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Hawes EM, Rahim M, Haratipour Z, Orun AR, O'Rourke ML, Oeser JK, Kim K, Claxton DP, Blind RD, Young JD, O'Brien RM. Biochemical and metabolic characterization of a G6PC2 inhibitor. Biochimie 2024; 222:109-122. [PMID: 38431189 DOI: 10.1016/j.biochi.2024.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/05/2024]
Abstract
Three glucose-6-phosphatase catalytic subunits, that hydrolyze glucose-6-phosphate (G6P) to glucose and inorganic phosphate, have been identified, designated G6PC1-3, but only G6PC1 and G6PC2 have been implicated in the regulation of fasting blood glucose (FBG). Elevated FBG has been associated with multiple adverse clinical outcomes, including increased risk for type 2 diabetes and various cancers. Therefore, G6PC1 and G6PC2 inhibitors that lower FBG may be of prophylactic value for the prevention of multiple conditions. The studies described here characterize a G6PC2 inhibitor, designated VU0945627, previously identified as Compound 3. We show that VU0945627 preferentially inhibits human G6PC2 versus human G6PC1 but activates human G6PC3. VU0945627 is a mixed G6PC2 inhibitor, increasing the Km but reducing the Vmax for G6P hydrolysis. PyRx virtual docking to an AlphaFold2-derived G6PC2 structural model suggests VU0945627 binds two sites in human G6PC2. Mutation of residues in these sites reduces the inhibitory effect of VU0945627. VU0945627 does not inhibit mouse G6PC2 despite its 84% sequence identity with human G6PC2. Mutagenesis studies suggest this lack of inhibition of mouse G6PC2 is due, in part, to a change in residue 318 from histidine in human G6PC2 to proline in mouse G6PC2. Surprisingly, VU0945627 still inhibited glucose cycling in the mouse islet-derived βTC-3 cell line. Studies using intact mouse liver microsomes and PyRx docking suggest that this observation can be explained by an ability of VU0945627 to also inhibit the G6P transporter SLC37A4. These data will inform future computational modeling studies designed to identify G6PC isoform-specific inhibitors.
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Affiliation(s)
- Emily M Hawes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Mohsin Rahim
- Department of Chemical and Biomolecular Engineering, Vanderbilt School of Engineering, Nashville, TN, 37232, USA
| | - Zeinab Haratipour
- Austin Peay State University, 601 College St, Clarksville, TN 37044, USA; Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Abigail R Orun
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Margaret L O'Rourke
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - James K Oeser
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Kwangho Kim
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Derek P Claxton
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Ray D Blind
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Jamey D Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt School of Engineering, Nashville, TN, 37232, USA
| | - Richard M O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
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Hu L, Brito LF, Zhang H, Zhao M, Liu H, Chai H, Wang D, Wu H, Cui J, Liu A, Xu Q, Wang Y. Metabolome profiling of plasma reveals different metabolic responses to acute cold challenge between Inner-Mongolia Sanhe and Holstein cattle. J Dairy Sci 2022; 105:9162-9178. [PMID: 36175226 DOI: 10.3168/jds.2022-21996] [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: 02/21/2022] [Accepted: 06/27/2022] [Indexed: 11/19/2022]
Abstract
Low-temperature conditions influence cattle productivity and survivability. Understanding the metabolic regulations of specific cattle breeds and identifying potential biomarkers related to cold challenges are important for cattle management and optimization of genetic improvement programs. In this study, 28 Inner-Mongolia Sanhe and 22 Holstein heifers were exposed to -25°C for 1 h to evaluate the differences in metabolic mechanisms of thermoregulation. In response to this acute cold challenge, altered rectal temperature was only observed in Holstein cattle. Further metabolome analyses showed a greater baseline of glycolytic activity and mobilization of AA in Sanhe cattle during normal conditions. Both breeds responded to the acute cold challenge by altering their metabolism of volatile fatty acids and AA for gluconeogenesis, which resulted in increased glucose levels. Furthermore, Sanhe cattle mobilized the citric acid cycle activity, and creatine and creatine phosphate metabolism to supply energy, whereas Holstein cattle used greater AA metabolism for this purpose. Altogether, we found that propionate and methanol are potential biomarkers of acute cold challenge response in cattle. Our findings provide novel insights into the biological mechanisms of acute cold response and climatic resilience, and will be used as the basis when developing breeding tools for genetically selecting for improved cold adaptation in cattle.
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Affiliation(s)
- Lirong Hu
- Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, National Engineering Laboratory for Animal Breeding, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Haidian District, Beijing, 100193, China; College of Life Sciences and Bioengineering, Beijing Jiaotong University, Haidian District, Beijing, 100044, China; Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
| | - Luiz F Brito
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
| | - Hailiang Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, National Engineering Laboratory for Animal Breeding, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Haidian District, Beijing, 100193, China
| | - Man Zhao
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Huazhu Liu
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - He Chai
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Dongsheng Wang
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Hongjun Wu
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Jiuhui Cui
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Airong Liu
- Xiertala Cattle Breeding Farm, Hailaer Farm Buro, Hailaer, Inner Mongolia, 021012, China
| | - Qing Xu
- College of Life Sciences and Bioengineering, Beijing Jiaotong University, Haidian District, Beijing, 100044, China.
| | - Yachun Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, National Engineering Laboratory for Animal Breeding, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Haidian District, Beijing, 100193, China.
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The Effect of Diet and Lifestyle on the Course of Diabetic Retinopathy-A Review of the Literature. Nutrients 2022; 14:nu14061252. [PMID: 35334909 PMCID: PMC8955064 DOI: 10.3390/nu14061252] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/23/2022] Open
Abstract
Diabetes is a major social problem. As shown by epidemiological studies, the world incidence of diabetes is increasing and so is the number of people suffering from its complications. Therefore, it is important to determine possible preventive tools. In the prevention of diabetic retinopathy, it is essential to control glycemia, lipid profile and blood pressure. This can be done not only by pharmacological treatment, but first of all by promoting a healthy lifestyle, changing dietary habits and increasing physical activity. In our work, we present a review of the literature to show that physical exercise and an adequate diet can significantly reduce the risk of diabetes and diabetic retinopathy.
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Liyanagamage DSNK, Jayasinghe S, Attanayake AP, Karunaratne V. Dual mechanisms of a Sri Lankan traditional polyherbal mixture in the improvement of pancreatic beta cell functions and restoration of lipoprotein alterations in streptozotocin induced diabetic rats. JOURNAL OF ETHNOPHARMACOLOGY 2021; 267:113613. [PMID: 33242620 DOI: 10.1016/j.jep.2020.113613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 11/08/2020] [Accepted: 11/19/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Traditional polyherbal preparations have been utilized in Sri Lanka since ancient times and have gained a wide acceptance throughout the country. Although an extensive body of evidence supports the use of traditional herbal mixtures in the treatment of diabetes mellitus, only a few polyherbal mixtures have been subjected to systematic scientific investigations and their mechanisms for long-term glucose control remain unclear. In general, scientific evaluations of the effectiveness of antidiabetic formulations which are prescribed by traditional practitioners have received great attention, and therefore uncovering their mechanism of action would be beneficial. AIM The aim of the present study was to investigate the therapeutic efficacy, in terms of antidiabetic and antihyperlipidaemic activities, of a well-known traditional polyherbal mixture composed of leaves of Murraya koenigii L., -cloves of Allium sativum L., - fruits of Garcinia quaesita Pierre and seeds of Piper nigrum L. in streptozotocin induced diabetic rats. MATERIALS AND METHODS Equal amounts from each of the above plant parts (100 g) were mixed together and extracted into cold water, hot water (3 h, refluxed) and water-acetone (1:1) separately. Dose response study of cold water, hot water, and water-acetone extracts of the polyherbal mixture at three selected doses of 0.5 g/kg, 1.0 g/kg and 1.5 g/kg was conducted in streptozotocin (STZ) induced diabetic rats. Based on the dose response data, hot water and water-acetone extracts at the therapeutic dose of 1.0 g/kg were administered to STZ induced diabetic rats (n = 6/group) daily for 30 days in the long-term study. Glibenclamide (0.5 mg/kg) was used as the positive control. Glycaemic parameters, pancreatic β cell restoration, and lipid profile were evaluated in diabetic rats treated with the plant extract mixture. HPLC fingerprints of hot water and water-acetone extracts of the polyherbal mixture were compared with those of extracts of individual plants with the respective solvents, in the standardisation protocol. RESULTS The hot water and water-acetone extracts were shown to be active in the dose response study and 1.0 g/kg was selected for the long term study. Treatment with the hot water and water-acetone extracts of the polyherbal mixture and glibenclamide significantly lowered the glycated haemoglobin by 19%, 26%, and 43%, respectively, at the end of the intervention (p < 0.05). The serum insulin concentration was significantly increased (p < 0.05) upon the plant treatment, corroborating the evidence of β-cell restoration in the pancreas of H and E stained sections. Moreover, the above extracts reported an impressive restoration of lipoproteins in diabetic rats compared to the diabetic control rats. The homeostatic assessment of β-cell functions (HOMA-β) was also improved in rats treated with the hot water and water-acetone extracts of the polyherbal mixture. The HPLC fingerprints of the polyherbal mixture and the individual plants showed shifts in some peaks and formation of new peaks. CONCLUSION The results revealed that the aforementioned polyherbal mixture possesses potent antihyperglycaemic and antihyperlipidaemic effects with considerable restoration of pancreatic β-cells, justifying the traditional use of the mixture in diabetes associated dyslipidaemia.
