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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 DOI: 10.1152/ajpendo.00316.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [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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2
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Abdelgani S, Khattab A, Adams J, Baskoy G, Triplitt C, DeFronzo RA, Abdul-Ghani M. The impact of increased hepatic glucose production caused by empagliflozin on plasma glucose concentration in individuals with type 2 diabetes and nondiabetic individuals. Diabetes Obes Metab 2024; 26:1033-1039. [PMID: 38131252 DOI: 10.1111/dom.15404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/25/2023] [Accepted: 11/25/2023] [Indexed: 12/23/2023]
Abstract
AIM To examine the impact of increased hepatic glucose production (HGP) on the decrease in plasma glucose concentration caused by empagliflozin in individuals living with diabetes and in nondiabetic individuals. METHODS A total of 36 individuals living with diabetes and 34 nondiabetic individuals were randomized to receive, in double-blind fashion, empagliflozin or matching placebo in a 2:1 treatment ratio. Following an overnight fast, HGP was measured with 3-3 H-glucose infusion before, at the start of, and 3 months after therapy with empagliflozin. RESULTS On Day 1 of empagliflozin administration, the increase in urinary glucose excretion (UGE) in individuals with normal glucose tolerance was smaller than in those with impaired glucose tolerance and those living with diabetes, and was accompanied by an increase in HGP in all three groups. The amount of glucose returned to the systemic circulation as a result of the increase in HGP was smaller than that excreted by the kidney during the first 3 h after empagliflozin administration, resulting in a decrease in fasting plasma glucose (FPG) concentration. After 3 h, the increase in HGP was in excess of UGE, leading to a small increase in plasma glucose concentration, which reached a new steady state. After 12 weeks, the amount of glucose returned to the circulation due to the empagliflozin-induced increase in HGP was comparable with that excreted by the kidney in all three groups. CONCLUSION The balance between UGE and increase in HGP immediately after sodium-glucose cotransporter-2 (SGLT2) inhibition determined the magnitude of decrease in FPG and the new steady state which was achieved. After 12 weeks, the increase in HGP caused by empagliflozin closely matched the amount of glucose excreted by the kidneys; thus, FPG level remained stable despite the continuous urinary excretion of glucose caused by SGLT2 inhibition.
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Affiliation(s)
- Siham Abdelgani
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - Ahmed Khattab
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - John Adams
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - Gozde Baskoy
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - Curtis Triplitt
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - Ralph A DeFronzo
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
| | - Muhammad Abdul-Ghani
- Division of Diabetes, University of Texas Health Science Center, and Texas Diabetes Institute, San Antonio, Texas, USA
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3
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Pan Q, Ai W, Guo S. TGF-β1 Signaling Impairs Metformin Action on Glycemic Control. Int J Mol Sci 2024; 25:2424. [PMID: 38397103 PMCID: PMC10889280 DOI: 10.3390/ijms25042424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/02/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
Hyperglycemia is a hallmark of type 2 diabetes (T2D). Metformin, the first-line drug used to treat T2D, maintains blood glucose within a normal range by suppressing hepatic glucose production (HGP). However, resistance to metformin treatment is developed in most T2D patients over time. Transforming growth factor beta 1 (TGF-β1) levels are elevated both in the liver and serum of T2D humans and mice. Here, we found that TGF-β1 treatment impairs metformin action on suppressing HGP via inhibiting AMPK phosphorylation at Threonine 172 (T172). Hepatic TGF-β1 deficiency improves metformin action on glycemic control in high fat diet (HFD)-induced obese mice. In our hepatic insulin resistant mouse model (hepatic insulin receptor substrate 1 (IRS1) and IRS2 double knockout (DKO)), metformin action on glycemic control was impaired, which is largely improved by further deletion of hepatic TGF-β1 (TKObeta1) or hepatic Foxo1 (TKOfoxo1). Moreover, blockade of TGF-β1 signaling by chemical inhibitor of TGF-β1 type I receptor LY2157299 improves to metformin sensitivity in mice. Taken together, our current study suggests that hepatic TGF-β1 signaling impairs metformin action on glycemic control, and suppression of TGF-β1 signaling could serve as part of combination therapy with metformin for T2D treatment.
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Affiliation(s)
| | | | - Shaodong Guo
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA; (Q.P.); (W.A.)
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4
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Barroso E, Montori-Grau M, Wahli W, Palomer X, Vázquez-Carrera M. Striking a gut-liver balance for the antidiabetic effects of metformin. Trends Pharmacol Sci 2023; 44:457-473. [PMID: 37188578 DOI: 10.1016/j.tips.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/17/2023]
Abstract
Metformin is the most prescribed drug for the treatment of type 2 diabetes mellitus (T2DM), but its mechanism of action has not yet been completely elucidated. Classically, the liver has been considered the major site of action of metformin. However, over the past few years, advances have unveiled the gut as an additional important target of metformin, which contributes to its glucose-lowering effect through new mechanisms of action. A better understanding of the mechanistic details of metformin action in the gut and the liver and its relevance in patients remains the challenge of present and future research and may impact drug development for the treatment of T2DM. Here, we offer a critical analysis of the current status of metformin-driven multiorgan glucose-lowering effects.
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Affiliation(s)
- Emma Barroso
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain; Pediatric Research Institute-Hospital Sant Joan de Déu, E-08950 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Avinguda Joan XXII 27-31, E-08028 Barcelona, Spain
| | - Marta Montori-Grau
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain; Pediatric Research Institute-Hospital Sant Joan de Déu, E-08950 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Avinguda Joan XXII 27-31, E-08028 Barcelona, Spain
| | - Walter Wahli
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland; Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 308232, Singapore; ToxAlim (Research Center in Food Toxicology), INRAE, UMR1331, 31300 Toulouse Cedex, France
| | - Xavier Palomer
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain; Pediatric Research Institute-Hospital Sant Joan de Déu, E-08950 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Avinguda Joan XXII 27-31, E-08028 Barcelona, Spain
| | - Manuel Vázquez-Carrera
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain; Pediatric Research Institute-Hospital Sant Joan de Déu, E-08950 Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Avinguda Joan XXII 27-31, E-08028 Barcelona, Spain.
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5
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Perry RJ. It's Not Just for Pain: A New Metabolic Function of Aspirin. Endocrinology 2023; 164:7049714. [PMID: 36809391 DOI: 10.1210/endocr/bqad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 02/23/2023]
Affiliation(s)
- Rachel J Perry
- Departments of Internal Medicine (Endocrinology) and Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
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6
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Edgerton DS, Kraft G, Smith M, Farmer B, Williams P, Cherrington AD. A physiologic increase in brain glucagon action alters the hepatic gluconeogenic/glycogenolytic ratio but not glucagon's overall effect on glucose production. Am J Physiol Endocrinol Metab 2023; 324:E199-E208. [PMID: 36652399 PMCID: PMC9925168 DOI: 10.1152/ajpendo.00304.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/12/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023]
Abstract
It has been proposed that brain glucagon action inhibits glucagon-stimulated hepatic glucose production (HGP), which may explain, at least in part, why glucagon's effect on HGP is transient. However, the pharmacologic off-target effects of glucagon in the brain may have been responsible for previously observed effects. Therefore, the aim of this study was to determine if central glucagon action plays a physiologic role in the regulation of HGP. Insulin was maintained at baseline while glucagon was either infused into the carotid and vertebral arteries or into a peripheral (leg) vein at rates designed to increase glucagon in the head in one group, while keeping glucagon at the liver matched between groups. The extraction rate of glucagon across the head was high (double that of the liver), and hypothalamic cAMP increased twofold, in proportion to the exposure of the brain to increased glucagon, but HGP was not reduced by the increase in brain glucagon signaling, as had been suggested previously (the areas under the curve for HGP were 840 ± 14 vs. 871 ± 36 mg/kg/240 min in head vs. peripheral infusion groups, respectively). Central nervous system glucagon action reduced circulating free fatty acids and glycerol, and this was associated with a modest reduction in net hepatic gluconeogenic flux. However, offsetting autoregulation by the liver (i.e., a reciprocal increase in net hepatic glycogenolysis) prevented a change in HGP. Thus, while physiologic engagement of the brain by glucagon can alter hepatic carbon flux, it does not appear to be responsible for the transient fall in HGP that occurs following the stimulation of HGP during a square wave rise in glucagon.NEW & NOTEWORTHY Glucagon stimulates hepatic glucose production through its direct effects on the liver but may indirectly inhibit this process by acting on the brain. This was tested by delivering glucagon via the cerebral circulatory system. Central nervous system glucagon action reduced liver gluconeogenic flux, but glycogenolysis increased, resulting in no net change in hepatic glucose production. Surprisingly, brain glucagon also appeared to suppress lipolysis (plasma free fatty acid and glycerol levels were reduced).
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Affiliation(s)
- Dale S Edgerton
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Guillaume Kraft
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Marta Smith
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Ben Farmer
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Phillip Williams
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
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7
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Wang Y, Spolitu S, Zadroga JA, Sarecha AK, Ozcan L. Hepatocyte Rap1a contributes to obesity- and statin-associated hyperglycemia. Cell Rep 2022; 40:111259. [PMID: 36001955 PMCID: PMC9446800 DOI: 10.1016/j.celrep.2022.111259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 05/26/2022] [Accepted: 08/03/2022] [Indexed: 12/28/2022] Open
Abstract
Excessive hepatic glucose production contributes to the development of hyperglycemia and is a key feature of type 2 diabetes. Here, we report that activation of hepatocyte Rap1a suppresses gluconeogenic gene expression and glucose production, whereas Rap1a silencing stimulates them. Rap1a activation is suppressed in obese mouse liver, and restoring its activity improves glucose intolerance. As Rap1a′s membrane localization and activation depends on its geranylgeranylation, which is inhibited by statins, we show that statin-treated hepatocytes and the human liver have lower active-Rap1a levels. Similar to Rap1a inhibition, statins stimulate hepatic gluconeogenesis and increase fasting blood glucose in obese mice. Geranylgeraniol treatment, which acts as the precursor for geranylgeranyl isoprenoids, restores Rap1a activity and improves statin-mediated glucose intolerance. Mechanistically, Rap1a activation induces actin polymerization, which suppresses gluconeogenesis by Akt-mediated FoxO1 inhibition. Thus, Rap1a regulates hepatic glucose homeostasis, and blocking its activity, via lowering geranylgeranyl isoprenoids, contributes to statin-induced glucose intolerance. Wang et al. show that activation of hepatic Rap1a suppresses gluconeogenic gene expression and improves glucose intolerance via Akt-mediated FoxO1 inhibition. Statins lower intracellular isoprenoid levels and inhibit Rap1a activation, which contributes to their hyperglycemic effect. These findings identify a role of hepatic Rap1a in obesity- and statin-associated glucose homeostasis.
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Affiliation(s)
- Yating Wang
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Cardiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Stefano Spolitu
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - John A Zadroga
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Amesh K Sarecha
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lale Ozcan
- Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA.
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8
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Liao W, Cao X, Xia H, Wang S, Sun G. Pea Protein-Derived Peptides Inhibit Hepatic Glucose Production via the Gluconeogenic Signaling in the AML-12 Cells. Int J Environ Res Public Health 2022; 19:10254. [PMID: 36011893 PMCID: PMC9408102 DOI: 10.3390/ijerph191610254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Pea protein is considered to be a high quality dietary protein source, but also it is an ideal raw material for the production of bioactive peptides. Although the hypoglycemic effect of pea protein hydrolysate (PPH) has been previously reported, the underlying mechanisms, in particular its effect on the hepatic gluconeogenesis, remain to be elucidated. In the present study, we found that PPH suppressed glucose production in mouse liver cell-line AML-12 cells. Although both of the gluconeogenic and insulin signaling pathways in the AML-12 cells could be regulated by PPH, the suppression of glucose production was dependent on the inhibition of the cAMP response element-binding protein (CREB)-mediated signaling in the gluconeogenic pathway, but not the activation of insulin signaling. Findings from the present study have unveiled a novel role of PPH underlying its anti-diabetic activity, which could be helpful to accelerate the development of functional foods and nutraceuticals using PPH as a starting material.
