLUD1 (encoding glutamate dehydrogenase), GCK (encoding glucokinase), HADH (encoding for L-3-hydroxyacyl-CoA dehydrogenase), SLC16A1 (encoding the monocarboxylat transporter 1), HNF4A (encoding hepatocyte nuclear factor 4α) or UCP2 (encoding mitochondrial uncoupling protein 2). The clinical presentation is very heterogeneous in regards to age of onset, severity, and manner of symptoms, as well as the response to medical treatment. Special individual characteristics have to be accounted in diagnosis and treatment. Diazoxide is the first-line drug for the rare forms of CHI for long-term treatment but is not entirely effective in some of these rarer defects (GCK, MCT1). The use of diazoxide is often limited by side effects and the use of octreotide as second-line drug has to be considered. A near-total pancreatectomy is only reserved for patients with diffuse disease and resistance to medical treatment as a last resort. Patients with CHI should be managed by centers with a highly experienced team in diagnostic work-up and treatment of this disease.
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Affiliation(s)
- Jan Marquard
- Department of General Pediatrics, University Children's Hospital Düsseldorf, Germany.
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Abstract
A genetic diagnosis is now possible for approximately 45%-55% of patients with hyperinsulinemic hypoglycemia. Understanding the genetic etiology of the disease in these patients is clinically important because a genetic diagnosis will provide information on prognosis, recurrence risk, and importantly may also guide clinical management. The aim of this review is to provide an outline of the 7 different molecular mechanisms underlying this heterogeneous disease and to demonstrate that the clinical phenotype can act as a useful guide when prioritizing the order of genetic testing.
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Affiliation(s)
- Sarah E Flanagan
- Institute of Biomedical and Clinical Science, Peninsula Medical School, University of Exeter, United Kingdom
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44
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Goetzman ES. Modeling Disorders of Fatty Acid Metabolism in the Mouse. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:389-417. [DOI: 10.1016/b978-0-12-384878-9.00010-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Matschinsky FM, Zelent B, Doliba NM, Kaestner KH, Vanderkooi JM, Grimsby J, Berthel SJ, Sarabu R. Research and development of glucokinase activators for diabetes therapy: theoretical and practical aspects. Handb Exp Pharmacol 2011:357-401. [PMID: 21484579 DOI: 10.1007/978-3-642-17214-4_15] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glucokinase Glucokinase (GK GK ; EC 2.7.1.1.) phosphorylates and regulates glucose metabolism in insulin-producing pancreatic beta-cells, hepatocytes, and certain cells of the endocrine and nervous systems allowing it to play a central role in glucose homeostasis glucose homeostasis . Most importantly, it serves as glucose sensor glucose sensor in pancreatic beta-cells mediating glucose-stimulated insulin biosynthesis and release and it governs the capacity of the liver to convert glucose to glycogen. Activating and inactivating mutations of the glucokinase gene cause autosomal dominant hyperinsulinemic hypoglycemia and hypoinsulinemic hyperglycemia in humans, respectively, illustrating the preeminent role of glucokinase in the regulation of blood glucose and also identifying the enzyme as a potential target for developing antidiabetic drugs antidiabetic drugs . Small molecules called glucokinase activators (GKAs) glucokinase activators (GKAs) which bind to an allosteric activator allosteric activator site of the enzyme have indeed been discovered and hold great promise as new antidiabetic agents. GKAs increase the enzyme's affinity for glucose and also its maximal catalytic rate. Consequently, they stimulate insulin biosynthesis and secretion, enhance hepatic glucose uptake, and augment glucose metabolism and related processes in other glucokinase-expressing cells. Manifestations of these effects, most prominently a lowering of blood glucose, are observed in normal laboratory animals and man but also in animal models of diabetes and patients with type 2 diabetes mellitus (T2DM T2DM ) type 2 diabetes mellitus (T2DM) . These compelling concepts and results sustain a strong R&D effort by many pharmaceutical companies to generate GKAs with characteristics allowing for a novel drug treatment of T2DM.
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Affiliation(s)
- Franz M Matschinsky
- Department of Biochemistry and Biophysics, University of Pennsylvania, Institute for Diabetes, Obesity and Metabolism, 415 Curie Blvd, 605 CRB, Philadelphia, PA 19104, USA.
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Stanley CA. Two genetic forms of hyperinsulinemic hypoglycemia caused by dysregulation of glutamate dehydrogenase. Neurochem Int 2010; 59:465-72. [PMID: 21130127 DOI: 10.1016/j.neuint.2010.11.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/18/2010] [Accepted: 11/24/2010] [Indexed: 02/02/2023]
Abstract
Glutamate dehydrogenase (GDH) has recently been shown to be involved in two genetic disorders of hyperinsulinemic hypoglycemia in children. These include the hyperinsulinism/hyperammonemia syndrome caused by dominant activating mutations of GLUD1 which interfere with inhibitory regulation by GTP and hyperinsulinism due to recessive deficiency of short-chain 3-hydroxy-acyl-CoA dehydrogenase (SCHAD, encoded by HADH1). The clinical manifestations of the abnormalities in pancreatic ß-cell insulin regulation include fasting hypoglycemia, as well as protein-sensitive hypoglycemia. The latter is due to abnormally increased sensitivity of affected children to stimulation of insulin secretion by the amino acid, leucine. In patients with GDH activating mutations, mild hyperammonemia occurs in both the basal and protein-fed state, possibly due to increased renal ammoniagenesis. Some patients with GDH activating mutations appear to be at unusual risk of developmental delay and generalized epilepsy, perhaps reflecting consequences of increased GDH activity in the brain. Studies of these two disorders have been carried out in mouse models to define the mechanisms of insulin dysregulation. In SCHAD deficiency, the activation of GDH is due to loss of a direct inhibitory protein-protein interaction between SCHAD and GDH. These two novel human disorders demonstrate the important role of GDH in insulin regulation and illustrate unexpectedly important reasons for the unusually complex allosteric regulation of GDH.
