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Zhang H, Yang N, Li J, Wang P, Li S, Xie L, Liao S. Radical Fluorosulfonyl Arylation of Alkenes: Accessing FSO 2-Functionalized Chromanes via Formal Endo and Exo Cyclization. Org Lett 2022; 24:8170-8175. [DOI: 10.1021/acs.orglett.2c03224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Honghai Zhang
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Na Yang
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Jing Li
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Peng Wang
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Shaojie Li
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Lili Xie
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
| | - Saihu Liao
- Key Laboratory of Molecule Synthesis and Function Discovery, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China
- Beijing National Laboratory for Molecular Sciences (BNLMS), Beijing 100190, P. R. China
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2
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Mitochondrial pyruvate carrier inhibitors improve metabolic parameters in diet-induced obese mice. J Biol Chem 2021; 298:101554. [PMID: 34973337 PMCID: PMC8808181 DOI: 10.1016/j.jbc.2021.101554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 11/21/2022] Open
Abstract
The mitochondrial pyruvate carrier (MPC) is an inner mitochondrial membrane complex that plays a critical role in intermediary metabolism. Inhibition of the MPC, especially in liver, may have efficacy for treating type 2 diabetes mellitus. Herein, we examined the antidiabetic effects of zaprinast and 7ACC2, small molecules which have been reported to act as MPC inhibitors. Both compounds activated a bioluminescence resonance energy transfer–based MPC reporter assay (reporter sensitive to pyruvate) and potently inhibited pyruvate-mediated respiration in isolated mitochondria. Furthermore, zaprinast and 7ACC2 acutely improved glucose tolerance in diet-induced obese mice in vivo. Although some findings were suggestive of improved insulin sensitivity, hyperinsulinemic–euglycemic clamp studies did not detect enhanced insulin action in response to 7ACC2 treatment. Rather, our data suggest acute glucose-lowering effects of MPC inhibition may be due to suppressed hepatic gluconeogenesis. Finally, we used reporter sensitive to pyruvate to screen a chemical library of drugs and identified 35 potentially novel MPC modulators. Using available evidence, we generated a pharmacophore model to prioritize which hits to pursue. Our analysis revealed carsalam and six quinolone antibiotics, as well as 7ACC1, share a common pharmacophore with 7ACC2. We validated that these compounds are novel inhibitors of the MPC and suppress hepatocyte glucose production and demonstrated that one quinolone (nalidixic acid) improved glucose tolerance in obese mice. In conclusion, these data demonstrate the feasibility of therapeutic targeting of the MPC for treating diabetes and provide scaffolds that can be used to develop potent and novel classes of MPC inhibitors.
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Kamm DR, Pyles KD, Sharpe MC, Healy LN, Colca JR, McCommis KS. Novel insulin sensitizer MSDC-0602K improves insulinemia and fatty liver disease in mice, alone and in combination with liraglutide. J Biol Chem 2021; 296:100807. [PMID: 34022222 PMCID: PMC8192871 DOI: 10.1016/j.jbc.2021.100807] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 01/04/2023] Open
Abstract
Insulin sensitizers and incretin mimetics are antidiabetic agents with vastly different mechanisms of action. Thiazolidinedione (TZD) insulin sensitizers are associated with weight gain, whereas glucagon-like peptide-1 receptor agonists can induce weight loss. We hypothesized that combination of a TZD insulin sensitizer and the glucagon-like peptide-1 receptor agonist liraglutide would more significantly improve mouse models of diabetes and nonalcoholic steatohepatitis (NASH). Diabetic db/db and MS-NASH mice were treated with the TZD MSDC-0602K by oral gavage, liraglutide (Lira) by s.c. injection, or combination 0602K+Lira. Lira slightly reduced body weight and modestly improved glycemia in db/db mice. Comparatively, 0602K-treated and 0602K+Lira-treated mice exhibited slight weight gain but completely corrected glycemia and improved glucose tolerance. 0602K reduced plasma insulin, whereas Lira further increased the hyperinsulinemia of db/db mice. Surprisingly, 0602K+Lira treatment reduced plasma insulin and C-peptide to the same extent as mice treated with 0602K alone. 0602K did not reduce glucose-stimulated insulin secretion in vivo, or in isolated islets, indicating the reduced insulinemia was likely compensatory to improved insulin sensitivity. In MS-NASH mice, both 0602K or Lira alone improved plasma alanine aminotransferase and aspartate aminotransferase, as well as liver histology, but more significant improvements were observed with 0602K+Lira treatment. 0602K or 0602K+Lira also increased pancreatic insulin content in both db/db and MS-NASH mice. In conclusion, MSDC-0602K corrected glycemia and reduced insulinemia when given alone, or in combination with Lira. However, 0602K+Lira combination more significantly improved glucose tolerance and liver histology, suggesting that this combination treatment may be an effective therapeutic strategy for diabetes and NASH.
