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Tran M, Gilling S, Wu J, Wang L, Shin DJ. miR-141/200c contributes to ethanol-mediated hepatic glycogen metabolism. Mol Metab 2024; 84:101942. [PMID: 38642890 PMCID: PMC11060962 DOI: 10.1016/j.molmet.2024.101942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 04/15/2024] [Indexed: 04/22/2024] Open
Abstract
OBJECTIVE Hepatic glucose metabolism is profoundly perturbed by excessive alcohol intake. miR-141/200c expression is significantly induced by chronic ethanol feeding. This study aimed at identifying the role of miR-141/200c in glucose homeostasis during chronic ethanol exposure. METHODS WT and miR-141/200c KO mice were fed a control or an ethanol diet for 30 days, followed by a single binge of maltose dextrin or ethanol, respectively. Untargeted metabolomics analysis of hepatic primary metabolites was performed along with analyses for liver histology, gene expression, intracellular signaling pathways, and physiological relevance. Primary hepatocytes were used for mechanistic studies. RESULTS miR-141/200c deficiency rewires hepatic glucose metabolism during chronic ethanol feeding, increasing the abundance of glucose intermediates including G6P, an allosteric activator for GS. miR-141/200c deficiency replenished glycogen depletion during chronic ethanol feeding accompanied by reduced GS phosphorylation in parallel with increased expression of PP1 glycogen targeting subunits. Moreover, miR-141/200c deficiency prevented ethanol-mediated increases in AMPK and CaMKK2 activity. Ethanol treatment reduced glycogen content in WT-hepatocytes, which was reversed by dorsomorphin, a selective AMPK inhibitor, while KO-hepatocytes displayed higher glycogen content than WT-hepatocytes in response to ethanol treatment. Furthermore, treatment of hepatocytes with A23187, a calcium ionophore activating CaMKK2, lowered glycogen content in WT-hepatocytes. Notably, the suppressive effect of A23187 on glycogen deposition was reversed by dorsomorphin, demonstrating that the glycogen depletion by A23187 is mediated by AMPK. KO-hepatocytes exhibited higher glycogen content than WT-hepatocytes in response to A23187. Finally, miR-141/200c deficiency led to improved glucose tolerance and insulin sensitivity during chronic ethanol feeding. CONCLUSIONS miR-141/200c deficiency replenishes ethanol-mediated hepatic glycogen depletion through the regulation of GS activity and calcium signaling coupled with the AMPK pathway, improving glucose homeostasis and insulin sensitivity. These results underscore miR-141/200c as a potential therapeutic target for the management of alcohol intoxication.
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Affiliation(s)
- Melanie Tran
- Department of Physiology and Neurobiology, University of Connecticut, 75 N. Eagleville Rd, Storrs, CT 06269, USA
| | - Shaynian Gilling
- Department of Physiology and Neurobiology, University of Connecticut, 75 N. Eagleville Rd, Storrs, CT 06269, USA
| | - Jianguo Wu
- Department of Physiology and Neurobiology, University of Connecticut, 75 N. Eagleville Rd, Storrs, CT 06269, USA
| | - Li Wang
- Department of Internal Medicine, Section of Digestive Diseases, Yale University, 333 Cedar St, New Haven, CT 06510, USA
| | - Dong-Ju Shin
- Department of Physiology and Neurobiology, University of Connecticut, 75 N. Eagleville Rd, Storrs, CT 06269, USA.
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2
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Coate KC, Ramnanan CJ, Smith M, Winnick JJ, Kraft G, Irimia-Dominguez J, Farmer B, Donahue EP, Roach PJ, Cherrington AD, Edgerton DS. Integration of metabolic flux with hepatic glucagon signaling and gene expression profiles in the conscious dog. Am J Physiol Endocrinol Metab 2024; 326:E428-E442. [PMID: 38324258 PMCID: PMC11193521 DOI: 10.1152/ajpendo.00316.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/08/2024]
Abstract
Glucagon rapidly and profoundly stimulates hepatic glucose production (HGP), but for reasons that are unclear, this effect normally wanes after a few hours, despite sustained plasma glucagon levels. This study characterized the time course of glucagon-mediated molecular events and their relevance to metabolic flux in the livers of conscious dogs. Glucagon was either infused into the hepato-portal vein at a sixfold basal rate in the presence of somatostatin and basal insulin, or it was maintained at a basal level in control studies. In one control group, glucose remained at basal, whereas in the other, glucose was infused to match the hyperglycemia that occurred in the hyperglucagonemic group. Elevated glucagon caused a rapid (30 min) and largely sustained increase in hepatic cAMP over 4 h, a continued elevation in glucose-6-phosphate (G6P), and activation and deactivation of glycogen phosphorylase and synthase activities, respectively. Net hepatic glycogenolysis increased rapidly, peaking at 15 min due to activation of the cAMP/PKA pathway, then slowly returned to baseline over the next 3 h in line with allosteric inhibition by glucose and G6P. Glucagon's stimulatory effect on HGP was sustained relative to the hyperglycemic control group due to continued PKA activation. Hepatic gluconeogenic flux did not increase due to the lack of glucagon's effect on substrate supply to the liver. Global gene expression profiling highlighted glucagon-regulated activation of genes involved in cellular respiration, metabolic processes, and signaling, as well as downregulation of genes involved in extracellular matrix assembly and development.NEW & NOTEWORTHY Glucagon rapidly stimulates hepatic glucose production, but these effects are transient. This study links the molecular and metabolic flux changes that occur in the liver over time in response to a rise in glucagon, demonstrating the strength of the dog as a translational model to couple findings in small animals and humans. In addition, this study clarifies why the rapid effects of glucagon on liver glycogen metabolism are not sustained.
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Affiliation(s)
- Katie C Coate
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Christopher J Ramnanan
- Department of Innovation in Medical Education, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | - Marta Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Jason J Winnick
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Guillaume Kraft
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Jose Irimia-Dominguez
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute, Duarte, California, United States
| | - Ben Farmer
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - E Patrick Donahue
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Dale S Edgerton
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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3
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Basset-Sagarminaga J, van de Weijer T, Iozzo P, Schrauwen P, Schrauwen-Hinderling V. Advances and challenges in measuring hepatic glucose uptake with FDG PET: implications for diabetes research. Diabetologia 2024; 67:407-419. [PMID: 38099962 DOI: 10.1007/s00125-023-06055-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/10/2023] [Indexed: 02/06/2024]
Abstract
The liver plays a crucial role in the control of glucose homeostasis and is therefore of great interest in the investigation of the development of type 2 diabetes. Hepatic glucose uptake (HGU) can be measured through positron emission tomography (PET) imaging with the tracer [18F]-2-fluoro-2-deoxy-D-glucose (FDG). HGU is dependent on many variables (e.g. plasma glucose, insulin and glucagon concentrations), and the metabolic state for HGU assessment should be chosen with care and coherence with the study question. In addition, as HGU is influenced by many factors, protocols and measurement conditions need to be standardised for reproducible results. This review provides insights into the protocols that are available for the measurement of HGU by FDG PET and discusses the current state of knowledge of HGU and its impairment in type 2 diabetes. Overall, a scanning modality that allows for the measurement of detailed kinetic information and influx rates (dynamic imaging) may be preferable to static imaging. The combination of FDG PET and insulin stimulation is crucial to measure tissue-specific insulin sensitivity. While the hyperinsulinaemic-euglycaemic clamp allows for standardised measurements under controlled blood glucose levels, some research questions might require a more physiological approach, such as oral glucose loading, with both advantages and complexities relating to fluctuations in blood glucose and insulin levels. The available approaches to address HGU hold great potential but await more systematic exploitation to improve our understanding of the mechanisms underlying metabolic diseases. Current findings from the investigation of HGU by FDG PET highlight the complex interplay between insulin resistance, hepatic glucose metabolism, NEFA levels and intrahepatic lipid accumulation in type 2 diabetes and obesity. Further research is needed to fully understand the underlying mechanisms and potential therapeutic targets for improving HGU in these conditions.
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Affiliation(s)
- Jeremy Basset-Sagarminaga
- Department of Nutrition and Movement Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands
| | - Tineke van de Weijer
- Department of Nutrition and Movement Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Patricia Iozzo
- Institute of Clinical Physiology, National Research Council (CNR), Pisa, Italy
| | - Patrick Schrauwen
- Department of Nutrition and Movement Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands
| | - Vera Schrauwen-Hinderling
- Department of Nutrition and Movement Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, the Netherlands.
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands.
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Institute for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.
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4
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Estes SK, Shiota C, O'Brien TP, Printz RL, Shiota M. The impact of glucagon to support postabsorptive glucose flux and glycemia in healthy rats and its attenuation in male Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2024; 326:E308-E325. [PMID: 38265288 PMCID: PMC11193518 DOI: 10.1152/ajpendo.00192.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 01/19/2024] [Accepted: 01/19/2024] [Indexed: 01/25/2024]
Abstract
Hyperglucagonemia is a hallmark of type 2 diabetes (T2DM), yet the role of elevated plasma glucagon (P-GCG) to promote excessive postabsorptive glucose production and contribute to hyperglycemia in patients with this disease remains debatable. We investigated the acute action of P-GCG to safeguard/support postabsorptive endogenous glucose production (EGP) and euglycemia in healthy Zucker control lean (ZCL) rats. Using male Zucker diabetic fatty (ZDF) rats that exhibit the typical metabolic disorders of human T2DM, such as excessive EGP, hyperglycemia, hyperinsulinemia, and hyperglucagonemia, we examined the ability of hyperglucagonemia to promote greater rates of postabsorptive EGP and hyperglycemia. Euglycemic or hyperglycemic basal insulin (INS-BC) and glucagon (GCG-BC) clamps were performed in the absence or during an acute setting of glucagon deficiency (GCG-DF, ∼10% of basal), either alone or in combination with insulin deficiency (INS-DF, ∼10% of basal). Glucose appearance, disappearance, and cycling rates were measured using [2-3H] and [3-3H]-glucose. In ZCL rats, GCG-DF reduced the levels of hepatic cyclic AMP, EGP, and plasma glucose (PG) by 50%, 32%, and 50%, respectively. EGP fell in the presence GCG-DF and INS-BC, but under GCG-DF and INS-DF, EGP and PG increased two- and threefold, respectively. GCG-DF revealed the hyperglucagonemia present in ZDF rats lacked the ability to regulate hepatic intracellular cyclic AMP levels and glucose flux, since EGP and PG levels fell by only 10%. We conclude that the liver in T2DM suffers from resistance to all three major regulatory factors, glucagon, insulin, and glucose, thus leading to a loss of metabolic flexibility.NEW & NOTEWORTHY In postabsorptive state, basal plasma insulin (P-INS) and plasma glucose (PG) act dominantly to increase hepatic glucose cycling and reduce endogenous glucose production (EGP) and PG in healthy rats, which is only counteracted by the acute action of basal plasma glucagon (P-GCG) to support EGP and euglycemia. Hyperglucagonemia, a hallmark of type 2 diabetes (T2DM) present in Zucker diabetic fatty (ZDF) rats, is not the primary mediator of hyperglycemia and high EGP as commonly thought; instead, the liver is resistant to glucagon as well as insulin and glucose.
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Affiliation(s)
- Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Chiyo Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Tracy P O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Richard L Printz
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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5
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Fatema N, Li X, Gan Q, Fan C. Characterizing lysine acetylation of glucokinase. Protein Sci 2024; 33:e4845. [PMID: 37996965 PMCID: PMC10731539 DOI: 10.1002/pro.4845] [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: 09/25/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Glucokinase (GK) catalyzes the phosphorylation of glucose to form glucose-6-phosphate as the substrate of glycolysis for energy production. Acetylation of lysine residues in Escherichia coli GK has been identified at multiple sites by a series of proteomic studies, but the impact of acetylation on GK functions remains largely unknown. In this study, we applied the genetic code expansion strategy to produce site-specifically acetylated GK variants which naturally exist in cells. Enzyme assays and kinetic analyses showed that lysine acetylation decreases the GK activity, mostly resulting from acetylation of K214 and K216 at the entrance of the active site, which impairs the binding of substrates. We also compared results obtained from the glutamine substitution method and the genetic acetyllysine incorporation approach, showing that glutamine substitution is not always effective for mimicking acetylated lysine. Further genetic studies as well as in vitro acetylation and deacetylation assays were performed to determine acetylation and deacetylation mechanisms, which showed that E. coli GK could be acetylated by acetyl-phosphate without enzymes and deacetylated by CobB deacetylase.
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Affiliation(s)
- Nour Fatema
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
| | - Xinyu Li
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
| | - Qinglei Gan
- Department of Chemistry and BiochemistryUniversity of ArkansasFayettevilleArkansasUSA
| | - Chenguang Fan
- Cell and Molecular Biology ProgramUniversity of ArkansasFayettevilleArkansasUSA
- Department of Chemistry and BiochemistryUniversity of ArkansasFayettevilleArkansasUSA
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6
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Paliwal A, Paliwal V, Jain S, Paliwal S, Sharma S. Current Insight on the Role of Glucokinase and Glucokinase Regulatory Protein in Diabetes. Mini Rev Med Chem 2024; 24:674-688. [PMID: 37612862 DOI: 10.2174/1389557523666230823151927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/19/2023] [Accepted: 07/13/2023] [Indexed: 08/25/2023]
Abstract
The glucokinase regulator (GCKR) gene encodes an inhibitor of the glucokinase enzyme (GCK), found only in hepatocytes and responsible for glucose metabolism. A common GCKR coding variation has been linked to various metabolic traits in genome-wide association studies. Rare GCKR polymorphisms influence GKRP activity, expression, and localization. Despite not being the cause, these variations are linked to hypertriglyceridemia. Because of their crystal structures, we now better understand the molecular interactions between GKRP and the GCK. Finally, small molecules that specifically bind to GKRP and decrease blood sugar levels in diabetic models have been identified. GCKR allelic spectrum changes affect lipid and glucose homeostasis. GKRP dysfunction has been linked to a variety of molecular causes, according to functional analysis. Numerous studies have shown that GKRP dysfunction is not the only cause of hypertriglyceridemia, implying that type 2 diabetes could be treated by activating liver-specific GCK via small molecule GKRP inhibition. The review emphasizes current discoveries concerning the characteristic roles of glucokinase and GKRP in hepatic glucose metabolism and diabetes. This information has influenced the growth of directed molecular therapies for diabetes, which has improved our understanding of lipid and glucose physiology.
