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Al Madhoun A. Glucokinase regulatory protein rs780094 polymorphism is associated with type 2 diabetes mellitus, dyslipidemia, non-alcoholic fatty liver disease, and nephropathy. World J Diabetes 2024; 15:814-817. [PMID: 38766433 PMCID: PMC11099372 DOI: 10.4239/wjd.v15.i5.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/31/2024] [Accepted: 03/11/2024] [Indexed: 05/10/2024] Open
Abstract
In this editorial, we comment on the article by Liu et al published in the recent issue of the World Journal of Diabetes (Relationship between GCKR gene rs780094 polymorphism and type 2 diabetes with albuminuria). Type 2 diabetes mellitus (T2DM) is a chronic disorder characterized by dysregulated glucose homeostasis. The persistent elevated blood glucose level in T2DM significantly increases the risk of developing severe complications, including cardiovascular disease, re-tinopathy, neuropathy, and nephropathy. T2DM arises from a complex interplay between genetic, epigenetic, and environmental factors. Global genomic studies have identified numerous genetic variations associated with an increased risk of T2DM. Specifically, variations within the glucokinase regulatory protein (GCKR) gene have been linked to heightened susceptibility to T2DM and its associated complications. The clinical trial by Liu et al further elucidates the role of the GCKR rs780094 polymorphism in T2DM and nephropathy development. Their findings demonstrate that individuals carrying the CT or TT genotype at the GCKR rs780094 locus are at a higher risk of developing T2DM with albuminuria compared to those with the CC genotype. These findings highlight the importance of genetic testing and risk assessment in T2DM to develop effective preventive strategies and personalized treatment plans.
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Affiliation(s)
- Ashraf Al Madhoun
- Department of Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15400, Kuwait
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Ali MH, Alshamrani AA, Napit PR, Briski KP. Single-cell multiplex qPCR evidence for sex-dimorphic glutamate decarboxylase, estrogen receptor, and 5'-AMP-activated protein kinase alpha subunit mRNA expression by ventromedial hypothalamic nucleus GABAergic neurons. J Chem Neuroanat 2022; 124:102132. [PMID: 35772680 PMCID: PMC9474596 DOI: 10.1016/j.jchemneu.2022.102132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/20/2022] [Accepted: 06/24/2022] [Indexed: 12/01/2022]
Abstract
The inhibitory amino acid transmitter γ-aminobutryic acid (GABA) acts within the ventromedial hypothalamus to regulate systemic glucose homeostasis, but the issue of whether this neurochemical signal originates locally or is supplied by afferent innervation remains controversial. Here, combinatory in situ immunocytochemistry/laser-catapult microdissection/single-cell multiplex qPCR techniques were used to investigate the premise that ventromedial hypothalamic nucleus ventrolateral (VMNvl) and/or dorsomedial (VMNdm) division neurons contain mRNAs that encode glutamate decarboxylase (GAD)65 or GAD67 and metabolic-sensory biomarkers, and that expression of these genes is sex-dimorphic. In male and female rats, GAD65 mRNA was elevated in VMNvl versus VMNdm GAD65/67-immunopositive (-ir) neurons, yet the female exhibited higher GAD67 transcript content in VMNdm versus VMNvl GABAergic nerve cells. Estrogen receptor (ER)-alpha transcripts were lower in female versus male GABA neurons from either VMN division; ER-beta and G-protein-coupled ER-1 mRNA expression profiles were also comparatively reduced in cells from female versus male VMNvl. VMNvl and VMNdm GAD65/67-ir-positive neurons showed equivalent levels of glucokinase and sulfonylurea receptor-1 mRNA between sexes. 5'-AMP-activated protein kinase-alpha 1 (AMPKα1) and -alpha 2 (AMPKα2) transcripts were lower in female versus male VMNdm GABAergic neurons, yet AMPKα2 mRNA levels were higher in cells acquired from female versus male VMNvl. Current studies document GAD65 and -67 gene expression in VMNvl and VMNdm GAD65/67-ir-positive neurons in each sex. Results infer that GABAergic neurons in each division may exhibit sex differences in receptiveness to estradiol. Outcomes also support the prospect that energy sensory function by this neurotransmitter cell type may predominate in the VMNvl in female versus VMNdm in the male.