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Affiliation(s)
| | - Susanthi Jayasinghe
- Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka.
| | | | - Veranja Karunaratne
- Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka
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Acute and Subchronic Toxicity Profile of a Polyherbal Drug Used in Sri Lankan Traditional Medicine. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:2189189. [PMID: 32765627 PMCID: PMC7388592 DOI: 10.1155/2020/2189189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/10/2020] [Accepted: 06/23/2020] [Indexed: 11/24/2022]
Abstract
A polyherbal drug composed of leaves of Murraya koenigii L. Spreng, cloves of Allium sativum L., fruits of Garcinia quaesita Pierre, and seeds of Piper nigrum L. is a popular drug which has been used by indigenous practitioners in Sri Lanka for the treatment of diabetes mellitus and dyslipidemia. The acute toxicity assessment was conducted, following a single oral dose of 0.25–2.0 g/kg in healthy rats, and rats were observed up to 14 days. The hot water extract (1.0 g/kg) and the water : acetone extract (0.5, 1.0, and 1.5 g/kg) were administered to Wistar rats for 28 days in the subchronic study. Hypoglycemic and antihyperglycemic activities (dose response studies) of cold water, hot water, and water : acetone extracts of the polyherbal mixture were evaluated at the doses of 0.5, 1.0, and 1.5 g/kg in healthy and streptozotocin-induced diabetic rats (70 mg/kg, ip), respectively. Acute toxicity study showed that the polyherbal drug did not cause any change in animals throughout the experimental period of 14 days. The administration of the hot water extract and the water : acetone extract of the polyherbal drug for 28 days did not produce changes in the selected biochemical and hematological parameters in Wistar rats (p > 0.05). The histological assessment corroborated the biochemical findings with no significant treatment-related changes in the kidney and liver. The treatment of polyherbal drug significantly lowered the serum glucose concentration compared to the diabetic control rats (p < 0.05) while it did not lead to a severe reduction of glucose concentration in healthy rats. The hot water and water : acetone extracts of the polyherbal drug showed a statistically significant improvement on total area under the glucose tolerance curve in diabetic rats (p < 0.05), reflecting dose-dependent antihyperglycemic effects of the drug. Based on the results, we conclude that the aforementioned antidiabetic polyherbal remedy is free of toxic/adverse effects at the equivalent human therapeutic dose in healthy Wistar rats and would be a safe therapeutic agent for long-term treatments.
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Chen Y, Zhao Y, Wang Y, Nazary-Vannani A, Clark CCT, Sedanur Macit M, Khani V, Zhang Y. The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials. Phytother Res 2020; 34:2159-2169. [PMID: 32159261 DOI: 10.1002/ptr.6667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/05/2020] [Accepted: 02/18/2020] [Indexed: 02/01/2023]
Abstract
Studies regarding the influence of green coffee extract (GCE) on blood glucose levels are conflicting. Thus, we sought to conduct a meta-analysis and systematic review of all available randomized controlled trials (RCTs) to quantify the effects of GCE and CGA intervention on blood glucose and insulin levels. We performed systematic online searches in Scopus, Web of science, and PubMed databases, from inception to July 2019. Data were combined analyzed using a random effects model (Der Simonian-Laird method) and reported as weighted mean differences (WMD). Ten trials reported the influences of GCE on FBS and insulin and were subsequently entered into the meta-analysis. Combined results highlighted that FBS was significantly altered after GCE consumption (WMD: -1.791 mg/dl, 95% CI -3.404, -0.177), with no significant heterogeneity among the studies (I2 = 35.0%, p = .128). However, overall results demonstrated that GCE administration did not result in any significant alteration in insulin levels (WMD: -0.925 μU/ml, 95% CI:-1.915, 0.064), with significant heterogeneity found across studies (I2 = 87.9%). In sub-group analysis, insulin levels were significantly reduced when GCE was supplemented in dosages of ≥400 mg/day (WMD:-1.942 mg/dl, 95% CI:-1.184, -0.975; I2 = 0.0%). The results of present study support the use of GCE for the enhancement of blood glucose, while subgroup analysis highlighted significant improvements in insulin levels when GCE is supplemented in doses ≥400 mg/day.
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Affiliation(s)
- Yan Chen
- Department of Endocrinology, the Second Hospital of Jilin University, Changchun, Jilin, China
| | - Ying Zhao
- Department of Endocrinology, the Second Hospital of Jilin University, Changchun, Jilin, China
| | - Yanjun Wang
- Department of Endocrinology, the Second Hospital of Jilin University, Changchun, Jilin, China
| | - Ali Nazary-Vannani
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Cain C T Clark
- Centre for Sport, Exercise, and Life Sciences, Coventry University, Coventry, UK
| | - Melahat Sedanur Macit
- Faculty of Health Sciences, Department of Nutrition and Dietetics, Ondokuz Mayis University, Samsun, Turkey
| | - Vahid Khani
- Department of Radiology, Taleghani Hospital, Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Yong Zhang
- School of Public Health and Health Management, Chongqing Medical University, Chongqing, China
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Hu GL, Wang X, Zhang L, Qiu MH. The sources and mechanisms of bioactive ingredients in coffee. Food Funct 2019; 10:3113-3126. [PMID: 31166336 DOI: 10.1039/c9fo00288j] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coffee bioactive components include caffeine, chlorogenic acids (CGAs), trigonelline, tryptophan alkaloids, diterpenes and other secondary metabolites. During roasting, coffee metabolites undergo complex Maillard reactions, producing melanoidins and other degradation products, the most controversial among which is acrylamide, an ingredient widely found in baked food and listed as a second class carcinogen. Green and roasted coffee ingredients have good biological activities for the prevention of cardiovascular disease, and antibacterial, anti-diabetic, neuroprotection, and anti-cancer activities. To better understand the relationship between coffee ingredients and human health, and to effectively use the active ingredients, it is essential to understand the sources of coffee active ingredients and their mechanisms of action in the organism. This paper systematizes the available information and provides a critical overview of the sources of coffee active ingredients and the mechanisms of action in vivo or in vitro, and their combined effects on common human diseases.
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Affiliation(s)
- G L Hu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.
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Cappello AR, Curcio R, Lappano R, Maggiolini M, Dolce V. The Physiopathological Role of the Exchangers Belonging to the SLC37 Family. Front Chem 2018; 6:122. [PMID: 29719821 PMCID: PMC5913288 DOI: 10.3389/fchem.2018.00122] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 03/30/2018] [Indexed: 12/14/2022] Open
Abstract
The human SLC37 gene family includes four proteins SLC37A1-4, localized in the endoplasmic reticulum (ER) membrane. They have been grouped into the SLC37 family due to their sequence homology to the bacterial organophosphate/phosphate (Pi) antiporter. SLC37A1-3 are the less characterized isoforms. SLC37A1 and SLC37A2 are Pi-linked glucose-6-phosphate (G6P) antiporters, catalyzing both homologous (Pi/Pi) and heterologous (G6P/Pi) exchanges, whereas SLC37A3 transport properties remain to be clarified. Furthermore, SLC37A1 is highly homologous to the bacterial glycerol 3-phosphate permeases, so it is supposed to transport also glycerol-3-phosphate. The physiological role of SLC37A1-3 is yet to be further investigated. SLC37A1 seems to be required for lipid biosynthesis in cancer cell lines, SLC37A2 has been proposed as a vitamin D and a phospho-progesterone receptor target gene, while mutations in the SLC37A3 gene appear to be associated with congenital hyperinsulinism of infancy. SLC37A4, also known as glucose-6-phosphate translocase (G6PT), transports G6P from the cytoplasm into the ER lumen, working in complex with either glucose-6-phosphatase-α (G6Pase-α) or G6Pase-β to hydrolyze intraluminal G6P to Pi and glucose. G6PT and G6Pase-β are ubiquitously expressed, whereas G6Pase-α is specifically expressed in the liver, kidney and intestine. G6PT/G6Pase-α complex activity regulates fasting blood glucose levels, whereas G6PT/G6Pase-β is required for neutrophil functions. G6PT deficiency is responsible for glycogen storage disease type Ib (GSD-Ib), an autosomal recessive disorder associated with both defective metabolic and myeloid phenotypes. Several kinds of mutations have been identified in the SLC37A4 gene, affecting G6PT function. An increased autoimmunity risk for GSD-Ib patients has also been reported, moreover, SLC37A4 seems to be involved in autophagy.
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Affiliation(s)
- Anna Rita Cappello
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Rosita Curcio
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Rosamaria Lappano
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Marcello Maggiolini
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Vincenza Dolce
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
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Al-Oanzi ZH, Fountana S, Moonira T, Tudhope SJ, Petrie JL, Alshawi A, Patman G, Arden C, Reeves HL, Agius L. Opposite effects of a glucokinase activator and metformin on glucose-regulated gene expression in hepatocytes. Diabetes Obes Metab 2017; 19:1078-1087. [PMID: 28206714 DOI: 10.1111/dom.12910] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/10/2017] [Accepted: 02/11/2017] [Indexed: 01/19/2023]
Abstract
AIM Small molecule activators of glucokinase (GKAs) have been explored extensively as potential anti-hyperglycaemic drugs for type 2 diabetes (T2D). Several GKAs were remarkably effective in lowering blood glucose during early therapy but then lost their glycaemic efficacy chronically during clinical trials. MATERIALS AND METHODS We used rat hepatocytes to test the hypothesis that GKAs raise hepatocyte glucose 6-phosphate (G6P, the glucokinase product) and down-stream metabolites with consequent repression of the liver glucokinase gene ( Gck). We compared a GKA with metformin, the most widely prescribed drug for T2D. RESULTS Treatment of hepatocytes with 25 mM glucose raised cell G6P, concomitantly with Gck repression and induction of G6pc (glucose 6-phosphatase) and Pklr (pyruvate kinase). A GKA mimicked high glucose by raising G6P and fructose-2,6-bisphosphate, a regulatory metabolite, causing a left-shift in glucose responsiveness on gene regulation. Fructose, like the GKA, repressed Gck but modestly induced G6pc. 2-Deoxyglucose, which is phosphorylated by glucokinase but not further metabolized caused Gck repression but not G6pc induction, implicating the glucokinase product in Gck repression. Metformin counteracted the effect of high glucose on the elevated G6P and fructose 2,6-bisphosphate and on Gck repression, recruitment of Mlx-ChREBP to the G6pc and Pklr promoters and induction of these genes. CONCLUSIONS Elevation in hepatocyte G6P and downstream metabolites, with consequent liver Gck repression, is a potential contributing mechanism to the loss of GKA efficacy during chronic therapy. Cell metformin loads within the therapeutic range attenuate the effect of high glucose on G6P and on glucose-regulated gene expression.
