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Ford BE, Chachra SS, Alshawi A, Oakley F, Fairclough RJ, Smith DM, Tiniakos D, Agius L. Compromised chronic efficacy of a glucokinase activator AZD1656 in mouse models for common human GCKR variants. Biochem Pharmacol 2024; 229:116499. [PMID: 39173844 DOI: 10.1016/j.bcp.2024.116499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/23/2024] [Accepted: 08/19/2024] [Indexed: 08/24/2024]
Abstract
Glucokinase activators (GKAs) have been developed as blood glucose lowering drugs for type 2 diabetes. Despite good short-term efficacy, several GKAs showed a decline in efficacy chronically during clinical trials. The underlying mechanisms remain incompletely understood. We tested the hypothesis that deficiency in the liver glucokinase regulatory protein (GKRP) as occurs with common human GCKR variants affects chronic GKA efficacy. We used a Gckr-P446L mouse model for the GCKR exonic rs1260326 (P446L) variant and the Gckr-del/wt mouse to model transcriptional deficiency to test for chronic efficacy of the GKA, AZD1656 in GKRP-deficient states. In the Gckr-P446L mouse, the blood glucose lowering efficacy of AZD1656 (3 mg/kg body wt) after 2 weeks was independent of genotype. However after 19 weeks, efficacy was maintained in wild-type but declined in the LL genotype, in conjunction with raised hepatic glucokinase activity and without raised liver lipids. Sustained blood glucose lowering efficacy in wild-type mice was associated with qualitatively similar but more modest changes in the liver transcriptome compared with the P446L genotype, consistent with GKA therapy representing a more modest glucokinase excess than the P446L genotype. Chronic treatment with AZD1656 in the Gckr-del/wt mouse was associated with raised liver triglyceride and hepatocyte microvesicular steatosis. The results show that in mouse models of liver GKRP deficiency in conjunction with functional liver glucokinase excess as occurs in association with common human GCKR variants, GKRP-deficiency predisposes to declining efficacy of the GKA in lowering blood glucose and to GKA induced elevation in liver lipids.
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Affiliation(s)
- Brian E Ford
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Shruti S Chachra
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Ahmed Alshawi
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Medical Laboratory Technique Department, Kufa Institute, Al-Furat Al-Awsat Technical University, Kufa, Iraq
| | - Fiona Oakley
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Rebecca J Fairclough
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - David M Smith
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Dina Tiniakos
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Dept of Pathology, Aretaieion Hospital Medical School, National and Kapodistrian University of Athens, Greece
| | - Loranne Agius
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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2
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Wang Y, Fan M, Qian H, Ying H, Li Y, Wang L. Whole grains-derived functional ingredients against hyperglycemia: targeting hepatic glucose metabolism. Crit Rev Food Sci Nutr 2023; 64:7268-7289. [PMID: 36847153 DOI: 10.1080/10408398.2023.2183382] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycemia. However, concerns have been raised about the safety and efficacy of current hypoglycemic drugs due to undesirable side effects. Increasing studies have shown that whole grains (WG) consumption is inversely associated with the risk of T2DM and its subsequent complications. Thus, dietary strategies involving functional components from the WG provide an intriguing approach to restoring and maintaining glucose homeostasis. This review provides a comprehensive understanding of the major functional components derived from WG and their positive effects on glucose homeostasis, demonstrates the underlying molecular mechanisms targeting hepatic glucose metabolism, and discusses the unclear aspects according to the latest viewpoints and current research. Improved glycemic response and insulin resistance were observed after consumption of WG-derived bioactive ingredients, which are involved in the integrated, multi-factorial, multi-targeted regulation of hepatic glucose metabolism. Promotion of glucose uptake, glycolysis, and glycogen synthesis pathways, while inhibition of gluconeogenesis, contributes to amelioration of abnormal hepatic glucose metabolism and insulin resistance by bioactive components. Hence, the development of WG-based functional food ingredients with potent hypoglycemic properties is necessary to manage insulin resistance and T2DM.
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Affiliation(s)
- Yu Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Mingcong Fan
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Haifeng Qian
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Hao Ying
- CAS Key laboratory of nutrition, metabolism and food safety, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yan Li
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Li Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, China
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3
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Chen B, Du YR, Zhu H, Sun ML, Wang C, Cheng Y, Pang H, Ding G, Gao J, Tan Y, Tong X, Lv P, Zhou F, Zhan Q, Xu ZM, Wang L, Luo D, Ye Y, Jin L, Zhang S, Zhu Y, Lin X, Wu Y, Jin L, Zhou Y, Yan C, Sheng J, Flatt PR, Xu GL, Huang H. Maternal inheritance of glucose intolerance via oocyte TET3 insufficiency. Nature 2022; 605:761-766. [PMID: 35585240 DOI: 10.1038/s41586-022-04756-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 04/12/2022] [Indexed: 02/05/2023]
Abstract
Diabetes mellitus is prevalent among women of reproductive age, and many women are left undiagnosed or untreated1. Gestational diabetes has profound and enduring effects on the long-term health of the offspring2,3. However, the link between pregestational diabetes and disease risk into adulthood in the next generation has not been sufficiently investigated. Here we show that pregestational hyperglycaemia renders the offspring more vulnerable to glucose intolerance. The expression of TET3 dioxygenase, responsible for 5-methylcytosine oxidation and DNA demethylation in the zygote4, is reduced in oocytes from a mouse model of hyperglycaemia (HG mice) and humans with diabetes. Insufficient demethylation by oocyte TET3 contributes to hypermethylation at the paternal alleles of several insulin secretion genes, including the glucokinase gene (Gck), that persists from zygote to adult, promoting impaired glucose homeostasis largely owing to the defect in glucose-stimulated insulin secretion. Consistent with these findings, mouse progenies derived from the oocytes of maternal heterozygous and homozygous Tet3 deletion display glucose intolerance and epigenetic abnormalities similar to those from the oocytes of HG mice. Moreover, the expression of exogenous Tet3 mRNA in oocytes from HG mice ameliorates the maternal effect in offspring. Thus, our observations suggest an environment-sensitive window in oocyte development that confers predisposition to glucose intolerance in the next generation through TET3 insufficiency rather than through a direct perturbation of the oocyte epigenome. This finding suggests a potential benefit of pre-conception interventions in mothers to protect the health of offspring.