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Affiliation(s)
- Md Haider Ali
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Ayed A Alshamrani
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Prabhat R Napit
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA.
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Ali MH, Alshamrani AA, Briski KP. Hindbrain lactate regulation of hypoglycemia-associated patterns of catecholamine and metabolic-sensory biomarker gene expression in A2 noradrenergic neurons innervating the male versus female ventromedial hypothalamic nucleus. J Chem Neuroanat 2022; 122:102102. [PMID: 35483611 DOI: 10.1016/j.jchemneu.2022.102102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 12/30/2022]
Abstract
Caudal hindbrain A2 noradrenergic neurons provide critical metabolic-sensory input to the brain glucostatic circuitry. In males, insulin-induced hypoglycemia (IIH)-associated patterns of A2 cell dopamine-beta-hydroxylase (DβH) protein expression reflect diminution of the oxidizable fuel L-lactate, yet DβH exhibits sex-dimorphic responses to IIH. Here, retrograde tracing and combinatory single-cell laser-microdissection/multiplex qPCR techniques were used to examine whether lactate imposes sex-specific control of hypoglycemia-associated metabolic-sensory function and noradrenergic neurotransmission in A2 neurons that innervate the ventromedial hypothalamic nucleus (VMN), a key glucose-regulatory structure. VMN-projecting A2 neurons from each sex were characterized by presence or absence of nuclear glucokinase regulatory protein (nGKRP) immunoreactivity (-ir). IIH caused lactate-reversible up- or down-regulation of DβH mRNA in male and female nGKRP-ir-positive A2 neurons, respectively, and stimulated glucokinase (GCK) and sulfonylurea receptor-1 (SUR-1) gene expression in these cells in each sex. Hypoglycemia did not alter DβH, GCK, and SUR-1 transcript profiles in nGKRP-ir-negative male or female A2 neurons innervating the VMN. Estrogen receptor (ER) gene profiles in nGKRP-ir-positive neurons showed sex-specific [ER-alpha; G-protein-coupled estrogen-receptor-1 (GPER)] or sex-monomorphic (ER-beta) transcriptional responses to IIH. Fewer ER gene profiles were affected by IIH in nGKRP-ir-negative A2 neurons from male or female rats. Results show that during IIH, VMN-projecting A2 neurons may deliver altered, sex-dependent (nGKRP-positive) or unaffected (nGKRP-negative) noradrenergic input to the VMN. In each sex, metabolic-sensory gene profiles were reactive to hypoglycemia in nGKRP-ir-positive, not -negative A2 cells. Further studies are needed to elucidate the role of GKRP in transduction of metabolic imbalance into noradrenergic signaling, and to determine if input by one or more ER variants establishes sex differences in DβH transcriptional sensitivity to IIH.
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Affiliation(s)
- Md Haider Ali
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Ayed A Alshamrani
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA.