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Affiliation(s)
- Ajita Paliwal
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, India
| | - Vartika Paliwal
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, India
| | - Smita Jain
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, India
| | - Sarvesh Paliwal
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, India
| | - Swapnil Sharma
- Department of Pharmacy, Banasthali Vidyapith, Banasthali, Rajasthan, India
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7
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Chen Y, Du X, Kuppa A, Feitosa MF, Bielak LF, O'Connell JR, Musani SK, Guo X, Kahali B, Chen VL, Smith AV, Ryan KA, Eirksdottir G, Allison MA, Bowden DW, Budoff MJ, Carr JJ, Chen YDI, Taylor KD, Oliveri A, Correa A, Crudup BF, Kardia SLR, Mosley TH, Norris JM, Terry JG, Rotter JI, Wagenknecht LE, Halligan BD, Young KA, Hokanson JE, Washko GR, Gudnason V, Province MA, Peyser PA, Palmer ND, Speliotes EK. Genome-wide association meta-analysis identifies 17 loci associated with nonalcoholic fatty liver disease. Nat Genet 2023; 55:1640-1650. [PMID: 37709864 PMCID: PMC10918428 DOI: 10.1038/s41588-023-01497-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/07/2023] [Indexed: 09/16/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is common and partially heritable and has no effective treatments. We carried out a genome-wide association study (GWAS) meta-analysis of imaging (n = 66,814) and diagnostic code (3,584 cases versus 621,081 controls) measured NAFLD across diverse ancestries. We identified NAFLD-associated variants at torsin family 1 member B (TOR1B), fat mass and obesity associated (FTO), cordon-bleu WH2 repeat protein like 1 (COBLL1)/growth factor receptor-bound protein 14 (GRB14), insulin receptor (INSR), sterol regulatory element-binding transcription factor 1 (SREBF1) and patatin-like phospholipase domain-containing protein 2 (PNPLA2), as well as validated NAFLD-associated variants at patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily 2 (TM6SF2), apolipoprotein E (APOE), glucokinase regulator (GCKR), tribbles homolog 1 (TRIB1), glycerol-3-phosphate acyltransferase (GPAM), mitochondrial amidoxime-reducing component 1 (MARC1), microsomal triglyceride transfer protein large subunit (MTTP), alcohol dehydrogenase 1B (ADH1B), transmembrane channel like 4 (TMC4)/membrane-bound O-acyltransferase domain containing 7 (MBOAT7) and receptor-type tyrosine-protein phosphatase δ (PTPRD). Implicated genes highlight mitochondrial, cholesterol and de novo lipogenesis as causally contributing to NAFLD predisposition. Phenome-wide association study (PheWAS) analyses suggest at least seven subtypes of NAFLD. Individuals in the top 10% and 1% of genetic risk have a 2.5-fold to 6-fold increased risk of NAFLD, cirrhosis and hepatocellular carcinoma. These genetic variants identify subtypes of NAFLD, improve estimates of disease risk and can guide the development of targeted therapeutics.
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Affiliation(s)
- Yanhua Chen
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Xiaomeng Du
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Annapurna Kuppa
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Mary F Feitosa
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Lawrence F Bielak
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Jeffrey R O'Connell
- Department of Endocrinology, Diabetes and Nutrition, University of Maryland - Baltimore, Baltimore, MD, USA
| | - Solomon K Musani
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Xiuqing Guo
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Bratati Kahali
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
- Centre for Brain Research, Indian Institute of Science, Bangalore, India
| | - Vincent L Chen
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Albert V Smith
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, USA
| | - Kathleen A Ryan
- Department of Endocrinology, Diabetes and Nutrition, University of Maryland - Baltimore, Baltimore, MD, USA
| | | | - Matthew A Allison
- Department of Family Medicine, University of California San Diego, San Diego, CA, USA
| | - Donald W Bowden
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Matthew J Budoff
- Department of Internal Medicine, Lundquist Institute at Harbor-UCLA, Torrance, CA, USA
| | - John Jeffrey Carr
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Yii-Der I Chen
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Kent D Taylor
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Antonino Oliveri
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Adolfo Correa
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Breland F Crudup
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Sharon L R Kardia
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Thomas H Mosley
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jill M Norris
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - James G Terry
- Department of Radiology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Lynne E Wagenknecht
- Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Brian D Halligan
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Kendra A Young
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - John E Hokanson
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - George R Washko
- Department of Medicine, Division of Pulmonary and Critical Care, Brigham and Women's Hospital, Boston, MA, USA
| | - Vilmundur Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Department of Medicine, University of Iceland, Reykjavik, Iceland
| | - Michael A Province
- Division of Statistical Genomics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Patricia A Peyser
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Nicholette D Palmer
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Elizabeth K Speliotes
- Department of Internal Medicine, Division of Gastroenterology and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA.
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8
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Farooq Z, Ismail H, Bhat SA, Layden BT, Khan MW. Aiding Cancer's "Sweet Tooth": Role of Hexokinases in Metabolic Reprogramming. Life (Basel) 2023; 13:946. [PMID: 37109475 PMCID: PMC10141071 DOI: 10.3390/life13040946] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/24/2023] [Accepted: 03/31/2023] [Indexed: 04/08/2023] Open
Abstract
Hexokinases (HKs) convert hexose sugars to hexose-6-phosphate, thus trapping them inside cells to meet the synthetic and energetic demands. HKs participate in various standard and altered physiological processes, including cancer, primarily through the reprogramming of cellular metabolism. Four canonical HKs have been identified with different expression patterns across tissues. HKs 1-3 play a role in glucose utilization, whereas HK 4 (glucokinase, GCK) also acts as a glucose sensor. Recently, a novel fifth HK, hexokinase domain containing 1 (HKDC1), has been identified, which plays a role in whole-body glucose utilization and insulin sensitivity. Beyond the metabolic functions, HKDC1 is differentially expressed in many forms of human cancer. This review focuses on the role of HKs, particularly HKDC1, in metabolic reprogramming and cancer progression.
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Affiliation(s)
- Zeenat Farooq
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Hagar Ismail
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Sheraz Ahmad Bhat
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Brian T. Layden
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
| | - Md. Wasim Khan
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
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9
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Pasula MB, Napit PR, Alhamyani A, Roy SC, Sylvester PW, Bheemanapally K, Briski KP. Sex Dimorphic Glucose Transporter-2 Regulation of Hypothalamic Astrocyte Glucose and Energy Sensor Expression and Glycogen Metabolism. Neurochem Res 2023; 48:404-417. [PMID: 36173588 PMCID: PMC9898103 DOI: 10.1007/s11064-022-03757-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/17/2022] [Accepted: 09/06/2022] [Indexed: 02/06/2023]
Abstract
The plasma membrane glucose transporter-2 (GLUT2) monitors brain cell uptake of the critical nutrient glucose, and functions within astrocytes of as-yet-unknown location to control glucose counter-regulation. Hypothalamic astrocyte-neuron metabolic coupling provides vital cues to the neural glucostatic network. Current research utilized an established hypothalamic primary astrocyte culture model along with gene knockdown tools to investigate whether GLUT2 imposes sex-specific regulation of glucose/energy sensor function and glycogen metabolism in this cell population. Data show that GLUT2 stimulates or inhibits glucokinase (GCK) expression in glucose-supplied versus -deprived male astrocytes, but does not control this protein in female. Astrocyte 5'-AMP-activated protein kinaseα1/2 (AMPK) protein is augmented by GLUT2 in each sex, but phosphoAMPKα1/2 is coincidently up- (male) or down- (female) regulated. GLUT2 effects on glycogen synthase (GS) diverges in the two sexes, but direction of this control is reversed by glucoprivation in each sex. GLUT2 increases (male) or decreases (female) glycogen phosphorylase-brain type (GPbb) protein during glucoprivation, yet simultaneously inhibits (male) or stimulates (female) GP-muscle type (GPmm) expression. Astrocyte glycogen accumulation is restrained by GLUT2 when glucose is present (male) or absent (both sexes). Outcomes disclose sex-dependent GLUT2 control of the astrocyte glycolytic pathway sensor GCK. Data show that glucose status determines GLUT2 regulation of GS (both sexes), GPbb (female), and GPmm (male), and that GLUT2 imposes opposite control of GS, GPbb, and GPmm profiles between sexes during glucoprivation. Ongoing studies aim to investigate molecular mechanisms underlying sex-dimorphic GLUT2 regulation of hypothalamic astrocyte metabolic-sensory and glycogen metabolic proteins, and to characterize effects of sex-specific astrocyte target protein responses to GLUT2 on glucose regulation.
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Affiliation(s)
- Madhu Babu Pasula
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Prabhat R Napit
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Abdulrahman Alhamyani
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Sagor C Roy
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Paul W Sylvester
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Khaggeswar Bheemanapally
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Rm 356 Bienville Building 1800 Bienville Drive, 71201, Monroe, LA, USA.
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Roy SC, Sapkota S, Pasula MB, Bheemanapally K, Briski KP. Diazepam Binding Inhibitor Control of Eu- and Hypoglycemic Patterns of Ventromedial Hypothalamic Nucleus Glucose-Regulatory Signaling. ASN Neuro 2023; 15:17590914231214116. [PMID: 38031405 PMCID: PMC10687944 DOI: 10.1177/17590914231214116] [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: 07/03/2023] [Revised: 10/20/2023] [Accepted: 10/28/2023] [Indexed: 12/01/2023] Open
Abstract
Pharmacological stimulation/antagonism of astrocyte glio-peptide octadecaneuropeptide signaling alters ventromedial hypothalamic nucleus (VMN) counterregulatory γ-aminobutyric acid (GABA) and nitric oxide transmission. The current research used newly developed capillary zone electrophoresis-mass spectrometry methods to investigate hypoglycemia effects on VMN octadecaneuropeptide content, along with gene knockdown tools to determine if octadecaneuropeptide signaling regulates these transmitters during eu- and/or hypoglycemia. Hypoglycemia caused dissimilar adjustments in the octadecaneuropeptide precursor, i.e., diazepam-binding-inhibitor and octadecaneuropeptide levels in dorsomedial versus ventrolateral VMN. Intra-VMN diazepam-binding-inhibitor siRNA administration decreased baseline 67 and 65 kDa glutamate decarboxylase mRNA levels in GABAergic neurons laser-microdissected from each location, but only affected hypoglycemic transcript expression in ventrolateral VMN. This knockdown therapy imposed dissimilar effects on eu- and hypoglycemic glucokinase and 5'-AMP-activated protein kinase-alpha1 (AMPKα1) and -alpha2 (AMPKα2) gene profiles in dorsomedial versus ventrolateral GABAergic neurons. Diazepam-binding-inhibitor gene silencing up-regulated baseline (dorsomedial) or hypoglycemic (ventrolateral) nitrergic neuron neuronal nitric oxide synthase mRNA profiles. Baseline nitrergic cell glucokinase mRNA was up- (ventrolateral) or down- (dorsomedial) regulated by diazepam-binding-inhibitor siRNA, but knockdown enhanced hypoglycemic profiles in both sites. Nitrergic nerve cell AMPKα1 and -α2 transcripts exhibited division-specific responses to this genetic manipulation during eu- and hypoglycemia. Results document the utility of capillary zone electrophoresis-mass spectrometric tools for quantification of ODN in small-volume brain tissue samples. Data show that hypoglycemia has dissimilar effects on ODN signaling in the two major neuroanatomical divisions of the VMN and that this glio-peptide imposes differential control of glucose-regulatory neurotransmission in the VMNdm versus VMNvl during eu- and hypoglycemia.
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Affiliation(s)
- Sagor C. Roy
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
| | - Subash Sapkota
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
| | - Madhu Babu Pasula
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
| | - Khaggeswar Bheemanapally
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
| | - Karen P. Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
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11
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Llanos P, Ordenes P, Rhoads DB, Santibanez JF, García-Robles M, Millán C. BMAL1 Regulates Glucokinase Expression Through E-Box Elements In Vitro. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1408:235-249. [PMID: 37093431 DOI: 10.1007/978-3-031-26163-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
The organization of a circadian system includes an endogenous pacemaker system, input pathways for environmental synchronizing (entraining) stimuli, and output pathways through which the clock regulates physiological and behavioral processes, for example, the glucose-sensing mechanism in the liver. The liver is the central regulator of metabolism and one of our peripherals clocks. In mammals, central to this pacemaker are the transcription factors Circadian Locomotor Output Cycles Kaput (CLOCK) and BMAL1 (Brain and Muscle ARNT-Like 1). BMAL1 dimerizes with CLOCK, and this heterodimer then binds to the E-box promoter elements (CACGTG) present in clock and clock-controlled genes (CCGs). However, we are just beginning to understand how output pathways and regulatory mechanisms of CCGs are involved in rhythmic physiological processes. Glucokinase (GCK) is a fundamental enzyme in glucose homeostasis, catalyzing the high Km phosphorylation of glucose and allowing its storage. Moreover, gck is a dependent circadian gene. This study aims to determine the contribution of clock genes to hepatic gck expression and to define the specific role of E-box sequences on the circadian regulation of hepatic gck. Results showed that gck expression follows a circadian rhythm in rat hepatocytes in vitro. Accordingly, bmal1 expression induces the glucokinase circadian rhythmic expression in hepatocytes and the analysis of human and rat gck promoters, indicating the presence of E-box regions. Moreover, the basal activity of gck promoter was increased by clock/bmal1 co-transfection but inhibited by Period1/Period2 (per1/per2) co-transfection. Thus, the data suggest that the clock proteins tightly regulate the transcriptional activity of the gck promoter.