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Affiliation(s)
- Ziad H Al-Oanzi
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
- Medical Laboratory Science, Aljouf University, Sakaka, Saudi Arabia
| | - Sophia Fountana
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Tabassum Moonira
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Susan J Tudhope
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - John L Petrie
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Ahmed Alshawi
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Gillian Patman
- Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Catherine Arden
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
| | - Helen L Reeves
- Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Loranne Agius
- Institute of Cellular Medicine and Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
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Tajik N, Tajik M, Mack I, Enck P. The potential effects of chlorogenic acid, the main phenolic components in coffee, on health: a comprehensive review of the literature. Eur J Nutr 2017; 56:2215-2244. [PMID: 28391515 DOI: 10.1007/s00394-017-1379-1] [Citation(s) in RCA: 369] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 01/10/2017] [Indexed: 02/08/2023]
Abstract
Chlorogenic acid (CGA), an important biologically active dietary polyphenol, is produced by certain plant species and is a major component of coffee. Reduction in the risk of a variety of diseases following CGA consumption has been mentioned in recent basic and clinical research studies. This systematic review discusses in vivo animal and human studies of the physiological and biochemical effects of chlorogenic acids (CGAs) on biomarkers of chronic disease. We searched PubMed, Embase, Amed and Scopus using the following search terms: ("chlorogenic acid" OR "green coffee bean extract") AND (human OR animal) (last performed on April 1st, 2015) for relevant literature on the in vivo effects of CGAs in animal and human models, including clinical trials on cardiovascular, metabolic, cancerogenic, neurological and other functions. After exclusion of editorials and letters, uncontrolled observations, duplicate and not relevant publications the remaining 94 studies have been reviewed. The biological properties of CGA in addition to its antioxidant and anti-inflammatory effects have recently been reported. It is postulated that CGA is able to exert pivotal roles on glucose and lipid metabolism regulation and on the related disorders, e.g. diabetes, cardiovascular disease (CVD), obesity, cancer, and hepatic steatosis. The wide range of potential health benefits of CGA, including its anti-diabetic, anti-carcinogenic, anti-inflammatory and anti-obesity impacts, may provide a non-pharmacological and non-invasive approach for treatment or prevention of some chronic diseases. In this study, the effects of CGAs on different aspects of health by reviewing the related literatures have been discussed.
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Affiliation(s)
- Narges Tajik
- Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy, University Hospital Tuebingen, Frondsbergstr 23, 72076, Tuebingen, Germany
| | - Mahboubeh Tajik
- Faculty of Physical Education and Sport Sciences, International Branch of Ferdowsi University of Mashhad, Mashhad, Iran
| | - Isabelle Mack
- Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy, University Hospital Tuebingen, Frondsbergstr 23, 72076, Tuebingen, Germany
| | - Paul Enck
- Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy, University Hospital Tuebingen, Frondsbergstr 23, 72076, Tuebingen, Germany.
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Recent Update on the Role of Chinese Material Medica and Formulations in Diabetic Retinopathy. Molecules 2017; 22:molecules22010076. [PMID: 28054988 PMCID: PMC6155640 DOI: 10.3390/molecules22010076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/27/2016] [Accepted: 12/28/2016] [Indexed: 12/25/2022] Open
Abstract
Diabetes mellitus is one of the most frequent endocrine disorders, affecting populations worldwide. Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes in patients aged 20 and over. Major complications of DR include intraocular neovascularization, inter-retinal edema, hemorrhage, exudates and microaneurysms. Therefore, timely medical attention and prevention are required. At present, laser-assisted therapy and other operational procedures are the most common treatment for DR. However, these treatments can cause retinal damage and scarring. Also, use of the majority of traditional medicines is not supported by clinical evidence. However, due to accumulating scientific evidence, traditional natural medications may assist in delaying or preventing the progression of DR. This review focuses on evidence for the role of traditional natural medicines and their mechanisms of action and pharmacological test results in relation to the progression of DR.
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Brachs S, Winkel AF, Polack J, Tang H, Brachs M, Margerie D, Brunner B, Jahn-Hofmann K, Ruetten H, Spranger J, Schmoll D. Chronic Activation of Hepatic Nrf2 Has No Major Effect on Fatty Acid and Glucose Metabolism in Adult Mice. PLoS One 2016; 11:e0166110. [PMID: 27814396 PMCID: PMC5096693 DOI: 10.1371/journal.pone.0166110] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/24/2016] [Indexed: 12/12/2022] Open
Abstract
The transcription factor NF-E2-related factor 2 (Nrf2) induces cytoprotective genes, but has also been linked to the regulation of hepatic energy metabolism. In order to assess the pharmacological potential of hepatic Nrf2 activation in metabolic disease, Nrf2 was activated over 7 weeks in mice on Western diet using two different siRNAs against kelch-like ECH-associated protein 1 (Keap1), the inhibitory protein of Nrf2. Whole genome expression analysis followed by pathway analysis demonstrated successful knock-down of Keap1 expression and induction of Nrf2-dependent genes involved in anti-oxidative stress defense and biotransformation, proving the activation of Nrf2 by the siRNAs against Keap1. Neither the expression of fatty acid- nor carbohydrate-handling proteins was regulated by Keap1 knock-down. Metabolic profiling of the animals did also not show effects on plasma and hepatic lipids, energy expenditure or glucose tolerance. The data indicate that hepatic Keap1/Nrf2 is not a major regulator of glucose or lipid metabolism in mice.
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Affiliation(s)
- Sebastian Brachs
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité –University School of Medicine, Berlin, Germany
- German Center for Cardiovascular Research, DZHK Partner site Berlin, Berlin, Germany
| | - Angelika F. Winkel
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
| | - James Polack
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité –University School of Medicine, Berlin, Germany
- German Center for Cardiovascular Research, DZHK Partner site Berlin, Berlin, Germany
| | - Hui Tang
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité –University School of Medicine, Berlin, Germany
- German Center for Cardiovascular Research, DZHK Partner site Berlin, Berlin, Germany
| | - Maria Brachs
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité –University School of Medicine, Berlin, Germany
- German Center for Cardiovascular Research, DZHK Partner site Berlin, Berlin, Germany
| | - Daniel Margerie
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
| | - Bodo Brunner
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
| | - Kerstin Jahn-Hofmann
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
| | - Hartmut Ruetten
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
| | - Joachim Spranger
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité –University School of Medicine, Berlin, Germany
- German Center for Cardiovascular Research, DZHK Partner site Berlin, Berlin, Germany
- * E-mail:
| | - Dieter Schmoll
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, Germany
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Long-term consumption of a green/roasted coffee blend positively affects glucose metabolism and insulin resistance in humans. Food Res Int 2016. [DOI: 10.1016/j.foodres.2015.12.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Brachs S, Winkel AF, Tang H, Birkenfeld AL, Brunner B, Jahn-Hofmann K, Margerie D, Ruetten H, Schmoll D, Spranger J. Inhibition of citrate cotransporter Slc13a5/mINDY by RNAi improves hepatic insulin sensitivity and prevents diet-induced non-alcoholic fatty liver disease in mice. Mol Metab 2016; 5:1072-1082. [PMID: 27818933 PMCID: PMC5081411 DOI: 10.1016/j.molmet.2016.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 08/02/2016] [Accepted: 08/08/2016] [Indexed: 12/22/2022] Open
Abstract
Objective Non-alcoholic fatty liver disease is a world-wide health concern and risk factor for cardio-metabolic diseases. Citrate uptake modifies intracellular hepatic energy metabolism and is controlled by the conserved sodium-dicarboxylate cotransporter solute carrier family 13 member 5 (SLC13A5, mammalian homolog of INDY: mINDY). In Drosophila melanogaster and Caenorhabditis elegans INDY reduction decreased whole-body lipid accumulation. Genetic deletion of Slc13a5 in mice protected from diet-induced adiposity and insulin resistance. We hypothesized that inducible hepatic mINDY inhibition should prevent the development of fatty liver and hepatic insulin resistance. Methods Adult C57BL/6J mice were fed a Western diet (60% kcal from fat, 21% kcal from carbohydrate) ad libitum. Knockdown of mINDY was induced by weekly injection of a chemically modified, liver-selective siRNA for 8 weeks. Mice were metabolically characterized and the effect of mINDY suppression on glucose tolerance as well as insulin sensitivity was assessed with an ipGTT and a hyperinsulinemic-euglycemic clamp. Hepatic lipid accumulation was determined by biochemical measurements and histochemistry. Results Within the 8 week intervention, hepatic mINDY expression was suppressed by a liver-selective siRNA by over 60%. mINDY knockdown improved hepatic insulin sensitivity (i.e. insulin-induced suppression of endogenous glucose production) of C57BL/6J mice in the hyperinsulinemic-euglycemic clamp. Moreover, the siRNA-mediated mINDY inhibition prevented neutral lipid storage and triglyceride accumulation in the liver, while we found no effect on body weight. Conclusions We show that inducible mINDY inhibition improved hepatic insulin sensitivity and prevented diet-induced non-alcoholic fatty liver disease in adult C57BL6/J mice. These effects did not depend on changes of body weight or body composition. mINDY/Slc13a5 knockdown was induced by liver-selective siRNA in mice. Liver-selective knockdown of mINDY improved hepatic insulin sensitivity. Liver-selective knockdown of mINDY prevented steatosis hepatis.