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Langer S, Waterstradt R, Hillebrand G, Santer R, Baltrusch S. The novel GCK variant p.Val455Leu associated with hyperinsulinism is susceptible to allosteric activation and is conducive to weight gain and the development of diabetes. Diabetologia 2021; 64:2687-2700. [PMID: 34532767 PMCID: PMC8563668 DOI: 10.1007/s00125-021-05553-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/21/2021] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS The mammalian enzyme glucokinase (GK), expressed predominantly in liver and pancreas, plays an essential role in carbohydrate metabolism. Monogenic GK disorders emphasise the role of GK in determining the blood glucose set point. METHODS A family with congenital hyperinsulinism (CHI) was examined for GCK gene variants by Sanger sequencing. A combined approach, involving kinetic analysis (also using GK activators and inhibitors), intracellular translocation assays, insulin secretion measurements and structural modelling, was used to investigate the novel variant compared with known variants. RESULTS We report on the novel gain-of-function GCK variant p.Val455Leu (V455L), inherited as an autosomal dominant trait in a German family with CHI and concomitant obesity (fasting blood glucose 2.1 mmol/l, BMI 45.0 kg/m2, HOMA-IR 1.5 in an adult female family member); one male family member developed type 2 diabetes until age 35 years (with fasting glucose 2.8-3.7 mmol/l, BMI 38.9 kg/m2, HOMA-IR 4.6). Kinetic characterisation of the V455L variant revealed a significant increase in glucose affinity (glucose concentration at which reaction rate is half its maximum rate [S0.5]: mutant 2.4 ± 0.3 mmol/l vs wild-type 7.6 ± 1.0 mmol/l), accompanied by a distinct additive susceptibility to both the endogenous activator fructose 2,6-bisphosphatase and the synthetic allosteric activator RO-28-1675. The effect of RO-28-1675 was more pronounced when compared with the previously known GK variants V455M and V455E. Binding to the inhibitor glucokinase regulatory protein was unimpaired for V455L and V455E but was reduced for V455M, whereas mannoheptulose inhibited all GK variants and the wild-type enzyme. Structural analyses suggested a role for residue 455 in rearrangements between the inactive and active conformations of GK and also in allosteric activation. Comparison with V455M and V455E and an overview of activating GK variants provided a context for the novel sequence aberration in terms of altered GK enzyme characteristics caused by single amino acid changes. CONCLUSION/INTERPRETATION We provide new knowledge on the structure-function relationship of GK, with special emphasis on enzyme activation, potentially yielding fresh strategic insights into breaking the vicious circle of fluctuating blood glucose levels and the attendant risk of long-lasting metabolic changes in both CHI and type 2 diabetes.
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Affiliation(s)
- Sara Langer
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany
| | - Rica Waterstradt
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany
| | - Georg Hillebrand
- Department of Pediatrics, University Medical Center Eppendorf, Hamburg, Germany
- Department of Pediatrics, Medical Center Itzehoe, Itzehoe, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Eppendorf, Hamburg, Germany
| | - Simone Baltrusch
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany.
- Department Life, Light & Matter, University of Rostock, Rostock, Germany.
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Buziau AM, Schalkwijk CG, Stehouwer CDA, Tolan DR, Brouwers MCGJ. Recent advances in the pathogenesis of hereditary fructose intolerance: implications for its treatment and the understanding of fructose-induced non-alcoholic fatty liver disease. Cell Mol Life Sci 2020; 77:1709-1719. [PMID: 31713637 DOI: 10.1007/s00018-019-03348-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 10/02/2019] [Accepted: 10/16/2019] [Indexed: 12/31/2022]
Abstract
Hereditary fructose intolerance (HFI) is a rare inborn disease characterized by a deficiency in aldolase B, which catalyzes the cleavage of fructose 1,6-bisphosphate and fructose 1-phosphate (Fru 1P) to triose molecules. In patients with HFI, ingestion of fructose results in accumulation of Fru 1P and depletion of ATP, which are believed to cause symptoms, such as nausea, vomiting, hypoglycemia, and liver and kidney failure. These sequelae can be prevented by a fructose-restricted diet. Recent studies in aldolase B-deficient mice and HFI patients have provided more insight into the pathogenesis of HFI, in particular the liver phenotype. Both aldolase B-deficient mice (fed a very low fructose diet) and HFI patients (treated with a fructose-restricted diet) displayed greater intrahepatic fat content when compared to controls. The liver phenotype in aldolase B-deficient mice was prevented by reduction in intrahepatic Fru 1P concentrations by crossing these mice with mice deficient for ketohexokinase, the enzyme that catalyzes the synthesis of Fru 1P. These new findings not only provide a potential novel treatment for HFI, but lend insight into the pathogenesis of fructose-induced non-alcoholic fatty liver disease (NAFLD), which has raised to epidemic proportions in Western society. This narrative review summarizes the most recent advances in the pathogenesis of HFI and discusses the implications for the understanding and treatment of fructose-induced NAFLD.