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Affiliation(s)
- Bin Chen
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China.,State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Ya-Rui Du
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Hong Zhu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Mei-Ling Sun
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chao Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yi Cheng
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Haiyan Pang
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Guolian Ding
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Juan Gao
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Yajing Tan
- Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaomei Tong
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Pingping Lv
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Feng Zhou
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Qitao Zhan
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhi-Mei Xu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Li Wang
- Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Donghao Luo
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yinghui Ye
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li Jin
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Songying Zhang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yimin Zhu
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaona Lin
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yanting Wu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Luyang Jin
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yin Zhou
- Center for Reproductive Medicine, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Caochong Yan
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianzhong Sheng
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Peter R Flatt
- Centre for Diabetes Research, School of Biomedical Sciences, Ulster University, Coleraine, UK
| | - Guo-Liang Xu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China. .,Shanghai Key Laboratory of Medical Epigenetics, Laboratory of Cancer Epigenetics, Institutes of Biomedical Sciences, Medical College of Fudan University, Chinese Academy of Medical Sciences (RU069), Shanghai, China.
| | - Hefeng Huang
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China. .,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China. .,Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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Song P, Shen X. Proteomic analysis of liver in diet-induced Hyperlipidemic mice under Fructus Rosa roxburghii action. J Proteomics 2020; 230:103982. [PMID: 32927110 DOI: 10.1016/j.jprot.2020.103982] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/28/2020] [Accepted: 09/08/2020] [Indexed: 12/23/2022]
Abstract
Fructus Rosae Roxburghii (FRR) has been considered as edible and medicinal fruit possessing antiatherosclerotic effect, but the mechanism is still unclear. HLP is material basis for AS formation. Under FRR action, TC, TG, LDL, HDL and ASI in serum were regulated to control level. Differentially expressed proteins in liver were analyzed by using TMT labeling and LC-MS/MS for better understanding the effect and molecular mechanism of FRR on diet-induced hyperlipidemic mice. In total, 4460 proteins were quantified, of which 469 proteins showed dramatic changes between each group. According to molecular functions, 25 differentially co-expressed proteins were divided into five categories: substance metabolism, energy transformation and signal transduction, transcription and translation, immune defense. 15 key proteins involved lipids metabolism, which were identified as Cyp7a1, Cyp3a11, Tm7sf2, COAT2, CSAD, RBP3, Lpin1, Dhrs4, Aldh1b1, GK, Acot 4, TSC22D1, PGFS, EHs, GSTM1. This suggested that FRR could maintain metabolic homeostasis by regulating the metabolism of fatty acids, biosynthesis of BAs and steroids, and production of LPOs. 20 oxidative lipids further confirmed their importance regulating lipids metabolism. It's first time potential antiatherosclerotic mechanism of FRR regulating blood lipids was explored from protein level, which is of great significance to explore new drug targets for AS. SIGNIFICANCE: Under the action of FRR juice, the blood lipids in mice were regulated to control level. By TMT proteomic analysis, the effect and molecular mechanism of FRR on diet-induced hyperlipidemic mice were further explored. 25 differentially co-expressed proteins obtained in three diet groups might cooperatively regulate the lipids metabolism and hepatic function of mice, thus maintaining the metabolism homeostasis. By lipidomics analysis, 20 oxidative lipids further confirmed the importance of ω-3 and ω-6 PUFAs in regulating the lipids metabolism. These findings provide an improved understanding for the regulation of FRR on the blood lipids and explores potential metabolic targets for AS prevention.
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Affiliation(s)
- Pingping Song
- The State Key Laboratory of Functions and Applications of Medicinal Plants (The high Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province and The high Educational Key laboratory of Guizhou Province for Natural Medicinal Pharmacology and Druggability), Guizhou Medical University, Guian New District, Guizhou 550000, China; Key Laboratory of Optimal Utilization of Natural Medicine Resources (The Union Key Laboratory of Guiyang City-Guizhou Medical University), School of Pharmaceutical Sciences, Guizhou Medical University, Guian New District, Guizhou 550000, China
| | - Xiangchun Shen
- The State Key Laboratory of Functions and Applications of Medicinal Plants (The high Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province and The high Educational Key laboratory of Guizhou Province for Natural Medicinal Pharmacology and Druggability), Guizhou Medical University, Guian New District, Guizhou 550000, China; Key Laboratory of Optimal Utilization of Natural Medicine Resources (The Union Key Laboratory of Guiyang City-Guizhou Medical University), School of Pharmaceutical Sciences, Guizhou Medical University, Guian New District, Guizhou 550000, China.