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9
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Jung IR, Anokye-Danso F, Jin S, Ahima RS, Kim SF. IPMK modulates hepatic glucose production and insulin signaling. J Cell Physiol 2022; 237:3421-3432. [PMID: 35822903 DOI: 10.1002/jcp.30827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/13/2022] [Accepted: 06/24/2022] [Indexed: 11/06/2022]
Abstract
Hepatic glucose production (HGP) is crucial for the maintenance of normal glucose homeostasis. Although hepatic insulin resistance contributes to excessive glucose production, its mechanism is not well understood. Here, we show that inositol polyphosphate multikinase (IPMK), a key enzyme in inositol polyphosphate biosynthesis, plays a role in regulating hepatic insulin signaling and gluconeogenesis both in vitro and in vivo. IPMK-deficient hepatocytes exhibit decreased insulin-induced activation of Akt-FoxO1 signaling. The expression of messenger RNA levels of phosphoenolpyruvate carboxykinase 1 (Pck1) and glucose 6-phosphatase (G6pc), key enzymes mediating gluconeogenesis, are increased in IPMK-deficient hepatocytes compared to wild type hepatocytes. Importantly, re-expressing IPMK restores insulin sensitivity and alleviates glucose production in IPMK-deficient hepatocytes. Moreover, hepatocyte-specific IPMK deletion exacerbates hyperglycemia and insulin sensitivity in mice fed a high-fat diet, accompanied by an increase in HGP during pyruvate tolerance test and reduction in Akt phosphorylation in IPMK deficient liver. Our results demonstrate that IPMK mediates insulin signaling and gluconeogenesis and may be potentially targeted for treatment of diabetes.
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Affiliation(s)
- Ik-Rak Jung
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Frederick Anokye-Danso
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sunghee Jin
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Rexford S Ahima
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sangwon F Kim
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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10
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Sancar G, Liu S, Gasser E, Alvarez JG, Moutos C, Kim K, van Zutphen T, Wang Y, Huddy TF, Ross B, Dai Y, Zepeda D, Collins B, Tilley E, Kolar MJ, Yu RT, Atkins AR, van Dijk TH, Saghatelian A, Jonker JW, Downes M, Evans RM. FGF1 and insulin control lipolysis by convergent pathways. Cell Metab 2022; 34:171-183.e6. [PMID: 34986332 PMCID: PMC8863067 DOI: 10.1016/j.cmet.2021.12.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 09/08/2021] [Accepted: 12/06/2021] [Indexed: 01/07/2023]
Abstract
Inexorable increases in insulin resistance, lipolysis, and hepatic glucose production (HGP) are hallmarks of type 2 diabetes. Previously, we showed that peripheral delivery of exogenous fibroblast growth factor 1 (FGF1) has robust anti-diabetic effects mediated by the adipose FGF receptor (FGFR) 1. However, its mechanism of action is not known. Here, we report that FGF1 acutely lowers HGP by suppressing adipose lipolysis. On a molecular level, FGF1 inhibits the cAMP-protein kinase A axis by activating phosphodiesterase 4D (PDE4D), which separates it mechanistically from the inhibitory actions of insulin via PDE3B. We identify Ser44 as an FGF1-induced regulatory phosphorylation site in PDE4D that is modulated by the feed-fast cycle. These findings establish the FGF1/PDE4 pathway as an alternate regulator of the adipose-HGP axis and identify FGF1 as an unrecognized regulator of fatty acid homeostasis.
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Affiliation(s)
- Gencer Sancar
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sihao Liu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Emanuel Gasser
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Jacqueline G Alvarez
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Christopher Moutos
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Kyeongkyu Kim
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Tim van Zutphen
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, the Netherlands
| | - Yuhao Wang
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Timothy F Huddy
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Brittany Ross
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yang Dai
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - David Zepeda
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Brett Collins
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Emma Tilley
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Matthew J Kolar
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Annette R Atkins
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Theo H van Dijk
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, the Netherlands
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Johan W Jonker
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, the Netherlands
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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11
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Sharma S, Choudhary M, Budhwar V. Role of Bioactive Phytoconstituents as Modulators of Hepatic Carbohydrates Metabolising Enzymes: A Target Specific Approach to Treat Diabetes Mellitus. Curr Diabetes Rev 2022; 18:e100222201016. [PMID: 35142270 DOI: 10.2174/1573399818666220210140745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/20/2021] [Accepted: 12/09/2021] [Indexed: 11/22/2022]
Abstract
Diabetes mellitus is the most prevalent malady, becoming a leading public health concern around the world. It is a chronic endocrine metabolic disturbance that is accompanied by the commencement of a sequence of complications. The liver primarily serves as the body's glucose or fuel reserve and also maintains standard blood sugar concentration. Hepatic gluconeogenesis, glycolysis and glycogenesis are the key contributors to fasting or post-prandial hyperglycaemia in type 2 diabetes mellitus subjects. So, regulating these channels could be a viable approach for mitigating hyperglycaemia in type 2 diabetes mellitus. Few potential synthetic drugs that precisely target hepatic glucose-producing metabolic pathways are presently available, but they have some serious negative effects like hypoglycaemia, hepatosteatosis and lactic acidosis. Therefore, scientists have veered to herbal products because of their edible nature, costeffectiveness and fewer side effects. Natural products and their isolated phytochemicals are progressively being employed to manage hyperglycaemia by modulating the enzyme's activity and regulating transcription factors concerned with hepatic glucose synthesis. We reviewed the potential effects of isolated bioactive phytochemicals on interesting targets that affect hepatic glucose homeostasis in diabetes. This study illustrates the benefit and feasibility of developing liver-specific drugs through secondary metabolites to restore hyperglycaemia.
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Affiliation(s)
- Sachin Sharma
- Institute of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra - 136118, Haryana, India
| | - Manjusha Choudhary
- Institute of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra - 136118, Haryana, India
| | - Vikas Budhwar
- Department of Pharmaceutical Sciences, Maharshi Dayanand University, Rohtak -124001, Haryana, India
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12
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Herz H, Song Y, Ye Y, Tian L, Linden B, Abu El Haija M, Chu Y, Grobe JL, Lengeling RW, Mokadem M. NSAID-Induced Enteropathy Affects Regulation of Hepatic Glucose Production by Decreasing GLP-1 Secretion. Nutrients 2021; 14. [PMID: 35010994 DOI: 10.3390/nu14010120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND/AIM Given their widespread use and their notorious effects on the lining of gut cells, including the enteroendocrine cells, we explored if chronic exposure to non-steroidal anti-inflammatory drugs (NSAIDs) affects metabolic balance in a mouse model of NSAID-induced enteropathy. METHOD We administered variable NSAIDs to C57Blk/6J mice through intragastric gavage and measured their energy balance, glucose hemostasis, and GLP-1 levels. We treated them with Exendin-9 and Exendin-4 and ran a euglycemic-hyperinsulinemic clamp. RESULTS Chronic administration of multiple NSAIDs to C57Blk/6J mice induces ileal ulcerations and weight loss in animals consuming a high-fat diet. Despite losing weight, NSAID-treated mice exhibit no improvement in their glucose tolerance. Furthermore, glucose-stimulated (glucagon-like peptide -1) GLP-1 is significantly attenuated in the NSAID-treated groups. In addition, Exendin-9-a GLP-1 receptor antagonist-worsens glucose tolerance in the control group but not in the NSAID-treated group. Finally, the hyper-insulinemic euglycemic clamp study shows that endogenous glucose production, total glucose disposal, and their associated insulin levels were similar among an ibuprofen-treated group and its control. Exendin-4, a GLP-1 receptor agonist, reduces insulin levels in the ibuprofen group compared to their controls for the same glucose exchange rates. CONCLUSIONS Chronic NSAID use can induce small intestinal ulcerations, which can affect intestinal GLP-1 production, hepatic insulin sensitivity, and consequently, hepatic glucose production.
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13
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Henaux L, Pereira KD, Thibodeau J, Pilon G, Gill T, Marette A, Bazinet L. Glucoregulatory and Anti-Inflammatory Activities of Peptide Fractions Separated by Electrodialysis with Ultrafiltration Membranes from Salmon Protein Hydrolysate and Identification of Four Novel Glucoregulatory Peptides. Membranes (Basel) 2021; 11:membranes11070528. [PMID: 34357178 PMCID: PMC8305187 DOI: 10.3390/membranes11070528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022]
Abstract
Natural bioactive peptides are suitable candidates for preventing the development of Type 2 diabetes (T2D), by reducing the various risk factors. The aim of this study was to concentrate glucoregulatory and anti-inflammatory peptides, from salmon by-products, by electrodialysis with ultrafiltration membrane (EDUF), and to identify peptides responsible for these bioactivities. Two EDUF configurations (1 and 2) were used to concentrate anionic and cationic peptides, respectively. After EDUF separation, two fractions demonstrated interesting properties: the initial fraction of the EDUF configuration 1 and the final fraction of the EDUF configuration 2 both showed biological activities to (1) increase glucose uptake in L6 muscle cells in insulin condition at 1 ng/mL (by 12% and 21%, respectively), (2) decrease hepatic glucose production in hepatic cells at 1 ng/mL in basal (17% and 16%, respectively), and insulin (25% and 34%, respectively) conditions, and (3) decrease LPS-induced inflammation in macrophages at 1 g/mL (45% and 30%, respectively). More impressive, the initial fraction of the EDUF configuration 1 (45% reduction) showed the same effect as the phenformin at 10 μM (40%), a drug used to treat T2D. Thirteen peptides were identified, chemically synthesized, and tested in-vitro for these three bioactivities. Thus, four new bioactive peptides were identified: IPVE increased glucose uptake by muscle cells, IVDI and IEGTL decreased hepatic glucose production (HGP) of insulin, whereas VAPEEHPTL decreased HGP under both basal condition and in the presence of insulin. To the best of our knowledge, this is the first time that (1) bioactive peptide fractions generated after separation by EDUF were demonstrated to be bioactive on three different criteria; all involved in the T2D, and (2) potential sequences involved in the improvement of glucose uptake and/or in the regulation of HGP were identified from a salmon protein hydrolysate.
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Affiliation(s)
- Loïc Henaux
- Department of Food Sciences and Laboratory of Food Processing and Electromembrane Processes (LTAPEM), Université Laval, Quebec City, QC G1V 0A6, Canada; (L.H.); (J.T.)
- Institute of Nutrition and Functional Foods (INAF), University Laval, Quebec City, QC G1V 0A6, Canada; (G.P.); (A.M.)
| | - Karina Danielle Pereira
- Laboratory of Biotechnology, School of Applied Sciences, University of Campinas (UNICAMP), Limeira 13484-350, SP, Brazil;
- Institute of Biosciences, State University (UNESP), Rio Claro 13506-900, SP, Brazil
| | - Jacinthe Thibodeau
- Department of Food Sciences and Laboratory of Food Processing and Electromembrane Processes (LTAPEM), Université Laval, Quebec City, QC G1V 0A6, Canada; (L.H.); (J.T.)
- Institute of Nutrition and Functional Foods (INAF), University Laval, Quebec City, QC G1V 0A6, Canada; (G.P.); (A.M.)
| | - Geneviève Pilon
- Institute of Nutrition and Functional Foods (INAF), University Laval, Quebec City, QC G1V 0A6, Canada; (G.P.); (A.M.)
- Department of Medicine, Faculty of Medicine, Quebec Heart and Lung Institute Cardiology Group, Université Laval, 2725 Chemin Ste-Foy, Quebec City, QC G1V 4G5, Canada
| | - Tom Gill
- Department of Process Engineering and Applied Science, Dalhousie University, P.O. Box 15000, Halifax, NS B3H 4R2, Canada;
| | - André Marette
- Institute of Nutrition and Functional Foods (INAF), University Laval, Quebec City, QC G1V 0A6, Canada; (G.P.); (A.M.)
