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Dalle S. Targeting Protein Kinases to Protect Beta-Cell Function and Survival in Diabetes. Int J Mol Sci 2024; 25:6425. [PMID: 38928130 PMCID: PMC11203834 DOI: 10.3390/ijms25126425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
The prevalence of diabetes is increasing worldwide. Massive death of pancreatic beta-cells causes type 1 diabetes. Progressive loss of beta-cell function and mass characterizes type 2 diabetes. To date, none of the available antidiabetic drugs promotes the maintenance of a functional mass of endogenous beta-cells, revealing an unmet medical need. Dysfunction and apoptotic death of beta-cells occur, in particular, through the activation of intracellular protein kinases. In recent years, protein kinases have become highly studied targets of the pharmaceutical industry for drug development. A number of drugs that inhibit protein kinases have been approved for the treatment of cancers. The question of whether safe drugs that inhibit protein kinase activity can be developed and used to protect the function and survival of beta-cells in diabetes is still unresolved. This review presents arguments suggesting that several protein kinases in beta-cells may represent targets of interest for the development of drugs to treat diabetes.
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Affiliation(s)
- Stéphane Dalle
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), 34094 Montpellier, France
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2
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Prabhakar PK, Batiha GES. Potential Therapeutic Targets for the Management of Diabetes Mellitus Type 2. Curr Med Chem 2024; 31:3167-3181. [PMID: 37125833 DOI: 10.2174/0929867330666230501172557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/14/2023] [Accepted: 03/26/2023] [Indexed: 05/02/2023]
Abstract
Diabetes is one of the lifelong chronic metabolic diseases which is prevalent globally. There is a continuous rise in the number of people suffering from this disease with time. It is characterized by hyperglycemia, which leads to severe damage to the body's system, such as blood vessels and nerves. Diabetes occurs due to the dysfunction of pancreatic β -cell which leads to the reduction in the production of insulin or body cells unable to use insulin produce efficiently. As per the data shared International diabetes federation (IDF), there are around 415 million affected by this disease worldwide. There are a number of hit targets available that can be focused on treating diabetes. There are many drugs available and still under development for the treatment of type 2 diabetes. Inhibition of gluconeogenesis, lipolysis, fatty acid oxidation, and glucokinase activator is emerging targets for type 2 diabetes treatment. Diabetes management can be supplemented with drug intervention for obesity. The antidiabetic drug sale is the second-largest in the world, trailing only that of cancer. The future of managing diabetes will be guided by research on various novel targets and the development of various therapeutic leads, such as GLP-1 agonists, DPP-IV inhibitors, and SGLT2 inhibitors that have recently completed their different phases of clinical trials. Among these therapeutic targets associated with type 2 diabetes, this review focused on some common therapeutic targets for developing novel drug candidates of the newer generation with better safety and efficacy.
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Affiliation(s)
- Pranav Kumar Prabhakar
- Division of Research and Development, Lovely Professional University, Phagwara (Punjab) 144411, India
| | - Gaber El-Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, AlBeheira, Egypt
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3
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Haddad D, Dsouza VS, Al-Mulla F, Al Madhoun A. New-Generation Glucokinase Activators: Potential Game-Changers in Type 2 Diabetes Treatment. Int J Mol Sci 2024; 25:571. [PMID: 38203742 PMCID: PMC10779250 DOI: 10.3390/ijms25010571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
Achieving glycemic control and sustaining functional pancreatic β-cell activity remains an unmet medical need in the treatment of type 2 diabetes mellitus (T2DM). Glucokinase activators (GKAs) constitute a class of anti-diabetic drugs designed to regulate blood sugar levels and enhance β-cell function in patients with diabetes. A significant progression in GKA development is underway to address the limitations of earlier generations. Dorzagliatin, a dual-acting GKA, targets both the liver and pancreas and has successfully completed two phase III trials, demonstrating favorable results in diabetes treatment. The hepato-selective GKA, TTP399, emerges as a strong contender, displaying clinically noteworthy outcomes with minimal adverse effects. This paper seeks to review the current literature, delve into the mechanisms of action of these new-generation GKAs, and assess their efficacy and safety in treating T2DM based on published preclinical studies and recent clinical trials.
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Affiliation(s)
- Dania Haddad
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (V.S.D.); (F.A.-M.)
| | - Vanessa Sybil Dsouza
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (V.S.D.); (F.A.-M.)
| | - Fahd Al-Mulla
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (V.S.D.); (F.A.-M.)
| | - Ashraf Al Madhoun
- Genetics and Bioinformatics Department, Dasman Diabetes Institute, Dasman 15462, Kuwait; (D.H.); (V.S.D.); (F.A.-M.)
- Animal and Imaging Core Facilities, Dasman Diabetes Institute, Dasman 15462, Kuwait
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4
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Remedi MS, Nichols CG. Glucokinase Inhibition: A Novel Treatment for Diabetes? Diabetes 2023; 72:170-174. [PMID: 36669001 PMCID: PMC9871191 DOI: 10.2337/db22-0731] [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: 08/25/2022] [Accepted: 11/12/2022] [Indexed: 01/21/2023]
Abstract
Chronic hyperglycemia increases pancreatic β-cell metabolic activity, contributing to glucotoxicity-induced β-cell failure and loss of functional β-cell mass, potentially in multiple forms of diabetes. In this perspective we discuss the novel paradoxical and counterintuitive concept of inhibiting glycolysis, particularly by targeted inhibition of glucokinase, the first enzyme in glycolysis, as an approach to maintaining glucose sensing and preserving functional β-cell mass, thereby improving insulin secretion, in the treatment of diabetes.