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5
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Pouwer MG, Heinonen SE, Behrendt M, Andréasson AC, van Koppen A, Menke AL, Pieterman EJ, van den Hoek AM, Jukema JW, Leighton B, Jönsson-Rylander AC, Princen HMG. The APOE ∗3-Leiden Heterozygous Glucokinase Knockout Mouse as Novel Translational Disease Model for Type 2 Diabetes, Dyslipidemia, and Diabetic Atherosclerosis. J Diabetes Res 2019; 2019:9727952. [PMID: 30949516 PMCID: PMC6425338 DOI: 10.1155/2019/9727952] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/31/2018] [Accepted: 11/08/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND There is a lack of predictive preclinical animal models combining atherosclerosis and type 2 diabetes. APOE∗3-Leiden (E3L) mice are a well-established model for diet-induced hyperlipidemia and atherosclerosis, and glucokinase+/- (GK+/-) mice are a translatable disease model for glucose control in type 2 diabetes. The respective mice respond similarly to lipid-lowering and antidiabetic drugs as humans. The objective of this study was to evaluate/characterize the APOE∗3-Leiden.glucokinase+/- (E3L.GK+/-) mouse as a novel disease model to study the metabolic syndrome and diabetic complications. METHODS Female E3L.GK+/-, E3L, and GK+/- mice were fed fat- and cholesterol-containing diets for 37 weeks, and plasma parameters were measured throughout. Development of diabetic macro- and microvascular complications was evaluated. RESULTS Cholesterol and triglyceride levels were significantly elevated in E3L and E3L.GK+/- mice compared to GK+/- mice, whereas fasting glucose was significantly increased in E3L.GK+/- and GK+/- mice compared to E3L. Atherosclerotic lesion size was increased 2.2-fold in E3L.GK+/- mice as compared to E3L (p = 0.037), which was predicted by glucose exposure (R 2 = 0.636, p = 0.001). E3L and E3L.GK+/- mice developed NASH with severe inflammation and fibrosis which, however, was not altered by introduction of the defective GK phenotype, whereas mild kidney pathology with tubular vacuolization was present in all three phenotypes. CONCLUSIONS We conclude that the E3L.GK+/- mouse is a promising novel diet-inducible disease model for investigation of the etiology and evaluation of drug treatment on diabetic atherosclerosis.
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Affiliation(s)
- Marianne G. Pouwer
- Metabolic Health Research, The Netherlands Organization of Applied Scientific Research (TNO), Gaubius Laboratory, Leiden, Netherlands
- Cardiology, Leiden University Medical Center, Leiden, Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Suvi E. Heinonen
- Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Margareta Behrendt
- Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | | | - Arianne van Koppen
- Metabolic Health Research, The Netherlands Organization of Applied Scientific Research (TNO), Gaubius Laboratory, Leiden, Netherlands
| | | | - Elsbet J. Pieterman
- Metabolic Health Research, The Netherlands Organization of Applied Scientific Research (TNO), Gaubius Laboratory, Leiden, Netherlands
| | - Anita M. van den Hoek
- Metabolic Health Research, The Netherlands Organization of Applied Scientific Research (TNO), Gaubius Laboratory, Leiden, Netherlands
| | - J. Wouter Jukema
- Cardiology, Leiden University Medical Center, Leiden, Netherlands
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Brendan Leighton
- Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
- The Research Network, Sandwich, Kent, UK
| | | | - Hans M. G. Princen
- Metabolic Health Research, The Netherlands Organization of Applied Scientific Research (TNO), Gaubius Laboratory, Leiden, Netherlands
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Hyperglycemia does not affect tissue repair responses in shear stress-induced atherosclerotic plaques in ApoE-/- mice. Sci Rep 2018; 8:7530. [PMID: 29760458 PMCID: PMC5951920 DOI: 10.1038/s41598-018-25942-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/30/2018] [Indexed: 12/31/2022] Open
Abstract
The mechanisms responsible for macrovascular complications in diabetes remain to be fully understood. Recent studies have identified impaired vascular repair as a possible cause of plaque vulnerability in diabetes. This notion is supported by observations of a reduced content of fibrous proteins and smooth muscle cell mitogens in carotid endarterectomy from diabetic patients along with findings of decreased circulating levels of endothelial progenitor cells. In the present study we used a diabetic mouse model to characterize how hyperglycemia affects arterial repair responses. We induced atherosclerotic plaque formation in ApoE-deficient (ApoE−/−) and heterozygous glucokinase knockout ApoE-deficient mice (ApoE−/− GK+/−) mice with a shear stress-modifying cast. There were no differences in cholesterol or triglyceride levels between the ApoE−/− and ApoE−/− GK+/− mice. Hyperglycemia did not affect the size of the formed atherosclerotic plaques, and no effects were seen on activation of cell proliferation, smooth muscle cell content or on the expression and localization of collagen, elastin and several other extracellular matrix proteins. The present study demonstrates that hyperglycemia per se has no significant effects on tissue repair processes in injured mouse carotid arteries, suggesting that other mechanisms are involved in diabetic plaque vulnerability.
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7
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Adingupu DD, Heinonen SE, Andréasson AC, Brusberg M, Ahnmark A, Behrendt M, Leighton B, Jönsson-Rylander AC. Hyperglycemia Induced by Glucokinase Deficiency Accelerates Atherosclerosis Development and Impairs Lesion Regression in Combined Heterozygous Glucokinase and the Apolipoprotein E-Knockout Mice. J Diabetes Res 2016; 2016:8630961. [PMID: 27774459 PMCID: PMC5059602 DOI: 10.1155/2016/8630961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/08/2016] [Indexed: 01/30/2023] Open
Abstract
Aim. Models combining diabetes and atherosclerosis are important in evaluating the cardiovascular (CV) effects and safety of antidiabetes drugs in the development of treatments targeting CV complications. Our aim was to evaluate if crossing the heterozygous glucokinase knockout mouse (GK+/-) and hyperlipidemic mouse deficient in apolipoprotein E (ApoE-/-) will generate a disease model exhibiting a diabetic and macrovascular phenotype. Methods. The effects of defective glucokinase on the glucose metabolism and on the progression and regression of atherosclerosis on high-fat diets were studied in both genders of GK+/-ApoE-/- and ApoE-/- mice. Coronary vascular function of the female GK+/-ApoE-/- and ApoE-/- mice was also investigated. Results. GK+/-ApoE-/- mice show a stable hyperglycemia which was increased on Western diet. In oral glucose tolerance test, GK+/-ApoE-/- mice showed significant glucose intolerance and impaired glucose-stimulated insulin secretion. Plasma lipids were comparable with ApoE-/- mice; nevertheless the GK+/-ApoE-/- mice showed slightly increased atherosclerosis development. Conclusions. The GK+/-ApoE-/- mice showed a stable and reproducible hyperglycemia, accelerated atherosclerotic lesion progression, and no lesion regression after lipid lowering. This novel model provides a promising tool for drug discovery, enabling the evaluation of compound effects against both diabetic and cardiovascular endpoints simultaneously in one animal model.