- Department of Medicine, Faculty of Medicine, Quebec Heart and Lung Institute Cardiology Group, Université Laval, 2725 Chemin Ste-Foy, Quebec City, QC G1V 4G5, Canada
| | - Laurent Bazinet
- Department of Food Sciences and Laboratory of Food Processing and Electromembrane Processes (LTAPEM), Université Laval, Quebec City, QC G1V 0A6, Canada; (L.H.); (J.T.)
- Institute of Nutrition and Functional Foods (INAF), University Laval, Quebec City, QC G1V 0A6, Canada; (G.P.); (A.M.)
- Correspondence: ; Tel.: +1-418-656-2131 (ext. 407445)
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14
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Abstract
Pancreatic insulin secretion produces an insulin gradient at the liver compared with the rest of the body (approximately 3:1). This physiological distribution is lost when insulin is injected subcutaneously, causing impaired regulation of hepatic glucose production and whole body glucose uptake, as well as arterial hyperinsulinemia. Thus, the hepatoportal insulin gradient is essential to the normal control of glucose metabolism during both fasting and feeding. Insulin can regulate hepatic glucose production and uptake through multiple mechanisms, but its direct effects on the liver are dominant under physiological conditions. Given the complications associated with iatrogenic hyperinsulinemia in patients treated with insulin, insulin designed to preferentially target the liver may have therapeutic advantages.
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Affiliation(s)
- Dale S Edgerton
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mary C Moore
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Justin M Gregory
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Guillaume Kraft
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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15
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London A, Lundsgaard AM, Kiens B, Bojsen-Møller KN. The Role of Hepatic Fat Accumulation in Glucose and Insulin Homeostasis-Dysregulation by the Liver. J Clin Med 2021; 10:390. [PMID: 33498493 DOI: 10.3390/jcm10030390] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 11/17/2022] Open
Abstract
Accumulation of hepatic triacylglycerol (TG) is associated with obesity and metabolic syndrome, which are important pathogenic factors in the development of type 2 diabetes. In this narrative review, we summarize the effects of hepatic TG accumulation on hepatic glucose and insulin metabolism and the underlying molecular regulation in order to highlight the importance of hepatic TG accumulation for whole-body glucose metabolism. We find that liver fat accumulation is closely linked to impaired insulin-mediated suppression of hepatic glucose production and reduced hepatic insulin clearance. The resulting systemic hyperinsulinemia has a major impact on whole-body glucose metabolism and may be an important pathogenic step in the development of type 2 diabetes.
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16
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Lyu K, Zhang Y, Zhang D, Kahn M, Ter Horst KW, Rodrigues MRS, Gaspar RC, Hirabara SM, Luukkonen PK, Lee S, Bhanot S, Rinehart J, Blume N, Rasch MG, Serlie MJ, Bogan JS, Cline GW, Samuel VT, Shulman GI. A Membrane-Bound Diacylglycerol Species Induces PKCϵ-Mediated Hepatic Insulin Resistance. Cell Metab 2020; 32:654-664.e5. [PMID: 32882164 PMCID: PMC7544641 DOI: 10.1016/j.cmet.2020.08.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 06/22/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022]
Abstract
Nonalcoholic fatty liver disease is strongly associated with hepatic insulin resistance (HIR); however, the key lipid species and molecular mechanisms linking these conditions are widely debated. We developed a subcellular fractionation method to quantify diacylglycerol (DAG) stereoisomers and ceramides in the endoplasmic reticulum (ER), mitochondria, plasma membrane (PM), lipid droplets, and cytosol. Acute knockdown (KD) of diacylglycerol acyltransferase-2 in liver induced HIR in rats. This was due to PM sn-1,2-DAG accumulation, which promoted PKCϵ activation and insulin receptor kinase (IRK)-T1160 phosphorylation, resulting in decreased IRK-Y1162 phosphorylation. Liver PM sn-1,2-DAG content and IRK-T1160 phosphorylation were also higher in humans with HIR. In rats, liver-specific PKCϵ KD ameliorated high-fat diet-induced HIR by lowering IRK-T1160 phosphorylation, while liver-specific overexpression of constitutively active PKCϵ-induced HIR by promoting IRK-T1160 phosphorylation. These data identify PM sn-1,2-DAGs as the key pool of lipids that activate PKCϵ and that hepatic PKCϵ is both necessary and sufficient in mediating HIR.
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Affiliation(s)
- Kun Lyu
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Ye Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Endocrinology & Metabolism, First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Dongyan Zhang
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Mario Kahn
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Kasper W Ter Horst
- Department of Endocrinology and Metabolism Amsterdam University Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Marcos R S Rodrigues
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; School of Medicine, State University of Ponta Grossa, Avenida General Carlos Cavalcanti, Ponta Grossa, PR 84030-900, Brazil
| | - Rafael C Gaspar
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Laboratory of Molecular Biology of Exercise, School of Applied Science, University of Campinas, Limeira, SP 13484-350, Brazil
| | - Sandro M Hirabara
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Postgraduate Interdisciplinary Program of Health Sciences, Cruzeiro do Sul University, Sao Paulo, SP 01506-000, Brazil
| | - Panu K Luukkonen
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Seohyuk Lee
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - Jesse Rinehart
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Niels Blume
- CV Research, Novo Nordisk A/S, Novo Nordisk Park, 2760 Maaloev, Denmark
| | | | - Mireille J Serlie
- Department of Endocrinology and Metabolism Amsterdam University Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Jonathan S Bogan
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA
| | - Varman T Samuel
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; VA Connecticut Healthcare System, West Haven, CT 06516, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06510, USA.
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17
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Gassaway BM, Cardone RL, Padyana AK, Petersen MC, Judd ET, Hayes S, Tong S, Barber KW, Apostolidi M, Abulizi A, Sheetz JB, Kshitiz, Aerni HR, Gross S, Kung C, Samuel VT, Shulman GI, Kibbey RG, Rinehart J. Distinct Hepatic PKA and CDK Signaling Pathways Control Activity-Independent Pyruvate Kinase Phosphorylation and Hepatic Glucose Production. Cell Rep 2020; 29:3394-3404.e9. [PMID: 31825824 DOI: 10.1016/j.celrep.2019.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 07/31/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022] Open
Abstract
Pyruvate kinase is an important enzyme in glycolysis and a key metabolic control point. We recently observed a pyruvate kinase liver isoform (PKL) phosphorylation site at S113 that correlates with insulin resistance in rats on a 3 day high-fat diet (HFD) and suggests additional control points for PKL activity. However, in contrast to the classical model of PKL regulation, neither authentically phosphorylated PKL at S12 nor S113 alone is sufficient to alter enzyme kinetics or structure. Instead, we show that cyclin-dependent kinases (CDKs) are activated by the HFD and responsible for PKL phosphorylation at position S113 in addition to other targets. These CDKs control PKL nuclear retention, alter cytosolic PKL activity, and ultimately influence glucose production. These results change our view of PKL regulation and highlight a previously unrecognized pathway of hepatic CDK activity and metabolic control points that may be important in insulin resistance and type 2 diabetes.
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Affiliation(s)
- Brandon M Gassaway
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Systems Biology Institute, Yale University, New Haven, CT, USA
| | - Rebecca L Cardone
- Department of Internal Medicine, Yale University, New Haven, CT, USA
| | | | - Max C Petersen
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Internal Medicine, Yale University, New Haven, CT, USA
| | | | | | | | - Karl W Barber
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Systems Biology Institute, Yale University, New Haven, CT, USA
| | - Maria Apostolidi
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Systems Biology Institute, Yale University, New Haven, CT, USA
| | | | - Joshua B Sheetz
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA
| | - Kshitiz
- Department of Systems Biology Institute, Yale University, New Haven, CT, USA; Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Hans R Aerni
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Systems Biology Institute, Yale University, New Haven, CT, USA
| | | | | | - Varman T Samuel
- Department of Internal Medicine, Yale University, New Haven, CT, USA; Veterans Affairs Medical Center, West Haven, CT, USA
| | - Gerald I Shulman
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Richard G Kibbey
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Jesse Rinehart
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, USA; Department of Systems Biology Institute, Yale University, New Haven, CT, USA.
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18
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Thielen LA, Chen J, Jing G, Moukha-Chafiq O, Xu G, Jo S, Grayson TB, Lu B, Li P, Augelli-Szafran CE, Suto MJ, Kanke M, Sethupathy P, Kim JK, Shalev A. Identification of an Anti-diabetic, Orally Available Small Molecule that Regulates TXNIP Expression and Glucagon Action. Cell Metab 2020; 32:353-365.e8. [PMID: 32726606 DOI: 10.1016/j.cmet.2020.07.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 06/03/2020] [Accepted: 07/10/2020] [Indexed: 12/20/2022]
Abstract
Diabetes is characterized by hyperglycemia, loss of functional islet beta cell mass, deficiency of glucose-lowering insulin, and persistent alpha cell secretion of gluconeogenic glucagon. Still, no therapies that target these underlying processes are available. We therefore performed high-throughput screening of 300,000 compounds and extensive medicinal chemistry optimization and here report the discovery of SRI-37330, an orally bioavailable, non-toxic small molecule, which effectively rescued mice from streptozotocin- and obesity-induced (db/db) diabetes. Interestingly, in rat cells and in mouse and human islets, SRI-37330 inhibited expression and signaling of thioredoxin-interacting protein, which we have previously found to be elevated in diabetes and to have detrimental effects on islet function. In addition, SRI-37330 treatment inhibited glucagon secretion and function, reduced hepatic glucose production, and reversed hepatic steatosis. Thus, these studies describe a newly designed chemical compound that, compared to currently available therapies, may provide a distinct and effective approach to treating diabetes.
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19
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Choumessi AT, Johanns M, Beaufay C, Herent MF, Stroobant V, Vertommen D, Corbet C, Jacobs R, Herinckx G, Steinberg GR, Feron O, Quetin-Leclercq J, Rider MH. Two isoprenylated flavonoids from Dorstenia psilurus activate AMPK, stimulate glucose uptake, inhibit glucose production and lower glycemia. Biochem J 2019; 476:3687-704. [PMID: 31782497 DOI: 10.1042/BCJ20190326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 11/26/2019] [Accepted: 11/28/2019] [Indexed: 12/19/2022]
Abstract
Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze-thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1-/- mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.
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20
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Timper K, Del Río-Martín A, Cremer AL, Bremser S, Alber J, Giavalisco P, Varela L, Heilinger C, Nolte H, Trifunovic A, Horvath TL, Kloppenburg P, Backes H, Brüning JC. GLP-1 Receptor Signaling in Astrocytes Regulates Fatty Acid Oxidation, Mitochondrial Integrity, and Function. Cell Metab 2020; 31:1189-1205.e13. [PMID: 32433922 PMCID: PMC7272126 DOI: 10.1016/j.cmet.2020.05.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/09/2019] [Accepted: 05/02/2020] [Indexed: 02/06/2023]
Abstract
Astrocytes represent central regulators of brain glucose metabolism and neuronal function. They have recently been shown to adapt their function in response to alterations in nutritional state through responding to the energy state-sensing hormones leptin and insulin. Here, we demonstrate that glucagon-like peptide (GLP)-1 inhibits glucose uptake and promotes β-oxidation in cultured astrocytes. Conversely, postnatal GLP-1 receptor (GLP-1R) deletion in glial fibrillary acidic protein (GFAP)-expressing astrocytes impairs astrocyte mitochondrial integrity and activates an integrated stress response with enhanced fibroblast growth factor (FGF)21 production and increased brain glucose uptake. Accordingly, central neutralization of FGF21 or astrocyte-specific FGF21 inactivation abrogates the improvements in glucose tolerance and learning in mice lacking GLP-1R expression in astrocytes. Collectively, these experiments reveal a role for astrocyte GLP-1R signaling in maintaining mitochondrial integrity, and lack of GLP-1R signaling mounts an adaptive stress response resulting in an improvement of systemic glucose homeostasis and memory formation.