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Affiliation(s)
- Charles A Stanley
- University of Pennsylvania School of Medicine, Endocrinology Division, The Children's Hospital of Philadelphia, Philadelphia, PA 19026, United States.
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Li M, Li C, Allen A, Stanley CA, Smith TJ. The structure and allosteric regulation of glutamate dehydrogenase. Neurochem Int 2010; 59:445-55. [PMID: 21070828 DOI: 10.1016/j.neuint.2010.10.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 10/19/2010] [Accepted: 10/27/2010] [Indexed: 01/17/2023]
Abstract
Glutamate dehydrogenase (GDH) has been extensively studied for more than 50 years. Of particular interest is the fact that, while considered by most to be a 'housekeeping' enzyme, the animal form of GDH is heavily regulated by a wide array of allosteric effectors and exhibits extensive inter-subunit communication. While the chemical mechanism for GDH has remained unchanged through epochs of evolution, it was not clear how or why animals needed to evolve such a finely tuned form of this enzyme. As reviewed here, recent studies have begun to elucidate these issues. Allosteric regulation first appears in the Ciliates and may have arisen to accommodate evolutionary changes in organelle function. The occurrence of allosteric regulation appears to be coincident with the formation of an 'antenna' like feature rising off the tops of the subunits that may be necessary to facilitate regulation. In animals, this regulation further evolved as GDH became integrated into a number of other regulatory pathways. In particular, mutations in GDH that abrogate GTP inhibition result in dangerously high serum levels of insulin and ammonium. Therefore, allosteric regulation of GDH plays an important role in insulin homeostasis. Finally, several compounds have been identified that block GDH-mediated insulin secretion that may be to not only find use in treating these insulin disorders but to kill tumors that require glutamine metabolism for cellular energy.
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Affiliation(s)
- Ming Li
- Donald Danforth Plant Science Center, Saint Louis, MO 63132, United States
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Bennett MJ. Pathophysiology of fatty acid oxidation disorders. J Inherit Metab Dis 2010; 33:533-7. [PMID: 20824345 DOI: 10.1007/s10545-010-9170-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/13/2009] [Accepted: 08/24/2009] [Indexed: 10/19/2022]
Abstract
Mitochondrial fatty acid oxidation represents an important pathway for energy generation during periods of increased energy demand such as fasting, febrile illness and muscular exertion. In liver, the primary end products of the pathway are ketone bodies, which are released into the circulation and provide energy to tissues that are not able to oxidize fatty acids such as brain. Other tissues, such as cardiac and skeletal muscle are capable of direct utilization of the fatty acids as sources of energy. This article provides an overview of the pathogenesis of fatty acid oxidation disorders. It describes the different tissue involvement with the disease processes and correlates disease phenotype with the nature of the genetic defect for the known disorders of the pathway.
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Affiliation(s)
- M J Bennett
- Department of Pathology & Laboratory Medicine, University of Pennsylvania and Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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Abstract
Mutations in the HADH and HNF4A genes are rare causes of diazoxide responsive congenital hyperinsulinism (CHI). This chapter details the phenotype known to be associated with mutations in these genes. Additionally, the authors give a brief overview of the role of these genes in glucose physiology and the possible mechanisms of CHI in patients with mutations in these genes.
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Affiliation(s)
- Ritika R Kapoor
- Clinical and Molecular Genetics Unit, The Developmental Endocrinology Research Group, Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
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Abstract
The hyperinsulinism/hyperammonemia (HI/HA) syndrome is the second most common form of congenital hyperinsulinism (HI). Children affected by this syndrome have both fasting and protein sensitive hypoglycemia combined with persistently elevated ammonia levels. Gain of function mutations in the mitochondrial enzyme glutamate dehydrogenase (GDH) are responsible for the HI/HA syndrome. GDH is expressed in liver, kidney, brain, and pancreatic beta-cells. Patients with the HI/HA syndrome have an increased frequency of generalized seizures, especially absence-type seizures, in the absence of hypoglycemia. The hypoglycemia of the HI/HA syndrome is well controlled with diazoxide, a KATP channel agonist. GDH has also been implicated in another form of HI, short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD) deficiency associated HI. The HI/HA syndrome provides a rare example of an inborn error of intermediary metabolism in which the effect of the mutation on enzyme activity is a gain of function.
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Affiliation(s)
- Andrew A Palladino
- The Children's Hospital of Philadelphia, Division of Endocrinology and Diabetes, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA.
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