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8
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Baker DJ, Wilkinson GP, Atkinson AM, Jones HB, Coghlan M, Charles AD, Leighton B. Chronic glucokinase activator treatment at clinically translatable exposures gives durable glucose lowering in two animal models of type 2 diabetes. Br J Pharmacol 2014; 171:1642-54. [PMID: 24772484 DOI: 10.1111/bph.12504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Pharmacological activation of glucokinase (GK) lowers blood glucose in animal models and humans, confirming proof of concept for this mechanism. However, recent clinical evidence from chronic studies suggests that the glucose-lowering effects mediated by glucokinase activators (GKAs) are not maintained in patients with type 2 diabetes (T2D). Existing preclinical data with GKAs do not explain this loss of sustained glucose-lowering efficacy in patients. Here, we have assessed the effects of chronic (up to 11 months) treatment with two different GKAs in two models of T2D. EXPERIMENTAL APPROACH Two validated animal models of T2D, insulin-resistant obese Zucker rats and hyperglycaemic gk(wt/del) mice, were treated with two different GKAs for 1 or 11 months respectively at exposures that translate to clinical exposures in humans. Blood glucose, cholesterol, triglycerides and insulin were measured. GKA pharmacokinetics were also determined. KEY RESULTS Treatment with either GKA provided sustained lowering of blood glucose for up to 1 month in the Zucker rat and up to 11 months in hyperglycaemic gk(wt/del) mice, with maintained compound exposures. This efficacy was achieved without increases in plasma or hepatic triglycerides, accumulation of hepatic glycogen or impairment of glucose-stimulated insulin secretion. CONCLUSIONS AND IMPLICATIONS Chronic treatment with two GKAs in two animal models of diabetes provided sustained lowering of blood glucose, in marked contrast to clinical findings. Therefore, either these animal models of T2D are not good predictors of responses in human T2D or we need a better understanding of the consequences of GK activation in humans.
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9
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Baker DJ, Atkinson AM, Wilkinson GP, Coope GJ, Charles AD, Leighton B. Characterization of the heterozygous glucokinase knockout mouse as a translational disease model for glucose control in type 2 diabetes. Br J Pharmacol 2014; 171:1629-41. [PMID: 24772483 DOI: 10.1111/bph.12498] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE The global heterozygous glucokinase (GK) knockout (gk(wt/del)) male mouse, fed on a high-fat (60% by energy) diet, has provided a robust and reproducible model of hyperglycaemia. This model could be highly relevant to some facets of human type 2 diabetes (T2D). We aimed to investigate the ability of standard therapeutic agents to lower blood glucose at translational doses, and to explore the glucose-lowering potential of novel glucokinase activators (GKAs) in this model. EXPERIMENTAL APPROACH We measured the ability of insulin, metformin, glipizide, exendin-4 and sitagliptin, after acute or repeat dose administration, to lower free-feeding glucose levels in gk(wt/del) mice. Further, we measured the ability of novel GKAs, GKA23, GKA71 and AZD6370 to control glucose either alone or in combination with some standard agents. KEY RESULTS A single dose of insulin (1 unit·kg(-1)), metformin (150, 300 mg·kg(-1)), glipizide (0.1, 0.3 mg·kg(-1)), exendin-4 (2, 20 μg·kg(-1)) and GKAs reduced free-feeding glucose levels. Sitagliptin (10 mg·kg(-1)), metformin (300 mg·kg(-1)) and AZD6370 (30, 400 mg·kg(-1)) reduced glucose excursions on repeat dosing. At a supra-therapeutic dose (400 mg·kg(-1)), AZD6370 also lowered basal levels of glucose without inducing hypoglycaemia. CONCLUSION AND IMPLICATIONS Standard glucose-lowering therapeutic agents demonstrated significant acute glucose lowering in male gk(wt/del) mice at doses corresponding to therapeutic free drug levels in man, suggesting the potential of these mice as a translatable model of human T2D. Novel GKAs also lowered glucose in this mouse model.
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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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Coate KC, Kraft G, Moore MC, Smith MS, Ramnanan C, Irimia JM, Roach PJ, Farmer B, Neal DW, Williams P, Cherrington AD. Hepatic glucose uptake and disposition during short-term high-fat vs. high-fructose feeding. Am J Physiol Endocrinol Metab 2014; 307:E151-60. [PMID: 24865981 PMCID: PMC4101635 DOI: 10.1152/ajpendo.00083.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In dogs consuming a high-fat and -fructose diet (52 and 17% of total energy, respectively) for 4 wk, hepatic glucose uptake (HGU) in response to hyperinsulinemia, hyperglycemia, and portal glucose delivery is markedly blunted with reduction in glucokinase (GK) protein and glycogen synthase (GS) activity. The present study compared the impact of selective increases in dietary fat and fructose on liver glucose metabolism. Dogs consumed weight-maintaining chow (CTR) or hypercaloric high-fat (HFA) or high-fructose (HFR) diets diet for 4 wk before undergoing clamp studies with infusion of somatostatin and intraportal insulin (3-4 times basal) and glucagon (basal). The hepatic glucose load (HGL) was doubled during the clamp using peripheral vein (Pe) glucose infusion in the first 90 min (P1) and portal vein (4 mg·kg(-1)·min(-1)) plus Pe glucose infusion during the final 90 min (P2). During P2, HGU was 2.8 ± 0.2, 1.0 ± 0.2, and 0.8 ± 0.2 mg·kg(-1)·min(-1) in CTR, HFA, and HFR, respectively (P < 0.05 for HFA and HFR vs. CTR). Compared with CTR, hepatic GK protein and catalytic activity were reduced (P < 0.05) 35 and 56%, respectively, in HFA, and 53 and 74%, respectively, in HFR. Liver glycogen concentrations were 20 and 38% lower in HFA and HFR than CTR (P < 0.05). Hepatic Akt phosphorylation was decreased (P < 0.05) in HFA (21%) but not HFR. Thus, HFR impaired hepatic GK and glycogen more than HFA, whereas HFA reduced insulin signaling more than HFR. HFA and HFR effects were not additive, suggesting that they act via the same mechanism or their effects converge at a saturable step.