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Affiliation(s)
- Paula Llanos
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile
| | - Patricio Ordenes
- Departmento de Biología Celular, Universidad de Concepción, Concepción, Chile
| | - David B Rhoads
- Harvard Medical School, Boston, MA, US
- Pediatric Endocrinology, Mass General Hospital for Children, Boston, MA, US
| | - Juan F Santibanez
- Institute for Medical Research, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Integrative Center for Biology and Applied Chemistry (CIBQA), Bernardo O'Higgins University, Santiago, Chile
| | - María García-Robles
- Departmento de Biología Celular, Universidad de Concepción, Concepción, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Carola Millán
- Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Viña del Mar, Chile.
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12
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Roy R, Marakkar S, Vayalil MP, Shahanaz A, Anil AP, Kunnathpeedikayil S, Rawal I, Shetty K, Shameer Z, Sathees S, Prasannakumar AP, Mathew OK, Subramanian L, Shameer K, Yadav KK. Drug-food Interactions in the Era of Molecular Big Data, Machine Intelligence, and Personalized Health. RECENT ADVANCES IN FOOD, NUTRITION & AGRICULTURE 2022; 13:27-50. [PMID: 36173075 DOI: 10.2174/2212798412666220620104809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/04/2022] [Accepted: 03/30/2022] [Indexed: 12/29/2022]
Abstract
The drug-food interaction brings forth changes in the clinical effects of drugs. While favourable interactions bring positive clinical outcomes, unfavourable interactions may lead to toxicity. This article reviews the impact of food intake on drug-food interactions, the clinical effects of drugs, and the effect of drug-food in correlation with diet and precision medicine. Emerging areas in drug-food interactions are the food-genome interface (nutrigenomics) and nutrigenetics. Understanding the molecular basis of food ingredients, including genomic sequencing and pharmacological implications of food molecules, helps to reduce the impact of drug-food interactions. Various strategies are being leveraged to alleviate drug-food interactions; measures including patient engagement, digital health, approaches involving machine intelligence, and big data are a few of them. Furthermore, delineating the molecular communications across dietmicrobiome- drug-food-drug interactions in a pharmacomicrobiome framework may also play a vital role in personalized nutrition. Determining nutrient-gene interactions aids in making nutrition deeply personalized and helps mitigate unwanted drug-food interactions, chronic diseases, and adverse events from their onset. Translational bioinformatics approaches could play an essential role in the next generation of drug-food interaction research. In this landscape review, we discuss important tools, databases, and approaches along with key challenges and opportunities in drug-food interaction and its immediate impact on precision medicine.
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Affiliation(s)
- Romy Roy
- Molecular Robotics, Cochin, Kerala, India
| | | | | | - Alisha Shahanaz
- Molecular Robotics, Cochin, Kerala, India.,Sanaria Inc, Rockville, MD, USA
| | - Athira Panicker Anil
- Molecular Robotics, Cochin, Kerala, India.,Mar Athanasious College for Advanced Studies, Tiruvalla, India
| | - Shameer Kunnathpeedikayil
- Molecular Robotics, Cochin, Kerala, India.,Thiruvalla, Kerala; People Care Health LLP Thrissur, Kerala, India
| | | | | | | | - Saraswathi Sathees
- Molecular Robotics, Cochin, Kerala, India.,University of Washington Seattle, Washington WA, USA
| | | | | | - Lakshminarayanan Subramanian
- Department of Computer Science, Courant Institute of Mathematical Sciences, New York University, New York, NY, USA
| | - Khader Shameer
- Northwell Health, New York, NY, USA and Faculty of Medicine, Imperial College London, London, UK
| | - Kamlesh K Yadav
- School of Engineering Medicine, Center for Genomic and Precision Medicine, Texas A&M University, Houston, TX 77030, USA.,Department of Translational Medical Sciences, Center for Genomic and Precision Medicine, Texas A&M University, Houston, TX 77030, USA
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13
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Ali MH, Alshamrani AA, Napit PR, Briski KP. Single-cell multiplex qPCR evidence for sex-dimorphic glutamate decarboxylase, estrogen receptor, and 5'-AMP-activated protein kinase alpha subunit mRNA expression by ventromedial hypothalamic nucleus GABAergic neurons. J Chem Neuroanat 2022; 124:102132. [PMID: 35772680 PMCID: PMC9474596 DOI: 10.1016/j.jchemneu.2022.102132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/20/2022] [Accepted: 06/24/2022] [Indexed: 12/01/2022]
Abstract
The inhibitory amino acid transmitter γ-aminobutryic acid (GABA) acts within the ventromedial hypothalamus to regulate systemic glucose homeostasis, but the issue of whether this neurochemical signal originates locally or is supplied by afferent innervation remains controversial. Here, combinatory in situ immunocytochemistry/laser-catapult microdissection/single-cell multiplex qPCR techniques were used to investigate the premise that ventromedial hypothalamic nucleus ventrolateral (VMNvl) and/or dorsomedial (VMNdm) division neurons contain mRNAs that encode glutamate decarboxylase (GAD)65 or GAD67 and metabolic-sensory biomarkers, and that expression of these genes is sex-dimorphic. In male and female rats, GAD65 mRNA was elevated in VMNvl versus VMNdm GAD65/67-immunopositive (-ir) neurons, yet the female exhibited higher GAD67 transcript content in VMNdm versus VMNvl GABAergic nerve cells. Estrogen receptor (ER)-alpha transcripts were lower in female versus male GABA neurons from either VMN division; ER-beta and G-protein-coupled ER-1 mRNA expression profiles were also comparatively reduced in cells from female versus male VMNvl. VMNvl and VMNdm GAD65/67-ir-positive neurons showed equivalent levels of glucokinase and sulfonylurea receptor-1 mRNA between sexes. 5'-AMP-activated protein kinase-alpha 1 (AMPKα1) and -alpha 2 (AMPKα2) transcripts were lower in female versus male VMNdm GABAergic neurons, yet AMPKα2 mRNA levels were higher in cells acquired from female versus male VMNvl. Current studies document GAD65 and -67 gene expression in VMNvl and VMNdm GAD65/67-ir-positive neurons in each sex. Results infer that GABAergic neurons in each division may exhibit sex differences in receptiveness to estradiol. Outcomes also support the prospect that energy sensory function by this neurotransmitter cell type may predominate in the VMNvl in female versus VMNdm in the male.
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Affiliation(s)
- Md Haider Ali
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Ayed A Alshamrani
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Prabhat R Napit
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA.
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14
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Alshamrani AA, Ibrahim MM, Briski KP. Effects of Short-Term Food Deprivation on Catecholamine and Metabolic-Sensory Biomarker Gene Expression in Hindbrain A2 Noradrenergic Neurons Projecting to the Forebrain Rostral Preoptic Area: Impact of Negative versus Positive Estradiol Feedback. IBRO Neurosci Rep 2022; 13:38-46. [PMID: 35711244 PMCID: PMC9193863 DOI: 10.1016/j.ibneur.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 11/29/2022] Open
Abstract
Hindbrain A2 noradrenergic neurons assimilate estrogenic and metabolic cues. In female mammals, negative- versus positive-feedback patterns of estradiol (E) secretion impose divergent regulation of the gonadotropin-releasing hormone (GnRH)-pituitary-gonadal (HPG) neuroendocrine axis. Current research used retrograde tracing, dual-label immunocytochemistry, single-cell laser-microdissection, and multiplex qPCR methods to address the premise that E feedback modes uniquely affect metabolic regulation of A2 neurons involved in HPG control. Ovariectomized female rats were given E replacement to replicate plasma hormone levels characteristic of positive (high-E dose) or negative (low-E dose) feedback. Animals were either full-fed (FF) or subjected to short-term, e.g., 18-h food deprivation (FD). After FF or FD, rostral preoptic area (rPO)-projecting A2 neurons were characterized by the presence or absence of nuclear glucokinase regulatory protein (nGKRP) immunostaining. FD augmented or suppressed mRNAs encoding the catecholamine enzyme dopamine-beta-hydroxylase (DβH) and the metabolic-sensory biomarker glucokinase (GCK), relative to FF controls, in nGKRP-immunoreactive (ir)-positive A2 neurons from low-E or high-E animals, respectively. Yet, these transcript profiles were unaffected by FD in nGKRP-ir-negative A2 neurons at either E dosage level. FD altered estrogen receptor (ER)-alpha and ATP-sensitive potassium channel subunit sulfonylurea receptor-1 gene expression in nGKRP-ir-positive neurons from low-E, but not high-E animals. Results provide novel evidence that distinct hindbrain A2 neuron populations exhibit altered versus unaffected transmission to the rPO during FD-associated metabolic imbalance, and that the direction of change in this noradrenergic input is controlled by E feedback mode. These A2 cell types are correspondingly distinguished by FD-sensitive or -insensitive GCK, which correlates with the presence versus absence of nGKRP-ir. Further studies are needed to determine how E signal volume regulates neurotransmitter and metabolic sensor responses to FD in GKRP-expressing A2 neurons.
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Affiliation(s)
| | | | - Karen P. Briski
- Correspondence to: School of Basic Pharmaceutical and Toxicological Sciences College of Pharmacy, University of Louisiana at Monroe, Rm 356 Bienville Building 1800 Bienville Drive, Monroe, LA 71201, USA.
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15
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Actinidia deliciosa Mitigates Oxidative Stress and Changes in Pancreatic α-, β-, and δ-Cells and Immunohistochemical and Histological Architecture in Diabetic Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:5224207. [PMID: 35529919 PMCID: PMC9068294 DOI: 10.1155/2022/5224207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/15/2022] [Accepted: 04/18/2022] [Indexed: 12/30/2022]
Abstract
The present study evaluated the antioxidant capacity and antidiabetic effect of Actinidia deliciosa in diabetic rats. Rats were grouped as follows: control, Actinidia deliciosa aqueous extract (ADAE, 1 g/kg, daily and orally), streptozotocin (STZ, 50 mg/kg BW, single intraperitoneal dose), and STZ plus ADAE, respectively. Twenty-eight components were detected by GC-MS analysis with high phenolic contents and high DPPH scavenging activity. In vivo results revealed that rats treated with STZ showed a highly significant elevation in blood glucose and a decrease in insulin hormone levels. Thiobarbituric acid-reactive substances and hydrogen peroxide levels were elevated, while bodyweight, enzymatic, and nonenzymatic antioxidants were significantly decreased. Furthermore, histopathological and immunohistochemical insulin expression, besides ultrastructure microscopic variations (β-cells, α-cells, and δ-cells), were seen in pancreas sections supporting the obtained biochemical changes. Otherwise, rats supplemented with ADAE alone showed an improved antioxidant status and declined lipid peroxidation. Moreover, diabetic rats augmented with ADAE showed significant modulation in oxidative stress markers and different pancreatic tissue investigations compared to diabetic ones. Conclusively, ADAE has a potent antioxidant and hypoglycemic influence that may be utilized as a health-promoting complementary therapy in diabetes mellitus.
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16
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Ali MH, Alshamrani AA, Briski KP. Hindbrain lactate regulation of hypoglycemia-associated patterns of catecholamine and metabolic-sensory biomarker gene expression in A2 noradrenergic neurons innervating the male versus female ventromedial hypothalamic nucleus. J Chem Neuroanat 2022; 122:102102. [PMID: 35483611 DOI: 10.1016/j.jchemneu.2022.102102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 12/30/2022]
Abstract
Caudal hindbrain A2 noradrenergic neurons provide critical metabolic-sensory input to the brain glucostatic circuitry. In males, insulin-induced hypoglycemia (IIH)-associated patterns of A2 cell dopamine-beta-hydroxylase (DβH) protein expression reflect diminution of the oxidizable fuel L-lactate, yet DβH exhibits sex-dimorphic responses to IIH. Here, retrograde tracing and combinatory single-cell laser-microdissection/multiplex qPCR techniques were used to examine whether lactate imposes sex-specific control of hypoglycemia-associated metabolic-sensory function and noradrenergic neurotransmission in A2 neurons that innervate the ventromedial hypothalamic nucleus (VMN), a key glucose-regulatory structure. VMN-projecting A2 neurons from each sex were characterized by presence or absence of nuclear glucokinase regulatory protein (nGKRP) immunoreactivity (-ir). IIH caused lactate-reversible up- or down-regulation of DβH mRNA in male and female nGKRP-ir-positive A2 neurons, respectively, and stimulated glucokinase (GCK) and sulfonylurea receptor-1 (SUR-1) gene expression in these cells in each sex. Hypoglycemia did not alter DβH, GCK, and SUR-1 transcript profiles in nGKRP-ir-negative male or female A2 neurons innervating the VMN. Estrogen receptor (ER) gene profiles in nGKRP-ir-positive neurons showed sex-specific [ER-alpha; G-protein-coupled estrogen-receptor-1 (GPER)] or sex-monomorphic (ER-beta) transcriptional responses to IIH. Fewer ER gene profiles were affected by IIH in nGKRP-ir-negative A2 neurons from male or female rats. Results show that during IIH, VMN-projecting A2 neurons may deliver altered, sex-dependent (nGKRP-positive) or unaffected (nGKRP-negative) noradrenergic input to the VMN. In each sex, metabolic-sensory gene profiles were reactive to hypoglycemia in nGKRP-ir-positive, not -negative A2 cells. Further studies are needed to elucidate the role of GKRP in transduction of metabolic imbalance into noradrenergic signaling, and to determine if input by one or more ER variants establishes sex differences in DβH transcriptional sensitivity to IIH.