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Key Words
- 2-DG, 2-Deoxy-d-glucose
- Citrate transport
- EE, energy expenditure
- EGP, endogenous glucose production
- FA, fatty acids
- FLD, fatty liver disease
- GIR, glucose infusion rate
- HE clamp, hyperinsulinemic-euglycemic clamp
- HFD, high-fat diet
- IEX, anion-exchange high-performance liquid chromatography
- INDY, ‘I'm not dead Yet’
- INDY/Slc13a5
- Insulin resistance
- KO, knockout
- Lipid accumulation
- ORO, oil red O
- RER, respiratory exchange ratio
- SCR, non-silencing scrambled control siRNA
- SKM, skeletal muscle
- Steatosis
- T2D, type-2 diabetes
- TCA, tricarboxylic acid
- WAT, white adipose tissue
- WD, western diet
- e, epididymal
- mINDY, Slc13a5/SLC13A5
- p, perirenal
- s, subcutaneous
- siINDY, mINDY-specific siRNA
- siRNA
- solute carrier family 13, member 5
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Affiliation(s)
- Sebastian Brachs
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité - University School of Medicine, Berlin, 10117, Germany; DZHK (German Center for Cardiovascular Research), Partner Site, Berlin, Germany.
| | - Angelika F Winkel
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Hui Tang
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité - University School of Medicine, Berlin, 10117, Germany; DZHK (German Center for Cardiovascular Research), Partner Site, Berlin, Germany.
| | - Andreas L Birkenfeld
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité - University School of Medicine, Berlin, 10117, Germany; DZHK (German Center for Cardiovascular Research), Partner Site, Berlin, Germany; Section of Metabolic Vascular Medicine, Medical Clinic III and Paul Langerhans Institute Dresden (PLID), a Member of the German Diabetes Center (DZD), Technische Universität, Dresden, 01307, Germany.
| | - Bodo Brunner
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Kerstin Jahn-Hofmann
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Daniel Margerie
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Hartmut Ruetten
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Dieter Schmoll
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main, 65926, Germany.
| | - Joachim Spranger
- Department of Endocrinology, Diabetes and Nutrition, Center for Cardiovascular Research, Charité - University School of Medicine, Berlin, 10117, Germany; DZHK (German Center for Cardiovascular Research), Partner Site, Berlin, Germany.
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Soty M, Chilloux J, Delalande F, Zitoun C, Bertile F, Mithieux G, Gautier-Stein A. Post-Translational Regulation of the Glucose-6-Phosphatase Complex by Cyclic Adenosine Monophosphate Is a Crucial Determinant of Endogenous Glucose Production and Is Controlled by the Glucose-6-Phosphate Transporter. J Proteome Res 2016; 15:1342-9. [PMID: 26958868 DOI: 10.1021/acs.jproteome.6b00110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The excessive endogenous glucose production (EGP) induced by glucagon participates in the development of type 2 diabetes. To further understand this hormonal control, we studied the short-term regulation by cyclic adenosine monophosphate (cAMP) of the glucose-6-phosphatase (G6Pase) enzyme, which catalyzes the last reaction of EGP. In gluconeogenic cell models, a 1-h treatment by the adenylate cyclase activator forskolin increased G6Pase activity and glucose production independently of any change in enzyme protein amount or G6P content. Using specific inhibitors or protein overexpression, we showed that the stimulation of G6Pase activity involved the protein kinase A (PKA). Results of site-directed mutagenesis, mass spectrometry analyses, and in vitro phosphorylation experiments suggested that the PKA stimulation of G6Pase activity did not depend on a direct phosphorylation of the enzyme. However, the temperature-dependent induction of both G6Pase activity and glucose release suggested a membrane-based mechanism. G6Pase is composed of a G6P transporter (G6PT) and a catalytic unit (G6PC). Surprisingly, we demonstrated that the increase in G6PT activity was required for the stimulation of G6Pase activity by forskolin. Our data demonstrate the existence of a post-translational mechanism that regulates G6Pase activity and reveal the key role of G6PT in the hormonal regulation of G6Pase activity and of EGP.
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Affiliation(s)
- Maud Soty
- INSERM U1213, 7-11 rue Paradin, F-69008 Lyon, France.,Université de Lyon, 7-11 rue Paradin, F-69008 Lyon, France.,Université Lyon1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Julien Chilloux
- INSERM U1213, 7-11 rue Paradin, F-69008 Lyon, France.,Université de Lyon, 7-11 rue Paradin, F-69008 Lyon, France.,Université Lyon1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - François Delalande
- Institut Pluridisciplinaire Hubert Curien, Département Sciences Analytiques, CNRS UMR7178 , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.,Université de Strasbourg, 4 rue Blaise Pascal, F-67081 Strasbourg Cedex, France
| | - Carine Zitoun
- INSERM U1213, 7-11 rue Paradin, F-69008 Lyon, France.,Université de Lyon, 7-11 rue Paradin, F-69008 Lyon, France.,Université Lyon1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Fabrice Bertile
- Institut Pluridisciplinaire Hubert Curien, Département Sciences Analytiques, CNRS UMR7178 , 25 rue Becquerel, 67087 Strasbourg Cedex 2, France.,Université de Strasbourg, 4 rue Blaise Pascal, F-67081 Strasbourg Cedex, France
| | - Gilles Mithieux
- INSERM U1213, 7-11 rue Paradin, F-69008 Lyon, France.,Université de Lyon, 7-11 rue Paradin, F-69008 Lyon, France.,Université Lyon1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Amandine Gautier-Stein
- INSERM U1213, 7-11 rue Paradin, F-69008 Lyon, France.,Université de Lyon, 7-11 rue Paradin, F-69008 Lyon, France.,Université Lyon1, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France
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Akash MSH, Rehman K, Chen S. Effects of coffee on type 2 diabetes mellitus. Nutrition 2014; 30:755-63. [DOI: 10.1016/j.nut.2013.11.020] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 11/05/2013] [Accepted: 11/08/2013] [Indexed: 12/13/2022]
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Abstract
The SLC37 family members are endoplasmic reticulum (ER)-associated sugar-phosphate/phosphate (P(i)) exchangers. Three of the four members, SLC37A1, SLC37A2, and SLC37A4, function as Pi-linked glucose-6-phosphate (G6P) antiporters catalyzing G6P:P(i) and P(i):P(i) exchanges. The activity of SLC37A3 is unknown. SLC37A4, better known as the G6P transporter (G6PT), has been extensively characterized, functionally and structurally, and is the best characterized family member. G6PT contains 10 transmembrane helices with both N and C termini facing the cytoplasm. The primary in vivo function of the G6PT protein is to translocate G6P from the cytoplasm into the ER lumen where it couples with either the liver/kidney/intestine-restricted glucose-6-phosphatase-α (G6Pase-α or G6PC) or the ubiquitously expressed G6Pase-β (or G6PC3) to hydrolyze G6P to glucose and P(i). The G6PT/G6Pase-α complex maintains interprandial glucose homeostasis, and the G6PT/G6Pase-β complex maintains neutrophil energy homeostasis and functionality. G6PT is highly selective for G6P and is competitively inhibited by cholorogenic acid and its derivatives. Neither SLC37A1 nor SLC37A2 can couple functionally with G6Pase-α or G6Pase-β, and the antiporter activities of SLC37A1 or SLC37A2 are not inhibited by cholorogenic acid. Deficiencies in G6PT cause glycogen storage disease type Ib (GSD-Ib), a metabolic and immune disorder. To date, 91 separate SLC37A4 mutations, including 39 missense mutations, have been identified in GSD-Ib patients. Characterization of missense mutations has yielded valuable information on functionally important residues in the G6PT protein. The biological roles of the other SLC37 proteins remain to be determined and deficiencies have not yet been correlated to diseases.
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Affiliation(s)
- Janice Y Chou
- Section on Cellular Differentiation, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
| | - Brian C Mansfield
- Section on Cellular Differentiation, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA; Foundation Fighting Blindness, Columbia, Maryland, USA
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Roles of chlorogenic Acid on regulating glucose and lipids metabolism: a review. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:801457. [PMID: 24062792 PMCID: PMC3766985 DOI: 10.1155/2013/801457] [Citation(s) in RCA: 273] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 01/29/2023]
Abstract
Intracellular glucose and lipid metabolic homeostasis is vital for maintaining basic life activities of a cell or an organism. Glucose and lipid metabolic disorders are closely related with the occurrence and progression of diabetes, obesity, hepatic steatosis, cardiovascular disease, and cancer. Chlorogenic acid (CGA), one of the most abundant polyphenol compounds in the human diet, is a group of phenolic secondary metabolites produced by certain plant species and is an important component of coffee. Accumulating evidence has demonstrated that CGA exerts many biological properties, including antibacterial, antioxidant, and anticarcinogenic activities. Recently, the roles and applications of CGA, particularly in relation to glucose and lipid metabolism, have been highlighted. This review addresses current studies investigating the roles of CGA in glucose and lipid metabolism.