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Affiliation(s)
- Katie C Coate
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Guillaume Kraft
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mary Courtney Moore
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee;
| | - Marta S Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Christopher Ramnanan
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jose M Irimia
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ben Farmer
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Doss W Neal
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee; Diabetes Research and Training Center, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Phil Williams
- Diabetes Research and Training Center, Vanderbilt University School of Medicine, Nashville, Tennessee; and Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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Mullooly N, Vernon W, Smith DM, Newsholme P. Elevated levels of branched-chain amino acids have little effect on pancreatic islet cells, but L-arginine impairs function through activation of the endoplasmic reticulum stress response. Exp Physiol 2013; 99:538-51. [PMID: 24334335 DOI: 10.1113/expphysiol.2013.077495] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent metabolic profiling studies have identified a correlation between branched-chain amino acid levels, insulin resistance associated with prediabetes and susceptibility to type 2 diabetes. Glucose and lipids in chronic excess have been reported to induce toxic effects in pancreatic β-cells, but the effect of elevated amino acid concentrations on primary islet cell function has not been investigated to date. The aim of this study was to investigate the effect of chronic exposure to various amino acids on islet cell function in vitro. Isolated rat islets were incubated over periods of 48 h with a range of concentrations of individual amino acids (0.1 μm to 10 mm). After 48 h, islets were assessed for glucose-dependent insulin secretion capacity, proliferation or islet cell apoptosis. We report that elevated levels of branched-chain amino acids have little effect on pancreatic islet cell function or viability; however, increased levels of the amino acid l-arginine were found to be β-cell toxic, causing a dose-dependent decrease in insulin secretion accompanied by a decrease in islet cell proliferation and an increase in islet cell apoptosis. These effects were not due to l-arginine-dependent increases in production of nitric oxide but arose through elicitation of the islet cell endoplasmic reticulum stress response. This novel finding indicates, for the first time, that the l-arginine concentration in vitro may impact negatively on islet cell function, thus indicating further complexity in relationship to in vivo susceptibility of β-cells to nutrient-induced dysfunction.
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Affiliation(s)
- Niamh Mullooly
- * Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
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Nakamura A, Togashi Y, Orime K, Sato K, Shirakawa J, Ohsugi M, Kubota N, Kadowaki T, Terauchi Y. Control of beta cell function and proliferation in mice stimulated by small-molecule glucokinase activator under various conditions. Diabetologia 2012; 55:1745-54. [PMID: 22456697 DOI: 10.1007/s00125-012-2521-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 02/20/2012] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS We investigated changes in the expression of genes involved in beta cell function and proliferation in mouse islets stimulated with glucokinase activator (GKA) in order to elucidate the mechanisms by which GKA stimulates beta cell function and proliferation. METHODS Islets isolated from mice were used to investigate changes in the expression of genes related to beta cell function and proliferation stimulated by GKA. In addition, Irs2 knockout (Irs2 (-/-)) mice on a high-fat diet or a high-fat diet containing GKA were used to investigate the effects of GKA on beta cell proliferation in vivo. RESULTS In wild-type mice, Irs2 and Pdx1 expression was increased by GKA. In Irs2 (-/-) mice, GKA administration increased the glucose-stimulated secretion of insulin and Pdx1 expression, but not beta cell proliferation. It was particularly noteworthy that oxidative stress inhibited the upregulation of the Irs2 and Pdx1 genes induced by GKA. Moreover, whereas neither GKA alone nor exendin-4 alone upregulated the expression of Irs2 and Pdx1 in the islets of db/db mice, prior administration of exendin-4 to the mice caused GKA to increase the expression of these genes. CONCLUSIONS/INTERPRETATION GKA-stimulated IRS2 production affected beta cell proliferation but not beta cell function. Oxidative stress diminished the effects of GKA on the changes in expression of genes involved in beta cell function and proliferation. A combination of GKA and an incretin-related agent might therefore be effective in therapy.
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Affiliation(s)
- A Nakamura
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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14
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Fenner D, Odili S, Hong HK, Kobayashi Y, Kohsaka A, Siepka SM, Vitaterna MH, Chen P, Zelent B, Grimsby J, Takahashi JS, Matschinsky FM, Bass J. Generation of N-ethyl-N-nitrosourea (ENU) diabetes models in mice demonstrates genotype-specific action of glucokinase activators. J Biol Chem 2011; 286:39560-72. [PMID: 21921030 PMCID: PMC3234779 DOI: 10.1074/jbc.m111.269100] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/16/2011] [Indexed: 11/06/2022] Open
Abstract
We performed genome-wide mutagenesis in C57BL/6J mice using N-ethyl-N-nitrosourea to identify mutations causing high blood glucose early in life and to produce new animal models of diabetes. Of a total of 13 new lines confirmed by heritability testing, we identified two semi-dominant pedigrees with novel missense mutations (Gck(K140E) and Gck(P417R)) in the gene encoding glucokinase (Gck), the mammalian glucose sensor that is mutated in human maturity onset diabetes of the young type 2 and the target of emerging anti-hyperglycemic agents that function as glucokinase activators (GKAs). Diabetes phenotype corresponded with genotype (mild-to-severe: Gck(+/+) < Gck(P417R/+), Gck(K140E)(/+) < Gck(P417R/P417R), Gck(P417R/K140E), and Gck(K140E/K140E)) and with the level of expression of GCK in liver. Each mutant was produced as the recombinant enzyme in Escherichia coli, and analysis of k(cat) and tryptophan fluorescence (I(320/360)) during thermal shift unfolding revealed a correlation between thermostability and the severity of hyperglycemia in the whole animal. Disruption of the glucokinase regulatory protein-binding site (GCK(K140E)), but not the ATP binding cassette (GCK(P417R)), prevented inhibition of enzyme activity by glucokinase regulatory protein and corresponded with reduced responsiveness to the GKA drug. Surprisingly, extracts from liver of diabetic GCK mutants inhibited activity of the recombinant enzyme, a property that was also observed in liver extracts from mice with streptozotocin-induced diabetes. These results indicate a relationship between genotype, phenotype, and GKA efficacy. The integration of forward genetic screening and biochemical profiling opens a pathway for preclinical development of mechanism-based diabetes therapies.