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Affiliation(s)
- Katharina Timper
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Almudena Del Río-Martín
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Anna Lena Cremer
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany
| | - Stephan Bremser
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Institute for Zoology, Biocenter, University of Cologne, Zuelpicher Str. 47B, 50674 Cologne, Germany
| | - Jens Alber
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Patrick Giavalisco
- Max Planck Institute for Biology of Aging, Joseph-Stelzmann-Str. 9b, 50931 Cologne, Germany
| | - Luis Varela
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Christian Heilinger
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Hendrik Nolte
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Aleksandra Trifunovic
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Institute for Mitochondrial Diseases and Aging, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Tamas L Horvath
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Program in Integrative Cell Signaling and Neurobiology of Metabolism, Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Anatomy and Histology, University of Veterinary Medicine, 1078 Budapest, Hungary
| | - Peter Kloppenburg
- Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Institute for Zoology, Biocenter, University of Cologne, Zuelpicher Str. 47B, 50674 Cologne, Germany
| | - Heiko Backes
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany
| | - Jens C Brüning
- Max Planck Institute for Metabolism Research, Department of Neuronal Control of Metabolism, Gleueler Str. 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Str. 26, 50924 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Center of Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; National Center for Diabetes Research (DZD), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
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21
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Thapa D, Xie B, Manning JR, Zhang M, Stoner MW, Huckestein BR, Edmunds LR, Zhang X, Dedousis NL, O'Doherty RM, Jurczak MJ, Scott I. Adropin reduces blood glucose levels in mice by limiting hepatic glucose production. Physiol Rep 2020; 7:e14043. [PMID: 31004398 PMCID: PMC6474842 DOI: 10.14814/phy2.14043] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 01/29/2023] Open
Abstract
Adropin is a liver- and brain-secreted peptide hormone with striking effects on fuel metabolism regulation in a number of tissues. Previous studies demonstrated that adropin secretion is decreased in obese mice subjected to a long-term high-fat diet (HFD), and that whole-body loss of adropin expression resulted in systemic insulin resistance. Treatment of obese mice with adropin improves glucose tolerance, which has been linked to increased glucose oxidation and inhibition of fatty acid utilization in isolated skeletal muscle homogenates. In this study, we used in vivo physiological measurements to determine how treatment of obese mice with adropin affects whole-body glucose metabolism. Treatment with adropin reduced fasting blood glucose and, as shown previously, increased glucose tolerance in HFD mice during standard glucose tolerance tests. Under hyperinsulinemic-euglycemic clamp conditions, adropin treatment led to a nonsignificant increase in whole-body insulin sensitivity, and a significant reduction in whole-body glucose uptake. Finally, we show that adropin treatment suppressed hepatic glucose production and improved hepatic insulin sensitivity. This correlated with reduced expression of fatty acid import proteins and gluconeogenic regulatory enzymes in the liver, suggesting that adropin treatment may impact the pathways that drive vital aspects of hepatic glucose metabolism.
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Affiliation(s)
- Dharendra Thapa
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bingxian Xie
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Janet R Manning
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Manling Zhang
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael W Stoner
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brydie R Huckestein
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lia R Edmunds
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Xueyang Zhang
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nikolaos L Dedousis
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert M O'Doherty
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael J Jurczak
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Iain Scott
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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22
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Zhou M, Xu X, Wang H, Yang G, Yang M, Zhao X, Guo H, Song J, Zheng H, Zhu Z, Li L. Effect of central JAZF1 on glucose production is regulated by the PI3K-Akt-AMPK pathway. FASEB J 2020; 34:7058-7074. [PMID: 32275331 DOI: 10.1096/fj.201901836rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 01/24/2023]
Abstract
The role of central juxtaposed with another zinc finger gene 1 (JAZF1) in glucose regulation remains unclear. Here, we activated mediobasal hypothalamus (MBH) JAZF1 in high-fat diet (HFD)-fed rats by an adenovirus expressing JAZF1 (Ad-JAZF1). We evaluated the changes in the hypothalamic insulin receptor (InsR)-PI3K-Akt-AMPK pathway and hepatic glucose production (HGP). To investigate the impact of MBH Ad-JAZF1 on HGP, we activated MBH JAZF1 in the presence or absence of ATP-dependent potassium (KATP ) channel inhibition, hepatic branch vagotomy (HVG), or an AMPK activator (AICAR). In HFD-fed rats, MBH Ad-JAZF1 decreased body weight and food intake, and inhibited HGP by increasing hepatic insulin signaling. Under insulin stimulation, MBH Ad-JAZF1 increased InsR and Akt phosphorylation, and phosphatidylinositol 3, 4, 5-trisphosphate (PIP3) formation; however, AMPK phosphorylation was decreased in the hypothalamus. The positive effect of MBH JAZF1 on hepatic insulin signaling and HGP was prevented by treatment with a KATP channel inhibitor or HVG. The metabolic impact of hypothalamic JAZF1 was also blocked by MBH AICAR. Ad-JAZF1 treatment in SH-SY5Y cells resulted in an elevation of InsR and Akt phosphorylation following insulin stimulation. Our findings show that hypothalamic JAZF1 regulates HGP via the InsR-PI3K-Akt-AMPK pathway and KATP channels.
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Affiliation(s)
- Mengjiao Zhou
- The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory for Oral Diseases and Biomedical Science, College of Stomatology, Chongqing Medical University, Chongqing, China
| | - Xiaohui Xu
- Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Han Wang
- The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Gangyi Yang
- Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Mengliu Yang
- The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, Chongqing, China.,School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Xinyi Zhao
- Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Huilin Guo
- Department of Endocrinology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Jinlin Song
- Chongqing Key Laboratory for Oral Diseases and Biomedical Science, College of Stomatology, Chongqing Medical University, Chongqing, China
| | - Hongting Zheng
- Department of Endocrinology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Zhiming Zhu
- Department of Hypertension and Endocrinology, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China
| | - Ling Li
- The Key Laboratory of Laboratory Medical Diagnostics in the Ministry of Education, Department of Clinical Biochemistry, College of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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23
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Warner SO, Yao MV, Cason RL, Winnick JJ. Exercise-Induced Improvements to Whole Body Glucose Metabolism in Type 2 Diabetes: The Essential Role of the Liver. Front Endocrinol (Lausanne) 2020; 11:567. [PMID: 32982968 PMCID: PMC7484211 DOI: 10.3389/fendo.2020.00567] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/13/2020] [Indexed: 01/22/2023] Open
Abstract
Type 2 diabetes (T2D) is a metabolic disease characterized by obesity, insulin resistance, and the dysfunction of several key glucoregulatory organs. Among these organs, impaired liver function is recognized as one of the earliest contributors to impaired whole-body glucose homeostasis, with well-characterized hepatic insulin resistance resulting in elevated rates of hepatic glucose production (HGP) and fasting hyperglycemia. One portion of this review will provide an overview of how HGP is regulated during the fasted state in healthy humans and how this process becomes dysregulated in patients with T2D. Less well-appreciated is the liver's role in post-prandial glucose metabolism, where it takes up and metabolizes one-third of orally ingested glucose. An abundance of literature has shown that the process of hepatic glucose uptake is impaired in patients with T2D, thereby contributing to glucose intolerance. A second portion of this review will outline how hepatic glucose uptake is regulated during the post-prandial state, and how it becomes dysfunctional in patients with T2D. Finally, it is well-known that exercise training has an insulin-sensitizing effect on the liver, which contributes to improved whole-body glucose metabolism in patients with T2D, thereby making it a cornerstone in the management of the disease. To this end, the impact of exercise on hepatic glucose metabolism will be thoroughly discussed, referencing key findings in the literature. At the same time, sources of heterogeneity that contribute to inconsistent findings in the field will be pointed out, as will important topics for future investigation.
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Affiliation(s)
- Shana O. Warner
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Michael V. Yao
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Rebecca L. Cason
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Jason J. Winnick
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- *Correspondence: Jason J. Winnick
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24
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Lundsgaard AM, Fritzen AM, Nicolaisen TS, Carl CS, Sjøberg KA, Raun SH, Klein AB, Sanchez-Quant E, Langer J, Ørskov C, Clemmensen C, Tschöp MH, Richter EA, Kiens B, Kleinert M. Glucometabolic consequences of acute and prolonged inhibition of fatty acid oxidation. J Lipid Res 2020; 61:10-19. [PMID: 31719103 PMCID: PMC6939602 DOI: 10.1194/jlr.ra119000177] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/20/2019] [Indexed: 12/22/2022] Open
Abstract
Excessive circulating FAs have been proposed to promote insulin resistance (IR) of glucose metabolism by increasing the oxidation of FAs over glucose. Therefore, inhibition of FA oxidation (FAOX) has been suggested to ameliorate IR. However, prolonged inhibition of FAOX would presumably cause lipid accumulation and thereby promote lipotoxicity. To understand the glycemic consequences of acute and prolonged FAOX inhibition, we treated mice with the carnitine palmitoyltransferase 1 (CPT-1) inhibitor, etomoxir (eto), in combination with short-term 45% high fat diet feeding to increase FA availability. Eto acutely increased glucose oxidation and peripheral glucose disposal, and lowered circulating glucose, but this was associated with increased circulating FAs and triacylglycerol accumulation in the liver and heart within hours. Several days of FAOX inhibition by daily eto administration induced hepatic steatosis and glucose intolerance, specific to CPT-1 inhibition by eto. Lower whole-body insulin sensitivity was accompanied by reduction in brown adipose tissue (BAT) uncoupling protein 1 (UCP1) protein content, diminished BAT glucose clearance, and increased hepatic glucose production. Collectively, these data suggest that pharmacological inhibition of FAOX is not a viable strategy to treat IR, and that sufficient rates of FAOX are required for maintaining liver and BAT metabolic function.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas M Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Trine S Nicolaisen
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Christian S Carl
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kim A Sjøberg
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Steffen H Raun
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Anders B Klein
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eva Sanchez-Quant
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Jakob Langer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research (DZD), Helmholtz Zentrum München, Neuherberg, Germany; Division of Metabolic Diseases, Technische Universität München, München, Germany
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
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25
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Liu B, Zhang Z, Hu Y, Lu Y, Li D, Liu J, Liao S, Hu M, Wang Y, Zhang D, Chen Y, Qian Q, Lv X, Wu D, Tan M, Hu C, Xiong X, Li X. Sustained ER stress promotes hyperglycemia by increasing glucagon action through the deubiquitinating enzyme USP14. Proc Natl Acad Sci U S A 2019; 116:21732-8. [PMID: 31594848 DOI: 10.1073/pnas.1907288116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Endoplasmic reticulum (ER) stress plays an important role in metabolic diseases like obesity and type 2 diabetes mellitus (T2DM), although the underlying mechanisms and regulatory pathways remain to be elucidated. Here, we induced chronic low-grade ER stress in lean mice to levels similar to those in high-fat diet (HFD)-fed obese mice and found that it promoted hyperglycemia due to enhanced hepatic gluconeogenesis. Mechanistically, sustained ER stress up-regulated the deubiquitinating enzyme ubiquitin-specific peptidase 14 (USP14), which increased the stability and levels of 3',5'-cyclic monophosphate-responsive element binding (CREB) protein (CBP) to enhance glucagon action and hepatic gluconeogenesis. Exogenous overexpression of USP14 in the liver significantly increased hepatic glucose output. Consistent with this, liver-specific knockdown of USP14 abrogated the effects of ER stress on glucose metabolism, and also improved hyperglycemia and glucose intolerance in obese mice. In conclusion, our findings show a mechanism underlying ER stress-induced disruption of glucose homeostasis, and present USP14 as a potential therapeutic target against T2DM.