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Choi EY, Cho YO. Interaction of physical trainings and coffee intakes in fuel utilization during exercise in rats. Nutr Res Pract 2013; 7:178-84. [PMID: 23766878 PMCID: PMC3679326 DOI: 10.4162/nrp.2013.7.3.178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 12/23/2022] Open
Abstract
This study investigates the impact of exercises, coffee intakes, and physical trainings on fuel utilization in rats. Ninety-six rats were fed a control diet with either water (C) or coffee (CF; 0.12 g freeze-dried instant coffee/100 g body weight/d). Additionally, the animals go through physical training (TC and TCF) or no training (NTC and NTCF) for 4 weeks. For physical training, animals have to exercise on treadmills for 30 minutes (5 d per week, 15° incline, 0.5-0.8 km/h). At the end of week 4, the animals in each group were subdivided into three exercise groups: before exercise (BE), during exercise (DE), and after exercise (AE). The DE rats exercised on treadmills for 1 hour immediately before being sacrificed. Hemoglobin, hematocrit, glucose, glycogen, protein, triglyceride (TG), and free fatty acid (FFA) levels in the plasma, liver, and skeletal muscle of the rats were compared accordingly. Organ weights were also measured. Coffee-training interaction had a significant impact on heart weight, visceral fat, hemoglobin, hematocrit, liver glycogen in DE and AE, and liver triglyceride in DE and AE. Exercise (meaning exercised on a treadmill for 1 hour immediately before being sacrificed) training interaction was significant in liver glycogen, muscle glycogen in control diet and control diet with coffee, FFA and muscle TG levels at control diet with coffee group. Exercise-coffee interactions significantly influenced the FFA with no training groups. Exercise-coffee-training interaction significantly effects on FFA, Liver TG and Muscle TG. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee can be an effective ergogenic aid during exercise for physically trained rats.
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Affiliation(s)
- Eun-Young Choi
- Department of Food and Nutrition, Duksung Women's University, 419 Ssangmun-dong, Dobong-gu, Seoul 132-714, Korea
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20
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Shin JY, Sohn J, Park KH. Chlorogenic acid decreases retinal vascular hyperpermeability in diabetic rat model. J Korean Med Sci 2013; 28:608-13. [PMID: 23579598 PMCID: PMC3617316 DOI: 10.3346/jkms.2013.28.4.608] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/15/2013] [Indexed: 11/20/2022] Open
Abstract
To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.
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Affiliation(s)
- Joo Young Shin
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | | | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea
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Charkoudian LK, Farrell BP, Khosla C. Natural product inhibitors of glucose-6-phosphate translocase. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md20008b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Beaudoin MS, Graham TE. Methylxanthines and human health: epidemiological and experimental evidence. Handb Exp Pharmacol 2011:509-548. [PMID: 20859811 DOI: 10.1007/978-3-642-13443-2_21] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
When considering methylxanthines and human health, it must be recognized that in many countries most caffeine is consumed as coffee. This is further confounded by the fact that coffee contains many bioactive substances in addition to caffeine; it is rich in phenols (quinides, chlorogenic acid, and lactones) and also has diterpenes (fatty acid esters), potassium, niacin, magnesium, and the vitamin B(3) precursor trigonelline. There is a paradox as consumption of either caffeine or caffeinated coffee results in a marked insulin resistance and yet habitual coffee consumption has repeatedly been reported to markedly reduce the risk for type 2 diabetes. There is strong evidence that caffeine reduces insulin sensitivity in skeletal muscle and this may be due to a combination of direct antagonism of A(1) receptors and indirectly β-adrenergic stimulation as a result of increased sympathetic activity. Caffeine may also induce reduced hepatic glucose output. With the exception of bone mineral, there is little evidence that caffeine impacts negatively on other health issues. Coffee does not increase the risk of cardiovascular diseases or cancers and there is some evidence suggesting a positive relationship for the former and for some cancers, particularly hepatic cancer.
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Affiliation(s)
- Marie-Soleil Beaudoin
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G 2W1
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Tousch D, Lajoix AD, Hosy E, Azay-Milhau J, Ferrare K, Jahannault C, Cros G, Petit P. Chicoric acid, a new compound able to enhance insulin release and glucose uptake. Biochem Biophys Res Commun 2008; 377:131-5. [PMID: 18834859 DOI: 10.1016/j.bbrc.2008.09.088] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 09/19/2008] [Indexed: 12/19/2022]
Abstract
Caffeic acid and chlorogenic acid (CGA), a mono-caffeoyl ester, have been described as potential antidiabetic agents. Using in vitro studies, we report the effects of a dicaffeoyl ester, chicoric acid (CRA) purified from Cichorium intybus, on glucose uptake and insulin secretion. Our results show that CRA and CGA increased glucose uptake in L6 muscular cells, an effect only observed in the presence of stimulating concentrations of insulin. Moreover, we found that both CRA and CGA were able to stimulate insulin secretion from the INS-1E insulin-secreting cell line and rat islets of Langerhans. In the later case, the effect of CRA is only observed in the presence of subnormal glucose levels. Patch clamps studies show that the mechanism of CRA and CGA was different from that of sulfonylureas, as they did not close K(ATP) channels. Chicoric acid is a new potential antidiabetic agent carrying both insulin sensitizing and insulin-secreting properties.
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Affiliation(s)
- Didier Tousch
- Faculté de Pharmacie, Centre de Pharmacologie & Innovation dans le Diabète, CNRS UMR 5232, Université Montpellier 1, Montpellier cedex 5, France.
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Bassoli BK, Cassolla P, Borba-Murad GR, Constantin J, Salgueiro-Pagadigorria CL, Bazotte RB, da Silva RSDSF, de Souza HM. Chlorogenic acid reduces the plasma glucose peak in the oral glucose tolerance test: effects on hepatic glucose release and glycaemia. Cell Biochem Funct 2008; 26:320-8. [DOI: 10.1002/cbf.1444] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
With an increasing number of studies describing the negative correlation of coffee consumption and the risk for type 2 diabetes mellitus, we were compelled to elucidate the nutrients which bring pharmacological effects on risk reduction for diabetes. In this review, the author's interest is focused on chlorogenic and caffeic acids derived from lightly roasted coffee beans, as well as nicotinic acid, volatile Maillard reaction products (vMRPs), and another structurally unknown compound contained in heavily roasted beans. Caffeine is a common compound in both lightly and heavily roasted beans and its anti-inflammatory effects on degenerative diseases such as diabetes mellitus has been reevaluated recently. The prophylactic effects of coffee on diabetes involve pleiotropy of plural components in accordance to the degree of the roasting. A new concept of nutritional blended coffee may be important to optimize the prophylactic effects of coffee on lowering the risk factors of diabetes and delaying the progress of diabetes complications as well.
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Affiliation(s)
- Kitaro Oka
- Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachiohji City, Japan.
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Abstract
Type-2 diabetes is associated with impaired glucose clearance by the liver in the postprandial state, and with elevated glucose production in the post-absorptive state. New targets within the liver are currently being investigated for development of antihyperglycaemic drugs for type-2 diabetes. They include glucokinase, which catalyses the first step in glucose metabolism, the glucagon receptor, and enzymes of gluconeogenesis and/or glycogenolysis such as glucose 6-phosphatase, fructose 1,6-bisphosphatase and glycogen phosphorylase. Preclinical studies with candidate drugs on animal models or cell-based assays suggest that these targets have the potential for pharmacological glycaemic control. Data from clinical studies is awaited. Further work is required for better understanding of the implications of targeting these sites in terms of possible side-effects or tachyphylaxis. The advantage of combined targeting of two or more sites within the liver for minimizing side-effects and tachyphylaxis caused by single-site targeting is discussed.
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Affiliation(s)
- Loranne Agius
- Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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Sloop KW, Showalter AD, Cox AL, Cao JXC, Siesky AM, Zhang HY, Irizarry AR, Murray SF, Booten SL, Finger EA, McKay RA, Monia BP, Bhanot S, Michael MD. Specific reduction of hepatic glucose 6-phosphate transporter-1 ameliorates diabetes while avoiding complications of glycogen storage disease. J Biol Chem 2007; 282:19113-21. [PMID: 17478431 DOI: 10.1074/jbc.m610759200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
D-Glucose-6-phosphatase is a key regulator of endogenous glucose production, and its inhibition may improve glucose control in type 2 diabetes. Herein, 2'-O-(2-methoxy)ethyl-modified phosphorothioate antisense oligonucleotides (ASOs) specific to the glucose 6-phosphate transporter-1 (G6PT1) enabled reduction of hepatic D-Glu-6-phosphatase activity in diabetic ob/ob mice. Treatment with G6PT1 ASOs decreased G6PT1 expression, reduced G6PT1 activity, blunted glucagon-stimulated glucose production, and lowered plasma glucose concentration in a dose-dependent manner. In contrast to G6PT1 knock-out mice and patients with glycogen storage disease, excess hepatic and renal glycogen accumulation, hyperlipidemia, neutropenia, and elevations in plasma lactate and uric acid did not occur. In addition, hypoglycemia was not observed in animals during extended periods of fasting, and the ability of G6PT1 ASO-treated mice to recover from an exogenous insulin challenge was not impaired. Together, these results demonstrate that effective glucose lowering by G6PT1 inhibitors can be achieved without adversely affecting carbohydrate and lipid metabolism.