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Affiliation(s)
- Amée M Buziau
- Division of Endocrinology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Laboratory for Metabolism and Vascular Medicine, Division of General Internal Medicine, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | - Casper G Schalkwijk
- Laboratory for Metabolism and Vascular Medicine, Division of General Internal Medicine, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | - Coen D A Stehouwer
- Laboratory for Metabolism and Vascular Medicine, Division of General Internal Medicine, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- Division of General Internal Medicine, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Dean R Tolan
- Department of Biology, Boston University, Boston, MA, USA.
| | - Martijn C G J Brouwers
- Division of Endocrinology, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
- Laboratory for Metabolism and Vascular Medicine, Division of General Internal Medicine, Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands.
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Kaushik A, Kaushik M. Recent Updates on Glucokinase Activators and Glucokinase Regulatory Protein Disrupters for the Treatment of Type 2 Diabetes Mellitus. Curr Diabetes Rev 2019; 15:205-212. [PMID: 30039763 DOI: 10.2174/1573399814666180724100749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 01/05/2023]
Abstract
INTRODUCTION The impairment of glucose metabolism leads to hyperglycemia and type-2 diabetes mellitus. Glucokinase enzyme is the key regulator of glucose homeostasis that catalyzes the conversion of glucose to glucose-6-phosphate in liver and pancreatic cells. In hepatocytes, GK controls the glucose uptake and glycogen synthesis. The action of liver GK is controlled by Glucokinase Regulatory Protein (GKRP) partially. In fasting conditions the GKRP binds with GK and inactivate it from carbohydrate metabolism and serve as new target for treatment of diabetes mellitus. However, the GK activators as potential antidiabetic agents but results in increased risks of hypoglycemia. CONCLUSION The allosteric inhibitors of the GK-GKRP interaction are coming as alternative agents that can mitigate the risk associated with GK activators. This review discusses the recent advances and current status of potential molecules targeted to GK activators and GK-GKRP disrupters.
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Affiliation(s)
- Aditi Kaushik
- I.K.Gujral Punjab Technical University, Jalandhar - Kapurthala Highway, Kapurthala, Punjab, India
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Patel V, Dwivedi AK, Deodhar S, Mishra I, Cistola DP. Aptamer-based search for correlates of plasma and serum water T 2: implications for early metabolic dysregulation and metabolic syndrome. Biomark Res 2018; 6:28. [PMID: 30237882 PMCID: PMC6142358 DOI: 10.1186/s40364-018-0143-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/29/2018] [Indexed: 12/13/2022] Open
Abstract
Background Metabolic syndrome is a cluster of abnormalities that increases the risk for type 2 diabetes and atherosclerosis. Plasma and serum water T2 from benchtop nuclear magnetic resonance relaxometry are early, global and practical biomarkers for metabolic syndrome and its underlying abnormalities. In a prior study, water T2 was analyzed against ~ 130 strategically selected proteins and metabolites to identify associations with insulin resistance, inflammation and dyslipidemia. In the current study, the analysis was broadened ten-fold using a modified aptamer (SOMAmer) library, enabling an unbiased search for new proteins correlated with water T2 and thus, metabolic health. Methods Water T2 measurements were recorded using fasting plasma and serum from non-diabetic human subjects. In parallel, plasma samples were analyzed using a SOMAscan assay that employed modified DNA aptamers to determine the relative concentrations of 1310 proteins. A multi-step statistical analysis was performed to identify the biomarkers most predictive of water T2. The steps included Spearman rank correlation, followed by principal components analysis with variable clustering, random forests for biomarker selection, and regression trees for biomarker ranking. Results The multi-step analysis unveiled five new proteins most predictive of water T2: hepatocyte growth factor, receptor tyrosine kinase FLT3, bone sialoprotein 2, glucokinase regulatory protein and endothelial cell-specific molecule 1. Three of the five strongest predictors of water T2 have been previously implicated in cardiometabolic diseases. Hepatocyte growth factor has been associated with incident type 2 diabetes, and endothelial cell specific molecule 1, with atherosclerosis in subjects with diabetes. Glucokinase regulatory protein