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26
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Mehta RJ, Gastaldelli A, Balas B, Ricotti A, DeFronzo RA, Tripathy D. Mechanism of Action of Inhaled Insulin on Whole Body Glucose Metabolism in Subjects with Type 2 Diabetes Mellitus. Int J Mol Sci 2019; 20:E4230. [PMID: 31470605 DOI: 10.3390/ijms20174230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 01/09/2023] Open
Abstract
In the current study we investigate the mechanisms of action of short acting inhaled insulin Exubera®, on hepatic glucose production (HGP), plasma glucose and free fatty acid (FFA) concentrations. 11 T2D (Type 2 Diabetes) subjects (age = 53 ± 3 years) were studied at baseline (BAS) and after 16-weeks of Exubera® treatment. At BAS and after 16-weeks subjects received: measurement of HGP (3-3H-glucose); oral glucose tolerance test (OGTT); and a 24-h plasma glucose (24-h PG) profile. At end of study (EOS) we observed a significant decrease in fasting plasma glucose (FPG, 215 ± 15 to 137 ± 11 mg/dl), 2-hour plasma glucose (2-h PG, 309 ± 9 to 264 ± 11 mg/dl), glycated hemoglobin (HbA1c, 10.3 ± 0.5% to 7.5 ± 0.3%,), mean 24-h PG profile (212 ± 17 to 141 ± 8 mg/dl), FFA fasting (665 ± 106 to 479 ± 61 μM), post-OGTT (433 ± 83 to 239 ± 28 μM), and triglyceride (213 ± 39 to 120 ± 14 mg/dl), while high density cholesterol (HDL-C) increased (35 ± 3 to 47 ± 9 mg/dl). The basal HGP decreased significantly and the insulin secretion/insulin resistance (disposition) index increased significantly. There were no episodes of hypoglycemia and no change in pulmonary function at EOS. After 16-weeks of inhaled insulin Exubera® we observed a marked improvement in glycemic control by decreasing HGP and 24-h PG profile, and decreased FFA and triglyceride concentrations.
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27
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Wu CS, Bongmba OYN, Lee JH, Tuchaai E, Zhou Y, Li DP, Xue B, Chen Z, Sun Y. Ghrelin receptor in agouti-related peptide neurones regulates metabolic adaptation to calorie restriction. J Neuroendocrinol 2019; 31:e12763. [PMID: 31251830 PMCID: PMC7233797 DOI: 10.1111/jne.12763] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/16/2022]
Abstract
Ghrelin is a gut hormone that signals to the hypothalamus to stimulate growth hormone release, increase food intake and promote fat deposition. The ghrelin receptor, also known as growth hormone secretagogue receptor (GHS-R), is highly expressed in the brain, with the highest expression in agouti-related peptide (AgRP) neurones in the hypothalamus. Compelling evidence indicates that ghrelin serves as a survival hormone with respect to maintaining blood glucose and body weight during nutritional deficiencies. Recent studies have demonstrated that AgRP neurones are involved in metabolic and behavioural adaptation to an energy deficit to improve survival. In the present study, we used a neuronal subtype-specific GHS-R knockout mouse (AgRP-Cre;Ghsrf/f ) to investigate the role of GHS-R in hypothalamic AgRP neurones in metabolic and behavioural adaptation to hypocaloric restricted feeding. We subjected the mice to a restricted feeding regimen of 40% mild calorie restriction (CR), with one-quarter of food allotment given in the beginning of the light cycle and three-quarters given at the beginning of the dark cycle, to mimic normal mouse intake pattern. The CR-fed AgRP-Cre;Ghsrf/f mice exhibited reductions in body weight, fat mass and blood glucose. Metabolic profiling of these CR-fed AgRP-Cre;Ghsrf/f mice showed a trend toward reduced basal metabolic rate, significantly reduced core body temperature and a decreased expression of thermogenic genes in brown adipose tissue. This suggests a metabolic reset to a lower threshold. Significantly increased physical activity, a trend toward increased food anticipatory behaviour and altered fuel preferences were also observed in these mice. In addition, these CR-fed AgRP-Cre;Ghsrf/f mice exhibited a decreased counter-regulatory response, showing impaired hepatic glucose production. Lastly, hypothalamic gene expression in AgRP-Cre;Ghsrf/f mice revealed increased AgRP expression and a decreased expression of genes in β-oxidation pathways. In summary, our data suggest that GHS-R in AgRP neurones is a key component of the neurocircuitry involved in metabolic adaptation to calorie restriction.
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Affiliation(s)
- Chia-Shan Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Odelia Y. N. Bongmba
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jong Han Lee
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- College of Pharmacy, Gachon University, Incheon, 21936, Korea
| | - Ellie Tuchaai
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Yu Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Qingdao University, Qingdao, Shandong, 266071, China
| | - De-Pei Li
- Center for precision medicine, School of Medicine, University of Missouri. Columbia, MO 65212, USA
| | - Bingzhong Xue
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - Zheng Chen
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, TX 77030, USA
| | - Yuxiang Sun
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
- To whom correspondence should be addressed: Dr. Yuxiang Sun, mailing address: Department of Nutrition and Food Science, Texas A&M University, 214C Cater-Mattil, 2253 TAMU, College Station, TX 77843. Phone: 979-862-9143;
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28
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Molinaro A, Becattini B, Mazzoli A, Bleve A, Radici L, Maxvall I, Sopasakis VR, Molinaro A, Bäckhed F, Solinas G. Insulin-Driven PI3K-AKT Signaling in the Hepatocyte Is Mediated by Redundant PI3Kα and PI3Kβ Activities and Is Promoted by RAS. Cell Metab 2019; 29:1400-1409.e5. [PMID: 30982732 DOI: 10.1016/j.cmet.2019.03.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 02/04/2019] [Accepted: 03/19/2019] [Indexed: 12/17/2022]
Abstract
Phosphatidylinositol-3-kinase (PI3K) activity is aberrant in tumors, and PI3K inhibitors are investigated as cancer therapeutics. PI3K signaling mediates insulin action in metabolism, but the role of PI3K isoforms in insulin signaling remains unresolved. Defining the role of PI3K isoforms in insulin signaling is necessary for a mechanistic understanding of insulin action and to develop PI3K inhibitors with optimal therapeutic index. We show that insulin-driven PI3K-AKT signaling depends on redundant PI3Kα and PI3Kβ activities, whereas PI3Kδ and PI3Kγ are largely dispensable. We have also found that RAS activity promotes AKT phosphorylation in insulin-stimulated hepatocytes and that promotion of insulin-driven AKT phosphorylation by RAS depends on PI3Kα. These findings reveal the detailed mechanism by which insulin activates AKT, providing an improved mechanistic understanding of insulin signaling. This improved model for insulin signaling predicts that isoform-selective PI3K inhibitors discriminating between PI3Kα and PI3Kβ should be dosed below their hyperglycemic threshold to achieve isoform selectivity.
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Affiliation(s)
- Angela Molinaro
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Barbara Becattini
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Arianna Mazzoli
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Augusto Bleve
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Lucia Radici
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Ingela Maxvall
- Translational Science, Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Victoria Rotter Sopasakis
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Antonio Molinaro
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Bäckhed
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden; Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Receptology and Enteroendocrinology, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Giovanni Solinas
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
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29
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Lundsgaard AM, Holm JB, Sjøberg KA, Bojsen-Møller KN, Myrmel LS, Fjære E, Jensen BAH, Nicolaisen TS, Hingst JR, Hansen SL, Doll S, Geyer PE, Deshmukh AS, Holst JJ, Madsen L, Kristiansen K, Wojtaszewski JFP, Richter EA, Kiens B. Mechanisms Preserving Insulin Action during High Dietary Fat Intake. Cell Metab 2019; 29:50-63.e4. [PMID: 30269983 DOI: 10.1016/j.cmet.2018.08.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 06/21/2018] [Accepted: 08/30/2018] [Indexed: 01/03/2023]
Abstract
Prolonged intervention studies investigating molecular metabolism are necessary for a deeper understanding of dietary effects on health. Here we provide mechanistic information about metabolic adaptation to fat-rich diets. Healthy, slightly overweight men ingested saturated or polyunsaturated fat-rich diets for 6 weeks during weight maintenance. Hyperinsulinemic clamps combined with leg balance technique revealed unchanged peripheral insulin sensitivity, independent of fatty acid type. Both diets increased fat oxidation potential in muscle. Hepatic insulin clearance increased, while glucose production, de novo lipogenesis, and plasma triacylglycerol decreased. High fat intake changed the plasma proteome in the immune-supporting direction and the gut microbiome displayed changes at taxonomical and functional level with polyunsaturated fatty acid (PUFA). In mice, eucaloric feeding of human PUFA and saturated fatty acid diets lowered hepatic triacylglycerol content compared with low-fat-fed control mice, and induced adaptations in the liver supportive of decreased gluconeogenesis and lipogenesis. Intake of fat-rich diets thus induces extensive metabolic adaptations enabling disposition of dietary fat without metabolic complications.
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Affiliation(s)
- Anne-Marie Lundsgaard
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Jacob B Holm
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Clinical Microbiomics, Copenhagen, Denmark
| | - Kim A Sjøberg
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | | | | | - Even Fjære
- Institute of Marine Research, Bergen, Norway
| | - Benjamin A H Jensen
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Department of Medicine, Laval University, Quebec, QC, Canada
| | - Trine S Nicolaisen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Janne R Hingst
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Sine L Hansen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Sophia Doll
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Munich, Germany
| | - Philip E Geyer
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Munich, Germany
| | - Atul S Deshmukh
- The Novo Nordisk Foundation Center for Protein Research, Clinical Proteomics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lise Madsen
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Institute of Marine Research, Bergen, Norway
| | - Karsten Kristiansen
- Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Institute of Metagenomics, BGI-Shenzhen, Shenzhen, China
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Universitetsparken 13, Copenhagen 2100, Denmark.
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30
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Logie L, Lees Z, Allwood JW, McDougall G, Beall C, Rena G. Regulation of hepatic glucose production and AMPK by AICAR but not by metformin depends on drug uptake through the equilibrative nucleoside transporter 1 (ENT1). Diabetes Obes Metab 2018; 20:2748-2758. [PMID: 29962100 PMCID: PMC6282725 DOI: 10.1111/dom.13455] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 01/15/2023]
Abstract
AIM Recently we have observed differences in the ability of metformin and AICAR to repress glucose production from hepatocytes using 8CPT-cAMP. Previous results indicate that, in addition to activating protein kinase A, 8CPT-modified cAMP analogues suppress the nitrobenzylthioinosine (NBMPR)-sensitive equilibrative nucleoside transporter ENT1. We aimed to exploit 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR, which is highly selective for a high-affinity binding-site on ENT1, to investigate the role of ENT1 in the liver-specific glucose-lowering properties of AICAR and metformin. METHODS Primary mouse hepatocytes were incubated with AICAR and metformin in combination with cAMP analogues, glucagon, forskolin and NBMPR. Hepatocyte glucose production (HGP) and AMPK signalling were measured, and a uridine uptake assay with supporting LC-MS was used to investigate nucleoside depletion from medium by cells. RESULTS AICAR and metformin increased AMPK pathway phosphorylation and decreased HGP induced by dibutyryl cAMP and glucagon. HGP was also induced by 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR; however, in each case this was resistant to suppression by AICAR but not by metformin. Cross-validation of tracer and mass spectrometry studies indicates that 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR inhibited the effects of AICAR, at least in part, by impeding its uptake into hepatocytes. CONCLUSIONS We report for the first time that suppression of ENT1 induces HGP. ENT1 inhibition also impedes uptake and the effects of AICAR, but not metformin, on HGP. Further investigation of nucleoside transport may illuminate a better understanding of how metformin and AICAR each regulate HGP.