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Affiliation(s)
- Maria S. Remedi
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO
- Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, MO
| | - Colin G. Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO
- Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, MO
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5
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Nakamura A, Omori K, Terauchi Y. Glucokinase activation or inactivation: Which will lead to the treatment of type 2 diabetes? Diabetes Obes Metab 2021; 23:2199-2206. [PMID: 34105236 DOI: 10.1111/dom.14459] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/24/2021] [Accepted: 06/02/2021] [Indexed: 12/14/2022]
Abstract
Glucokinase, which phosphorylates glucose to form glucose-6-phosphate, plays a critical role in regulating blood glucose levels. On the basis of data of glucokinase-knockout and transgenic mice and humans with glucokinase mutations, glucokinase was targeted for drug development aiming to augment its activity, and thereby reduce hyperglycaemia in patients with diabetes. In fact, various small molecule compounds have been developed and clinically tested as glucokinase activators. However, some have been discontinued because of efficacy and safety issues. One of these issues is loss of the drug's efficacy over time. This unsustained glycaemic efficacy may be associated with the excess glycolysis by glucokinase activation in pancreatic beta cells, resulting in beta-cell failure. Recently, we have shown that glucokinase haploinsufficiency ameliorated glucose intolerance by increasing beta-cell function and mass in a mouse model of diabetes. Given that a similar phenotype has been observed in glucokinase-activated beta cells and diabetic beta cells, glucokinase inactivation may be a new therapeutic target for type 2 diabetes.
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Affiliation(s)
- Akinobu Nakamura
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Kazuno Omori
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
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Wu P, Liu Z, Jiang X, Fang H. An Overview of Prospective Drugs for Type 1 and Type 2 Diabetes. Curr Drug Targets 2020; 21:445-457. [PMID: 31670620 DOI: 10.2174/1389450120666191031104653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/07/2019] [Accepted: 10/16/2019] [Indexed: 12/14/2022]
Abstract
Aims:
The aim of this study is to provide an overview of several emerging anti-diabetic
molecules.
Background:
Diabetes is a complex metabolic disorder involving the dysregulation of glucose homeostasis
at various levels. Insulin, which is produced by β-pancreatic cells, is a chief regulator of glucose
metabolism, regulating its consumption within cells, which leads to energy generation or storage as glycogen.
Abnormally low insulin secretion from β-cells, insulin insensitivity, and insulin tolerance lead to
higher plasma glucose levels, resulting in metabolic complications. The last century has witnessed extraordinary
efforts by the scientific community to develop anti-diabetic drugs, and these efforts have resulted
in the discovery of exogenous insulin and various classes of oral anti-diabetic drugs.
Objective:
Despite these exhaustive anti-diabetic pharmaceutical and therapeutic efforts, long-term
glycemic control, hypoglycemic crisis, safety issues, large-scale economic burden and side effects remain
the core problems.
Method:
The last decade has witnessed the development of various new classes of anti-diabetic drugs
with different pharmacokinetic and pharmacodynamic profiles. Details of their FDA approvals and
advantages/disadvantages are summarized in this review.
Results:
The salient features of insulin degludec, sodium-glucose co-transporter 2 inhibitors, glucokinase
activators, fibroblast growth factor 21 receptor agonists, and GLP-1 agonists are discussed.
Conclusion :
In the future, these new anti-diabetic drugs may have broad clinical applicability. Additional
multicenter clinical studies on these new drugs should be conducted.
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Affiliation(s)
- Ping Wu
- Department of Pharmacology, 3rd Affiliated Hospital, Soochow University, Changzhou, Jiangsu Province, China
| | - Zhenyu Liu
- Department of Endocrinology, 3rd Affiliated Hospital, Soochow University, Changzhou, Jiangsu Province, China
| | - Xiaohong Jiang
- Department of Endocrinology, 3rd Affiliated Hospital, Soochow University, Changzhou, Jiangsu Province, China
| | - Hao Fang
- Department of Pharmacology, 3rd Affiliated Hospital, Soochow University, Changzhou, Jiangsu Province, China
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Gutierrez-Nogués A, García-Herrero CM, Oriola J, Vincent O, Navas MA. Functional characterization of MODY2 mutations in the nuclear export signal of glucokinase. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2385-2394. [PMID: 29704611 DOI: 10.1016/j.bbadis.2018.04.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/23/2018] [Accepted: 04/23/2018] [Indexed: 11/17/2022]
Abstract
Glucokinase (GCK) plays a key role in glucose homeostasis. Heterozygous inactivating mutations in the GCK gene cause the familial, mild fasting hyperglycaemia named MODY2. Besides its particular kinetic characteristics, glucokinase is regulated by subcellular compartmentation in hepatocytes. Glucokinase regulatory protein (GKRP) binds to GCK, leading to enzyme inhibition and import into the nucleus at fasting. When glucose concentration increases, GCK-GKRP dissociates and GCK is exported to the cytosol due to a nuclear export signal (NES). With the aim to characterize the GCK-NES, we have functionally analysed nine MODY2 mutations located within the NES sequence. Recombinant GCK mutants showed reduced catalytic activity and, in most cases, protein instability. Most of the mutants interact normally with GKRP, although mutations L306R and L309P impair GCK nuclear import in cotransfected cells. We demonstrated that GCK-NES function depends on exportin 1. We further showed that none of the mutations fully inactivate the NES, with the exception of mutation L304P, which likely destabilizes its α-helicoidal structure. Finally, we found that residue Glu300 negatively modulates the NES activity, whereas other residues have the opposite effect, thus suggesting that some of the NES spacer residues contribute to the low affinity of the NES for exportin 1, which is required for its proper functioning. In conclusion, our results have provided functional and structural insights regarding the GCK-NES and contributed to a better knowledge of the molecular mechanisms involved in the nucleo-cytoplasmic shuttling of glucokinase. Impairment of this regulatory mechanism by some MODY2 mutations might contribute to the hyperglycaemia in the patients.