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Affiliation(s)
- Md Haider Ali
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Ayed A Alshamrani
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA
| | - Karen P Briski
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA 71201, USA.
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17
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Aoun R, Chokor FAZ, Taktouk M, Nasrallah M, Ismaeel H, Tamim H, Nasreddine L. Dietary fructose and its association with the metabolic syndrome in Lebanese healthy adults: a cross-sectional study. Diabetol Metab Syndr 2022; 14:29. [PMID: 35139893 PMCID: PMC8827166 DOI: 10.1186/s13098-022-00800-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epidemiological studies investigating the association between dietary fructose intake and the metabolic syndrome (MetS) are scarce and have produced controversial findings. This study aimed at (1) assessing total dietary fructose intake in a sample of Lebanese healthy adults, and determining the intake levels of natural vs. added fructose; (2) investigating the association of dietary fructose with MetS; and (3) identifying the socioeconomic and lifestyle factors associated with high fructose intake. METHODS A cross-sectional survey was conducted on a representative sample of adults living in Beirut, Lebanon (n = 283). Anthropometric and biochemical data were collected, and dietary intake was assessed using a food frequency questionnaire. Intakes of naturally-occurring fructose from fructose-containing food sources, such as fruits, vegetables, honey, were considered as "natural fructose". Acknowledging that the most common form of added sugar in commodities is sucrose or High Fructose Corn Syrup (HFCS), 50% of added sugar in food products was considered as added fructose. Total dietary fructose intake was calculated by summing up natural and added fructose intakes. Logistic regression analyses were conducted to investigate the association of total, added and natural fructose intakes with the MetS and to identify the socioeconomic predictors of high fructose intake. RESULTS Mean intake of total fructose was estimated at 51.42 ± 35.54 g/day, representing 6.58 ± 3.71% of energy intakes (EI). Natural and added fructose intakes were estimated at 12.29 ± 8.57 and 39.12 ± 34.10 g/day (1.78 ± 1.41% EI and 4.80 ± 3.56% EI), respectively. Participants in the highest quartile of total and added fructose intakes had higher odds of MetS (OR = 2.84, 95%CI: 1.01, 7.94 and OR = 3.18, 95%CI: 1.06, 9.49, respectively). In contrast, natural fructose intake was not associated with MetS. Age, gender and crowding index were identified as factors that may modulate dietary fructose intakes. CONCLUSIONS The observed association between high added fructose intake and the MetS highlights the need for public health strategies aimed at limiting sugar intake from industrialized foods and promoting healthier dietary patterns in Lebanon.
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Affiliation(s)
- Rita Aoun
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Fatima Al Zahraa Chokor
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Mandy Taktouk
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Mona Nasrallah
- Department of Internal Medicine, Division of Endocrinology, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
- Vascular Medicine Program, American University of Beirut Medical Center, Beirut, Lebanon
| | - Hussain Ismaeel
- Vascular Medicine Program, American University of Beirut Medical Center, Beirut, Lebanon
- Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Hani Tamim
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
- Clinical Research Institute, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
| | - Lara Nasreddine
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon.
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18
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Chen Q, Zhang W, Cai J, Ni Y, Xiao L, Zhang J. Transcriptome analysis in comparing carcass and meat quality traits of Jiaxing Black Pig and Duroc × Duroc × Berkshire × Jiaxing Black Pig crosses. Gene 2022; 808:145978. [PMID: 34592352 DOI: 10.1016/j.gene.2021.145978] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 08/31/2021] [Accepted: 09/24/2021] [Indexed: 01/17/2023]
Abstract
This study compares two typical strains: Chinese local excellent meat quality of Jiaxing Black (JXB) Pig and quadratic crossbred pig strain Duroc × Duroc × Berkshire × Jiaxing Black (DDBJ). It was found that between the two pig strains, carcass traits and meat quality traits differed significantly. This is exemplified by the leanness and dressing out percent of DDBJ that were significantly higher than JXB pigs of the same age (P < 0.05) and the better growth rate of DDBJ pigs as to JXB pigs was shown by quantifying muscle proliferation and differentiation of longissimus dorsi muscle employing Hematoxylin and Eosin staining of longissimus dorsi muscle. Nutrients such as inosinic acid, intramuscular fat, and free amino acids in the longissimus dorsi muscle were significantly higher in JXB pigs than DDBJ pigs (p < 0.0001); saturated fatty acids were higher in JXB than in DDBJ pigs (p = 0.0097); essential amino acids and fresh taste amino acids (serine, glutamic acid, proline, glycine, alanine) of JXB pigs was higher than that of DDBJ pigs (p < 0.0001) and amino acids in longissimus dorsi muscle of JXB pigs surpasses the amino acid concentration of DDBJ pigs (p < 0.0001), thus showing the superiority of JXB in terms of meat quality. However, the content of polyunsaturated fatty acids, which is responsible for poor meat quality, was significantly higher in the longissimus dorsi muscle of DDBJ pig than JXB pigs (p < 0.0001); RNA-seq analysis of 5 biological replicates from two of the strains was performed. The screening of 164 up-regulated genes and 183 down-regulated genes found in longissimus dorsi muscle of DDBJ was done and the results identified differentially expressed genes related to muscle development, adipogenesis, amino acid metabolism, fatty acid metabolism and inosine synthesis. In conclusion, the study identified functional genes, elucidated the mechanisms associated with carcass quality traits, meat quality traits and other related traits, and provided means of genetic enhancement to improve meat quality traits and carcass traits in Chinese commercial pigs.
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Affiliation(s)
- Qiangqiang Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Wei Zhang
- Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310058, China.
| | - Jianfeng Cai
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Yifan Ni
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Lixia Xiao
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Jinzhi Zhang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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19
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Præstholm SM, Correia CM, Goitea VE, Siersbæk MS, Jørgensen M, Havelund JF, Pedersen TÅ, Færgeman NJ, Grøntved L. Impaired glucocorticoid receptor expression in liver disrupts feeding-induced gene expression, glucose uptake, and glycogen storage. Cell Rep 2021; 37:109938. [PMID: 34731602 DOI: 10.1016/j.celrep.2021.109938] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 09/08/2021] [Accepted: 10/13/2021] [Indexed: 10/19/2022] Open
Abstract
The transition from a fasted to a fed state is associated with extensive transcriptional remodeling in hepatocytes facilitated by hormonal- and nutritional-regulated transcription factors. Here, we use a liver-specific glucocorticoid receptor (GR) knockout (L-GRKO) model to investigate the temporal hepatic expression of GR target genes in response to feeding. Interestingly, in addition to the well-described fasting-regulated genes, we identify a subset of hepatic feeding-induced genes that requires GR for full expression. This includes Gck, which is important for hepatic glucose uptake, utilization, and storage. We show that insulin and glucocorticoids cooperatively regulate hepatic Gck expression in a direct GR-dependent manner by a 4.6 kb upstream GR binding site operating as a Gck enhancer. L-GRKO blunts preprandial and early postprandial Gck expression, which ultimately affects early postprandial hepatic glucose uptake, phosphorylation, and glycogen storage. Thus, GR is positively involved in feeding-induced gene expression and important for postprandial glucose metabolism in the liver.
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Affiliation(s)
- Stine M Præstholm
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Catarina M Correia
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Victor E Goitea
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Majken S Siersbæk
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Mathilde Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper F Havelund
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | | | - Nils J Færgeman
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Lars Grøntved
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark.
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20
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Wang J, Conti DV, Bogumil D, Sheng X, Noureddin M, Wilkens LR, Le Marchand L, Rosen HR, Haiman CA, Setiawan VW. Association of Genetic Risk Score With NAFLD in An Ethnically Diverse Cohort. Hepatol Commun 2021; 5:1689-1703. [PMID: 34558842 PMCID: PMC8485887 DOI: 10.1002/hep4.1751] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/03/2021] [Indexed: 12/15/2022] Open
Abstract
Most genetic studies of nonalcoholic fatty liver disease (NAFLD) have been conducted in Whites. In this large and ethnically diverse cohort, we assessed the transportability of previously identified genetic variants for NAFLD, built a genetic risk score (GRS), and examined its association with NAFLD risk in multiple ethnic groups. Thirty previously identified genome-wide association studies (GWAS) variants (P < 5 × 10-8 ) and 17 other variants associated with NAFLD were examined in a nested case-control study of NAFLD (1,448 cases/8,444 controls) in this multi-ethnic cohort study. We then built a GRS using 11 independent single-nucleotide polymorphisms from these prior studies and examined its association with NAFLD by cirrhosis status across multiple ethnic groups. Of the 30 GWAS SNPs, 20 (67%) were replicated (P < 0.05) in the pooled multi-ethnic population. The highest percentage of replication was seen in Latinos (43%), followed by Japanese Americans (37%), Whites (17%), and Native Hawaiians and African Americans (≤10%). Several genetic variants, including those in PNPLA3 (patatin-like phospholipase domain containing 3), HSD17B13 (hydroxysteroid 17-beta dehydrogenase 13), TM6SF2 (transmembrane 6 superfamily member 2), GATAD2A (GATA zinc finger domain containing 2A), GCKR (glucokinase regulator), SUGP1 (SURP and G-patch domain containing 1), MBOAT7 (membrane bound O-acyltransferase domain containing 7), TRIB1 (tribbles pseudokinase 1), SAMM50 (sorting and assembly machinery component), and ERLIN1 (ER lipid raft associated 1)-CHUK (component of inhibitor of nuclear factor kappa B kinase complex)-CWF19L1 (CWF19 like cell cycle control factor 1) gene cluster, were replicated in at least two ethnic groups. An 11-SNP weighted GRS was associated with NAFLD risk in the multi-ethnic population (odds ratio [OR] per SD increase = 1.41; 95% confidence interval [CI] = 1.32-1.50), as well as in each ethnic group (OR ranged from 1.30 in African Americans to 1.52 in Latinos). The GRS-NAFLD association was stronger for NAFLD with cirrhosis (OR = 1.67; 95% CI = 1.46-1.92) compared to NAFLD without cirrhosis (OR = 1.37; 95% CI = 1.28-1.46) (P heterogeneity = 0.003). Conclusion: In this ethnically diverse cohort, we replicated several key genetic variants for NAFLD and showed the utility of GRS based on the risk alleles for NAFLD risk stratification in multiple ethnic groups.
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Affiliation(s)
- Jun Wang
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - David V. Conti
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
- Center for Genetic EpidemiologyKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA
- Norris Comprehensive Cancer CenterKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - David Bogumil
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - Xin Sheng
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - Mazen Noureddin
- Division of Gastroenterology and HepatologyDepartment of MedicineCedars‐Sinai Medical CenterLos AngelesCAUSA
| | - Lynne R. Wilkens
- Epidemiology ProgramUniversity of Hawaii Cancer CenterHonoluluHIUSA
| | - Loic Le Marchand
- Epidemiology ProgramUniversity of Hawaii Cancer CenterHonoluluHIUSA
| | - Hugo R. Rosen
- Department of MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - Christopher A. Haiman
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
- Center for Genetic EpidemiologyKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA
- Norris Comprehensive Cancer CenterKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
| | - Veronica Wendy Setiawan
- Department of Preventive MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
- Center for Genetic EpidemiologyKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA
- Norris Comprehensive Cancer CenterKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
- Department of MedicineKeck School of Medicine of University of Southern CaliforniaLos AngelesCAUSA
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21
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Wang L, Liu M, Wu Y, Li X, Yin F, Yin L, Liu J. Free fatty acids induce the demethylation of the fructose 1,6-biphosphatase 2 gene promoter and potentiate its expression in hepatocytes. Food Funct 2021; 12:4165-4175. [PMID: 33977939 DOI: 10.1039/d0fo02654a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Obesity is a serious health issue as it is a social burden and the main risk factor for other metabolic diseases. Increasing evidence indicates that a high-fat diet (HFD) is the key factor for the development of obesity, but the key genes and their associated molecular mechanisms are still not fully understood. In this study, we performed integrated bioinformatic analysis and identified that fructose-1,6 biphosphatase 2 (FBP2) was involved in free fatty acids (FFAs)-induced lipid droplet accumulation in hepatocytes and HFD-induced obesity in mice. Our data showed that palmitate (PA) and oleic acid (OA) induced the expression of FBP2 in time- and dose-dependent manners, and accelerated the development of lipid droplets in LO2 human normal liver cells. In HFD-fed C57BL/6 mice, accompanied by insulin resistance and lipid droplet accumulation, the mRNA and protein levels of FBP2 in the livers also increased significantly. The results from the methylation sequencing PCR (MSP) and bisulfite specific PCR (BSP) indicated that PA/OA induced the demethylation of the FBP2 gene promoter in LO2 cells. Moreover, betaine, a methyl donor, attenuated the expression of the FBP2 gene, the accumulation of lipid droplets, and the expression of perilipin-2, a biomarker of lipid droplets, in LO2 cells. All these findings revealed that FBP2 might be involved in HFD-induced obesity, and it is of interest to investigate the role of FBP2 in the treatment and prevention of obesity and its associated complications.