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Affiliation(s)
- Deborah Fenner
- From the Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- the Department of Neurobiology and Physiology and
| | - Stella Odili
- the Department of Biochemistry and Biophysics, Children's Hospital of Pennsylvania and Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Hee-Kyung Hong
- the Department of Neurobiology and Physiology and
- the Center for Sleep and Circadian Biology, Northwestern University, Evanston, Illinois 60208
| | - Yumiko Kobayashi
- From the Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- the Department of Neurobiology and Physiology and
| | - Akira Kohsaka
- the Department of Neurobiology and Physiology and
- the Departments of Medicine and Physiology II, Wakayama Medical University, Wakayama City, 640-8265, Japan
| | - Sandra M. Siepka
- the Department of Neurobiology and Physiology and
- the Center for Sleep and Circadian Biology, Northwestern University, Evanston, Illinois 60208
| | - Martha H. Vitaterna
- the Department of Neurobiology and Physiology and
- the Center for Sleep and Circadian Biology, Northwestern University, Evanston, Illinois 60208
| | - Pan Chen
- the Department of Biochemistry and Biophysics, Children's Hospital of Pennsylvania and Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Bogumil Zelent
- the Department of Biochemistry and Biophysics, Children's Hospital of Pennsylvania and Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Joseph Grimsby
- the Department of Metabolic Diseases, Hoffmann-La Roche, Nutley, New Jersey 07110
| | - Joseph S. Takahashi
- the Department of Neurobiology and Physiology and
- the Department of Neuroscience and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, and
| | - Franz M. Matschinsky
- the Department of Biochemistry and Biophysics, Children's Hospital of Pennsylvania and Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Joseph Bass
- From the Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- the Department of Neurobiology and Physiology and
- the Center for Sleep and Circadian Biology, Northwestern University, Evanston, Illinois 60208
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Regulation of glucose metabolism via hepatic forkhead transcription factor 1 (FoxO1) by Morinda citrifolia (noni) in high-fat diet-induced obese mice. Br J Nutr 2011; 108:218-228. [PMID: 22011624 DOI: 10.1017/s0007114511005563] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Renewed interest in alternative medicine among diabetic individuals prompted us to investigate anti-diabetic effects of Morinda citrifolia (noni) in high-fat diet (HFD)-fed mice. Type 2 diabetes is associated with increased glucose production due to the inability of insulin to suppress hepatic gluconeogenesis and promote glycolysis. Insulin inhibits gluconeogenesis by modulating transcription factors such as forkhead box O (FoxO1). Based on microarray analysis data, we tested the hypothesis that fermented noni fruit juice (fNJ) improves glucose metabolism via FoxO1 phosphorylation. C57BL/6 male mice were fed a HFD and fNJ for 12 weeks. Body weights and food intake were monitored daily. FoxO1 expression was analysed by real-time PCR and Western blotting. Specificity of fNJ-associated FoxO1 regulation of gluconeogenesis was confirmed by small interfering RNA (siRNA) studies using human hepatoma cells, HepG2. Supplementation with fNJ inhibited weight gain and improved glucose and insulin tolerance and fasting glucose in HFD-fed mice. Hypoglycaemic properties of fNJ were associated with the inhibition of hepatic FoxO1 mRNA expression, with a concomitant increase in FoxO1 phosphorylation and nuclear expulsion of the proteins. Gluconeogenic genes, phosphoenolpyruvate C kinase (PEPCK) and glucose-6-phosphatase (G6P), were significantly inhibited in mice fed a HFD+fNJ. HepG2 cells demonstrated more than 80 % inhibition of PEPCK and G6P mRNA expression in cells treated with FoxO1 siRNA and fNJ. These data suggest that fNJ improves glucose metabolism via FoxO1 regulation in HFD-fed mice.
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Gill D, Brocklehurst KJ, Brown HWG, Smith DM. Upregulation of β-cell genes and improved function in rodent islets following chronic glucokinase activation. J Mol Endocrinol 2011; 47:59-67. [PMID: 21571864 DOI: 10.1530/jme-10-0157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glucokinase (GK) plays a critical role in controlling blood glucose; GK activators have been shown to stimulate insulin secretion acutely both in vitro and in vivo. Sustained stimulation of insulin secretion could potentially lead to β-cell exhaustion; this study examines the effect of chronic GK activation on β-cells. Gene expression and insulin secretion were measured in rodent islets treated in vitro with GKA71 for 72 h. Key β-cell gene expression was measured in rat, mouse and global GK heterozygous knockout mouse islets (gk(del/wt)). Insulin secretion, after chronic exposure to GKA71, was measured in perifused rat islets. GKA71 acutely increased insulin secretion in rat islets in a glucose-dependent manner. Chronic culture of mouse islets with GKA71 in 5 mmol/l glucose significantly increased the expression of insulin, IAPP, GLUT2, PDX1 and PC1 and decreased the expression of C/EBPβ compared with 5 mmol/l glucose alone. Similar increases were shown for insulin, GLUT2, IAPP and PC1 in chronically treated rat islets. Insulin mRNA was also increased in GKA71-treated gk(del/wt) islets. No changes in GK mRNA were observed. Glucose-stimulated insulin secretion was improved in perifused rat islets following chronic treatment with GKA71. This was associated with a greater insulin content and GK protein level. Chronic treatment of rodent islets with GKA71 showed an upregulation of key β-cell genes including insulin and an increase in insulin content and GK protein compared with glucose alone.