plays a critical role in hepatic glucose uptake and metabolism and is a drug target for type 2 diabetes. By contrast, receptor tyrosine kinase FLT3 and bone sialoprotein 2 have not been previously associated with metabolic conditions. In addition to the five most predictive biomarkers, the analysis unveiled other strong correlates of water T2 that would not have been identified in a hypothesis-driven biomarker search. Conclusions The identification of new proteins associated with water T2 demonstrates the value of this approach to biomarker discovery. It provides new insights into the metabolic significance of water T2 and the pathophysiology of metabolic syndrome. Electronic supplementary material The online version of this article (10.1186/s40364-018-0143-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vipulkumar Patel
- 1Nanoparticle Diagnostics Laboratory, Institute for Cardiovascular & Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, TX 76107 USA.,2Center of Emphasis in Diabetes & Metabolism, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USA
| | - Alok K Dwivedi
- 3Division of Biostatistics & Epidemiology, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USA
| | - Sneha Deodhar
- 1Nanoparticle Diagnostics Laboratory, Institute for Cardiovascular & Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, TX 76107 USA
| | - Ina Mishra
- 1Nanoparticle Diagnostics Laboratory, Institute for Cardiovascular & Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, TX 76107 USA.,2Center of Emphasis in Diabetes & Metabolism, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USA
| | - David P Cistola
- 1Nanoparticle Diagnostics Laboratory, Institute for Cardiovascular & Metabolic Diseases, University of North Texas Health Science Center, Fort Worth, TX 76107 USA.,2Center of Emphasis in Diabetes & Metabolism, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905 USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hovsepian S, Javanmard SH, Mansourian M, Tajadini M, Hashemipour M, Kelishadi R. Relationship of lipid regulatory gene polymorphisms and dyslipidemia in a pediatric population: the CASPIAN III study. Hormones (Athens) 2018; 17:97-105. [PMID: 29858861 DOI: 10.1007/s42000-018-0020-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 02/23/2018] [Indexed: 01/10/2023]
Abstract
OBJECTIVE In this study, we aimed to assess the association between four variants in three genes whose association has been reported in adults but not in children. We evaluated the relationship of the GCKR (rs780094), GCKR (rs1260333), FADS (rs174547), and MLXIPL (rs3812316) polymorphisms with serum lipid levels in Iranian children. DESIGN This cross-sectional study was conducted in a subpopulation of the CASPIAN III study. During this study, 550 frozen whole blood samples were selected randomly. Using the recorded information of selected cases, those with and without abnormal lipid levels were determined. Allelic and genotypic frequencies of GCKR (rs780094), GCKR (rs1260333), MLXIPL (rs3812316), and FADS (rs174547) polymorphisms were determined and compared in dyslipidemic and normal children. The association between the studied polymorphisms and lipid profiles was determined using logistic regression analysis. RESULTS Prevalence of hypercholesterolemia, hypertriglyceridemia, high low-density lipoprotein cholesterol (LDL-C), and low high-density lipoprotein cholesterol (HDL-C) were 24.9, 34.5, 19.0, and 40.7%, respectively. Significant correlations were found between GCKR (rs780094) and GCKR (rs1260333) polymorphisms and cholesterol and triglyceride levels, between FADS (rs174547) polymorphism and level of triglyceride, and also between MLXIPL (rs3812316) and levels of HDL-C. CONCLUSIONS The results of this population-based study provide evidence for a relationship between lipid regulatory gene polymorphisms including GCKR (rs780094), GCKR (rs1260333), FADS (rs174547), and MLXIPL (rs3812316) with dyslipidemia in an Iranian population. These results could provide baseline information on as well as further insight into the genetic makeup of lipid profiles in Iranian children, which could be used for preventative strategies.
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Affiliation(s)
- Silva Hovsepian
- Pediatrics Department, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Emam Hossein Children's Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Marjan Mansourian
- Department of Biostatistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohamadhasan Tajadini
- Applied Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahin Hashemipour
- Pediatrics Department, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roya Kelishadi
- Pediatrics Department, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Hezar-Jarib Ave, Isfahan, Iran.