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Affiliation(s)
- Lujing Wang
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Min Liu
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Yucui Wu
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xingan Li
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Fei Yin
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Li Yin
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
| | - Jianhui Liu
- Chongqing Key Lab of Medicinal Chemistry & Molecular Pharmacology, Chongqing University of Technology, Chongqing 400054, China. and College of Pharmacy& Bioengineering, Chongqing University of Technology, Chongqing 400054, China
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22
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Kraft G, Coate KC, Smith M, Farmer B, Scott M, Cherrington AD, Edgerton DS. The Importance of the Mechanisms by Which Insulin Regulates Meal-Associated Liver Glucose Uptake in the Dog. Diabetes 2021; 70:1292-1302. [PMID: 33757993 PMCID: PMC8275892 DOI: 10.2337/db20-1271] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/18/2021] [Indexed: 12/17/2022]
Abstract
Hepatic glucose uptake (HGU) is critical for maintaining normal postprandial glucose metabolism. Insulin is clearly a key regulator of HGU, but the physiologic mechanisms by which it acts have yet to be established. This study sought to determine the mechanisms by which insulin regulates liver glucose uptake under postprandial-like conditions (hyperinsulinemia, hyperglycemia, and a positive portal vein-to-arterial glucose gradient). Portal vein insulin infusion increased hepatic insulin levels fivefold in healthy dogs. In one group (n = 7), the physiologic response was allowed to fully occur, while in another (n = 7), insulin's indirect hepatic effects, occurring secondary to its actions on adipose tissue, pancreas, and brain, were blocked. This was accomplished by infusing triglyceride (intravenous), glucagon (portal vein), and inhibitors of brain insulin action (intracerebroventricular) to prevent decreases in plasma free fatty acids or glucagon, while blocking increased hypothalamic insulin signaling for 4 h. In contrast to the indirect hepatic effects of insulin, which were previously shown capable of independently generating a half-maximal stimulation of HGU, direct hepatic insulin action was by itself able to fully stimulate HGU. This suggests that under hyperinsulinemic/hyperglycemic conditions insulin's indirect effects are redundant to direct engagement of hepatocyte insulin receptors.
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Affiliation(s)
- Guillaume Kraft
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Katie C Coate
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Marta Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Ben Farmer
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Melanie Scott
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Dale S Edgerton
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
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23
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Aslam M, Syed NIH, Jahan S. Effect of Caralluma tuberculata on regulation of carbohydrate metabolizing genes in alloxan-induced rats. JOURNAL OF ETHNOPHARMACOLOGY 2021; 271:113897. [PMID: 33567306 DOI: 10.1016/j.jep.2021.113897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Caralluma tuberculata (C. tuberculata) has traditionally been used in Pakistan and other parts of the world as a folk treatment for diabetes mellitus. A few studies indicated its antihyperglycemic effect, however, the mystery remained unfolded as how did it modify the pathophysiological condition. AIM OF STUDY Hence, this study aimed to explore underlying mechanism(s) for its hypoglycemic activity at biochemical and molecular levels. MATERIALS AND METHODS Methanol extract (ME) of C. tuberculata as well as its hexane (HF) and aqueous (AF) fractions were explored for their effect on total glycogen in liver and skeletal muscle of alloxan-induced rats by spectroscopy. Moreover, the expression of genes related to hepatic carbohydrate metabolizing enzymes was quantified. At molecular level, mRNA expression of glucose transporter 2 (GLUT-2), glycogen synthase (GS), glucokinase (GK), hexokinase 1 (HK-1), pyruvate kinase (PK), glucose 6 phosphate dehydrogenase (G-6-PDH), pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G-6-Pase) was determined by using quantitative real time polymerase chain reaction (qRT-PCR) after administration of ME (350 mg), HF(3 mg), AF (10 mg) and metformin (500 mg). The doses were administered twice daily according to per kg of body weight. RESULTS A significant reduction in hepatic and skeletal muscle glycogen content was exhibited. The data of qRT-PCR revealed that gene's expression of GLUT-2 was significantly decreased after treatment with ME and HF, whilst it was unaltered by AF, however, a significant decrease was observed in genes corresponding to GS, GK and HK-1 after treatment with ME. Similarly, there was a significant decrease in expression of genes corresponding to GS, GK and HK-1 following treatment with HF. Surprisingly, post-treatment with AF didn't modify the gene's expression of GS and GK, whilst it caused a profound decrease in expression of HK-1 gene. Contrarily, the expression of gene related to PK was significantly up-regulated post-administration with ME, HF and AF. The expression levels of G-6-PDH, however, remained unaltered after treatment with the experimental extract and fractions of the plant. In addition, HF and AF did not cause any modification in PEPCK, whereas ME caused a significant down-regulation of the gene. Treatment with all the extract and fractions of the plant caused a substantial decrease in the gene's expression of PC, while there was a significant increase in the expression of gene related to G-6-Pase. CONCLUSION The three experimental extract and fractions caused a substantial decrease in glycogen content in liver and skeletal muscle tissues. The analysis by qRT-PCR showed that glucose transport via GLUT-2 was profoundly declined by ME and HF. The expression of genes related to various metabolic pathways involved in metabolism of carbohydrate in hepatocytes revealed explicitly that the ME, HF and AF decreased the phenomena of glycogenesis and gluconeogenesis. Contrarily, all the extract and fractions of the plant activated glycogenolysis and glycolysis but did not modify the pentose phosphate shunt pathway.
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Affiliation(s)
- Maria Aslam
- Department of Pharmacology, Punjab University College of Pharmacy, University of the Punjab, Old Campus, Lahore, 54000, Pakistan.
| | - Nawazish-I-Husain Syed
- Department of Pharmacology, Punjab University College of Pharmacy, University of the Punjab, Old Campus, Lahore, 54000, Pakistan.
| | - Shah Jahan
- Department of Immunology, University of Health Sciences, Lahore, Pakistan.
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24
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Adaptive and maladaptive roles for ChREBP in the liver and pancreatic islets. J Biol Chem 2021; 296:100623. [PMID: 33812993 PMCID: PMC8102921 DOI: 10.1016/j.jbc.2021.100623] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/14/2022] Open
Abstract
Excessive sugar consumption is a contributor to the worldwide epidemic of cardiometabolic disease. Understanding mechanisms by which sugar is sensed and regulates metabolic processes may provide new opportunities to prevent and treat these epidemics. Carbohydrate Responsive-Element Binding Protein (ChREBP) is a sugar-sensing transcription factor that mediates genomic responses to changes in carbohydrate abundance in key metabolic tissues. Carbohydrate metabolites activate the canonical form of ChREBP, ChREBP-alpha, which stimulates production of a potent, constitutively active ChREBP isoform called ChREBP-beta. Carbohydrate metabolites and other metabolic signals may also regulate ChREBP activity via posttranslational modifications including phosphorylation, acetylation, and O-GlcNAcylation that can affect ChREBP’s cellular localization, stability, binding to cofactors, and transcriptional activity. In this review, we discuss mechanisms regulating ChREBP activity and highlight phenotypes and controversies in ChREBP gain- and loss-of-function genetic rodent models focused on the liver and pancreatic islets.
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25
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Guzmán TJ, Gurrola-Díaz CM. Glucokinase activation as antidiabetic therapy: effect of nutraceuticals and phytochemicals on glucokinase gene expression and enzymatic activity. Arch Physiol Biochem 2021; 127:182-193. [PMID: 31210550 DOI: 10.1080/13813455.2019.1627458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Diabetes represents an important public health problem. Recently, new molecular targets have been identified and exploited to treat this disease. Due to its pivotal role in glucose homeostasis, glucokinase (GCK) is a promising target for the development of novel antidiabetic drugs; however, pharmacological agents that modulate GCK activity have been linked to undesirable side-effects, limiting its use. Interestingly, plants might be a valuable source of new therapeutic compounds with GCK-activating properties and presumably no adverse effects. In this review, we describe biochemical characteristics related to the physiological and pathological importance of GCK, as well as the mechanisms involved in its regulation at different molecular levels. Posteriorly, we present a compendium of findings supporting the potential use of nutraceuticals and phytochemicals in the management of diabetes through modulation of GCK expression and activity. Finally, we propose critical aspects to keep in mind when designing experiments to evaluate GCK modulation properly.
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Affiliation(s)
- Tereso J Guzmán
- Departamento de Biología Molecular y Genómica, Instituto Transdisciplinar de Investigación e Innovación en Salud/Instituto de Investigación en Enfermedades Crónico-Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Carmen M Gurrola-Díaz
- Departamento de Biología Molecular y Genómica, Instituto Transdisciplinar de Investigación e Innovación en Salud/Instituto de Investigación en Enfermedades Crónico-Degenerativas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
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26
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Mascolo E, Liguori F, Stufera Mecarelli L, Amoroso N, Merigliano C, Amadio S, Volonté C, Contestabile R, Tramonti A, Vernì F. Functional Inactivation of Drosophila GCK Orthologs Causes Genomic Instability and Oxidative Stress in a Fly Model of MODY-2. Int J Mol Sci 2021; 22:ijms22020918. [PMID: 33477627 PMCID: PMC7831483 DOI: 10.3390/ijms22020918] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
Maturity-onset diabetes of the young (MODY) type 2 is caused by heterozygous inactivating mutations in the gene encoding glucokinase (GCK), a pivotal enzyme for glucose homeostasis. In the pancreas GCK regulates insulin secretion, while in the liver it promotes glucose utilization and storage. We showed that silencing the DrosophilaGCK orthologs Hex-A and Hex-C results in a MODY-2-like hyperglycemia. Targeted knock-down revealed that Hex-A is expressed in insulin producing cells (IPCs) whereas Hex-C is specifically expressed in the fat body. We showed that Hex-A is essential for insulin secretion and it is required for Hex-C expression. Reduced levels of either Hex-A or Hex-C resulted in chromosome aberrations (CABs), together with an increased production of advanced glycation end-products (AGEs) and reactive oxygen species (ROS). This result suggests that CABs, in GCK depleted cells, are likely due to hyperglycemia, which produces oxidative stress through AGE metabolism. In agreement with this hypothesis, treating GCK-depleted larvae with the antioxidant vitamin B6 rescued CABs, whereas the treatment with a B6 inhibitor enhanced genomic instability. Although MODY-2 rarely produces complications, our data revealed the possibility that MODY-2 impacts genome integrity.
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Affiliation(s)
- Elisa Mascolo
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University, 00185 Rome, Italy; (E.M.); (L.S.M.); (N.A.); (C.M.)
| | - Francesco Liguori
- Preclinical Neuroscience, IRCCS Santa Lucia Foundation, 00143 Rome, Italy; (F.L.); (S.A.); (C.V.)
| | - Lorenzo Stufera Mecarelli
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University, 00185 Rome, Italy; (E.M.); (L.S.M.); (N.A.); (C.M.)
| | - Noemi Amoroso
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University, 00185 Rome, Italy; (E.M.); (L.S.M.); (N.A.); (C.M.)
| | - Chiara Merigliano
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University, 00185 Rome, Italy; (E.M.); (L.S.M.); (N.A.); (C.M.)
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
| | - Susanna Amadio
- Preclinical Neuroscience, IRCCS Santa Lucia Foundation, 00143 Rome, Italy; (F.L.); (S.A.); (C.V.)
| | - Cinzia Volonté
- Preclinical Neuroscience, IRCCS Santa Lucia Foundation, 00143 Rome, Italy; (F.L.); (S.A.); (C.V.)
- Institute for Systems Analysis and Computer Science “A. Ruberti”, National Research Council (IASI-CNR), 00185 Rome, Italy
| | - Roberto Contestabile
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti and Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University, 00185 Rome, Italy; (R.C.); (A.T.)
| | - Angela Tramonti
- Istituto Pasteur Italia-Fondazione Cenci Bolognetti and Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University, 00185 Rome, Italy; (R.C.); (A.T.)
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, 00185 Rome, Italy
| | - Fiammetta Vernì
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University, 00185 Rome, Italy; (E.M.); (L.S.M.); (N.A.); (C.M.)
- Correspondence:
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27
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Regulation of Postabsorptive and Postprandial Glucose Metabolism by Insulin-Dependent and Insulin-Independent Mechanisms: An Integrative Approach. Nutrients 2021; 13:nu13010159. [PMID: 33419065 PMCID: PMC7825450 DOI: 10.3390/nu13010159] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/18/2020] [Accepted: 12/24/2020] [Indexed: 12/18/2022] Open
Abstract
Glucose levels in blood must be constantly maintained within a tight physiological range to sustain anabolism. Insulin regulates glucose homeostasis via its effects on glucose production from the liver and kidneys and glucose disposal in peripheral tissues (mainly skeletal muscle). Blood levels of glucose are regulated simultaneously by insulin-mediated rates of glucose production from the liver (and kidneys) and removal from muscle; adipose tissue is a key partner in this scenario, providing nonesterified fatty acids (NEFA) as an alternative fuel for skeletal muscle and liver when blood glucose levels are depleted. During sleep at night, the gradual development of insulin resistance, due to growth hormone and cortisol surges, ensures that blood glucose levels will be maintained within normal levels by: (a) switching from glucose to NEFA oxidation in muscle; (b) modulating glucose production from the liver/kidneys. After meals, several mechanisms (sequence/composition of meals, gastric emptying/intestinal glucose absorption, gastrointestinal hormones, hyperglycemia mass action effects, insulin/glucagon secretion/action, de novo lipogenesis and glucose disposal) operate in concert for optimal regulation of postprandial glucose fluctuations. The contribution of the liver in postprandial glucose homeostasis is critical. The liver is preferentially used to dispose over 50% of the ingested glucose and restrict the acute increases of glucose and insulin in the bloodstream after meals, thus protecting the circulation and tissues from the adverse effects of marked hyperglycemia and hyperinsulinemia.