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Affiliation(s)
- D Gill
- AstraZeneca Diabetes and Obesity Drug Discovery, CVGI iMED, 3S42C Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
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Winzell MS, Coghlan M, Leighton B, Frangioudakis G, Smith DM, Storlien LH, Ahrén B. Chronic glucokinase activation reduces glycaemia and improves glucose tolerance in high-fat diet fed mice. Eur J Pharmacol 2011; 663:80-6. [DOI: 10.1016/j.ejphar.2011.05.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 04/15/2011] [Accepted: 05/03/2011] [Indexed: 11/29/2022]
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18
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PANcreatic-DERived factor: novel hormone PANDERing to glucose regulation. FEBS Lett 2011; 585:2137-43. [PMID: 21664909 DOI: 10.1016/j.febslet.2011.05.059] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 05/25/2011] [Accepted: 05/26/2011] [Indexed: 12/20/2022]
Abstract
PANcreatic-DERived factor (PANDER, FAM3B) is a member of the FAM3 family of cytokine molecules that were initially described in 2002. PANDER expression is primarily localized to the endocrine pancreas and is secreted from both pancreatic α and β-cells. Initial characterization of PANDER revealed a potential role in pancreatic islet apoptosis. However, recent animal models have indicated PANDER functions as a hormone by regulating glucose levels via interaction with both the liver and the endocrine pancreas. An understanding of the function of PANDER can further the insight into the mechanisms of glucose regulation and potentially provide additional therapeutic targets for the treatment of diabetes. This review details the supporting data demonstrating PANDER has a biological function in glycemic regulation.
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Maurer AD, Eller LK, Hallam MC, Taylor K, Reimer RA. Consumption of diets high in prebiotic fiber or protein during growth influences the response to a high fat and sucrose diet in adulthood in rats. Nutr Metab (Lond) 2010; 7:77. [PMID: 20920272 PMCID: PMC2958159 DOI: 10.1186/1743-7075-7-77] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 09/29/2010] [Indexed: 02/06/2023] Open
Abstract
Background Early dietary exposure can influence susceptibility to obesity and type 2 diabetes later in life. We examined the lasting effects of a high protein or high prebiotic fiber weaning diet when followed by a high energy diet in adulthood. Methods At birth, litters of Wistar rats were culled to 10 pups. At 21 d pups were weaned onto control (C), high prebiotic fiber (HF) or high protein (HP) diet. Rats consumed the experimental diets until 14 wk when they were switched to a high fat/sucrose (HFHS) diet for 6 wk. Body composition and energy intake were measured and an oral glucose tolerance test (OGTT) performed. Blood was analyzed for satiety hormones and tissues collected for real-time PCR. Results Weight gain was attenuated in male rats fed HF from 12 wk until study completion. In females there were early reductions in body weight that moderated until the final two wk of HFHS diet wherein HF females weighed less than HP. Final body weight was significantly higher following the high fat challenge in male and female rats that consumed HP diet from weaning compared to HF. Lean mass was higher and fat mass lower with HF compared to HP and compared to C in males. Energy intake was highest in HP rats, particularly at the start of HFHS feeding. Plasma glucose was higher in HP rats compared to HF during an OGTT. Plasma amylin was higher in HF females compared to C and glucagon-like peptide-1 (GLP-1) was higher in HF rats during the OGTT. Leptin was higher in HP rats during the OGTT. HF upregulated GLUT 5 mRNA expression in the intestine and downregulated hepatic hydroxymethylglutaryl coenzyme A reductase. Male rats fed HP had higher hepatic triglyceride content than C or HF. Conclusion These data suggest that while a long-term diet high in protein predisposes to an obese phenotype when rats are given a high energy diet in adulthood, consumption of a high fiber diet during growth may provide some protection.
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Affiliation(s)
- Alannah D Maurer
- Department of Biochemistry and Molecular Biology, University of Calgary, 3280 Hospital Drive NW, Calgary, T2N 4Z6, Canada.
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Lomba A, Milagro FI, García-Díaz DF, Marti A, Campión J, Martínez JA. Obesity induced by a pair-fed high fat sucrose diet: methylation and expression pattern of genes related to energy homeostasis. Lipids Health Dis 2010; 9:60. [PMID: 20534152 PMCID: PMC2909242 DOI: 10.1186/1476-511x-9-60] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 06/09/2010] [Indexed: 02/03/2023] Open
Abstract
Background The expression of some genes controlling energy homeostasis could be regulated by epigenetic mechanisms that may play a role in body weight regulation. Thus, it is known that various nutritional factors affect DNA methylation. In order to assess whether the macronutrient composition of the diet could be related to the epigenetic regulation of gene expression and with obesity development, we investigated the effects on methylation and expression patterns of two pair-fed isocaloric diets in rats: control (rich in starch) and HFS (rich in fat and sucrose). Results The pair-fed HFS diet induced higher weight gain and adiposity as compared to the controls as well as liver triglyceride accumulation and oxidative stress. Feeding the HFS diet impaired glucose tolerance and serum triglycerides and cholesterol. Liver glucokinase expression, a key glycolytic gene, remained unaltered, as well as the mRNA values of fatty acid synthase and NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 6 (NDUFB6) in liver and visceral adipocytes, which regulate lipogenesis and mitochondrial oxidative metabolism, respectively. Liver expression of hydroxyacyl-coenzyme A dehydrogenase (HADHB), a key gene of β-oxidation pathway, was higher in the HFS-fed animals. However, the methylation status of CpG islands in HADHB and glucokinase genes remained unchanged after feeding the HFS diet. Conclusions These results confirm that the distribution and type of macronutrients (starch vs. sucrose, and percent of fat) influence obesity onset and the associated metabolic complications. HFS diets produce obesity independently of total energy intake, although apparently no epigenetic (DNA methylation) changes accompanied the modifications observed in gene expression.