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Affiliation(s)
- Kyle W Sloop
- Endocrine Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
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Luedde T, Beraza N, Kotsikoris V, van Loo G, Nenci A, De Vos R, Roskams T, Trautwein C, Pasparakis M. Deletion of NEMO/IKKgamma in liver parenchymal cells causes steatohepatitis and hepatocellular carcinoma. Cancer Cell 2007; 11:119-32. [PMID: 17292824 DOI: 10.1016/j.ccr.2006.12.016] [Citation(s) in RCA: 468] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 11/02/2006] [Accepted: 12/05/2006] [Indexed: 02/08/2023]
Abstract
The IkappaB kinase (IKK) subunit NEMO/IKKgamma is essential for activation of the transcription factor NF-kappaB, which regulates cellular responses to inflammation. The function of NEMO in the adult liver remains elusive. Here we show that ablation of NEMO in liver parenchymal cells caused the spontaneous development of hepatocellular carcinoma in mice. Tumor development was preceded by chronic liver disease resembling human nonalcoholic steatohepatitis (NASH). Antioxidant treatment and genetic ablation of FADD demonstrated that death receptor-mediated and oxidative stress-dependent death of NEMO-deficient hepatocytes triggered disease pathogenesis in this model. These results reveal that NEMO-mediated NF-kappaB activation in hepatocytes has an essential physiological function to prevent the spontaneous development of steatohepatitis and hepatocellular carcinoma, identifying NEMO as a tumor suppressor in the liver.
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Affiliation(s)
- Tom Luedde
- Institute for Genetics, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany
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29
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Härndahl L, Schmoll D, Herling AW, Agius L. The role of glucose 6-phosphate in mediating the effects of glucokinase overexpression on hepatic glucose metabolism. FEBS J 2006; 273:336-46. [PMID: 16403021 DOI: 10.1111/j.1742-4658.2005.05067.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Pharmacological activation or overexpression of glucokinase in hepatocytes stimulates glucose phosphorylation, glycolysis and glycogen synthesis. We used an inhibitor of glucose 6-phosphate (Glc6P) hydrolysis, namely the chlorogenic derivative, 1-[2-(4-chloro-phenyl)-cyclopropylmethoxy]-3, 4-dihydroxy-5-(3-imidazo[4,5-b]pyridin-1-yl-3-phenyl-acryloyloxy)-cyclohexanecarboxylic acid (also known as S4048), to determine the contribution of Glc6P concentration, as distinct from glucokinase protein or activity, to the control of glycolysis and glycogen synthesis by glucokinase overexpression. The validity of S4048 for testing the role of Glc6P was supported by its lack of effect on glucokinase binding and its nuclear/cytoplasmic distribution. The stimulation of glycolysis by glucokinase overexpression correlated strongly with glucose phosphorylation, whereas glycogen synthesis correlated strongly with Glc6P concentration. Metabolic control analysis was used to determine the sensitivity of glycogenic flux to glucokinase or Glc6P at varying glucose concentrations (5-20 mm). The concentration control coefficient of glucokinase on Glc6P (1.4-1.7) was relatively independent of glucose concentration, whereas the flux control coefficients of Glc6P (2.4-1.0) and glucokinase (3.7-1.8) on glycogen synthesis decreased with glucose concentration. The high sensitivity of glycogenic flux to Glc6P at low glucose concentration is consistent with covalent modification by Glc6P of both phosphorylase and glycogen synthase. The high control strength of glucokinase on glycogenic flux is explained by its concentration control coefficient on Glc6P and the high control strength of Glc6P on glycogen synthesis. It is suggested that the regulatory strength of pharmacological glucokinase activators on glycogen metabolism can be predicted from their effect on the Glc6P content.
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Affiliation(s)
- Linda Härndahl
- School of Clinical Medical Sciences-Diabetes, The University of Newcastle upon Tyne, Medical School, Newcastle upon Tyne, UK
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van Dam RM. Coffee and type 2 diabetes: from beans to beta-cells. Nutr Metab Cardiovasc Dis 2006; 16:69-77. [PMID: 16399494 DOI: 10.1016/j.numecd.2005.10.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Revised: 09/12/2005] [Accepted: 10/09/2005] [Indexed: 12/15/2022]
Abstract
Coffee consumption has been associated with improved glucose tolerance and a lower risk of type 2 diabetes in diverse populations in the U.S., Europe, and Japan. This review discusses the strength of the evidence, relevant mechanisms, possible implications, and directions for further research. The finding that higher consumption of decaffeinated coffee was associated with a lower risk of type 2 diabetes suggests that coffee constituents other than caffeine play a role. Coffee is a source of several compounds that improved glucose metabolism in animal studies, including the chlorogenic acids and lignans. Further research on phytochemicals in coffee may lead to the identification of novel mechanisms for effects of diet on the development of type 2 diabetes. In addition, knowledge on effects of coffee components may aid in the development or selection of types of coffee with improved health effects. Longer-term randomized intervention studies that test the effects of coffee consumption on glucose tolerance are warranted. Physical activity and weight management should be the mainstay of public health strategies to prevent type 2 diabetes. For individual choices regarding coffee consumption, potential effects of coffee on various health outcomes should be considered.
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Affiliation(s)
- R M van Dam
- Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Building 2, Boston, MA 02115, USA.
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31
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Westergaard N, Madsen P. Glucose-6-phosphatase inhibitors for the treatment of Type 2 diabetes. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.11.9.1429] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Gonzalez-Mujica F, Motta N, Estrada O, Perdomo E, Méndez J, Hasegawa M. Inhibition of hepatic neoglucogenesis and glucose-6-phosphatase by quercetin 3-O-α(2″-galloyl)rhamnoside isolated fromBauhinia megalandra leaves. Phytother Res 2005; 19:624-7. [PMID: 16161025 DOI: 10.1002/ptr.1704] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In intact microsomes, quercetin 3-O-alpha-(2''-galloyl)rhamnoside (QGR) inhibits glucose-6-phosphatase (G-6-Pase) in a concentration-dependent manner. QGR increased the G-6-Pase K(m) for glucose-6-phosphate without change in the V(max). The flavonol did not change the kinetic parameters of disrupted microsomal G-6-Pase or intact or disrupted microsomal G-6-Pase pyrophosphatase (PPase) activity. This result allowed the conclusion that QGR competitively inhibits the glucose-6-phosphate (G-6-P) transporter (T1) without affecting the catalytic subunit or the phosphate/pyrophosphate transporter (T2) of the G-6-Pase system.QGR strongly inhibits the neoglucogenic capacity of rat liver slices incubated in a Krebs-Ringer bicarbonate buffer, supplemented with lactate and oleate saturated albumin. The QGR G-6-Pase inhibition might explain the decrease in the liver slice neoglucogenic capacity and, in turn, could reduce glucose levels in diabetic patients.
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Affiliation(s)
- Freddy Gonzalez-Mujica
- Sección de Bioquímica Médica, Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
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van Dam RM, Dekker JM, Nijpels G, Stehouwer CDA, Bouter LM, Heine RJ. Coffee consumption and incidence of impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes: the Hoorn Study. Diabetologia 2004; 47:2152-9. [PMID: 15662556 DOI: 10.1007/s00125-004-1573-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Accepted: 08/05/2004] [Indexed: 10/26/2022]
Abstract
AIMS/HYPOTHESIS Coffee contains several substances that may affect glucose metabolism. The aim of this study was to evaluate the relationship between habitual coffee consumption and the incidence of IFG, IGT and type 2 diabetes. METHODS We used cross-sectional and prospective data from the population-based Hoorn Study, which included Dutch men and women aged 50-74 years. An OGTT was performed at baseline and after a mean follow-up period of 6.4 years. Associations were adjusted for potential confounders including BMI, cigarette smoking, physical activity, alcohol consumption and dietary factors. RESULTS At baseline, a 5 cup per day higher coffee consumption was significantly associated with lower fasting insulin concentrations (-5.6%, 95% CI -9.3 to -1.6%) and 2-h glucose concentrations (-8.8%, 95% CI -11.8 to -5.6%), but was not associated with lower fasting glucose concentrations (-0.8%, 95% CI -2.1 to 0.6%). In the prospective analyses, the odds ratio (OR) for IGT was 0.59 (95% CI 0.36-0.97) for 3-4 cups per day, 0.46 (95% CI 0.26-0.81) for 5-6 cups per day, and 0.37 (95% CI 0.16-0.84) for 7 or more cups per day, as compared with the corresponding values for the consumption of 2 or fewer cups of coffee per day (p=0.001 for trend). Higher coffee consumption also tended to be associated with a lower incidence of type 2 diabetes (OR 0.69, CI 0.31-1.51 for >/=7 vs </=2 cups per day, p=0.09 for trend), but was not associated with the incidence of IFG (OR 1.35, CI 0.80-2.27 for >/=7 vs </=2 cups per day, p=0.49 for trend). CONCLUSIONS/INTERPRETATION Our findings indicate that habitual coffee consumption can reduce the risk of IGT, and affects post-load rather than fasting glucose metabolism.
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Affiliation(s)
- R M van Dam
- Department of Nutrition and Health, Faculty of Earth and Life Sciences, Vrije University Amsterdam, de Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
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Proietto J, Andrikopoulos S. Molecular Mechanisms of Increased Glucose Production: Identifying Potential Therapeutic Targets. J Investig Med 2004. [DOI: 10.1177/108155890405200633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Many patients with type 2 diabetes go on to require insulin therapy to achieve adequate control. A need remains to develop new classes of oral hypoglycemic agents to complement those already in use. A useful target is the inappropriately elevated endogenous glucose production present in patients with type 2 diabetes. This review discusses mechanisms of increased glucose production and possible strategies and targets for its suppression. Several approaches are being investigated, including inhibitors of glycogenolysis and gluconeogenesis, inhibitors of stimulatory hormones or their receptors, metabolic modulators, and agents that alter gene expression. There is a high probability that one of these approaches will soon result in a safe and effective inhibitor of glucose production.