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Ford BE, Chachra SS, Alshawi A, Brennan A, Harnor S, Cano C, Baker DJ, Smith DM, Fairclough RJ, Agius L. Chronic glucokinase activator treatment activates liver Carbohydrate response element binding protein and improves hepatocyte ATP homeostasis during substrate challenge. Diabetes Obes Metab 2020; 22:1985-1994. [PMID: 32519798 DOI: 10.1111/dom.14111] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/01/2020] [Accepted: 06/07/2020] [Indexed: 01/16/2023]
Abstract
AIM To test the hypothesis that glucokinase activators (GKAs) induce hepatic adaptations that alter intra-hepatocyte metabolite homeostasis. METHODS C57BL/6 mice on a standard rodent diet were treated with a GKA (AZD1656) acutely or chronically. Hepatocytes were isolated from the mice after 4 or 8 weeks of treatment for analysis of cellular metabolites and gene expression in response to substrate challenge. RESULTS Acute exposure of mice to AZD1656 or a liver-selective GKA (PF-04991532), before a glucose tolerance test, or challenge of mouse hepatocytes with GKAs ex vivo induced various Carbohydrate response element binding protein (ChREBP) target genes, including Carbohydrate response element binding protein beta isoform (ChREBP-β), Gckr and G6pc. Both glucokinase activation and ChREBP target gene induction by PF-04991532 were dependent on the chirality of the molecule, confirming a mechanism linked to glucokinase activation. Hepatocytes from mice treated with AZD1656 for 4 or 8 weeks had lower basal glucose 6-phosphate levels and improved ATP homeostasis during high substrate challenge. They also had raised basal ChREBP-β mRNA and AMPK-α mRNA (Prkaa1, Prkaa2) and progressively attenuated substrate induction of some ChREBP target genes and Prkaa1 and Prkaa2. CONCLUSIONS Chronic GKA treatment of C57BL/6 mice for 8 weeks activates liver ChREBP and improves the resilience of hepatocytes to compromised ATP homeostasis during high-substrate challenge. These changes are associated with raised mRNA levels of ChREBP-β and both catalytic subunits of AMP-activated protein kinase.
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Affiliation(s)
- Brian E Ford
- Biosciences Institute, Newcastle University, Medical School, Newcastle upon Tyne, UK
| | - Shruti S Chachra
- Biosciences Institute, Newcastle University, Medical School, Newcastle upon Tyne, UK
| | - Ahmed Alshawi
- Biosciences Institute, Newcastle University, Medical School, Newcastle upon Tyne, UK
| | - Alfie Brennan
- Newcastle Drug Discovery, Newcastle Centre for Cancer, School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Suzannah Harnor
- Newcastle Drug Discovery, Newcastle Centre for Cancer, School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Celine Cano
- Newcastle Drug Discovery, Newcastle Centre for Cancer, School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - David J Baker
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - David M Smith
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Rebecca J Fairclough
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Loranne Agius
- Biosciences Institute, Newcastle University, Medical School, Newcastle upon Tyne, UK
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Agius L, Ford BE, Chachra SS. The Metformin Mechanism on Gluconeogenesis and AMPK Activation: The Metabolite Perspective. Int J Mol Sci 2020; 21:ijms21093240. [PMID: 32375255 PMCID: PMC7247334 DOI: 10.3390/ijms21093240] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/13/2022] Open
Abstract
Metformin therapy lowers blood glucose in type 2 diabetes by targeting various pathways including hepatic gluconeogenesis. Despite widespread clinical use of metformin the molecular mechanisms by which it inhibits gluconeogenesis either acutely through allosteric and covalent mechanisms or chronically through changes in gene expression remain debated. Proposed mechanisms include: inhibition of Complex 1; activation of AMPK; and mechanisms independent of both Complex 1 inhibition and AMPK. The activation of AMPK by metformin could be consequent to Complex 1 inhibition and raised AMP through the canonical adenine nucleotide pathway or alternatively by activation of the lysosomal AMPK pool by other mechanisms involving the aldolase substrate fructose 1,6-bisphosphate or perturbations in the lysosomal membrane. Here we review current interpretations of the effects of metformin on hepatic intermediates of the gluconeogenic and glycolytic pathway and the candidate mechanistic links to regulation of gluconeogenesis. In conditions of either glucose excess or gluconeogenic substrate excess, metformin lowers hexose monophosphates by mechanisms that are independent of AMPK-activation and most likely mediated by allosteric activation of phosphofructokinase-1 and/or inhibition of fructose bisphosphatase-1. The metabolite changes caused by metformin may also have a prominent role in counteracting G6pc gene regulation in conditions of compromised intracellular homeostasis.
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30
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Krawczyk M, Liebe R, Lammert F. Toward Genetic Prediction of Nonalcoholic Fatty Liver Disease Trajectories: PNPLA3 and Beyond. Gastroenterology 2020; 158:1865-1880.e1. [PMID: 32068025 DOI: 10.1053/j.gastro.2020.01.053] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 12/14/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is on the verge of becoming the leading cause of liver disease. NAFLD develops at the interface between environmental factors and inherited predisposition. Genome-wide association studies, followed by exome-wide analyses, led to identification of genetic risk variants (eg, PNPLA3, TM6SF2, and SERPINA1) and key pathways involved in fatty liver disease pathobiology. Functional studies improved our understanding of these genetic factors and the molecular mechanisms underlying the trajectories from fat accumulation to fibrosis, cirrhosis, and cancer over time. Here, we summarize key NAFLD risk genes and illustrate their interactions in a 3-dimensional "risk space." Although NAFLD genomics sometimes appears to be "lost in translation," we envision clinical utility in trial design, outcome prediction, and NAFLD surveillance.
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Affiliation(s)
- Marcin Krawczyk
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg; Laboratory of Metabolic Liver Diseases, Center for Preclinical Research, Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland
| | - Roman Liebe
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg; Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Frank Lammert
- Department of Medicine II (Gastroenterology and Endocrinology), Saarland University Medical Center, Saarland University, Homburg.
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López-Soldado I, Bertini A, Adrover A, Duran J, Guinovart JJ. Maintenance of liver glycogen during long-term fasting preserves energy state in mice. FEBS Lett 2020; 594:1698-1710. [PMID: 32159852 DOI: 10.1002/1873-3468.13770] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/20/2020] [Accepted: 03/04/2020] [Indexed: 12/17/2022]
Abstract
Glycogen shortage during fasting coincides with dramatic changes in hepatic adenine nucleotide levels. The aim of this work was to study the relevance of liver glycogen in the regulation of the hepatic energy state during food deprivation. To this end, we examined the response of mice with sustained increased liver glycogen content to prolonged fasting. In order to increase hepatic glycogen content, we generated mice that overexpress protein targeting to glycogen (PTG) in the liver (PTGOE mice). Control and PTGOE mice were fed ad libitum or fasted for 36 h. Upon fasting, PTGOE mice retained significant hepatic glycogen stores and maintained hepatic energy status. Furthermore, we show that liver glycogen controls insulin sensitivity, gluconeogenesis, lipid metabolism, and ketogenesis upon nutrient deprivation.
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Affiliation(s)
- Iliana López-Soldado
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Angelo Bertini
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Spain
| | - Anna Adrover
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain.,Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Spain
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Agius L, Chachra SS, Ford BE. The Protective Role of the Carbohydrate Response Element Binding Protein in the Liver: The Metabolite Perspective. Front Endocrinol (Lausanne) 2020; 11:594041. [PMID: 33281747 PMCID: PMC7705168 DOI: 10.3389/fendo.2020.594041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/16/2020] [Indexed: 12/15/2022] Open
Abstract
The Carbohydrate response element binding protein, ChREBP encoded by the MLXIPL gene, is a transcription factor that is expressed at high levels in the liver and has a prominent function during consumption of high-carbohydrate diets. ChREBP is activated by raised cellular levels of phosphate ester intermediates of glycolysis, gluconeogenesis and the pentose phosphate pathway. Its target genes include a wide range of enzymes and regulatory proteins, including G6pc, Gckr, Pklr, Prkaa1,2, and enzymes of lipogenesis. ChREBP activation cumulatively promotes increased disposal of phosphate ester intermediates to glucose, via glucose 6-phosphatase or to pyruvate via glycolysis with further metabolism by lipogenesis. Dietary fructose is metabolized in both the intestine and the liver and is more lipogenic than glucose. It also induces greater elevation in phosphate ester intermediates than glucose, and at high concentrations causes transient depletion of inorganic phosphate, compromised ATP homeostasis and degradation of adenine nucleotides to uric acid. ChREBP deficiency predisposes to fructose intolerance and compromised cellular phosphate ester and ATP homeostasis and thereby markedly aggravates the changes in metabolite levels caused by dietary fructose. The recent evidence that high fructose intake causes more severe hepatocyte damage in ChREBP-deficient models confirms the crucial protective role for ChREBP in maintaining intracellular phosphate homeostasis. The improved ATP homeostasis in hepatocytes isolated from mice after chronic activation of ChREBP with a glucokinase activator supports the role of ChREBP in the control of intracellular homeostasis. It is hypothesized that drugs that activate ChREBP confer a protective role in the liver particularly in compromised metabolic states.
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Association between lncRNA and GCKR gene in type 2 diabetes mellitus. Clin Chim Acta 2019; 501:66-71. [PMID: 31756311 DOI: 10.1016/j.cca.2019.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/02/2019] [Accepted: 10/06/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To screen long non-coding RNA (lncRNA) related to glucokinase regulatory protein gene (GCKR), its differential expression was analyzed in patients with Type 2 diabetes mellitus (T2DM) and control samples. The correlation of lncRNA with GCKR was verified and its potential value as a molecular marker of T2DM was assessed. METHODS Lymphocyte RNA was extracted from five patients with T2DM and five patients with non-T2DM. The expression profiles of circulating lncRNAs and mRNAs were obtained by microarray. Bioinformatics analysis was used to screen lncRNAs associated with the GCKR gene in 127 patients with T2DM and 130 patients with non-T2DM were selected. The expression levels of the GCKR gene and lncRNA (ENST00000588707.1 and TCONS_00004187) in the T2DM group and control group were verified by real-time PCR. Additionally, a correlation analysis was conducted. The value of circulating ENST00000588707.1 and TCONS_00004187 as biomarkers for the diagnosis of T2DM was performed by receiver operating characteristic curve analysis. RESULTS We identified 68 lncRNAs and 74 mRNAs differentially expressed from the expression profile. Compared with the control group, the expression levels of the GCKR gene and lncRNA ENST00000588707.1 and TCONS_00004187 in the T2DM group were significantly lower (P < 0.05). The correlation analysis revealed that ENST00000588707.1 and TCONS_00004187 were correlated with GCKR gene expression and glycolipid metabolism (P < 0.05). ROC analysis showed that the area under the curve value of ENST00000588707.1 between T2DM patients and non-T2DM patients was 0.816 (95% CI: 0.764-0.869, sensitivity 72.0%, specificity 80.3%) and the AUC value of TCONS_00004187 was 0.826 (95% CI: 0.774-0.879, sensitivity 81.6%, specificity 61.3%). CONCLUSION lncRNA ENST0000588707.1 and TCONS_00004187 could serve as potential biomarkers for T2DM, which could involve in glycolipid metabolism by regulating the GCKR gene.
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Rajas F, Gautier-Stein A, Mithieux G. Glucose-6 Phosphate, A Central Hub for Liver Carbohydrate Metabolism. Metabolites 2019; 9:metabo9120282. [PMID: 31756997 PMCID: PMC6950410 DOI: 10.3390/metabo9120282] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/14/2019] [Accepted: 11/18/2019] [Indexed: 12/23/2022] Open
Abstract
Cells efficiently adjust their metabolism according to the abundance of nutrients and energy. The ability to switch cellular metabolism between anabolic and catabolic processes is critical for cell growth. Glucose-6 phosphate is the first intermediate of glucose metabolism and plays a central role in the energy metabolism of the liver. It acts as a hub to metabolically connect glycolysis, the pentose phosphate pathway, glycogen synthesis, de novo lipogenesis, and the hexosamine pathway. In this review, we describe the metabolic fate of glucose-6 phosphate in a healthy liver and the metabolic reprogramming occurring in two pathologies characterized by a deregulation of glucose homeostasis, namely type 2 diabetes, which is characterized by fasting hyperglycemia; and glycogen storage disease type I, where patients develop severe hypoglycemia during short fasting periods. In these two conditions, dysfunction of glucose metabolism results in non-alcoholic fatty liver disease, which may possibly lead to the development of hepatic tumors. Moreover, we also emphasize the role of the transcription factor carbohydrate response element-binding protein (ChREBP), known to link glucose and lipid metabolisms. In this regard, comparing these two metabolic diseases is a fruitful approach to better understand the key role of glucose-6 phosphate in liver metabolism in health and disease.
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Affiliation(s)
- Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
- Correspondence:
| | - Amandine Gautier-Stein
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213, F-69008 Lyon, France; (A.G.-S.); (G.M.)