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Affiliation(s)
- Almudena Lomba
- Department of Nutrition and Food Sciences, Physiology and Toxicology, University of Navarra, Pamplona, Spain
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21
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Osbak KK, Colclough K, Saint-Martin C, Beer NL, Bellanné-Chantelot C, Ellard S, Gloyn AL. Update on mutations in glucokinase (GCK), which cause maturity-onset diabetes of the young, permanent neonatal diabetes, and hyperinsulinemic hypoglycemia. Hum Mutat 2010; 30:1512-26. [PMID: 19790256 DOI: 10.1002/humu.21110] [Citation(s) in RCA: 339] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Glucokinase is a key regulatory enzyme in the pancreatic beta-cell. It plays a crucial role in the regulation of insulin secretion and has been termed the glucose sensor in pancreatic beta-cells. Given its central role in the regulation of insulin release it is understandable that mutations in the gene encoding glucokinase (GCK) can cause both hyper- and hypoglycemia. Heterozygous inactivating mutations in GCK cause maturity-onset diabetes of the young (MODY) subtype glucokinase (GCK), characterized by mild fasting hyperglycemia, which is present at birth but often only detected later in life during screening for other purposes. Homozygous inactivating GCK mutations result in a more severe phenotype presenting at birth as permanent neonatal diabetes mellitus (PNDM). A growing number of heterozygous activating GCK mutations that cause hypoglycemia have also been reported. A total of 620 mutations in the GCK gene have been described in a total of 1,441 families. There are no common mutations, and the mutations are distributed throughout the gene. The majority of activating mutations cluster in a discrete region of the protein termed the allosteric activator site. The identification of a GCK mutation in patients with both hyper- and hypoglycemia has implications for the clinical course and clinical management of their disorder.
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Affiliation(s)
- Kara K Osbak
- Diabetes Research Laboratories, Oxford Centre for Diabetes Endocrinology & Metabolism, University of Oxford, United Kingdom
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22
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Wei P, Shi M, Barnum S, Cho H, Carlson T, Fraser JD. Effects of glucokinase activators GKA50 and LY2121260 on proliferation and apoptosis in pancreatic INS-1 beta cells. Diabetologia 2009; 52:2142-50. [PMID: 19641898 DOI: 10.1007/s00125-009-1446-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/11/2009] [Indexed: 01/24/2023]
Abstract
AIMS/HYPOTHESIS Glucokinase (GK), an enzyme that phosphorylates glucose to form glucose 6-phosphate, serves as the glucose sensor that regulates insulin secretion in beta cells. GK activators (GKAs) activate GK via binding to an allosteric site of the enzyme. GKAs increase glucose-stimulated insulin secretion and decrease blood glucose levels. Using the differentiated beta cell line INS-1, we investigated the role of GKAs in promoting beta cell growth and survival and preventing beta cell apoptosis induced by chronic exposure to high levels of glucose. METHODS Proliferation was assessed using BrdU incorporation. Apoptosis was measured using caspase-3 activity. Immunoblot analysis was used to detect protein levels and the degree of phosphorylation. RESULTS The GK agonists GKA50 and LY2121260 increased both cell replication and cell numbers when tested at basal levels of glucose (3 mmol/l) in INS-1 cells. GKAs promoted INS-1 cell proliferation via upregulation of insulin receptor substrate-2 and subsequent activation of protein kinase B phosphorylation. GKA50 also prevented the INS-1 cell apoptosis that was induced by chronic high glucose conditions, probably via an increase in GK protein levels and normalisation of the apoptotic protein BCL2-associated agonist of cell death (BAD) and its phosphorylation. As a result of the reduction in cell apoptosis, GKA50 prevented cell loss and maintained glucose-stimulated insulin secretion. In addition, the anti-apoptotic activity of GKA50 was significantly abrogated by other GKAs that do not inhibit apoptosis, suggesting that direct binding of GKA50 to GK is essential for its anti-apoptotic effect. CONCLUSION/INTERPRETATION Our results suggest novel roles of GKAs in promoting beta cell growth and preventing chronic-hyperglycaemia-induced beta cell apoptosis. Thus, GKAs may provide novel therapeutics that increase beta cell mass to maintain euglycaemia in diabetes.
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Affiliation(s)
- P Wei
- Diabetes Biology Department, Pfizer Global Research and Development, La Jolla Laboratories, CA 92121, USA.
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23
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Current literature in diabetes. Diabetes Metab Res Rev 2009; 25:i-x. [PMID: 19219862 DOI: 10.1002/dmrr.918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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The long-chain fatty acid receptor, GPR40, and glucolipotoxicity: investigations using GPR40-knockout mice. Biochem Soc Trans 2008; 36:950-4. [PMID: 18793167 DOI: 10.1042/bst0360950] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
GPR40 (G-protein-coupled receptor 40) has been shown to be a physiologically relevant receptor for long-chain fatty acids. It is a family A G-protein-coupled receptor highly expressed in the beta-cell where it increases insulin secretion by signalling via Gq and phospholipase C. Fatty acids are well known to mediate both acute stimulatory effects and chronic detrimental effects on the beta-cell. GPR40-transgenic and GPR40-/- animals have been important tools in studies of the metabolic effects of GPR40. In the present article, we review the literature on transgenic GPR40 models and present some of our own studies on the effects of a high-fat diet on the metabolic phenotype of GPR40-/- mice. GPR40 ligands represent interesting novel therapies for Type 2 diabetes but it is presently unclear whether agonists or antagonists represent the best therapeutic approach.
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