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Ling B, Yan X, Sun M, Bi S. Theoretical investigations on the interactions of glucokinase regulatory protein with fructose phosphates. Comput Biol Chem 2015; 60:21-31. [PMID: 26629747 DOI: 10.1016/j.compbiolchem.2015.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 07/16/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
Glucokinase (GK) plays a critical role in maintaining glucose homeostasis in the human liver and pancreas. In the liver, the activity of GK is modulated by the glucokinase regulatory protein (GKRP) which functions as a competitive inhibitor of glucose to bind to GK. Moreover, the inhibitory intensity of GKRP-GK is suppressed by fructose 1-phosphate (F1P), and reinforced by fructose 6-phosphate (F6P). Here, we employed a series of computational techniques to explore the interactions of fructose phosphates with GKRP. Calculation results reveal that F1P and F6P can bind to the same active site of GKRP with different binding modes, and electrostatic interaction provides a major driving force for the ligand binding. The presence of fructose phosphate severely influences the motions of protein and the conformational space, and the structural change of sugar phosphate influences its interactions with GKRP, leading to a large conformational rearrangement of loop2 in the SIS2 domain. In particular, the binding of F6P to GKRP facilitates the protruding loop2 contacting with GK to form the stable GK-GKRP complex. The conserved residues 179-184 of GKRP play a major role in the binding of phosphate group and maintaining the stability of GKRP. These results may provide deep insight into the regulatory mechanism of GKRP to the activity of GK.
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Affiliation(s)
- Baoping Ling
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong Province 273165, China.
| | - Xueyuan Yan
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong Province 273165, China
| | - Min Sun
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong Province 273165, China
| | - Siwei Bi
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong Province 273165, China.
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11
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Tam CHT, Wang Y, Lee HM, Luk AOY, Tong PCY, Chan MHM, Ozaki R, Kong APS, So WY, Chan JCN, Ma RCW. Early gene-diet interaction between glucokinase regulatory protein (GCKR) polymorphism, vegetable and fish intakes in modulating triglyceride levels in healthy adolescents. Nutr Metab Cardiovasc Dis 2015; 25:951-958. [PMID: 26234566 DOI: 10.1016/j.numecd.2015.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 06/29/2015] [Accepted: 06/29/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND AIMS The benefits of dietary vegetable and fish consumptions on improving glucose and lipid metabolism have been well established. Recently, the T-allele of a common genetic variant rs780094 at glucokinase regulatory protein (GCKR) was reported to be associated with elevated triglyceride (TG) levels but reduced fasting plasma glucose (FPG) and type 2 diabetes risk. However, the dietary modulation on genetic risk is not clearly understood. METHODS AND RESULTS A cohort of 2095 Chinese adolescents (mean age 15.6 ± 2.0 years, 45.3% male) recruited from a population-based school survey for cardiovascular risk factor assessment, with dietary data including weekly vegetable and fish consumptions as well as clinical data were genotyped for the GCKR rs780094 polymorphism. In the linear regression analysis with adjustment for sex, age, body mass index, and socioeconomic status (school banding, paternal and maternal education levels), the frequency of vegetable intake per week was inversely associated with FPG (P = 0.044). Individuals with low fish intake generally had elevated TG levels but reduced TC, HDL-C and LDL-C (0.006 < P < 0.029). We also observed significant associations of the minor T-allele of GCKR rs780094 with decreased FPG (P = 0.013) and increased TG levels (P = 2.7 × 10(-8)). There were significant gene-diet interactions between rs780094 and vegetable consumption (P(interaction) = 0.009), and between rs780094 and fish consumption (P(interaction) = 0.031) in modulating TG levels. The T-allele of GCKR locus was associated with higher TG levels amongst individuals with ≥7 vegetable meals per week (P = 6.4 × 10(-9)), and among individuals with <7 fish meals per week (P = 0.020 and 7.0 × 10(-7) for 4-6 and ≤3 meals per week, respectively). High intake of vegetable exerted a reduction in TG levels only among CC genotype carriers (Ptrend = 0.020), while high intake of fish was associated with reduced TG levels only among TT genotype carriers (Ptrend = 0.026). CONCLUSIONS In summary, our data indicated that the favorable associations of higher vegetable and fish intakes on TG levels are dependent on the genetic background of an individual. In particular, at-risk TT- genotype carriers of the GCKR variant may derive more benefits from a high fish intake, while the CC-genotype carriers may find further benefits from a high consumption of vegetable.