- Université de Lyon, F-69008 Lyon, France
- Université Lyon 1, F-69622 Villeurbanne, France
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Lane EA, Choi DW, Garcia-Haro L, Levine ZG, Tedoldi M, Walker S, Danial NN. HCF-1 Regulates De Novo Lipogenesis through a Nutrient-Sensitive Complex with ChREBP. Mol Cell 2019; 75:357-371.e7. [PMID: 31227231 DOI: 10.1016/j.molcel.2019.05.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/26/2019] [Accepted: 05/10/2019] [Indexed: 12/21/2022]
Abstract
Carbohydrate response element binding protein (ChREBP) is a key transcriptional regulator of de novo lipogenesis (DNL) in response to carbohydrates and in hepatic steatosis. Mechanisms underlying nutrient modulation of ChREBP are under active investigation. Here we identify host cell factor 1 (HCF-1) as a previously unknown ChREBP-interacting protein that is enriched in liver biopsies of nonalcoholic steatohepatitis (NASH) patients. Biochemical and genetic studies show that HCF-1 is O-GlcNAcylated in response to glucose as a prerequisite for its binding to ChREBP and subsequent recruitment of OGT, ChREBP O-GlcNAcylation, and activation. The HCF-1:ChREBP complex resides at lipogenic gene promoters, where HCF-1 regulates H3K4 trimethylation to prime recruitment of the Jumonji C domain-containing histone demethylase PHF2 for epigenetic activation of these promoters. Overall, these findings define HCF-1's interaction with ChREBP as a previously unappreciated mechanism whereby glucose signals are both relayed to ChREBP and transmitted for epigenetic regulation of lipogenic genes.
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Affiliation(s)
- Elizabeth A Lane
- The Biological and Biomedical Sciences Program, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Dong Wook Choi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Luisa Garcia-Haro
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Zebulon G Levine
- Department of Microbiology and Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Meghan Tedoldi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Suzanne Walker
- Department of Microbiology and Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Nika N Danial
- Department of Cancer Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
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Chen H, Cai X, Xu A, Zhu L, Lu Y, Chen X, Liu S. Characterization of Glucokinase Catalysis from a Pseudo-Dimeric View. Appl Biochem Biotechnol 2019; 189:345-358. [PMID: 31011989 DOI: 10.1007/s12010-019-02998-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/27/2019] [Indexed: 11/30/2022]
Abstract
Glucose phosphorylation by glucokinase exhibits a sigmoidal dependency on substrate concentration regardless of its simple structure. Dimorph mechanism suggested the existence of two enzymatic states with different catalytic properties, which has been shown to be plausible by structural analysis. However, the dimorph mechanism gives rise to a complicated or non-explicit non-closed mathematical form. It is neither feasible to apply the dimorph mechanism in effector characterizations. To improve the area of glucokinase study with stronger theoretical support and less complication in computation, we proposed the investigation of the enzyme from a pseudo-dimeric angle. The proposed mechanism started from the idealization of two monomeric glucokinase as a dimeric complex, which significantly simplified the glucose phosphorylation kinetics, while the differences in enzyme reconfiguration caused by variable substrates and effectors have been successfully characterized. The study presented a simpler and more reliable way in studying the properties of glucokinase and its effectors, providing guidelines of effector developments for hyperglycemia and hypoglycemia treatment.
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Affiliation(s)
- Hanchi Chen
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China.,Department of Paper and Bioprocess Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA
| | - Xiaoqing Cai
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China
| | - Anjie Xu
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China
| | - Linjiang Zhu
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China
| | - Yuele Lu
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China
| | - Xiaolong Chen
- Institution of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, Zhejiang, China.
| | - Shijie Liu
- Department of Paper and Bioprocess Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA.
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Nutritional Regulation of Gene Expression: Carbohydrate-, Fat- and Amino Acid-Dependent Modulation of Transcriptional Activity. Int J Mol Sci 2019; 20:ijms20061386. [PMID: 30893897 PMCID: PMC6470599 DOI: 10.3390/ijms20061386] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/21/2022] Open
Abstract
The ability to detect changes in nutrient levels and generate an adequate response to these changes is essential for the proper functioning of living organisms. Adaptation to the high degree of variability in nutrient intake requires precise control of metabolic pathways. Mammals have developed different mechanisms to detect the abundance of nutrients such as sugars, lipids and amino acids and provide an integrated response. These mechanisms include the control of gene expression (from transcription to translation). This review reports the main molecular mechanisms that connect nutrients’ levels, gene expression and metabolism in health. The manuscript is focused on sugars’ signaling through the carbohydrate-responsive element binding protein (ChREBP), the role of peroxisome proliferator-activated receptors (PPARs) in the response to fat and GCN2/activating transcription factor 4 (ATF4) and mTORC1 pathways that sense amino acid concentrations. Frequently, alterations in these pathways underlie the onset of several metabolic pathologies such as obesity, insulin resistance, type 2 diabetes, cardiovascular diseases or cancer. In this context, the complete understanding of these mechanisms may improve our knowledge of metabolic diseases and may offer new therapeutic approaches based on nutritional interventions and individual genetic makeup.
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Matschinsky FM, Wilson DF. The Central Role of Glucokinase in Glucose Homeostasis: A Perspective 50 Years After Demonstrating the Presence of the Enzyme in Islets of Langerhans. Front Physiol 2019; 10:148. [PMID: 30949058 PMCID: PMC6435959 DOI: 10.3389/fphys.2019.00148] [Citation(s) in RCA: 157] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 02/07/2019] [Indexed: 01/05/2023] Open
Abstract
It is hypothesized that glucokinase (GCK) is the glucose sensor not only for regulation of insulin release by pancreatic β-cells, but also for the rest of the cells that contribute to glucose homeostasis in mammals. This includes other cells in endocrine pancreas (α- and δ-cells), adrenal gland, glucose sensitive neurons, entero-endocrine cells, and cells in the anterior pituitary. Glucose transport is by facilitated diffusion and is not rate limiting. Once inside, glucose is phosphorylated to glucose-6-phosphate by GCK in a reaction that is dependent on glucose throughout the physiological range of concentrations, is irreversible, and not product inhibited. High glycerol phosphate shuttle, pyruvate dehydrogenase, and pyruvate carboxylase activities, combined with low pentose-P shunt, lactate dehydrogenase, plasma membrane monocarboxylate transport, and glycogen synthase activities constrain glucose-6-phosphate to being metabolized through glycolysis. Under these conditions, glycolysis produces mostly pyruvate and little lactate. Pyruvate either enters the citric acid cycle through pyruvate dehydrogenase or is carboxylated by pyruvate carboxylase. Reducing equivalents from glycolysis enter oxidative phosphorylation through both the glycerol phosphate shuttle and citric acid cycle. Raising glucose concentration increases intramitochondrial [NADH]/[NAD+] and thereby the energy state ([ATP]/[ADP][Pi]), decreasing [Mg2+ADP] and [AMP]. [Mg2+ADP] acts through control of KATP channel conductance, whereas [AMP] acts through regulation of AMP-dependent protein kinase. Specific roles of different cell types are determined by the diverse molecular mechanisms used to couple energy state to cell specific responses. Having a common glucose sensor couples complementary regulatory mechanisms into a tightly regulated and stable glucose homeostatic network.
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Affiliation(s)
- Franz M Matschinsky
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - David F Wilson
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Sternisha SM, Miller BG. Molecular and cellular regulation of human glucokinase. Arch Biochem Biophys 2019; 663:199-213. [PMID: 30641049 DOI: 10.1016/j.abb.2019.01.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 01/23/2023]
Abstract
Glucose metabolism in humans is tightly controlled by the activity of glucokinase (GCK). GCK is predominantly produced in the pancreas, where it catalyzes the rate-limiting step of insulin secretion, and in the liver, where it participates in glycogen synthesis. A multitude of disease-causing mutations within the gck gene have been identified. Activating mutations manifest themselves in the clinic as congenital hyperinsulinism, while loss-of-function mutations produce several diabetic conditions. Indeed, pharmaceutical companies have shown great interest in developing GCK-associated treatments for diabetic patients. Due to its essential role in maintaining whole-body glucose homeostasis, GCK activity is extensively regulated at multiple levels. GCK possesses a unique ability to self-regulate its own activity via slow conformational dynamics, which allows for a cooperative response to glucose. GCK is also subject to a number of protein-protein interactions and post-translational modification events that produce a broad range of physiological consequences. While significant advances in our understanding of these individual regulatory mechanisms have been recently achieved, how these strategies are integrated and coordinated within the cell is less clear. This review serves to synthesize the relevant findings and offer insights into the connections between molecular and cellular control of GCK.
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Affiliation(s)
- Shawn M Sternisha
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA
| | - Brian G Miller
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
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Suwal A, Hao JL, Liu XF, Zhou DD, Pant OP, Gao Y, Hui P, Dai XX, Lu CW. NONRATT021972 long-noncoding RNA: A promising lncRNA in diabetes-related diseases. Int J Med Sci 2019; 16:902-908. [PMID: 31337964 PMCID: PMC6643109 DOI: 10.7150/ijms.34200] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/02/2019] [Indexed: 12/14/2022] Open
Abstract
Diabetes mellitus (DM) is a principal health problem with increasing incidence worldwide. It can be associated with various systemic diseases. Long non-coding RNA (lncRNA), a member of non-coding RNA has been newly linked with various human diseases. Recent evidence from animal experiments has shown that the incidence and development of type 2 diabetes are contributed by the atypical expression of lncRNA in which the biomarker with capable clinical potential was lncRNA NONRATT021972. In this review, we demonstrated the numerous functions of NONRATT021972 in different diabetes-related diseases including diabetic neuropathy, diabetic cardiac autonomic neuropathy, myocardial ischemia, and hepatic glucokinase dysfunction. The emerging evidence shows that the role of NONRATT021972 in diabetic-related disease is novel and therapeutic. These results direct us to conclude that NONRATT021972 is a potential diagnostic and future targeted therapy for diabetes-associated diseases.
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Affiliation(s)
- Abhishek Suwal
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Ji-Long Hao
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Xiu-Fen Liu
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Dan-Dan Zhou
- Department of Radiology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Om Prakash Pant
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Ying Gao
- Department of Endocrinology, The First Hospital of Jilin University, No. 71 of xinmin St., Changchun, Jilin Province, 130021, China
| | - Peng Hui
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Xin-Xuan Dai
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
| | - Cheng-Wei Lu
- Department of Ophthalmology, The First Hospital of Jilin University, No. 71 of Xinmin St., Changchun, Jilin Province, 130021, China
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López Rodríguez M, Fernandes Silva L, Vangipurapu J, Modi S, Kuusisto J, Kaikkonen MU, Laakso M. Functional Variant in the GCKR Gene Affects Lactate Levels Differentially in the Fasting State and During Hyperglycemia. Sci Rep 2018; 8:15989. [PMID: 30375486 PMCID: PMC6207693 DOI: 10.1038/s41598-018-34501-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 10/06/2018] [Indexed: 12/31/2022] Open
Abstract
The rs780094 single nucleotide polymorphism (SNP; C/T) of glucokinase regulatory protein gene (GCKR) is a regulatory genetic variant that has been associated with lactate levels in the fasting state. However, the association of this locus with lactate during hyperglycemia, and the mechanisms underlying these associations remain unknown. We investigated the association of rs780094 with lactate levels in a frequently sampled oral glucose tolerance test in humans and evaluated the effect of increasing GCKR expression on lactate production in liver cells. The C allele of rs780094 was associated with lower lactate levels in fasting but increased lactate level during hyperglycemia independently of insulin levels. Increased expression of GKRP induced higher lactate level in HepG2 cells and in human primary hepatocytes (HPH) upon glucose stimulation by increasing the amount of GCK. Glucagon induced the expression of GCKR in HepG2 and HPH cells. Our results suggest that the association of rs780094 with lactate levels may involve differential GCKR expression between the carriers of the C and T alleles.
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Affiliation(s)
- Maykel López Rodríguez
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Lilian Fernandes Silva
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Jagadish Vangipurapu
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Shalem Modi
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Johanna Kuusisto
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Medicine, Kuopio University Hospital, P.O. Box 100 FI 70029 KYS, Kuopio, Finland
| | - Minna U Kaikkonen
- A.I. Virtanen Institute for Molecular Sciences, Department of Biotechnology and Molecular Medicine, University of Eastern Finland, Kuopio, Finland
| | - Markku Laakso
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland.
- Department of Medicine, Kuopio University Hospital, P.O. Box 100 FI 70029 KYS, Kuopio, Finland.
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Wei L, Xiao Y, Li L, Xiong X, Han Y, Zhu X, Sun L. The Susceptibility Genes in Diabetic Nephropathy. KIDNEY DISEASES 2018; 4:226-237. [PMID: 30574499 DOI: 10.1159/000492633] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/03/2018] [Indexed: 12/22/2022]
Abstract
Background Diabetes mellitus (DM) poses a severe threat to global public health. Diabetic nephropathy (DN) is one of the most common complications of diabetes and the leading cause of end-stage renal disease (ESRD). Approximately 30-40% of DM patients in the world progress to ESRD, which emphasizes the effect of genetic factors on DN. Family clustering also supports the important role of hereditary factors in DN and ESRD. Therefore, a large number of genetic studies have been carried out to identify susceptibility genes in different diabetic cohorts. Extensive susceptibility genes of DN and ESRD have not been identified until recently. Summary and Key Messages Some of these associated genes function as pivotal regulators in the pathogenesis of DN, such as those related to glycometabolism and lipid metabolism. However, the functions of most of these genes remain unclear. In this article, we review several susceptibility genes according to their genetic functions to make it easier to determine their exact effect on DN and to provide a better understanding of the advancements from genetic studies. However, several challenges associated with investigating the genetic factors of DN still exist. For instance, it is difficult to determine whether these variants affect the expression of the protein they encode or other cytokines. More efforts should be made to determine how these genes influence the progression of DN. In addition, many results could not be replicated among races, suggesting that the association between genetic polymorphisms and DN is race-specific. Therefore, large, well-designed studies involving more relevant variables and ethnic groups and more relevant functional studies are urgently needed. These studies may be beneficial and retard the progression of DN by early intervention, especially for patients who carry certain risk alleles or genotypes.