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Affiliation(s)
- Dakota R Kamm
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Kelly D Pyles
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Martin C Sharpe
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Laura N Healy
- LNH Tox Path Consulting LLC, Newbury Park, California, USA
| | - Jerry R Colca
- Cirius Therapeutics, Kalamazoo, Michigan, USA; Cirius Therapeutics, San Diego, California, USA
| | - Kyle S McCommis
- Biochemistry & Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA.
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Nakashima M, Kinoshita M, Nakashima H, Kotani A, Ishikiriyama T, Kato S, Hiroi S, Seki S. Pioglitazone improves phagocytic activity of liver recruited macrophages in elderly mice possibly by promoting glucose catabolism. Innate Immun 2019; 25:356-368. [PMID: 31096821 PMCID: PMC7103614 DOI: 10.1177/1753425919849620] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent studies have revealed that the immunological function of leukocytes is dependent on their cellular metabolism, and some researchers have advocated the beneficial effects of pioglitazone against sepsis in young mice, although bacterial infections are more prevalent in elderly hosts. Here, we investigated pioglitazone’s preventative effect against sepsis induced by intravenous injection of a lethal dose of Escherichia coli in elderly mice (50–60 wk old) and examined its immunological and metabolic effects on liver leukocytes. Pioglitazone improved bacterial elimination in the peripheral blood, lowered serum pro-inflammatory cytokines (TNF-α, IL-12, IFN-γ), and prevented septic death. It also enhanced bacterial elimination in the liver, by increasing the phagocytic and bactericidal activities of liver F4/80+CD11b+ recruited macrophages (Mφ), their CD206 expression and reactive oxygen species production. Quantitative PCR revealed that pioglitazone treatment enhanced gene expression of rate-limiting enzymes for glycolysis in hepatic CD11b+ cells (including neutrophils and recruited Mφ), and their improved phagocytic and bactericidal activities were abolished by glycolysis inhibiting reagents. These findings present the possibility that pioglitazone strengthens the phagocytic and bactericidal activities of liver recruited Mφ and that these immunological activities are closely associated with their glucose catabolism.
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Affiliation(s)
- Masahiro Nakashima
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
| | - Manabu Kinoshita
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
| | - Hiroyuki Nakashima
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
| | - Aya Kotani
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
| | - Takuya Ishikiriyama
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
| | - Shoichiro Kato
- 2 Department of Internal Medicine, National Defense Medical College, Tokorozawa, Japan
| | - Sadayuki Hiroi
- 3 Department of Pathology, Nitobebunka College, Nakano, Tokyo, Japan
| | - Shuhji Seki
- 1 Department of Immunology and Microbiology, National Defense Medical College, Tokorozawa, Japan
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Vigueira PA, McCommis KS, Hodges WT, Schweitzer GG, Cole SL, Oonthonpan L, Taylor EB, McDonald WG, Kletzien RF, Colca JR, Finck BN. The beneficial metabolic effects of insulin sensitizers are not attenuated by mitochondrial pyruvate carrier 2 hypomorphism. Exp Physiol 2017; 102:985-999. [PMID: 28597936 DOI: 10.1113/ep086380] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/06/2017] [Indexed: 12/24/2022]
Abstract
NEW FINDINGS What is the central question of this study? The antidiabetic effects of thiazolidinedione (TZD) drugs may be mediated in part by a molecular interaction with the constituent proteins of the mitochondrial pyruvate carrier complex (MPC1 and MPC2). We examined the ability of a mutant mouse strain expressing an N-terminal truncation of MPC2 (Mpc2Δ16 mice) to respond to TZD treatment. What is the main finding and its importance? The response of Mpc2Δ16 mice to TZD treatment was not significantly different from that of wild-type C57BL6/J control animals, suggesting that the 16 N-terminal amino acids of MPC2 are dispensable for the effects of TZD treatment. Rosiglitazone and pioglitazone are thiazolidinedione (TZD) compounds that have been used clinically as insulin-sensitizing drugs and are generally believed to mediate their effects