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Affiliation(s)
- Angel Gutierrez-Nogués
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Carmen-María García-Herrero
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Josep Oriola
- Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Departamento de Ciencias Fisiológicas I, Facultad de Medicina, Universidad de Barcelona, Barcelona, Spain
| | - Olivier Vincent
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - María-Angeles Navas
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), www.ciberdem.net, Instituto de Salud Carlos III, Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
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Martínez R, Gutierrez-Nogués Á, Fernández-Ramos C, Velayos T, Vela A, Navas MÁ, Castaño L. Heterogeneity in phenotype of hyperinsulinism caused by activating glucokinase mutations: a novel mutation and its functional characterization. Clin Endocrinol (Oxf) 2017; 86:778-783. [PMID: 28247534 DOI: 10.1111/cen.13318] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/12/2016] [Accepted: 02/23/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Mutations in the GCK gene lead to different forms of glucokinase (GCK)-disease, activating mutations cause hyperinsulinaemic hypoglycaemia while inactivating mutations cause monogenic diabetes. Hyperinsulinism (HI) is a heterogeneous condition with a significant genetic component. The major causes are channelopathies, the other forms are rare and being caused by mutations in genes such as GCK. OBJECTIVE To describe the clinical and genetic presentation of four families with activating GCK mutations, and to explore the pathogenicity of the novel mutation identified through functional studies. RESULTS Four cases of HI with mutations in GCK were identified. These include one novel mutation (p.Trp99Cys). Functional analysis of the purified mutant fusion protein glutathione-S-transferase (GST)-GCK-p.Trp99Cys demonstrated that p.Trp99Cys is an activating mutation as it induces a higher affinity for glucose and increases the relative activity index more than 11 times. Moreover, the thermal stability of the mutant protein was similar to that of its wild type. All patients were responsive to diazoxide treatment. One of the mutations arose de novo, and two were dominantly inherited, although only one of them from an HI affected parent. The age of presentation in our cases varied widely from the neonatal period to adulthood. CONCLUSION The clinical phenotype of the GCK activating mutation carriers was heterogeneous, the severity of symptoms and age at presentation varied markedly between affected individuals, even within the same family. The novel activating GCK mutation (p.Trp99Cys) has a strong activating effect in vitro although it has been identified in one case of a milder and late-onset form of HI.
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Affiliation(s)
- Rosa Martínez
- Endocrinology and Diabetes Research Group, BioCruces Health Research Institute, UPV-EHU, CIBERDEM, CIBERER, Cruces University Hospital, Barakaldo, Spain
| | - Ángel Gutierrez-Nogués
- Department of Biochemistry and Molecular Biology III, Faculty of Medicine, CIBERDEM and Hospital Clínico San Carlos Health Research Institute, Complutense University of Madrid, Madrid, Spain
| | - Concepción Fernández-Ramos
- Pediatric Endocrinology Section, BioCruces Health Research Institute, UPV/EHU, Basurto University Hospital, Bilbao, Spain
| | - Teresa Velayos
- Endocrinology and Diabetes Research Group, BioCruces Health Research Institute, UPV-EHU, CIBERDEM, CIBERER, Cruces University Hospital, Barakaldo, Spain
| | - Amaia Vela
- Pediatric Endocrinology Section, BioCruces Health Research Institute, UPV/EHU, Cruces University Hospital, CIBERDEM, CIBERER, Barakaldo, Bizkaia, Spain
| | - María-Ángeles Navas
- Department of Biochemistry and Molecular Biology III, Faculty of Medicine, CIBERDEM and Hospital Clínico San Carlos Health Research Institute, Complutense University of Madrid, Madrid, Spain
| | - Luis Castaño
- Endocrinology and Diabetes Research Group, BioCruces Health Research Institute, UPV-EHU, CIBERDEM, CIBERER, Cruces University Hospital, Barakaldo, Spain
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Martínez R, Fernández-Ramos C, Vela A, Velayos T, Aguayo A, Urrutia I, Rica I, Castaño L. Clinical and genetic characterization of congenital hyperinsulinism in Spain. Eur J Endocrinol 2016; 174:717-26. [PMID: 27188453 DOI: 10.1530/eje-16-0027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/07/2016] [Indexed: 12/30/2022]
Abstract
CONTEXT Congenital hyperinsulinism (CHI) is a clinically and genetically heterogeneous disease characterized by severe hypoglycemia caused by inappropriate insulin secretion by pancreatic β-cells. OBJECTIVE To characterize clinically and genetically CHI patients in Spain. DESIGN AND METHODS We included 50 patients with CHI from Spain. Clinical information was provided by the referring clinicians. Mutational analysis was carried out for KCNJ11, ABCC8, and GCK genes. The GLUD1, HNF4A, HNF1A, UCP2, and HADH genes were sequenced depending on the clinical phenotype. RESULTS We identified the genetic etiology in 28 of the 50 CHI patients tested: 21 had a mutation in KATP channel genes (42%), three in GLUD1 (6%), and four in GCK (8%). Most mutations were found in ABCC8 (20/50). Half of these patients (10/20) were homozygous or compound heterozygous, with nine being unresponsive to diazoxide treatment. The other half had heterozygous mutations in ABCC8, six of them being unresponsive to diazoxide treatment and four being responsive to diazoxide treatment. We identified 22 different mutations in the KATP channel genes, of which ten were novel. Notably, patients with ABCC8 mutations were diagnosed earlier, with lower blood glucose levels and required higher doses of diazoxide than those without a genetic diagnosis. CONCLUSIONS Genetic analysis revealed mutations in 56% of the CHI patients. ABCC8 mutations are the most frequent cause of CHI in Spain. We found ten novel mutations in the KATP channel genes. The genetic diagnosis is more likely to be achieved in patients with onset within the first week of life and in those who fail to respond to diazoxide treatment.