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Affiliation(s)
- C H T Tam
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong
| | - Y Wang
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong
| | - H M Lee
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong
| | - A O Y Luk
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - P C Y Tong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - M H M Chan
- Department of Chemical Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | - R Ozaki
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - A P S Kong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - W Y So
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - J C N Chan
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong
| | - R C W Ma
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong (CUHK), Prince of Wales Hospital (PWH), Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong; Hong Kong Institute of Diabetes and Obesity, The Chinese University of Hong Kong, Hong Kong; CUHK-PWH International Diabetes Federation (IDF) Centre of Education, Hong Kong.
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12
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Marzuillo P, Miraglia del Giudice E, Santoro N. Pediatric fatty liver disease: Role of ethnicity and genetics. World J Gastroenterol 2014; 20:7347-7355. [PMID: 24966605 PMCID: PMC4064080 DOI: 10.3748/wjg.v20.i23.7347] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/04/2014] [Accepted: 01/20/2014] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) comprehends a wide range of conditions, encompassing from fatty liver or steatohepatitis with or without fibrosis, to cirrhosis and its complications. NAFLD has become the most common form of liver disease in childhood as its prevalence has more than doubled over the past 20 years, paralleling the increased prevalence of childhood obesity. It currently affects between 3% and 11% of the pediatric population reaching the rate of 46% among overweight and obese children and adolescents. The prevalence of hepatic steatosis varies among different ethnic groups. The ethnic group with the highest prevalence is the Hispanic one followed by the Caucasian and the African-American. This evidence suggests that there is a strong genetic background in the predisposition to fatty liver. In fact, since 2008 several common gene variants have been implicated in the pathogenesis of fatty liver disease. The most important is probably the patatin like phospholipase containing domain 3 gene (PNPLA3) discovered by the Hobbs’ group in 2008. This article reviews the current knowledge regarding the role of ethnicity and genetics in pathogenesis of pediatric fatty liver.
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13
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Cullen KS, Al-Oanzi ZH, O'Harte FPM, Agius L, Arden C. Glucagon induces translocation of glucokinase from the cytoplasm to the nucleus of hepatocytes by transfer between 6-phosphofructo 2-kinase/fructose 2,6-bisphosphatase-2 and the glucokinase regulatory protein. Biochim Biophys Acta 2014; 1843:1123-34. [PMID: 24566088 PMCID: PMC4024195 DOI: 10.1016/j.bbamcr.2014.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/07/2014] [Accepted: 02/12/2014] [Indexed: 01/28/2023]
Abstract
Glucokinase activity is a major determinant of hepatic glucose metabolism and blood glucose homeostasis. Liver glucokinase activity is regulated acutely by adaptive translocation between the nucleus and the cytoplasm through binding and dissociation from its regulatory protein (GKRP) in the nucleus. Whilst the effect of glucose on this mechanism is well established, the role of hormones in regulating glucokinase location and its interaction with binding proteins remains unsettled. Here we show that treatment of rat hepatocytes with 25mM glucose caused decreased binding of glucokinase to GKRP, translocation from the nucleus and increased binding to 6-phosphofructo 2-kinase/fructose 2,6 bisphosphatase-2 (PFK2/FBPase2) in the cytoplasm. Glucagon caused dissociation of glucokinase from PFK2/FBPase2, concomitant with phosphorylation of PFK2/FBPase2 on Ser-32, uptake of glucokinase into the nucleus and increased interaction with GKRP. Two novel glucagon receptor antagonists attenuated the action of glucagon. This establishes an unequivocal role for hormonal control of glucokinase translocation. Given that glucagon excess contributes to the pathogenesis of diabetes, glucagon may play a role in the defect in glucokinase translocation and activity evident in animal models and human diabetes.
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Affiliation(s)
- Kirsty S Cullen
- Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK
| | - Ziad H Al-Oanzi
- Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK; Department of Laboratory Medicine, Al-Jouf University, Sakaka, Saudi Arabia
| | - Finbarr P M O'Harte
- The Saad Centre for Pharmacy & Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine, UK
| | - Loranne Agius
- Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK
| | - Catherine Arden
- Institute of Cellular Medicine, Newcastle University, Newcastle Upon Tyne, UK.