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Affiliation(s)
- Ling Wei
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Ying Xiao
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Li Li
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Xiaofen Xiong
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Yachun Han
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Xuejing Zhu
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Lin Sun
- Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, China
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Gutierrez-Nogués A, García-Herrero CM, Oriola J, Vincent O, Navas MA. Functional characterization of MODY2 mutations in the nuclear export signal of glucokinase. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2385-2394. [PMID: 29704611 DOI: 10.1016/j.bbadis.2018.04.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/23/2018] [Accepted: 04/23/2018] [Indexed: 11/17/2022]
Abstract
Glucokinase (GCK) plays a key role in glucose homeostasis. Heterozygous inactivating mutations in the GCK gene cause the familial, mild fasting hyperglycaemia named MODY2. Besides its particular kinetic characteristics, glucokinase is regulated by subcellular compartmentation in hepatocytes. Glucokinase regulatory protein (GKRP) binds to GCK, leading to enzyme inhibition and import into the nucleus at fasting. When glucose concentration increases, GCK-GKRP dissociates and GCK is exported to the cytosol due to a nuclear export signal (NES). With the aim to characterize the GCK-NES, we have functionally analysed nine MODY2 mutations located within the NES sequence. Recombinant GCK mutants showed reduced catalytic activity and, in most cases, protein instability. Most of the mutants interact normally with GKRP, although mutations L306R and L309P impair GCK nuclear import in cotransfected cells. We demonstrated that GCK-NES function depends on exportin 1. We further showed that none of the mutations fully inactivate the NES, with the exception of mutation L304P, which likely destabilizes its α-helicoidal structure. Finally, we found that residue Glu300 negatively modulates the NES activity, whereas other residues have the opposite effect, thus suggesting that some of the NES spacer residues contribute to the low affinity of the NES for exportin 1, which is required for its proper functioning. In conclusion, our results have provided functional and structural insights regarding the GCK-NES and contributed to a better knowledge of the molecular mechanisms involved in the nucleo-cytoplasmic shuttling of glucokinase. Impairment of this regulatory mechanism by some MODY2 mutations might contribute to the hyperglycaemia in the patients.
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Affiliation(s)
- Angel Gutierrez-Nogués
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Carmen-María García-Herrero
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Josep Oriola
- Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Departamento de Ciencias Fisiológicas I, Facultad de Medicina, Universidad de Barcelona, Barcelona, Spain
| | - Olivier Vincent
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - María-Angeles Navas
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), www.ciberdem.net, Instituto de Salud Carlos III, Madrid, Spain; Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
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44
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Jideonwo V, Hou Y, Ahn M, Surendran S, Morral N. Impact of silencing hepatic SREBP-1 on insulin signaling. PLoS One 2018; 13:e0196704. [PMID: 29723221 PMCID: PMC5933792 DOI: 10.1371/journal.pone.0196704] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
Sterol Regulatory Element Binding Protein-1 (SREBP-1) is a conserved transcription factor of the basic helix-loop-helix leucine zipper family (bHLH-Zip) that plays a central role in regulating expression of genes of carbohydrate and fatty acid metabolism in the liver. SREBP-1 activity is essential for the control of insulin-induced anabolic processes during the fed state. In addition, SREBP-1 regulates expression of key molecules in the insulin signaling pathway, including insulin receptor substrate 2 (IRS2) and a subunit of the phosphatidylinositol 3-kinase (PI3K) complex, PIK3R3, suggesting that feedback mechanisms exist between SREBP-1 and this pathway. Nevertheless, the overall contribution of SREBP-1 activity to maintain insulin signal transduction is unknown. Furthermore, Akt is a known activator of mTORC1, a sensor of energy availability that plays a fundamental role in metabolism, cellular growth and survival. We have silenced SREBP-1 and explored the impact on insulin signaling and mTOR in mice under fed, fasted and refed conditions. No alterations in circulating levels of insulin were observed. The studies revealed that depletion of SREBP-1 had no impact on IRS1Y612, AktS473, and downstream effectors GSK3αS21 and FoxO1S256 during the fed state. Nevertheless, reduced levels of these molecules were observed under fasting conditions. These effects were not associated with changes in phosphorylation of mTOR. Overall, our data indicate that the contribution of SREBP-1 to maintain insulin signal transduction in liver is modest.
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Affiliation(s)
- Victoria Jideonwo
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Yongyong Hou
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Miwon Ahn
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sneha Surendran
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Núria Morral
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Basco D, Zhang Q, Salehi A, Tarasov A, Dolci W, Herrera P, Spiliotis I, Berney X, Tarussio D, Rorsman P, Thorens B. α-cell glucokinase suppresses glucose-regulated glucagon secretion. Nat Commun 2018; 9:546. [PMID: 29416045 PMCID: PMC5803227 DOI: 10.1038/s41467-018-03034-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 01/15/2018] [Indexed: 02/08/2023] Open
Abstract
Glucagon secretion by pancreatic α-cells is triggered by hypoglycemia and suppressed by high glucose levels; impaired suppression of glucagon secretion is a hallmark of both type 1 and type 2 diabetes. Here, we show that α-cell glucokinase (Gck) plays a role in the control of glucagon secretion. Using mice with α-cell-specific inactivation of Gck (αGckKO mice), we find that glucokinase is required for the glucose-dependent increase in intracellular ATP/ADP ratio and the closure of KATP channels in α-cells and the suppression of glucagon secretion at euglycemic and hyperglycemic levels. αGckKO mice display hyperglucagonemia in the fed state, which is associated with increased hepatic gluconeogenic gene expression and hepatic glucose output capacity. In adult mice, fed hyperglucagonemia is further increased and glucose intolerance develops. Thus, glucokinase governs an α-cell metabolic pathway that suppresses secretion at or above normoglycemic levels; abnormal suppression of glucagon secretion deregulates hepatic glucose metabolism and, over time, induces a pre-diabetic phenotype.
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Affiliation(s)
- Davide Basco
- Center for Integrative Genomics, University of Lausanne, 1015, Lausanne, Switzerland
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Albert Salehi
- Department of Clinical Science, UMAS, Division of Islet Cell Physiology, Lund, Sweden
| | - Andrei Tarasov
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Wanda Dolci
- Center for Integrative Genomics, University of Lausanne, 1015, Lausanne, Switzerland
| | - Pedro Herrera
- Department of Genetic Medicine and Development, 1200, Geneva, Switzerland
| | - Ioannis Spiliotis
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Xavier Berney
- Center for Integrative Genomics, University of Lausanne, 1015, Lausanne, Switzerland
| | - David Tarussio
- Center for Integrative Genomics, University of Lausanne, 1015, Lausanne, Switzerland
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Bernard Thorens
- Center for Integrative Genomics, University of Lausanne, 1015, Lausanne, Switzerland.
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Jayaraman R, Subramani S, Sheik Abdullah SH, Udaiyar M. Antihyperglycemic effect of hesperetin, a citrus flavonoid, extenuates hyperglycemia and exploring the potential role in antioxidant and antihyperlipidemic in streptozotocin-induced diabetic rats. Biomed Pharmacother 2017; 97:98-106. [PMID: 29080465 DOI: 10.1016/j.biopha.2017.10.102] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/16/2017] [Accepted: 10/21/2017] [Indexed: 12/25/2022] Open
Abstract
Diabetes is the major health problem in modern civilization which occurs due to inadequate metabolism of carbohydrate and lipid could cause tremendous changes in the metabolic activities of liver. In this study, we investigated the antihyperglycemic, antioxidant and antihyperlipidemic effects of hesperetin, a citrus flavonoid against streptozotocin (STZ)-induced experimental rats. To stimulate diabetes mellitus, rats were injected with STZ intraperitoneally at a single dose of 45mg/kg. STZ induced rats showed marked increase in the level of plasma glucose and significant reduction in the level of plasma insulin. The activities of carbohydrate metabolic enzymes, hepatic glycogen, lipid profiles, enzymic antioxidants in circulatory system and pancreas, hepatic and renal functional markers were explored. Supplementation with hesperetin (40mg/kg b.w) to STZ-induced experimental rats for 45days established a significant decline in plasma glucose and a marked improvement in plasma insulin and glycogen levels in STZ-induced rats. The altered activities of hepatic glucose metabolic enzymes, lipid profiles, enzymic antioxidants and serum biomarkers of liver and kidney toxicity were restored to almost normal. The acquired outcome were compared with glibenclamide (1mg/kg b.w), a standard oral hypoglycemic drug. Hesperetin treatment was found to be efficient in protecting the normal histological manifestation of hepatic, renal and insulin positive β-cells in STZ induced rats. On the basis of current experimental findings, we concluded that administration of hesperetin attenuates the hyperglycemia and dyslipidemia through ameliorating antioxidant competence in STZ-induced experimental rats.
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Affiliation(s)
- Revathy Jayaraman
- Research and Development Centre, Bharathiyar University, Coimbatore, Tamilnadu, India
| | - Srinivasan Subramani
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608 002, Tamilnadu, India; Postgraduate and Research Department of Biochemistry, Government Arts College for Women, Krishnagiri 635 002, Tamil Nadu, India.
| | - Shahul Hameed Sheik Abdullah
- Research and Development Centre, Bharathiyar University, Coimbatore, Tamilnadu, India; Department of Chemistry and Biosciences, Sastra University, Srinivasa Ramanujan Centre, Kumbakonam, Tamilnadu, India
| | - Muruganathan Udaiyar
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608 002, Tamilnadu, India
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Geidl-Flueck B, Gerber PA. Insights into the Hexose Liver Metabolism-Glucose versus Fructose. Nutrients 2017; 9:E1026. [PMID: 28926951 PMCID: PMC5622786 DOI: 10.3390/nu9091026] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/09/2017] [Accepted: 09/11/2017] [Indexed: 12/15/2022] Open
Abstract
High-fructose intake in healthy men is associated with characteristics of metabolic syndrome. Extensive knowledge exists about the differences between hepatic fructose and glucose metabolism and fructose-specific mechanisms favoring the development of metabolic disturbances. Nevertheless, the causal relationship between fructose consumption and metabolic alterations is still debated. Multiple effects of fructose on hepatic metabolism are attributed to the fact that the liver represents the major sink of fructose. Fructose, as a lipogenic substrate and potent inducer of lipogenic enzyme expression, enhances fatty acid synthesis. Consequently, increased hepatic diacylglycerols (DAG) are thought to directly interfere with insulin signaling. However, independently of this effect, fructose may also counteract insulin-mediated effects on liver metabolism by a range of mechanisms. It may drive gluconeogenesis not only as a gluconeogenic substrate, but also as a potent inducer of carbohydrate responsive element binding protein (ChREBP), which induces the expression of lipogenic enzymes as well as gluconeogenic enzymes. It remains a challenge to determine the relative contributions of the impact of fructose on hepatic transcriptome, proteome and allosterome changes and consequently on the regulation of plasma glucose metabolism/homeostasis. Mathematical models exist modeling hepatic glucose metabolism. Future models should not only consider the hepatic adjustments of enzyme abundances and activities in response to changing plasma glucose and insulin/glucagon concentrations, but also to varying fructose concentrations for defining the role of fructose in the hepatic control of plasma glucose homeostasis.
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Affiliation(s)
- Bettina Geidl-Flueck
- Division of Endocrinology, Diabetes, and Clinical Nutrition, University Hospital Zurich, 8091 Zurich, Switzerland.
| | - Philipp A Gerber
- Division of Endocrinology, Diabetes, and Clinical Nutrition, University Hospital Zurich, 8091 Zurich, Switzerland.
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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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49
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Anghebem-Oliveira MI, Webber S, Alberton D, de Souza EM, Klassen G, Picheth G, Rego FGDM. The GCKR Gene Polymorphism rs780094 is a Risk Factor for Gestational Diabetes in a Brazilian Population. J Clin Lab Anal 2016; 31. [PMID: 27554451 DOI: 10.1002/jcla.22035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/19/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The glucokinase regulatory protein (GCKR) regulates the activity of the glucokinase (GCK), which plays a key role in glucose homeostasis. Genetic variants in GCK have been associated with diabetes and gestational diabetes (GDM). Due to the relationship between GCKRP and GCK, polymorphisms in GCKR are also candidates for genetic association with GDM. The aim of this study was to evaluate the association between the GCKR rs780094 polymorphism and GDM in a Brazilian population. METHODS 252 unrelated Euro-Brazilian pregnant women were classified as control (healthy pregnant women, n = 125) and GDM (pregnant women with GDM, n = 127) age-matched groups. Clinical and anthropometric data were obtained from all subjects. The GCKR rs780094 polymorphism was genotyped using fluorescent probes (TaqMan® , code C_2862873_10). RESULTS Both groups were in Hardy-Weinberg equilibrium. The GCKR rs780094 polymorphism was associated with GDM in codominant and dominant models (P = 0.022 and P = 0.010, respectively). The minor allele (T) frequency for the control group in the study was 38.4% (95% CI: 32-44%), similar to frequencies reported for other Caucasian populations. CONCLUSION Carriers of the C allele of rs780094 were 1.41 (odds ratio, 95% CI, 0.97-2.03) times more likely to develop GDM.
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Affiliation(s)
- Mauren Isfer Anghebem-Oliveira
- Department of Clinical Analysis, Federal University of Parana, Curitiba, Brazil.,Health and Biosciences School, Pontifical Catholic University of Parana, Curitiba, Brazil
| | - Susan Webber
- Department of Clinical Analysis, Federal University of Parana, Curitiba, Brazil
| | - Dayane Alberton
- Department of Clinical Analysis, Federal University of Parana, Curitiba, Brazil
| | | | - Giseli Klassen
- Department of Basic Pathology, Federal University of Parana, Curitiba, Brazil
| | - Geraldo Picheth
- Department of Clinical Analysis, Federal University of Parana, Curitiba, Brazil
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