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Affiliation(s)
- R Martínez
- Endocrinology and Diabetes Research GroupBioCruces Health Research Institute, Cruces University Hospital, CIBERDEM, CIBERER, UPV-EHU, Barakaldo, Spain
| | - C Fernández-Ramos
- Pediatric Endocrinology SectionBasurto University Hospital, BioCruces Health Research Institute, UPV/EHU, Bilbao, Spain
| | - A Vela
- Pediatric Endocrinology SectionCruces University Hospital, BioCruces Health Research Institute, CIBERDEM, CIBERER, UPV/EHU, Barakaldo, Spain
| | - T Velayos
- Endocrinology and Diabetes Research GroupBioCruces Health Research Institute, Cruces University Hospital, CIBERDEM, CIBERER, UPV-EHU, Barakaldo, Spain
| | - A Aguayo
- Endocrinology and Diabetes Research GroupBioCruces Health Research Institute, Cruces University Hospital, CIBERDEM, CIBERER, UPV-EHU, Barakaldo, Spain
| | - I Urrutia
- Endocrinology and Diabetes Research GroupBioCruces Health Research Institute, Cruces University Hospital, CIBERDEM, CIBERER, UPV-EHU, Barakaldo, Spain
| | - I Rica
- Pediatric Endocrinology SectionCruces University Hospital, BioCruces Health Research Institute, CIBERDEM, CIBERER, UPV/EHU, Barakaldo, Spain
| | - L Castaño
- Endocrinology and Diabetes Research GroupBioCruces Health Research Institute, Cruces University Hospital, CIBERDEM, CIBERER, UPV-EHU, Barakaldo, Spain
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10
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Esquiaveto-Aun AM, De Mello MP, Paulino MFVM, Minicucci WJ, Guerra-Júnior G, De Lemos-Marini SHV. A new compound heterozygosis for inactivating mutations in the glucokinase gene as cause of permanent neonatal diabetes mellitus (PNDM) in double-first cousins. Diabetol Metab Syndr 2015; 7:101. [PMID: 26587058 PMCID: PMC4652399 DOI: 10.1186/s13098-015-0101-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/05/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Permanent neonatal diabetes mellitus (PNDM) is a rare disorder, characterized by uncontrolled hyperglycemia diagnosed during the first 6 months of life. In general, PNDM has a genetic origin and most frequently it results from heterozygous mutations in KCNJ11, INS and ABCC8 genes. Homozygous or compound heterozygous inactivating mutations in GCK gene as cause of PNDM are rare. In contrast, heterozygosis for GCK inactivating mutations is frequent and results in the maturity-onset diabetes of young (MODY), manifested by a mild fasting hyperglycemia usually detected later in life. Therefore, as an autosomal recessive disorder, GCK-PNDM should be considered in families with history of glucose intolerance or MODY in first relatives, especially when consanguinity is suspected. RESULTS Here we describe two patients born from non-consanguineous parents within a family. They presented low birth weight with persistent hyperglycemia during the first month of life. Molecular analyses for KCNJ11, INS, ABCC8 did not show any mutation. GCK gene sequencing, however, revealed that both patients were compound heterozygous for two missense combined in a novel GCK-PNDM genotype. The p.Asn254His and p.Arg447Gly mutations had been inherited from their mothers and fathers, respectively, as their mothers are sisters and their fathers are brothers. Parents had been later diagnosed as having GCK-MODY. CONCLUSIONS Mutations' in silico analysis was carried out to elucidate the role of the amino acid changes on the enzyme structure. Both p.Asn254His and p.Arg447Gly mutations appeared to be quite damaging. This is the first report of GCK-PNDM in a Brazilian family.
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Affiliation(s)
- Adriana Mangue Esquiaveto-Aun
- />Department of Pediatrics, School of Medical Sciences (FCM), State University of Campinas (UNICAMP), Campinas, SP Brazil
- />Center of Molecular Biology and Genetic Engineering (CBMEG), UNICAMP, Campinas, Brazil
- />Center for Investigation in Pediatrics (CIPED), FCM, UNICAMP, Campinas, Brazil
| | | | | | - Walter José Minicucci
- />Division of Endocrinology, Department of Clinical Medicine, FCM, UNICAMP, Campinas, Brazil
| | - Gil Guerra-Júnior
- />Department of Pediatrics, School of Medical Sciences (FCM), State University of Campinas (UNICAMP), Campinas, SP Brazil
- />Center for Investigation in Pediatrics (CIPED), FCM, UNICAMP, Campinas, Brazil
| | - Sofia Helena Valente De Lemos-Marini
- />Department of Pediatrics, School of Medical Sciences (FCM), State University of Campinas (UNICAMP), Campinas, SP Brazil
- />Center for Investigation in Pediatrics (CIPED), FCM, UNICAMP, Campinas, Brazil
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11
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Nakamura A, Terauchi Y. Present status of clinical deployment of glucokinase activators. J Diabetes Investig 2014; 6:124-32. [PMID: 25802718 PMCID: PMC4364845 DOI: 10.1111/jdi.12294] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/14/2022] Open
Abstract
Glucokinase is one of four members of the hexokinase family of enzymes. Its expression is limited to the major organs (such as the pancreas, liver, brain and the gastrointestinal tract) that are thought to have an integrated role in glucose sensing. In the liver, phosphorylation of glucose by glucokinase promotes glycogen synthesis, whereas in the β-cells, it results in insulin release. Studies of glucokinase-linked genetically-modified mice and mutations in humans have illustrated the important roles played by glucokinase in whole-body glucose homeostasis, and suggest that the use of pharmacological agents that augment glucokinase activity could represent a viable treatment strategy in patients with type 2 diabetes. Since 2003, many glucokinase activators (GKAs) have been developed, and their ability to lower the blood glucose has been shown in several animal models of type 2 diabetes. Also, we and others have shown in mouse models that GKAs also have the effect of stimulating the proliferation of β-cells. However, the results of recent phase II trials have shown that GKAs lose their efficacy within several months of use, and that their use is associated with a high incidence of hypoglycemia; furthermore, patients treated with GKAs frequently developed dyslipidemia. A better understanding of the role of glucokinase in metabolic effects is required to resolve several issues identified in clinical trials.