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Affiliation(s)
- Joseph Proietto
- Department of Medicine (J.P., S.A.), Repatriation Hospital, Heidelberg, Australia
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Sumida KD, Qureshi T, Catanzaro MJ, Arimoto SM, Hill JM. Chronic alcohol consumption yields sex differences in whole-body glucose production in rats. Alcohol Alcohol 2004; 39:418-26. [PMID: 15289210 DOI: 10.1093/alcalc/agh082] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The effects of chronic alcohol consumption (8 weeks) on glucose kinetics, in the absence (water, 4 g/kg) and presence of an acute ethanol dose (4 g/kg), were examined in 48 h fasted male and female Wistar rats. METHODS Primed continuous infusions of [6-3H]- and [U-14C]glucose were employed to assess rates of glucose appearance (Ra), glucose disappearance (Rd), and apparent glucose carbon recycling. RESULTS After injecting the male and female controls with water, there were no significant alterations in glucose kinetics. Compared to controls, chronic alcohol-fed female animals (injected with water) demonstrated significantly lower: glucose Ra, blood glucose concentration, and apparent glucose carbon recycling for a majority of the experimental period. In separate groups injected with ethanol, the glucose Ra fell by 31% for male rats fed the control diet (MC), 43% for male rats fed the ethanol diet (ME), 29% for female rats fed the control diet (FC), and 42% for female rats fed the ethanol diet (FE). Further, compared to controls (MC and FC), the blood glucose concentration was significantly lower prior to and following the ethanol injection for FE. In addition, FE animals had significantly lower rates of glucose Ra and glucose carbon recycling compared to controls prior to and after the ethanol injection. ME animals demonstrated similar declines in glucose Ra (compared to FE), but only after the ethanol injection. Conversely, ME were able to match the decrease in glucose Ra with comparable declines in glucose Rd resulting in blood glucose concentrations that did not differ from controls. CONCLUSIONS Chronic alcohol consumption results in sex differences in whole-body glucose production and glucose regulation.
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Affiliation(s)
- Ken D Sumida
- Department of Biological Sciences, Chapman University, Orange, California, USA.
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Huang A, Chen Y, Wang X, Zhao S, Su N, White DW. Functional silencing of hepatic microsomal glucose-6-phosphatase gene expression in vivo by adenovirus-mediated delivery of short hairpin RNA. FEBS Lett 2004; 558:69-73. [PMID: 14759518 DOI: 10.1016/s0014-5793(03)01499-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Revised: 11/21/2003] [Accepted: 12/15/2003] [Indexed: 12/12/2022]
Abstract
An expression cassette containing mouse U6 polymerase III promoter directing expression of short hairpin RNA (shRNA) targeting murine microsomal glucose-6-phosphatase (G6P) transcript was generated. This construct was packaged into an adenoviral (AdV) backbone and viral stocks generated. Mice injected intravenously with AdV-G6PshRNA exhibited a significant reduction in postprandial glucose levels and had significantly elevated steady-state hepatic glycogen stores. Target gene silencing was confirmed by measurements demonstrating a significant reduction in both hepatic G6P transcript level and phosphohydrolase activity. These findings provide evidence that AdV delivery of expressed shRNA can be a productive tool to explore gene function in vivo.
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Affiliation(s)
- Alan Huang
- Millennium Pharmaceuticals, 75 Sidney St., Cambridge, MA 02139, USA
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Dubbelhuis PF, Van Sluijters DA, Blommaart EFC, Gustafson LA, Van Woerkom GM, Herling AW, Burger HJ, Meijer AJ. Inhibition of autophagic proteolysis by inhibitors of phosphoinositide 3-kinase can interfere with the regulation of glycogen synthesis in isolated hepatocytes. Biochem J 2002; 368:827-33. [PMID: 12371905 PMCID: PMC1223050 DOI: 10.1042/bj20021340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2002] [Accepted: 10/08/2002] [Indexed: 12/24/2022]
Abstract
Amino acid-induced cell swelling stimulates conversion of glucose into glycogen in isolated hepatocytes. Activation of glycogen synthase (GS) phosphatase, caused by the fall in intracellular chloride accompanying regulatory volume decrease, and activation of phosphoinositide 3-kinase (PI 3-kinase), induced by cell swelling, have been proposed as underlying mechanisms. Because PI 3-kinase controls autophagic proteolysis, we examined the possibility that PI 3-kinase inhibitors interfere with glycogen production due to their anti-proteolytic action. The PI 3-kinase inhibitor wortmannin inhibited endogenous proteolysis, the production of glycogen from glucose and the activity of active (dephosphorylated) GS (GS a ) in the absence of added amino acids. The stimulation by amino acids of glycogen production and of GS a was only slightly affected by wortmannin. These effects of wortmannin could be mimicked by proteinase inhibitors. A combination of leucine, phenylalanine and tyrosine, which we showed previously to stimulate PI 3-kinase-dependent phosphorylation of ribosomal protein S6, did not stimulate glycogen production from glucose. In contrast with wortmannin, LY294002, another PI 3-kinase inhibitor, strongly inhibited both glycogen synthesis and GS a activity, irrespective of the presence of amino acids. Inhibition of glycogen synthesis by LY294002 could be ascribed in part to increased glycogenolysis and glycolysis. It is concluded that, in hepatocytes, activation of PI 3-kinase may not be responsible for the stimulation of glycogen synthesis by amino acids; LY294002 inhibits glycogen synthesis and stimulates glycogen breakdown by a mechanism that is unrelated to its action as an inhibitor of PI 3-kinase.
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Affiliation(s)
- Peter F Dubbelhuis
- Department of Biochemistry, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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Abstract
The existence of glucose-6-phosphate transport across the liver microsomal membrane is still controversial. In this paper, we show that S3483, a chlorogenic acid derivative known to inhibit glucose-6-phosphatase in intact microsomes, caused the intravesicular accumulation of glucose-6-phosphate when the latter was produced by glucose-6-phosphatase from glucose and carbamoyl-phosphate. S3483 also inhibited the conversion of glucose-6-phosphate to 6-phosphogluconate occurring inside microsomes in the presence of electron acceptors (NADP or metyrapone). These data indicate that liver microsomal membranes contain a reversible glucose-6-phosphate transporter, which furnishes substrate not only to glucose-6-phosphatase, but also to hexose-6-phosphate dehydrogenase.
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Affiliation(s)
- Isabelle Gerin
- Laboratory of Physiological Chemistry, ICP and Université Catholique de Louvain, Brussels, Belgium
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Abstract
Glucose-6-phosphatase (G6Pase), an enzyme found mainly in the liver and the kidneys, plays the important role of providing glucose during starvation. Unlike most phosphatases acting on water-soluble compounds, it is a membrane-bound enzyme, being associated with the endoplasmic reticulum. In 1975, W. Arion and co-workers proposed a model according to which G6Pase was thought to be a rather unspecific phosphatase, with its catalytic site oriented towards the lumen of the endoplasmic reticulum [Arion, Wallin, Lange and Ballas (1975) Mol. Cell. Biochem. 6, 75--83]. Substrate would be provided to this enzyme by a translocase that is specific for glucose 6-phosphate, thereby accounting for the specificity of the phosphatase for glucose 6-phosphate in intact microsomes. Distinct transporters would allow inorganic phosphate and glucose to leave the vesicles. At variance with this substrate-transport model, other models propose that conformational changes play an important role in the properties of G6Pase. The last 10 years have witnessed important progress in our knowledge of the glucose 6-phosphate hydrolysis system. The genes encoding G6Pase and the glucose 6-phosphate translocase have been cloned and shown to be mutated in glycogen storage disease type Ia and type Ib respectively. The gene encoding a G6Pase-related protein, expressed specifically in pancreatic islets, has also been cloned. Specific potent inhibitors of G6Pase and of the glucose 6-phosphate translocase have been synthesized or isolated from micro-organisms. These as well as other findings support the model initially proposed by Arion. Much progress has also been made with regard to the regulation of the expression of G6Pase by insulin, glucocorticoids, cAMP and glucose.
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Affiliation(s)
- Emile van Schaftingen
- Laboratoire de Chimie Physiologique, UCL and ICP, Avenue Hippocrate 75, B-1200 Brussels, Belgium.
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Westergaard N, Madsen P, Lundbeck JM, Jakobsen P, Varming A, Andersen B. Identification of two novel and potent competitive inhibitors of the glucose-6-phosphatase catalytic protein. Diabetes Obes Metab 2002; 4:96-105. [PMID: 11940106 DOI: 10.1046/j.1463-1326.2002.00179.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM In this study, we show that inhibitors of the glucose-6-phosphatase (G-6-Pase) catalytic protein could be an alternative approach to the recent G-6-Pase T1-translocase inhibitors to target this enzyme for the treatment of type 2 diabetes. METHOD The active enantiomers of 4-methoxyphenyl-[4-(4-methoxyphenyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-5-yl]methanone (Compound A-1) and 4-methoxyphenyl-[4-(4-trifluoromethoxyphenyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridin-5-yl]methanone (Compound B-1) were characterized as inhibitors of the G-6-Pase catalytic protein using pig and rat liver microsomes and cultured rat hepatocytes. RESULTS Both compounds were found to be potent competitive inhibitors of the G-6-Pase catalytic protein obtained from pig and rat liver microsomes. The K(i) values (microM) were calculated to be 0.61 +/- 0.02 and 0.63 +/- 0.08 for compound A-1 and B-1 on intact pig microsomes, and 0.27 +/- 0.02 and 0.29 +/- 0.06 on disrupted pig microsomes. The corresponding values for rat liver microsomes were found to be 3.3 +/- 0.6 and 4.0 +/- 1.2 for compound A-1 and B-1 on intact microsomes, and 1.54 +/- 0.1 and 1.21 +/- 0.1 on disrupted microsomes. Compound A-1 was also able to inhibit pyrophosphatase activities from both intact and disrupted microsomes with equal potency (IC50; 0.43-0.55 microm). Using cultured rat hepatocytes and glycerol as the substrate, these compounds were able to prevent glucose production up to 60% with a concomitant increase in the G-6-P content (2.3-fold) using compound A-1. No increase in glycogen levels was seen. CONCLUSION These data demonstrated that these compounds were more potent inhibitors on G-6-Pase obtained from pig microsomes and were able to penetrate the microsomal membrane. The hepatocyte data further support the kinetic data, and are also consistent with the evoked mechanism of action.