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Affiliation(s)
- Lisa Logie
- Division of Cellular MedicineNinewells Hospital and Medical School, University of DundeeDundeeUK
| | - Zoe Lees
- Division of Cellular MedicineNinewells Hospital and Medical School, University of DundeeDundeeUK
- Environmental and Biochemical SciencesThe James Hutton InstituteDundeeUK
| | - J. William Allwood
- Environmental and Biochemical SciencesThe James Hutton InstituteDundeeUK
| | - Gordon McDougall
- Environmental and Biochemical SciencesThe James Hutton InstituteDundeeUK
| | - Craig Beall
- Institute of Biomedical and Clinical ScienceUniversity of Exeter Medical SchoolExeterUK
| | - Graham Rena
- Division of Cellular MedicineNinewells Hospital and Medical School, University of DundeeDundeeUK
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31
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Alkhalidy H, Moore W, Wang Y, Luo J, McMillan RP, Zhen W, Zhou K, Liu D. The Flavonoid Kaempferol Ameliorates Streptozotocin-Induced Diabetes by Suppressing Hepatic Glucose Production. Molecules 2018; 23:E2338. [PMID: 30216981 DOI: 10.3390/molecules23092338] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/04/2018] [Accepted: 09/08/2018] [Indexed: 12/20/2022] Open
Abstract
In diabetes mellitus, the excessive rate of glucose production from the liver is considered a primary contributor for the development of hyperglycemia, in particular, fasting hyperglycemia. In this study, we investigated whether kaempferol, a flavonol present in several medicinal herbs and foods, can be used to ameliorate diabetes in an animal model of insulin deficiency and further explored the mechanism underlying the anti-diabetic effect of this flavonol. We demonstrate that oral administration of kaempferol (50 mg/kg/day) to streptozotocin-induced diabetic mice significantly improved hyperglycemia and reduced the incidence of overt diabetes from 100% to 77.8%. This outcome was accompanied by a reduction in hepatic glucose production and an increase in glucose oxidation in the muscle of the diabetic mice, whereas body weight, calorie intake, body composition, and plasma insulin and glucagon levels were not altered. Consistently, treatment with kaempferol restored hexokinase activity in the liver and skeletal muscle of diabetic mice while suppressed hepatic pyruvate carboxylase activity and gluconeogenesis. These results suggest that kaempferol may exert antidiabetic action via promoting glucose metabolism in skeletal muscle and inhibiting gluconeogenesis in the liver.
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32
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Abstract
Metformin has been the first-line drug treatment for hyperglycemia and insulin resistance for over 50 years. However, the molecular basis of its therapeutic role remained incompletely understood. Recent advances demonstrate that metformin could exert its glucose-lowering effect by multiple mechanisms, including activation of 5′-AMP-activated protein kinase, decreasing production of cyclic AMP, suppressing mitochondrial complex I of the electron transport chain, targeting glycerophosphate dehydrogenase, and altering the gut microbiome. In addition, epidemiological and clinical observation studies suggest that metformin reduced cancer risk in patients with type 2 diabetes and improved survival outcome of human cancers. Experimental studies have shown that this drug can inhibit cancer cell viability, growth, and proliferation through inhibiting mTORC1 signaling and mitochondrial complex I, suggesting that it may be a promising drug candidate for malignancy. Here, we summarize recent progress in studies of metformin in type 2 diabetes and tumorigenesis, which provides novel insight on the therapeutic development of human diseases.
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Affiliation(s)
- Min Li
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoying Li
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Huijie Zhang
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China.,Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yan Lu
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
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33
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Ter Horst KW, Gilijamse PW, Versteeg RI, Ackermans MT, Nederveen AJ, la Fleur SE, Romijn JA, Nieuwdorp M, Zhang D, Samuel VT, Vatner DF, Petersen KF, Shulman GI, Serlie MJ. Hepatic Diacylglycerol-Associated Protein Kinase Cε Translocation Links Hepatic Steatosis to Hepatic Insulin Resistance in Humans. Cell Rep 2018; 19:1997-2004. [PMID: 28591572 PMCID: PMC5469939 DOI: 10.1016/j.celrep.2017.05.035] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 04/17/2017] [Accepted: 05/10/2017] [Indexed: 12/12/2022] Open
Abstract
Hepatic lipid accumulation has been implicated in the development of insulin resistance, but translational evidence in humans is limited. We investigated the relationship between liver fat and tissue-specific insulin sensitivity in 133 obese subjects. Although the presence of hepatic steatosis in obese subjects was associated with hepatic, adipose tissue, and peripheral insulin resistance, we found that intrahepatic triglycerides were not strictly sufficient or essential for hepatic insulin resistance. Thus, to examine the molecular mechanisms that link hepatic steatosis to hepatic insulin resistance, we comprehensively analyzed liver biopsies from a subset of 29 subjects. Here, hepatic cytosolic diacylglycerol content, but not hepatic ceramide content, was increased in subjects with hepatic insulin resistance. Moreover, cytosolic diacylglycerols were strongly associated with hepatic PKCε activation, as reflected by PKCε translocation to the plasma membrane. These results demonstrate the relevance of hepatic diacylglycerol-induced PKCε activation in the pathogenesis of NAFLD-associated hepatic insulin resistance in humans. The presence of hepatic steatosis is associated with insulin resistance Intrahepatic triglycerides are not sufficient for hepatic insulin resistance Diacylglycerol in hepatic cytosol predicts insulin inhibition of glucose production Diacylglycerol-associated insulin resistance is characterized by PKCε translocation
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Affiliation(s)
- Kasper W Ter Horst
- Department of Endocrinology and Metabolism, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Pim W Gilijamse
- Department of Endocrinology and Metabolism, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Ruth I Versteeg
- Department of Endocrinology and Metabolism, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Mariette T Ackermans
- Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Aart J Nederveen
- Department of Radiology, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Susanne E la Fleur
- Department of Endocrinology and Metabolism, Academic Medical Center, 1105AZ Amsterdam, the Netherlands; Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, 1105AZ Amsterdam, the Netherlands; Metabolism and Reward Group, Netherlands Institute for Neuroscience, 1105BA Amsterdam, the Netherlands
| | - Johannes A Romijn
- Department of Medicine, Academic Medical Center, 1105AZ Amsterdam, the Netherlands
| | - Max Nieuwdorp
- Department of Vascular Medicine, Academic Medical Center, 1105AZ Amsterdam, the Netherlands; Department of Internal Medicine, VU University Medical Center, 1081HV Amsterdam, the Netherlands; Institute for Cardiovascular Research, VU University Medical Center, 1081HV Amsterdam, the Netherlands
| | - Dongyan Zhang
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06519, USA
| | - Varman T Samuel
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Daniel F Vatner
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kitt F Petersen
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Gerald I Shulman
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06519, USA; Department of Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Mireille J Serlie
- Department of Endocrinology and Metabolism, Academic Medical Center, 1105AZ Amsterdam, the Netherlands.
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34
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Langlet F, Haeusler RA, Lindén D, Ericson E, Norris T, Johansson A, Cook JR, Aizawa K, Wang L, Buettner C, Accili D. Selective Inhibition of FOXO1 Activator/Repressor Balance Modulates Hepatic Glucose Handling. Cell 2017; 171:824-835.e18. [PMID: 29056338 DOI: 10.1016/j.cell.2017.09.045] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/26/2017] [Accepted: 09/25/2017] [Indexed: 01/08/2023]
Abstract
Insulin resistance is a hallmark of diabetes and an unmet clinical need. Insulin inhibits hepatic glucose production and promotes lipogenesis by suppressing FOXO1-dependent activation of G6pase and inhibition of glucokinase, respectively. The tight coupling of these events poses a dual conundrum: mechanistically, as the FOXO1 corepressor of glucokinase is unknown, and clinically, as inhibition of glucose production is predicted to increase lipogenesis. Here, we report that SIN3A is the insulin-sensitive FOXO1 corepressor of glucokinase. Genetic ablation of SIN3A abolishes nutrient regulation of glucokinase without affecting other FOXO1 target genes and lowers glycemia without concurrent steatosis. To extend this work, we executed a small-molecule screen and discovered selective inhibitors of FOXO-dependent glucose production devoid of lipogenic activity in hepatocytes. In addition to identifying a novel mode of insulin action, these data raise the possibility of developing selective modulators of unliganded transcription factors to dial out adverse effects of insulin sensitizers.
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35
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Abstract
During insulin-resistant states such as type 2 diabetes mellitus (T2DM), insulin fails to suppress hepatic glucose production but promotes lipid synthesis leading to hyperglycemia and hypertriglyceridemia. Defining the downstream signaling pathways underlying the control of hepatic metabolism by insulin is necessary for understanding both normal physiology and the pathogenesis of metabolic disease. We summarize recent literature highlighting the importance of both hepatic and extrahepatic mechanisms in insulin regulation of liver glucose and lipid metabolism. We posit that a failure of insulin to inappropriately regulate liver metabolism during T2DM is not exclusively from an inherent defect in canonical liver insulin signaling but is instead due to a combination of hyperinsulinemia, altered substrate supply, and the input of several extrahepatic signals.
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Affiliation(s)
- Paul M Titchenell
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Morris J Birnbaum
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Present address: Internal Medicine, Pfizer Inc., Cambridge, MA, USA.
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36
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Sharabi K, Lin H, Tavares CDJ, Dominy JE, Camporez JP, Perry RJ, Schilling R, Rines AK, Lee J, Hickey M, Bennion M, Palmer M, Nag PP, Bittker JA, Perez J, Jedrychowski MP, Ozcan U, Gygi SP, Kamenecka TM, Shulman GI, Schreiber SL, Griffin PR, Puigserver P. Selective Chemical Inhibition of PGC-1α Gluconeogenic Activity Ameliorates Type 2 Diabetes. Cell 2017; 169:148-160.e15. [PMID: 28340340 DOI: 10.1016/j.cell.2017.03.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 12/22/2016] [Accepted: 02/27/2017] [Indexed: 01/27/2023]
Abstract
Type 2 diabetes (T2D) is a worldwide epidemic with a medical need for additional targeted therapies. Suppression of hepatic glucose production (HGP) effectively ameliorates diabetes and can be exploited for its treatment. We hypothesized that targeting PGC-1α acetylation in the liver, a chemical modification known to inhibit hepatic gluconeogenesis, could be potentially used for treatment of T2D. Thus, we designed a high-throughput chemical screen platform to quantify PGC-1α acetylation in cells and identified small molecules that increase PGC-1α acetylation, suppress gluconeogenic gene expression, and reduce glucose production in hepatocytes. On the basis of potency and bioavailability, we selected a small molecule, SR-18292, that reduces blood glucose, strongly increases hepatic insulin sensitivity, and improves glucose homeostasis in dietary and genetic mouse models of T2D. These studies have important implications for understanding the regulatory mechanisms of glucose metabolism and treatment of T2D.
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37
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Nicolas S, Blasco-Baque V, Fournel A, Gilleron J, Klopp P, Waget A, Ceppo F, Marlin A, Padmanabhan R, Iacovoni JS, Tercé F, Cani PD, Tanti JF, Burcelin R, Knauf C, Cormont M, Serino M. Transfer of dysbiotic gut microbiota has beneficial effects on host liver metabolism. Mol Syst Biol 2017; 13:921. [PMID: 28302863 PMCID: PMC5371731 DOI: 10.15252/msb.20167356] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Gut microbiota dysbiosis has been implicated in a variety of systemic disorders, notably metabolic diseases including obesity and impaired liver function, but the underlying mechanisms are uncertain. To investigate this question, we transferred caecal microbiota from either obese or lean mice to antibiotic-free, conventional wild-type mice. We found that transferring obese-mouse gut microbiota to mice on normal chow (NC) acutely reduces markers of hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-inoculated mice, a phenotypic trait blunted in conventional NOD2 KO mice. Furthermore, transferring of obese-mouse microbiota changes both the gut microbiota and the microbiome of recipient mice. We also found that transferring obese gut microbiota to NC-fed mice then fed with a high-fat diet (HFD) acutely impacts hepatic metabolism and prevents HFD-increased hepatic gluconeogenesis compared to non-inoculated mice. Moreover, the recipient mice exhibit reduced hepatic PEPCK and G6Pase activity, fed glycaemia and adiposity. Conversely, transfer of lean-mouse microbiota does not affect markers of hepatic gluconeogenesis. Our findings provide a new perspective on gut microbiota dysbiosis, potentially useful to better understand the aetiology of metabolic diseases.