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Affiliation(s)
- Akinobu Nakamura
- Division of Immunology and Metabolism, Hokkaido University Graduate School of Medicine Sapporo, Japan
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University Yokohama, Japan
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12
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Yorifuji T, Masue M, Nishibori H. Congenital hyperinsulinism: global and Japanese perspectives. Pediatr Int 2014; 56:467-76. [PMID: 24865345 DOI: 10.1111/ped.12390] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 05/12/2014] [Indexed: 12/12/2022]
Abstract
Over the past 20 years, there has been remarkable progress in the diagnosis and treatment of congenital hyperinsulinism (CHI). These advances have been supported by the understanding of the molecular mechanism and the development of diagnostic modalities to identify the focal form of ATP-sensitive potassium channel CHI. Many patients with diazoxide-unresponsive focal CHI have been cured by partial pancreatectomy without developing postsurgical diabetes mellitus. Important novel findings on the genetic basis of the other forms of CHI have also been obtained, and several novel medical treatments have been explored. However, the management of patients with CHI is still far from ideal. First, state-of-the-art treatment is not widely available worldwide. Second, it appears that the management strategy needs to be adjusted according to the patient's ethnic group. Third, optimal management of patients with the diazoxide-unresponsive, diffuse form of CHI is still insufficient and requires further improvement. In this review, we describe the current landscape of this disorder, discuss the racial disparity of CHI using Japanese patients as an example, and briefly note unanswered questions and unmet needs that should be addressed in the near future.
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Affiliation(s)
- Tohru Yorifuji
- Pediatric Endocrinology and Metabolism, Children's Medical Center, Osaka City General Hospital, Osaka, Japan; Clinical Research Center, Osaka City General Hospital, Osaka, Japan; Department of Genetic Medicine, Osaka City General Hospital, Osaka, Japan
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Short AD, Holder A, Rothwell S, Massey J, Scholey R, Kennedy LJ, Catchpole B, Ollier WE. Searching for "monogenic diabetes" in dogs using a candidate gene approach. Canine Genet Epidemiol 2014; 1:8. [PMID: 26401325 PMCID: PMC4579387 DOI: 10.1186/2052-6687-1-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/23/2014] [Indexed: 11/24/2022] Open
Abstract
Background Canine diabetes is a common endocrine disorder with an estimated breed-related prevalence ranging from 0.005% to 1.5% in pet dogs. Increased prevalence in some breeds suggests that diabetes in dogs is influenced by genetic factors and similarities between canine and human diabetes phenotypes suggest that the same genes might be associated with disease susceptibility in both species. Between 1-5% of human diabetes cases result from mutations in a single gene, including maturity onset diabetes of the adult (MODY) and neonatal diabetes mellitus (NDM). It is not clear whether monogenic forms of diabetes exist within some dog breeds. Identification of forms of canine monogenic diabetes could help to resolve the heterogeneity of the condition and lead to development of breed-specific genetic tests for diabetes susceptibility. Results Seventeen dog breeds were screened for single nucleotide polymorphisms (SNPs) in eighteen genes that have been associated with human MODY/NDM. Six SNP associations were found from five genes, with one gene (ZFP57) being associated in two different breeds. Conclusions Some of the genes that have been associated with susceptibility to MODY and NDM in humans appear to also be associated with canine diabetes, although the limited number of associations identified in this study indicates canine diabetes is a heterogeneous condition and is most likely to be a polygenic trait in most dog breeds. Electronic supplementary material The online version of this article (doi:10.1186/2052-6687-1-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrea D Short
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
| | - Angela Holder
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts AL9 7TA UK
| | - Simon Rothwell
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
| | - Jonathan Massey
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
| | - Rachel Scholey
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
| | - Lorna J Kennedy
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
| | - Brian Catchpole
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts AL9 7TA UK
| | - William Er Ollier
- Centre for Integrated Genomic Medical Research, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT UK
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Muller YL, Piaggi P, Hoffman D, Huang K, Gene B, Kobes S, Thearle MS, Knowler WC, Hanson RL, Baier LJ, Bogardus C. Common genetic variation in the glucokinase gene (GCK) is associated with type 2 diabetes and rates of carbohydrate oxidation and energy expenditure. Diabetologia 2014; 57:1382-90. [PMID: 24728127 PMCID: PMC4052004 DOI: 10.1007/s00125-014-3234-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/14/2014] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS Glucokinase (GCK) plays a role in glucose metabolism and glucose-stimulated insulin secretion. Rare mutations in GCK cause MODY. We investigated whether common variation (minor allele frequency ≥0.01) in GCK is associated with metabolic traits and type 2 diabetes. METHODS Four exonic single-nucleotide polymorphisms (SNPs) and three SNPs predicted to cause loss of promoter function were identified in whole-genome sequence data from 234 Pima Indians. These seven tag SNPs and rs4607517, a type 2 diabetes variant established in other studies, were analysed in 415 full-heritage non-diabetic Pima Indians characterised for metabolic traits, and 7,667 American Indians who had data on type 2 diabetes and BMI. RESULTS A novel 3' untranslated region (3'UTR) SNP, chr7:44184184-G/A, was associated with the rate of carbohydrate oxidation post-absorptively (β = 0.22 mg [kg estimated metabolic body size (EMBS)](-1) min(-1), p = 0.005) and during a hyperinsulinaemic-euglycaemic clamp (β = 0.24 mg [kg EMBS](-1) min(-1), p = 0.0002), the rate of carbohydrate oxidation in a respiratory chamber (β = 311 kJ/day, p = 0.03) and 24 h energy expenditure, which was attributable to the thermic effect of food (β = 520 kJ/day, p = 3.39 × 10(-6)). This 3'UTR SNP was also associated with diabetes (OR 1.36, 95% CI 1.11, 1.65, p = 0.002), where the A allele (allele frequency 0.05) was associated with a lower rate of carbohydrate oxidation, lower 24 h energy expenditure and higher risk for diabetes. In a Cox proportional hazards model, a rate of insulin-stimulated carbohydrate oxidation lower than the mean rate at baseline predicted a higher risk for developing diabetes than for those above the mean (hazard rate ratio 2.2, 95% CI 1.3, 3.6, p = 0.002). CONCLUSIONS/INTERPRETATION Common variation in GCK influences the rate of carbohydrate oxidation, 24 h energy expenditure and diabetes risk in Pima Indians.