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Affiliation(s)
- N Westergaard
- Department of Diabetes Biochemistry and Metabolism, Novo Nordisk A/S, DK-2760 Måløv, Denmark
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Herling AW, Schwab D, Burger HJ, Maas J, Hammerl R, Schmidt D, Strohschein S, Hemmerle H, Schubert G, Petry S, Kramer W. Prolonged blood glucose reduction in mrp-2 deficient rats (GY/TR(-)) by the glucose-6-phosphate translocase inhibitor S 3025. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1569:105-10. [PMID: 11853963 DOI: 10.1016/s0304-4165(01)00239-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chlorogenic acid derivatives are potent inhibitors of hepatic glucose production by inhibition of the glucose-6-phosphate translocase component of the hepatic glucose-6-phosphatase system. The pharmacological proof of concept was clearly demonstrated during i.v. infusion of potent derivatives (S 4048, S 3483) in rats. However, the blood glucose lowering effect of S 4048 after bolus i.v. injection lasted only 60-90 min. Plasma clearance of S 4048 was very high, and the parent compound was rapidly and efficiently excreted into the bile of Wistar and GY/TR(-) rats, indicating that mrp-2 was not involved in this hepatobiliary elimination process. About 72% of the total administered radioactivity appeared in the bile within 20 min after i.v. bolus injection of the radiolabeled analogue [(3)H]S 1743 in a Wistar rat. However, in GY/TR(-) rats the dicarboxylic analogue of S 4048, S 3025, was cleared from the plasma less rapidly than its parent compound and its biliary elimination was comparatively low. In contrast, S 3025 exhibited comparable pharmacokinetics and biliary elimination profile as S 4048 in Wistar rats, suggesting that biliary elimination of S 3025 is facilitated by mrp-2, functionally absent in GY/TR(-) rats. Targeting to mrp-2 resulted in a significantly prolonged reduction of blood glucose levels in GY/TR(-) rats after i.v. bolus administration of S 3025.
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Affiliation(s)
- Andreas W Herling
- Aventis Pharma Deutschland GmbH, H 821 Pharmacology, 65926 Frankfurt am Main, Germany.
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Bandsma RH, Wiegman CH, Herling AW, Burger HJ, ter Harmsel A, Meijer AJ, Romijn JA, Reijngoud DJ, Kuipers F. Acute inhibition of glucose-6-phosphate translocator activity leads to increased de novo lipogenesis and development of hepatic steatosis without affecting VLDL production in rats. Diabetes 2001; 50:2591-7. [PMID: 11679439 DOI: 10.2337/diabetes.50.11.2591] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glucose-6-phosphatase (G6Pase) is a key enzyme in hepatic glucose metabolism. Altered G6Pase activity in glycogen storage disease and diabetic states is associated with disturbances in lipid metabolism. We studied the effects of acute inhibition of G6Pase activity on hepatic lipid metabolism in nonanesthetized rats. Rats were infused with an inhibitor of the glucose-6-phosphate (G6P) translocator (S4048, 30 mg. kg(-1). h(-1)) for 8 h. Simultaneously, [1-(13)C]acetate was administered for determination of de novo lipogenesis and fractional cholesterol synthesis rates by mass isotopomer distribution analysis. In a separate group of rats, Triton WR 1339 was injected for determination of hepatic VLDL-triglyceride production. S4048 infusion significantly decreased plasma glucose (-11%) and insulin (-48%) levels and increased hepatic G6P (201%) and glycogen (182%) contents. Hepatic triglyceride contents increased from 5.8 +/- 1.4 micromol/g liver in controls to 20.6 +/- 5.5 micromol/g liver in S4048-treated animals. De novo lipogenesis was increased >10-fold in S4048-treated rats, without changes in cholesterol synthesis rates. Hepatic mRNA levels of acetyl-CoA carboxylase and fatty acid synthase were markedly induced. Plasma triglyceride levels increased fourfold, but no differences in plasma cholesterol levels were seen. Surprisingly, hepatic VLDL-triglyceride secretion was not increased in S4048-treated rats. These studies demonstrate that inhibition of the G6Pase system leads to acute stimulation of fat synthesis and development of hepatic steatosis, without affecting hepatic cholesterol synthesis and VLDL secretion. The results emphasize the strong interactions that exist between hepatic carbohydrate and fat metabolism.
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Affiliation(s)
- R H Bandsma
- Groningen University Institute for Drug Exploration, Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics, Academic Hospital Groningen, Groningen, the Netherlands.
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Gustafson LA, Neeft M, Reijngoud DJ, Kuipers F, Sauerwein HP, Romijn JA, Herling AW, Burger HJ, Meijer AJ. Fatty acid and amino acid modulation of glucose cycling in isolated rat hepatocytes. Biochem J 2001; 358:665-71. [PMID: 11535127 PMCID: PMC1222100 DOI: 10.1042/0264-6021:3580665] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We studied the influence of glucose/glucose 6-phosphate cycling on glycogen deposition from glucose in fasted-rat hepatocytes using S4048 and CP320626, specific inhibitors of glucose-6-phosphate translocase and glycogen phosphorylase respectively. The effect of amino acids and oleate was also examined. The following observations were made: (1) with glucose alone, net glycogen production was low. Inhibition of glucose-6-phosphate translocase increased intracellular glucose 6-phosphate (3-fold), glycogen accumulation (5-fold) without change in active (dephosphorylated) glycogen synthase (GSa) activity, and lactate production (4-fold). With both glucose 6-phosphate translocase and glycogen phosphorylase inhibited, glycogen deposition increased 8-fold and approached reported in vivo rates of glycogen deposition during the fasted-->fed transition. Addition of a physiological mixture of amino acids in the presence of glucose increased glycogen accumulation (4-fold) through activation of GS and inhibition of glucose-6-phosphatase flux. Addition of oleate with glucose present decreased glycolytic flux and increased the flux through glucose 6-phosphatase with no change in glycogen deposition. With glucose 6-phosphate translocase inhibited by S4048, oleate increased intracellular glucose 6-phosphate (3-fold) and net glycogen production (1.5-fold), without a major change in GSa activity. It is concluded that glucose cycling in hepatocytes prevents the net accumulation of glycogen from glucose. Amino acids activate GS and inhibit flux through glucose-6-phosphatase, while oleate inhibits glycolysis and stimulates glucose-6-phosphatase flux. Variation in glucose 6-phosphate does not always result in activity changes of GSa. Activation of glucose 6-phosphatase flux by fatty acids may contribute to the increased hepatic glucose production as seen in Type 2 diabetes.
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Affiliation(s)
- L A Gustafson
- Department of Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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van Dijk TH, van der Sluijs FH, Wiegman CH, Baller JF, Gustafson LA, Burger HJ, Herling AW, Kuipers F, Meijer AJ, Reijngoud DJ. Acute inhibition of hepatic glucose-6-phosphatase does not affect gluconeogenesis but directs gluconeogenic flux toward glycogen in fasted rats. A pharmacological study with the chlorogenic acid derivative S4048. J Biol Chem 2001; 276:25727-35. [PMID: 11346646 DOI: 10.1074/jbc.m101223200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Effects of acute inhibition of glucose-6-phosphatase activity by the chlorogenic acid derivative S4048 on hepatic carbohydrate fluxes were examined in isolated rat hepatocytes and in vivo in rats. Fluxes were calculated using tracer dilution techniques and mass isotopomer distribution analysis in plasma glucose and urinary paracetamol-glucuronide after infusion of [U-(13)C]glucose, [2-(13)C]glycerol, [1-(2)H]galactose, and paracetamol. In hepatocytes, glucose-6-phosphate (Glc-6-P) content, net glycogen synthesis, and lactate production from glucose and dihydroxyacetone increased strongly in the presence of S4048 (10 microm). In livers of S4048-treated rats (0.5 mg kg(-1)min(-)); 8 h) Glc-6-P content increased strongly (+440%), and massive glycogen accumulation (+1260%) was observed in periportal areas. Total glucose production was diminished by 50%. The gluconeogenic flux to Glc-6-P was unaffected (i.e. 33.3 +/- 2.0 versus 33.2 +/- 2.9 micromol kg(-1)min(-1)in control and S4048-treated rats, respectively). Newly synthesized Glc-6-P was redistributed from glucose production (62 +/- 1 versus 38 +/- 1%; p < 0.001) to glycogen synthesis (35 +/- 5% versus 65 +/- 5%; p < 0.005) by S4048. This was associated with a strong inhibition (-82%) of the flux through glucokinase and an increase (+83%) of the flux through glycogen synthase, while the flux through glycogen phosphorylase remained unaffected. In livers from S4048-treated rats, mRNA levels of genes encoding Glc-6-P hydrolase (approximately 9-fold), Glc-6-P translocase (approximately 4-fold), glycogen synthase (approximately 7-fold) and L-type pyruvate kinase (approximately 4-fold) were increased, whereas glucokinase expression was almost abolished. In accordance with unaltered gluconeogenic flux, expression of the gene encoding phosphoenolpyruvate carboxykinase was unaffected in the S4048-treated rats. Thus, acute inhibition of glucose-6-phosphatase activity by S4048 elicited 1) a repartitioning of newly synthesized Glc-6-P from glucose production into glycogen synthesis without affecting the gluconeogenic flux to Glc-6-P and 2) a cellular response aimed at maintaining cellular Glc-6-P homeostasis.
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Affiliation(s)
- T H van Dijk
- Laboratory of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University Hospital Groningen, Groningen 9700 RB, The Netherlands
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