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Affiliation(s)
- Simon Nicolas
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Vincent Blasco-Baque
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France.,Faculté de Chirurgie Dentaire de Toulouse, Université Paul Sabatier, Toulouse Cedex, France
| | - Audren Fournel
- Toulouse III, Institut de Recherche en Santé Digestive (IRSD) Team 3, "Intestinal Neuroimmune Interactions" INSERM U1220, Université Paul Sabatier, Toulouse Cedex 3, France.,European Associated Laboratory NeuroMicrobiota (INSERM/UCL), Bâtiment B - Pavillon Lefebvre, Toulouse Cedex 3, France
| | - Jerome Gilleron
- INSERM Unité 1065/Centre Méditerranéen de Médecine Moléculaire (C3M), Université Côte d'Azur, Nice, France
| | - Pascale Klopp
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Aurelie Waget
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Franck Ceppo
- INSERM Unité 1065/Centre Méditerranéen de Médecine Moléculaire (C3M), Université Côte d'Azur, Nice, France
| | - Alysson Marlin
- Toulouse III, Institut de Recherche en Santé Digestive (IRSD) Team 3, "Intestinal Neuroimmune Interactions" INSERM U1220, Université Paul Sabatier, Toulouse Cedex 3, France.,European Associated Laboratory NeuroMicrobiota (INSERM/UCL), Bâtiment B - Pavillon Lefebvre, Toulouse Cedex 3, France
| | - Roshan Padmanabhan
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Jason S Iacovoni
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - François Tercé
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Patrice D Cani
- Walloon Excellence in Life Sciences and BIOtechnology (WELBIO), Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-François Tanti
- INSERM Unité 1065/Centre Méditerranéen de Médecine Moléculaire (C3M), Université Côte d'Azur, Nice, France
| | - Remy Burcelin
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France.,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
| | - Claude Knauf
- Toulouse III, Institut de Recherche en Santé Digestive (IRSD) Team 3, "Intestinal Neuroimmune Interactions" INSERM U1220, Université Paul Sabatier, Toulouse Cedex 3, France.,European Associated Laboratory NeuroMicrobiota (INSERM/UCL), Bâtiment B - Pavillon Lefebvre, Toulouse Cedex 3, France
| | - Mireille Cormont
- INSERM Unité 1065/Centre Méditerranéen de Médecine Moléculaire (C3M), Université Côte d'Azur, Nice, France
| | - Matteo Serino
- Institut National de la Santé et de la Recherche Médicale (INSERM), Toulouse, France .,Unité Mixte de Recherche (UMR) 1048, Institut de Maladies Métaboliques et Cardiovasculaires (I2MC), Université Paul Sabatier (UPS), Toulouse Cedex 4, France
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38
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Xue N, Wei C, Zhang L, Liu H, Wang X, Wang L. The Characteristics of Hepatic Gsα-cAMP Axis in HSHF Diet-Fed Obese Insulin Resistance Rats and Genetic Diabetic Mice. Biol Pharm Bull 2017; 40:774-781. [PMID: 28260721 DOI: 10.1248/bpb.b16-00749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stimulatory G protein α-subunit (Gsα) mediated cAMP signal is required for elevated hepatic glucose production (HGP) in diabetic patients. However, it remains obscure of the exact characteristics of hepatic Gsα-cAMP signal axis (including Gsα, glucagon receptor, β2-adrenergic receptor, cAMP, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase) in insulin resistance (IR) and type 2 diabetes mellitus (T2DM). In current study, we investigated the changing characteristics of hepatic Gsα-cAMP signal axis and blood glucose in high-sugar-high-fat (HSHF)-diet-induced IR Wistar rats and db/db diabetic mice. As expected, the HSHF-diet rats were characterized by hyperinsulinemia, hyperglycemia and impaired glucose tolerance. According to a threshold (1.7) of homeostasis model assessment ratio (HOMA-R), the process of IR in HSHF-diet rats could be divided into slight and high IR stages, with the week-23 as the cut-off point. In early slight IR stage, key molecules expressions of hepatic Gsα-cAMP signal axis in HSHF-diet rats were up-regulated with significantly elevated fasting blood glucose (FBG) from 18 to 23 weeks. Unexpectedly, in high IR stage, hepatic Gsα-cAMP signal axis was recovered comparatively to that of normal chow-diet rats, and no significant differences in FBG levels were found. However, in diabetic db/db mice, up-regulation of hepatic Gsα-cAMP signal axis was responsible for its severely increased fasting hyperglycaemia. Our data revealed a positive correlation between hepatic Gsα-cAMP signal axis and FBG in slight IR stage of HSHF-diet rats and diabetic db/db mice. The current finding thus suggested hepatic Gsα-cAMP signal axis plays a central role in regulating of FBG during the developing and development of T2DM.
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Affiliation(s)
- Nina Xue
- Beijing Institute of Pharmacology and Toxicology.,State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College
| | - Chen Wei
- Beijing Institute of Pharmacology and Toxicology
| | - Lihong Zhang
- Beijing Institute of Pharmacology and Toxicology
| | - Hongying Liu
- Beijing Institute of Pharmacology and Toxicology
| | - Xiaojuan Wang
- Department of Pharmacology, School of Stomatology, The Fourth Military Medical University
| | - Lili Wang
- Beijing Institute of Pharmacology and Toxicology
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39
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Abstract
Metformin is established as the first-line therapy for type 2 diabetes (T2DM), but its mode of action remains elusive. Elucidation of the mechanisms underlying the anti-diabetic action of metformin may have the potential to optimise its glucose-lowering efficacy and lead to the development of agents acting on novel targets for the management of type 2 diabetes. Areas covered: This review highlights key pharmacokinetic features of metformin, summarises recent insights into its hepatic and gastrointestinal actions relevant to blood glucose homeostasis, and discusses the common gastrointestinal side effects of metformin. Literature concerning these areas was reviewed on PubMed. Expert commentary: The mechanisms by which metformin improves glycaemic control in type 2 diabetes are complex. Although novel hepatic pathways continue to be reported in preclinical studies, there is a lack of human evidence for most of these. Considering the fundamental role of the gastrointestinal tract in the regulation of blood glucose homeostasis and pleiotropic actions of metformin on several gastrointestinal targets relevant to glycaemic control, the gut is likely to represent at least as important a site of metformin action as the liver in the management of type 2 diabetes.
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Affiliation(s)
- Tongzhi Wu
- a Discipline of Medicine and Centre of Research Excellence in Translating Nutritional Science to Good Health , The University of Adelaide , Adelaide , Australia
| | - Michael Horowitz
- a Discipline of Medicine and Centre of Research Excellence in Translating Nutritional Science to Good Health , The University of Adelaide , Adelaide , Australia
| | - Christopher K Rayner
- a Discipline of Medicine and Centre of Research Excellence in Translating Nutritional Science to Good Health , The University of Adelaide , Adelaide , Australia
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40
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Abstract
The mechanism underlying the increased rate of endogenous glucose production from the liver during exercise remains unknown. The cytokine interleukin-6 (IL-6) is known to be released during exercise and is thought that either IL-6 directly or via a "contraction factor" stimulates the release of stored glucose from the liver. Here we show that IL-6 does not directly increase hepatic glucose output (HGO). Moreover, IL-6 infused at the same time as glucagon caused a significant reduction in HGO. IL-6 infused with epinephrine caused no synergenic increase in HGO. To test if an unknown "contraction factor" was needed along with IL-6 to increase HGO, we used human fasted and exercised plasma perfused with or without IL-6 in our isolated liver system. We found that exercised plasma increased HGO, as expected, but when infused with IL-6, reductions in HGO were found. Our results provide evidence that IL-6 works as a negative regulator of HGO.
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Affiliation(s)
- Jessica R Dent
- a Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology , Auckland , New Zealand
| | - Md Kamrul H Chowdhury
- b Department of Pharmacology , University of New South Wales , Sydney , NSW , Australia
| | - Sergei Tchijov
- c Goldcoast University Hospital , Gold Coast , Sydney , Australia , and
| | - Deborah Dulson
- a Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology , Auckland , New Zealand
| | - Greg Smith
- b Department of Pharmacology , University of New South Wales , Sydney , NSW , Australia
- d Department of Molecular Medicine , University of Auckland , Auckland , New Zealand
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41
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Choi K, Weber JM. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming. Am J Physiol Regul Integr Comp Physiol 2015; 310:R493-501. [PMID: 26719305 DOI: 10.1152/ajpregu.00330.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/29/2015] [Indexed: 11/22/2022]
Abstract
This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise.
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Affiliation(s)
- Kevin Choi
- Biology Department, University of Ottawa, Ottawa, Ontario, Canada
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42
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Yu H, Jia W, Guo Z. Reducing Liver Fat by Low Carbohydrate Caloric Restriction Targets Hepatic Glucose Production in Non-Diabetic Obese Adults with Non-Alcoholic Fatty Liver Disease. J Clin Med 2014; 3:1050-63. [PMID: 25411646 DOI: 10.3390/jcm3031050] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) impairs liver functions, the organ responsible for the regulation of endogenous glucose production and thus plays a key role in glycemic homeostasis. Therefore, interventions designed to normalize liver fat content are needed to improve glucose metabolism in patients affected by NAFLD such as obesity. Objective: this investigation is designed to determine the effects of caloric restriction on hepatic and peripheral glucose metabolism in obese humans with NAFLD. Methods: eight non-diabetic obese adults were restricted for daily energy intake (800 kcal) and low carbohydrate (<10%) for 8 weeks. Body compositions, liver fat and hepatic glucose production (HGP) and peripheral glucose disposal before and after the intervention were determined. Results: the caloric restriction reduced liver fat content by 2/3 (p = 0.004). Abdominal subcutaneous and visceral fat, body weight, BMI, waist circumference and fasting plasma triglyceride and free fatty acid concentrations all significantly decreased (p < 0.05). The suppression of post-load HGP was improved by 22% (p = 0.002) whereas glucose disposal was not affected (p = 0.3). Fasting glucose remained unchanged and the changes in the 2-hour plasma glucose and insulin concentration were modest and statistically insignificant (p > 0.05). Liver fat is the only independent variable highly correlated to HGP after the removal of confounders. Conclusion: NAFLD impairs HGP but not peripheral glucose disposal; low carbohydrate caloric restriction effectively lowers liver fat which appears to directly correct the HGP impairment.
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43
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Vaillancourt E, Weber JM. Fuel metabolism in Canada geese: effects of glucagon on glucose kinetics. Am J Physiol Regul Integr Comp Physiol 2015; 309:R535-43. [PMID: 26108869 DOI: 10.1152/ajpregu.00080.2015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/18/2015] [Indexed: 11/22/2022]
Abstract
During prolonged fasting, birds must rely on glucose mobilization to maintain normoglycemia. Glucagon is known to modulate avian energy metabolism during prolonged fasting, but the metabolic effects of this hormone on long-distance migrant birds have never been investigated. Our goal was to determine whether glucagon regulates the mobilization of the main lipid and carbohydrate fuels in migrant birds. Using the Canada goose (Branta canadensis) as a model species, we looked for evidence of fuel mobilization via changes in metabolite concentrations. No changes could be found for any lipid fraction, but glucagon elicited a strong increase in glucose concentration. Therefore, we aimed to quantify the effects of this hormone on glucose kinetics using continuous infusion of 6-[(3)H]-d-glucose. Glucagon was found to cause a 50% increase in glucose mobilization (from 22.2 ± 2.4 μmol·kg(-1)·min(-1) to 33.5 ± 3.3 μmol·kg(-1)·min(-1)) and, together with an unchanged rate of carbohydrate oxidation, led to a 90% increase in plasma glucose concentration. This hormone also led to a twofold increase in plasma lactate concentration. No changes in plasma lipid concentration or composition were observed. This study is the first to demonstrate how glucagon modulates glucose kinetics in a long-distance migrant bird and to quantify its rates of glucose mobilization.