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Affiliation(s)
- Yunhua L. Muller
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Paolo Piaggi
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Duncan Hoffman
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Ke Huang
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Brittany Gene
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Sayuko Kobes
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Marie S. Thearle
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - William C. Knowler
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Robert L. Hanson
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Leslie J. Baier
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
| | - Clifton Bogardus
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, 445 North 5th street, Phoenix, AZ 85004 USA
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15
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Abstract
The glucokinase (GK) enzyme (EC 2.7.1.1.) is essential for the use of dietary glucose because it is the first enzyme to phosphorylate glucose in excess in different key tissues such as the pancreas and liver. The objective of the present review is not to fully describe the biochemical characteristics and the genetics of this enzyme but to detail its nutritional regulation in different vertebrates from fish to human. Indeed, the present review will describe the existence of the GK enzyme in different animal species that have naturally different levels of carbohydrate in their diets. Thus, some studies have been performed to analyse the nutritional regulation of the GK enzyme in humans and rodents (having high levels of dietary carbohydrates in their diets), in the chicken (moderate level of carbohydrates in its diet) and rainbow trout (no carbohydrate intake in its diet). All these data illustrate the nutritional importance of the GK enzyme irrespective of feeding habits, even in animals known to poorly use dietary carbohydrates (carnivorous species).
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16
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Johnson AK, Gaudio DD. Clinical utility of next-generation sequencing for the molecular diagnosis of monogenic diabetes. Per Med 2014; 11:155-165. [PMID: 29751380 DOI: 10.2217/pme.13.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Monogenic diabetes resulting from mutations that primarily reduce insulin-secreting pancreatic β-cell function accounts for 1-2% of all cases of diabetes, and is genetically and clinically heterogeneous. Currently, genetic testing for monogenic diabetes relies on selection of the appropriate gene for analysis based on the availability of comprehensive phenotypic information, which can be time consuming, costly and can limit the differential diagnosis to a few selected genes. In recent years, the exponential growth in the field of high-throughput capture and sequencing technology has made it possible and cost effective to sequence many genes simultaneously, making it an efficient diagnostic tool for clinically and genetically heterogeneous disorders such as monogenic diabetes. Making a diagnosis of monogenic diabetes is important as it enables more appropriate treatment, better prediction of disease prognosis and progression, and counseling and screening of family members. We provide a concise overview of the genetic etiology of some forms of monogenic diabetes, as well as a discussion of the clinical utility of genetic testing by comprehensive multigene panel using next-generation sequencing methodologies.
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Affiliation(s)
- Amy Knight Johnson
- Department of Human Genetics, University of Chicago, 5841 S Maryland MC0077, Chicago, IL 60637, USA
| | - Daniela Del Gaudio
- Department of Human Genetics, University of Chicago, 5841 S Maryland MC0077, Chicago, IL 60637, USA
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Hoenig M. Carbohydrate Metabolism and Pathogenesis of Diabetes Mellitus in Dogs and Cats. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 121:377-412. [DOI: 10.1016/b978-0-12-800101-1.00012-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Wang ZY, Jin L, Tan H, Irwin DM. Evolution of hepatic glucose metabolism: liver-specific glucokinase deficiency explained by parallel loss of the gene for glucokinase regulatory protein (GCKR). PLoS One 2013; 8:e60896. [PMID: 23573289 PMCID: PMC3613411 DOI: 10.1371/journal.pone.0060896] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/04/2013] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Glucokinase (GCK) plays an important role in the regulation of carbohydrate metabolism. In the liver, phosphorylation of glucose to glucose-6-phosphate by GCK is the first step for both glycolysis and glycogen synthesis. However, some vertebrate species are deficient in GCK activity in the liver, despite containing GCK genes that appear to be compatible with function in their genomes. Glucokinase regulatory protein (GCKR) is the most important post-transcriptional regulator of GCK in the liver; it participates in the modulation of GCK activity and location depending upon changes in glucose levels. In experimental models, loss of GCKR has been shown to associate with reduced hepatic GCK protein levels and activity. METHODOLOGY/PRINCIPAL FINDINGS GCKR genes and GCKR-like sequences were identified in the genomes of all vertebrate species with available genome sequences. The coding sequences of GCKR and GCKR-like genes were identified and aligned; base changes likely to disrupt coding potential or splicing were also identified. CONCLUSIONS/SIGNIFICANCE GCKR genes could not be found in the genomes of 9 vertebrate species, including all birds. In addition, in multiple mammalian genomes, whereas GCKR-like gene sequences could be identified, these genes could not predict a functional protein. Vertebrate species that were previously reported to be deficient in hepatic GCK activity were found to have deleted (birds and lizard) or mutated (mammals) GCKR genes. Our results suggest that mutation of the GCKR gene leads to hepatic GCK deficiency due to the loss of the stabilizing effect of GCKR.