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14
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Marzuillo P, Giudice EMD, Santoro N. Pediatric non-alcoholic fatty liver disease: New insights and future directions. World J Hepatol 2014; 6:217-225. [PMID: 24799990 PMCID: PMC4009477 DOI: 10.4254/wjh.v6.i4.217] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 02/25/2014] [Accepted: 03/18/2014] [Indexed: 02/06/2023] Open
Abstract
One of the most common complications of childhood obesity is the non-alcoholic fatty liver disease (NAFLD), which is the most common form of liver disease in children. NAFLD is defined by hepatic fat infiltration > 5% hepatocytes, as assessed by liver biopsy, in the absence of excessive alcohol intake, viral, autoimmune and drug-induced liver disease. It encompasses a wide spectrum of liver diseases ranging from simple steatosis to non-alcoholic steatohepatitis, which, in turn, can evolve into cirrhosis and end stage liver disease. Obesity and insulin resistance are the main risk factors for pediatric NAFLD. In fact, NAFLD is strongly associated with the clinical features of insulin resistance especially the metabolic syndrome, prediabetes and type 2 diabetes mellitus (T2D). In particular, it has been clearly shown in obese youth that the prevalence of metabolic syndrome, pre-diabetes and type 2 diabetes increases with NAFLD severity progression. Evidence that not all of the obese patients develop NAFLD suggests that the disease progression is likely to depend on complex interplay between environmental factors and genetic predisposition. Recently, a non-synonymous SNP (rs738409), characterized by a C to G substitution encoding an isoleucine to methionine substitution at the amino acid position 148 in the patatin like phospholipase containing domain 3 gene (PNPLA3), has been associated with hepatic steatosis in a multiethnic cohort of adults as well as in children. Another important polymorphisms that acts with PNPLA3 to convey susceptibility to fatty liver in obese youths is the rs1260326 polymorphism in the glucokinase regulatory protein. The pharmacological approach in NAFLD children poorly adherent to or being unresponsive/partially responsive to lifestyle changes, is aimed at acting upon specific targets involved in the pathogenesis. There are some therapeutic approaches that are being studied in children. This article reviews the current knowledge regarding the pediatric fatty liver disease, the new insights and the future directions.
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15
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Ouyang LZ, Lu FE, Liu WJ, Gao ZQ, Xu LJ. Effect of berberine on hepatic glucokinase and its regulatory protein in insulin-resistant rats. Shijie Huaren Xiaohua Zazhi 2007; 15:885-889. [DOI: 10.11569/wcjd.v15.i8.885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effects of berberine on hepatic glucokinase (GK) activity, protein expression and GK's regulatory protein (GKRP) in insulin-resistant rats.
METHODS: Male Wistar rats were fed with high-fat diet for 8 wk to induce the model of insulin resistance. Then the insulin-resistant rats were randomly divided into 3 groups: model, berberine, and metformin groups which were treated with the corresponding preparations. Meanwhile, a normal control group was designed. The differences in insulin sensitivity, hepatic glycogen, hepatic GK activity, and protein expression (using Western blot) of hepatic GK and GKRP were compared among the groups.
RESULTS: As compared with those in model group, the insulin sensitivity (-4.93 ± 0.30 vs -5.35 ± 0.40, P < 0.05), hepatic glycogen level (136.58 ± 52.57 µg/g vs 65.88 ± 27.80 µg/g, P < 0.05), GK activity (226.55 ± 10.62 µkat/g vs 92.69 ± 6.43 µkat/g, P < 0.05), and hepatic GK protein expression (1.71±0.49 vs 1.24±0.22, P < 0.05) were significantly elevated in berberine group, while the expression of GKRP protein weaker (1.19 ± 0.20 vs 1.94 ± 0.56, P < 0.01). Meanwhile, the hepatic glycogen level in berberine group was markedly higher than that in metformin group (136.584 ± 52.574 µg/g vs 89.427 ± 31.971 µg/g, P < 0.05), but the other indexes were not significantly different between them (all P > 0.05).
CONCLUSION: Berberine may decrease insulin resistance by increasing of the hepatic GK activity.
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