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Affiliation(s)
- Eric Vaillancourt
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Michel Weber
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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44
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Cordoba-Chacon J, Gahete MD, McGuinness OP, Kineman RD. Differential impact of selective GH deficiency and endogenous GH excess on insulin-mediated actions in muscle and liver of male mice. Am J Physiol Endocrinol Metab 2014; 307:E928-34. [PMID: 25269484 PMCID: PMC4233257 DOI: 10.1152/ajpendo.00420.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A reciprocal relationship between insulin sensitivity and glucose tolerance has been reported in some mouse models and humans with isolated changes in growth hormone (GH) production and signaling. To determine if this could be explained in part by tissue-specific changes in insulin sensitivity, hyperinsulinemic-euglycemic clamps were performed in mice with adult-onset, isolated GH deficiency and in mice with elevated endogenous GH levels due to somatotrope-specific loss of IGF-I and insulin receptors. Our results demonstrate that circulating GH levels are negatively correlated with insulin-mediated glucose uptake in muscle but positively correlated with insulin-mediated suppression of hepatic glucose production. A positive relationship was also observed between GH levels and endpoints of hepatic lipid metabolism known to be regulated by insulin. These results suggest hepatic insulin resistance could represent an early metabolic defect in GH deficiency.
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Affiliation(s)
- Jose Cordoba-Chacon
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Manuel D Gahete
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Department of Cell Biology, Physiology, and Immunology, University of Córdoba, Instituto Maimónides de Investigación Biomédica de Córdoba/Hospital Universitario Reina Sofia, and CIBER de la Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain; and
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Rhonda D Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois;
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45
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Abstract
Dysregulation of hepatic glucose uptake (HGU) and inability of insulin to suppress hepatic glucose production (HGP) contribute to hyperglycaemia in patients with type 2 diabetes (T2D). Growing evidence suggests that insulin can inhibit HGP not only through a direct effect on the liver but also through a mechanism involving the brain. Yet, the notion that insulin action in the brain plays a physiological role in the control of HGP continues to be controversial. Although studies in dogs suggest that the direct hepatic effect of insulin is sufficient to explain day-to-day control of HGP, a surprising outcome has been revealed by recent studies in mice, investigating whether the direct hepatic action of insulin is necessary for normal HGP: when the hepatic insulin signalling pathway was genetically disrupted, HGP was maintained normally even in the absence of direct input from insulin. Here, we present evidence that points to a potentially important role of the brain in the physiological control of both HGU and HGP in response to input from insulin as well as other hormones and nutrients.
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Affiliation(s)
- Jennifer M. Rojas
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Michael W. Schwartz
- Diabetes and Obesity Center of Excellence, Department of Medicine, University of Washington, Seattle, Washington, USA
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46
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Zhang L, Jia X, Dong J, Chen D, Liu J, Zhang L, Wen X. Synthesis and evaluation of novel oleanolic acid derivatives as potential antidiabetic agents. Chem Biol Drug Des 2014; 83:297-305. [PMID: 24119242 DOI: 10.1111/cbdd.12241] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/28/2013] [Accepted: 09/24/2013] [Indexed: 10/26/2022]
Abstract
Antidiabetic agents simultaneously inhibiting hepatic glucose production and stimulating hepatic glucose consumption could apply a better control over hyperglycemia. A series of oleanolic acid derivatives with bulky substituents at C-3 position were designed and synthesized in order to search for this kind of agents. All of the compounds were evaluated biologically in vitro using glycogen phosphorylase and HepG2 cells. The results indicated that several derivatives exhibited moderate-to-good inhibitory activities against glycogen phosphorylase. Compound 8g showed the best inhibition with an IC50 value of 5.4 μm. Moreover, most of the derivatives were found to increase the glucose consumption in HepG2 cells in a dose-dependent manner. The possible binding mode of compound 8g with glycogen phosphorylase was also explored by docking study. 8g was found to have hydrogen bonding interactions with Arg193, Arg310, and Arg60 of the allosteric site.
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Affiliation(s)
- Liying Zhang
- Key Laboratory of Traditional Chinese Medicine Research and Development of Hebei Province, Institute of Traditional Chinese Medicine, Chengde Medical University, Chengde, 067000, China
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47
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Kim SJ, Quan HY, Jeong KJ, Kim DY, Kim GW, Jo HK, Chung SH. Beneficial effect of betulinic acid on hyperglycemia via suppression of hepatic glucose production. J Agric Food Chem 2014; 62:434-442. [PMID: 24354358 DOI: 10.1021/jf4030739] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The inhibitory effect of betulinic acid (BA) on hepatic glucose production was examined in HepG2 cells and high fat diet (HFD)-fed ICR mice. BA significantly inhibited the hepatic glucose production (HGP) and gene expression levels of PGC-1α, PEPCK, and G6Pase. BA activated AMPK and suppressed the expression level of phosphorylated CREB. These effects were all abolished in the presence of compound C (an AMPK inhibitor). Moreover, inhibition of AMPK by overexpression of dominant negative AMPK prevented BA from suppression of HGP, indicating that the inhibitory effect of BA on HGP is AMPK-dependent. In addition, BA markedly phosphorylated CAMKK, and phosphorylation of AMPK and ACC, and suppression of HGP were all reversed in the presence of STO-609 (a CAMKK inhibitor), suggesting that CAMKK is an upstream kinase for AMPK. In an animal study, HFD-fed ICR mice were orally administered with 5 or 10 mg of BA per kg (B5 and B10) for three weeks. Plasma glucose, triglyceride, and the insulin resistance index of the B10 group were decreased by 34%, 59%, and 38%, respectively. In a pyruvate tolerance test, pyruvate-induced glucose excursion was decreased by 27% when mice were pretreated with 10 mg/kg of BA. In summary, BA effectively ameliorates hyperglycemia through inhibition of hepatic gluconeogenesis via modulating the CAMKK-AMPK-CREB signaling pathway.
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Affiliation(s)
- Soo Jung Kim
- Department of Pharmacology and Clinical Pharmacy, College of Pharmacy, Kyung Hee University , 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701, Korea
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48
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Ip W, Shao W, Chiang YTA, Jin T. GLP-1-derived nonapeptide GLP-1(28-36)amide represses hepatic gluconeogenic gene expression and improves pyruvate tolerance in high-fat diet-fed mice. Am J Physiol Endocrinol Metab 2013; 305:E1348-58. [PMID: 24085036 DOI: 10.1152/ajpendo.00376.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Certain "degradation" products of GLP-1 were found to possess beneficial effects on metabolic homeostasis. Here, we investigated the function of the COOH-terminal fragment of GLP-1, the nonapeptide GLP-1(28-36)amide, in hepatic glucose metabolism. C57BL/6 mice fed a high-fat diet (HFD) for 13 wk were injected intraperitoneally with GLP-1(28-36)amide for 6 wk. A significant reduction in body weight gain in response to HFD feeding was observed in GLP-1(28-36)amide-treated mice. GLP-1(28-36)amide administration moderately improved glucose disposal during glucose tolerance test but more drastically attenuated glucose production during pyruvate tolerance test, which was associated with reduced hepatic expression of the gluconeogenic genes Pck1, G6pc, and Ppargc1a. Mice treated with GLP-1(28-36)amide exhibited increased phosphorylation of PKA targets, including cAMP response element-binding protein (CREB), ATF-1, and β-catenin. In primary hepatocytes, GLP-1(28-36)amide reduced glucose production and expression of Pck1, G6pc, and Ppargc1a, which was associated with increased cAMP content and PKA target phosphorylation. These effects were attenuated by PKA inhibition. We suggest that GLP-1(28-36)amide represses hepatic gluconeogenesis involving the activation of components of the cAMP/PKA signaling pathway. This study further confirmed that GLP-1(28-36)amide possesses therapeutic potential for diabetes and other metabolic disorders.
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Affiliation(s)
- Wilfred Ip
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
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49
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Edgerton DS, An Z, Johnson KMS, Farmer T, Farmer B, Neal D, Cherrington AD. Effects of intraportal exenatide on hepatic glucose metabolism in the conscious dog. Am J Physiol Endocrinol Metab 2013; 305:E132-9. [PMID: 23673158 PMCID: PMC3725568 DOI: 10.1152/ajpendo.00160.2013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Incretins improve glucose metabolism through multiple mechanisms. It remains unclear whether direct hepatic effects are an important part of exenatide's (Ex-4) acute action. Therefore, the objective of this study was to determine the effect of intraportal delivery of Ex-4 on hepatic glucose production and uptake. Fasted conscious dogs were studied during a hyperglycemic clamp in which glucose was infused into the hepatic portal vein. At the same time, portal saline (control; n = 8) or exenatide was infused at low (0.3 pmol·kg⁻¹·min⁻¹, Ex-4-low; n = 5) or high (0.9 pmol·kg⁻¹·min⁻¹, Ex-4-high; n = 8) rates. Arterial plasma glucose levels were maintained at 160 mg/dl during the experimental period. This required a greater rate of glucose infusion in the Ex-4-high group (1.5 ± 0.4, 2.0 ± 0.7, and 3.7 ± 0.7 mg·kg⁻¹·min⁻¹ between 30 and 240 min in the control, Ex-4-low, and Ex-4-high groups, respectively). Plasma insulin levels were elevated by Ex-4 (arterial: 4,745 ± 428, 5,710 ± 355, and 7,262 ± 1,053 μU/ml; hepatic sinusoidal: 14,679 ± 1,700, 15,341 ± 2,208, and 20,445 ± 4,020 μU/ml, 240 min, area under the curve), whereas the suppression of glucagon was nearly maximal in all groups. Although glucose utilization was greater during Ex-4 infusion (5.92 ± 0.53, 6.41 ± 0.57, and 8.12 ± 0.54 mg·kg⁻¹·min⁻¹), when indices of hepatic, muscle, and whole body glucose uptake were expressed relative to circulating insulin concentrations, there was no indication of insulin-independent effects of Ex-4. Thus, this study does not support the notion that Ex-4 generates acute changes in hepatic glucose metabolism through direct effects on the liver.
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Affiliation(s)
- Dale S Edgerton
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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50
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Winnick JJ, Ramnanan CJ, Saraswathi V, Roop J, Scott M, Jacobson P, Jung P, Basu R, Cherrington AD, Edgerton DS. Effects of 11β-hydroxysteroid dehydrogenase-1 inhibition on hepatic glycogenolysis and gluconeogenesis. Am J Physiol Endocrinol Metab 2013; 304:E747-56. [PMID: 23403942 PMCID: PMC3625750 DOI: 10.1152/ajpendo.00639.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to determine the effect of prolonged 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1) inhibition on basal and hormone-stimulated glucose metabolism in fasted conscious dogs. For 7 days prior to study, either an 11β-HSD1 inhibitor (HSD1-I; n = 6) or placebo (PBO; n = 6) was administered. After the basal period, a 4-h metabolic challenge followed, where glucagon (3×-basal), epinephrine (5×-basal), and insulin (2×-basal) concentrations were increased. Hepatic glucose fluxes did not differ between groups during the basal period. In response to the metabolic challenge, hepatic glucose production was stimulated in PBO, resulting in hyperglycemia such that exogenous glucose was required in HSD-I (P < 0.05) to match the glycemia between groups. Net hepatic glucose output and endogenous glucose production were decreased by 11β-HSD1 inhibition (P < 0.05) due to a reduction in net hepatic glycogenolysis (P < 0.05), with no effect on gluconeogenic flux compared with PBO. In addition, glucose utilization (P < 0.05) and the suppression of lipolysis were increased (P < 0.05) in HSD-I compared with PBO. These data suggest that inhibition of 11β-HSD1 may be of therapeutic value in the treatment of diseases characterized by insulin resistance and excessive hepatic glucose production.
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Affiliation(s)
- J. J. Winnick
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - C. J. Ramnanan
- 2Department of Cellular and Molecular Medicine, University of Ottawa School of Medicine, Ottawa, Ontario, Canada;
| | - V. Saraswathi
- 3Department of Medicine, University of Nebraska Medical Center, Omaha, Nebraska;
| | - J. Roop
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - M. Scott
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - P. Jacobson
- 4Abbott Laboratories, Chicago, Illinois; and
| | - P. Jung
- 4Abbott Laboratories, Chicago, Illinois; and
| | - R. Basu
- 5Department of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - A. D. Cherrington
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - D. S. Edgerton
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
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