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Affiliation(s)
- Zhao Yang Wang
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Ling Jin
- Department of Pharmacology, Peking University, Health Science Center, Beijing, China
| | - Huanran Tan
- Department of Pharmacology, Peking University, Health Science Center, Beijing, China
| | - David M. Irwin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology, Peking University, Health Science Center, Beijing, China
- Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario, Canada
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Catchpole B, Adams JP, Holder AL, Short AD, Ollier WER, Kennedy LJ. Genetics of canine diabetes mellitus: are the diabetes susceptibility genes identified in humans involved in breed susceptibility to diabetes mellitus in dogs? Vet J 2012; 195:139-47. [PMID: 23265864 DOI: 10.1016/j.tvjl.2012.11.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 11/09/2012] [Accepted: 11/15/2012] [Indexed: 01/22/2023]
Abstract
Diabetes mellitus is a common endocrinopathy in companion animals, characterised by hyperglycaemia, glycosuria and weight loss, resulting from an absolute or relative deficiency in the pancreatic hormone insulin. There are breed differences in susceptibility to diabetes mellitus in dogs, with the Samoyed breed being overrepresented, while Boxers are relatively absent in the UK population of diabetic dogs, suggesting that genetic factors play an important role in determining susceptibility to the disease. A number of genes, linked with susceptibility to diabetes mellitus in humans, are associated with an increased risk of diabetes mellitus in dogs, some of which appear to be relatively breed-specific. Diabetes mellitus in dogs has been associated with major histocompatibility complex (MHC) class II genes (dog leucocyte antigen; DLA), with similar haplotypes and genotypes being identified in the most susceptible breeds. A region containing a variable number of tandem repeats (VNTR) and several polymorphisms have been identified in the canine insulin gene, with some alleles associated with susceptibility or resistance to diabetes mellitus in a breed-specific manner. Polymorphisms in the canine CTLA4 promoter and in other immune response genes are associated with susceptibility to diabetes mellitus in a number of pedigree breeds. Genome wide association studies are currently underway that should shed further light on the genetic factors responsible for the breed profile seen in the diabetic dog population.
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Affiliation(s)
- Brian Catchpole
- Department of Pathology and Infectious Diseases, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK.
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Capuano M, Garcia-Herrero CM, Tinto N, Carluccio C, Capobianco V, Coto I, Cola A, Iafusco D, Franzese A, Zagari A, Navas MA, Sacchetti L. Glucokinase (GCK) mutations and their characterization in MODY2 children of southern Italy. PLoS One 2012; 7:e38906. [PMID: 22761713 PMCID: PMC3385652 DOI: 10.1371/journal.pone.0038906] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/14/2012] [Indexed: 01/24/2023] Open
Abstract
Type 2 Maturity Onset Diabetes of the Young (MODY2) is a monogenic autosomal disease characterized by a primary defect in insulin secretion and hyperglycemia. It results from GCK gene mutations that impair enzyme activity. Between 2006 and 2010, we investigated GCK mutations in 66 diabetic children from southern Italy with suspected MODY2. Denaturing High Performance Liquid Chromatography (DHPLC) and sequence analysis revealed 19 GCK mutations in 28 children, six of which were novel: p.Glu40Asp, p.Val154Leu, p.Arg447Glyfs, p.Lys458_Cys461del, p.Glu395_Arg397del and c.580-2A>T. We evaluated the effect of these 19 mutations using bioinformatic tools such as Polymorphism Phenotyping (Polyphen), Sorting Intolerant From Tolerant (SIFT) and in silico modelling. We also conducted a functional study to evaluate the pathogenic significance of seven mutations that are among the most severe mutations found in our population, and have never been characterized: p.Glu70Asp, p.His137Asp, p.Phe150Tyr, p.Val154Leu, p.Gly162Asp, p.Arg303Trp and p.Arg392Ser. These seven mutations, by altering one or more kinetic parameters, reduced enzyme catalytic activity by >40%. All mutations except p.Glu70Asp displayed thermal-instability, indeed >50% of enzyme activity was lost at 50°C/30 min. Thus, these seven mutations play a pathogenic role in MODY2 insurgence. In conclusion, this report revealed six novel GCK mutations and sheds some light on the structure-function relationship of human GCK mutations and MODY2.
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Affiliation(s)
- Marina Capuano
- Department of Biochemistry and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
| | - Carmen Maria Garcia-Herrero
- Department of Biochemistry and Molecular Biology III, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Nadia Tinto
- Department of Biochemistry and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
| | - Carla Carluccio
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
- Department of Biological Science, University of Naples “Federico II”, Naples, Italy
| | - Valentina Capobianco
- Fondazione SDN-IRCSS (Istituto di Diagnostica Nucleare-Istituto di Ricerca e Cura a Carattere Scientifico), Naples, Italy
| | - Iolanda Coto
- Department of Biochemistry and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
| | - Arturo Cola
- Department of Biochemistry and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
| | - Dario Iafusco
- Department of Pediatrics, Second University of Naples, Naples, Italy
| | - Adriana Franzese
- Department of Pediatrics, University of Naples “Federico II”, Naples, Italy
| | - Adriana Zagari
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
- Department of Biological Science, University of Naples “Federico II”, Naples, Italy
| | - Maria Angeles Navas
- Department of Biochemistry and Molecular Biology III, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Lucia Sacchetti
- Department of Biochemistry and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
- Centro di Ingegneria Genetica (CEINGE) Advanced Biotechnology, s. c. a r. l., Naples, Italy
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Futamura M, Yao J, Li X, Bergeron R, Tran JL, Zycband E, Woods J, Zhu Y, Shao Q, Maruki-Uchida H, Goto-Shimazaki H, Langdon RB, Erion MD, Eiki J, Zhou YP. Chronic treatment with a glucokinase activator delays the onset of hyperglycaemia and preserves beta cell mass in the Zucker diabetic fatty rat. Diabetologia 2012; 55:1071-80. [PMID: 22234649 DOI: 10.1007/s00125-011-2439-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/02/2011] [Indexed: 01/07/2023]
Abstract
AIMS/HYPOTHESIS Glucokinase activators (GKAs) are currently being developed as new therapies for type 2 diabetes and have been shown to enhance beta cell survival and proliferation in vitro. Here, we report the effects of chronic GKA treatment on the development of hyperglycaemia and beta cell loss in the male Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes with severe obesity. METHODS Cell protection by GKA was studied in MIN6 and INS-1 cells exposed to hydrogen peroxide. Glucose homeostasis and beta cell mass were evaluated in ZDF rats dosed for 41 days with Cpd-C (a GKA) or glipizide (a sulfonylurea) as food admixtures at doses of approximately 3 and 10 mg kg(-1) day(-1). RESULTS Incubation of MIN6 and INS-1 832/3 insulinoma cell cultures with GKA significantly reduced cell death and impairment of intracellular NADH production caused by exposure to hydrogen peroxide. Progression from prediabetes (normoglycaemia and hyperinsulinaemia) to overt diabetes (hyperglycaemia and hypoinsulinaemia) was significantly delayed in male ZDF rats by in-feed treatment with Cpd-C, but not glipizide. Glucose tolerance, tested in the fifth week of treatment, was also significantly improved by Cpd-C, as was pancreatic insulin content and beta cell area. In a limited immunohistochemical analysis, Cpd-C modestly and significantly enhanced the rate of beta cell proliferation, but not rates of beta cell apoptosis relative to untreated ZDF rats. CONCLUSIONS/INTERPRETATION These findings suggest that chronic activation of glucokinase preserves beta cell mass and delays disease in the ZDF rat, a model of insulin resistance and progressive beta cell failure.
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Affiliation(s)
- M Futamura
- Banyu Tsukuba Research Institute, Okubo, Tsukuba, Ibaraki, Japan
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McCulloch LJ, van de Bunt M, Braun M, Frayn KN, Clark A, Gloyn AL. GLUT2 (SLC2A2) is not the principal glucose transporter in human pancreatic beta cells: implications for understanding genetic association signals at this locus. Mol Genet Metab 2011; 104:648-53. [PMID: 21920790 DOI: 10.1016/j.ymgme.2011.08.026] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 08/23/2011] [Accepted: 08/23/2011] [Indexed: 11/30/2022]
Abstract
SLC2A2 encoding glucose transporter -2 (GLUT2) acts as the primary glucose transporter and sensor in rodent pancreatic islets and is widely assumed to play a similar role in humans. In healthy adults SLC2A2 variants are associated with elevated fasting plasma glucose (fpg) concentrations but physiological characterisation does not support a defect in pancreatic beta-cell function. Interspecies differences can create barriers for the follow up of disease association signals. We hypothesised that GLUT2 is not the principal glucose transporter in human beta-cells and that SLC2A2 variants exert their effect on fpg levels through defects in other tissues. SLC2A1-4 (GLUT 1-4) mRNA expression levels were determined in human and mouse islets, beta-cells, liver, muscle and adipose tissue by qRT-PCR whilst GLUT1-3 protein levels were examined by immunohistochemistry. The presence of all three glucose transporters was demonstrated in human and mouse islets and purified beta-cells. Quantitative expression profiling demonstrated that Slc2a2 is the predominant glucose transporter (expression >10 fold higher that Slc2a1) in mouse islets whilst SLC2A1 and SLC2A3 predominate in both human islets and beta-cells (expression 2.8 and 2.7 fold higher than SLC2A2 respectively). Our data therefore suggest that GLUT2 is unlikely to be the principal glucose transporter in human beta-cells and that SLC2A2 defects in other metabolic tissues drive the observed differences in glucose levels between carriers of SLC2A2 variants. Direct extrapolation from rodent to human islet glucose transporter activity is unlikely to be appropriate.
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Affiliation(s)
- Laura J McCulloch
- Oxford Centre for Diabetes Endocrinology and Metabolism, University of Oxford, Oxford, UK
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Quan Y, Barszczyk A, Feng ZP, Sun HS. Current understanding of K ATP channels in neonatal diseases: focus on insulin secretion disorders. Acta Pharmacol Sin 2011; 32:765-80. [PMID: 21602835 PMCID: PMC4009965 DOI: 10.1038/aps.2011.57] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 04/13/2011] [Indexed: 12/25/2022] Open
Abstract
ATP-sensitive potassium (K(ATP)) channels are cell metabolic sensors that couple cell metabolic status to electric activity, thus regulating many cellular functions. In pancreatic beta cells, K(ATP) channels modulate insulin secretion in response to fluctuations in plasma glucose level, and play an important role in glucose homeostasis. Recent studies show that gain-of-function and loss-of-function mutations in K(ATP) channel subunits cause neonatal diabetes mellitus and congenital hyperinsulinism respectively. These findings lead to significant changes in the diagnosis and treatment for neonatal insulin secretion disorders. This review describes the physiological and pathophysiological functions of K(ATP) channels in glucose homeostasis, their specific roles in neonatal diabetes mellitus and congenital hyperinsulinism, as well as future perspectives of K(ATP) channels in neonatal diseases.
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Affiliation(s)
- Yi Quan
- Departments of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Andrew Barszczyk
- Departments of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Zhong-ping Feng
- Departments of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
| | - Hong-shuo Sun
- Departments of Physiology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
- Departments of Surgery, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
- Departments of Pharmacology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
- Institute of Medical Science, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
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