via activation of the peroxisome proliferator-activated receptor γ (PPARγ). Recent work has shown that it is possible to synthesize TZD compounds with potent insulin-sensitizing effects and markedly diminished affinity for PPARγ. Both clinically used TZDs and investigational PPARγ-sparing TZDs, such as MSDC-0602, interact with the mitochondrial pyruvate carrier (MPC) and inhibit its activity. The MPC complex is composed of two proteins, MPC1 and MPC2. Herein, we used mice expressing a hypomorphic MPC2 protein missing 16 amino acids in the N-terminus (Mpc2Δ16 mice) to determine the effects of these residues in mediating the insulin-sensitizing effects of TZDs in diet-induced obese mice. We found that both pioglitazone and MSDC-0602 elicited their beneficial metabolic effects, including improvement in glucose tolerance, attenuation of hepatic steatosis, reduction of adipose tissue inflammation and stimulation of adipocyte browning, in both wild-type and Mpc2Δ16 mice after high-fat diet feeding. In addition, truncation of MPC2 failed to attenuate the interaction between TZDs and the MPC in a bioluminescence resonance energy transfer-based assay or to affect the suppression of pyruvate-stimulated respiration in cells. Collectively, these data suggest that the interaction between TZDs and MPC2 is not affected by loss of the N-terminal 16 amino acids nor are these residues required for the insulin-sensitizing effects of these compounds.
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Affiliation(s)
- Patrick A Vigueira
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Kyle S McCommis
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Wesley T Hodges
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - George G Schweitzer
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Serena L Cole
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Lalita Oonthonpan
- Department of Biochemistry and Fraternal Order of the Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52240, USA
| | - Eric B Taylor
- Department of Biochemistry and Fraternal Order of the Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52240, USA
| | | | - Rolf F Kletzien
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Jerry R Colca
- Metabolic Solutions Development Company, Kalamazoo, MI, 49007, USA
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St Louis, MO, 63110, USA
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McCommis KS, Chen Z, Fu X, McDonald WG, Colca JR, Kletzien RF, Burgess SC, Finck BN. Loss of Mitochondrial Pyruvate Carrier 2 in the Liver Leads to Defects in Gluconeogenesis and Compensation via Pyruvate-Alanine Cycling. Cell Metab 2015; 22:682-94. [PMID: 26344101 PMCID: PMC4598280 DOI: 10.1016/j.cmet.2015.07.028] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/29/2015] [Accepted: 07/30/2015] [Indexed: 01/04/2023]
Abstract
Pyruvate transport across the inner mitochondrial membrane is believed to be a prerequisite for gluconeogenesis in hepatocytes, which is important for the maintenance of normoglycemia during prolonged food deprivation but also contributes to hyperglycemia in diabetes. To determine the requirement for mitochondrial pyruvate import in gluconeogenesis, mice with liver-specific deletion of mitochondrial pyruvate carrier 2 (LS-Mpc2(-/-)) were generated. Loss of MPC2 impaired, but did not completely abolish, hepatocyte conversion of labeled pyruvate to TCA cycle intermediates and glucose. Unbiased metabolomic analyses of livers from fasted LS-Mpc2(-/-) mice suggested that alterations in amino acid metabolism, including pyruvate-alanine cycling, might compensate for the loss of MPC2. Indeed, inhibition of pyruvate-alanine transamination further reduced mitochondrial pyruvate metabolism and glucose production by LS-Mpc2(-/-) hepatocytes. These data demonstrate an important role for MPC2 in controlling hepatic gluconeogenesis and illuminate a compensatory mechanism for circumventing a block in mitochondrial pyruvate import.
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Affiliation(s)
- Kyle S McCommis
- Division of Geriatrics and Nutritional Sciences, Center for Human Nutrition, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhouji Chen
- Division of Geriatrics and Nutritional Sciences, Center for Human Nutrition, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xiaorong Fu
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | | | - Jerry R Colca
- Metabolic Solutions Development Company, Kalamazoo, MI 49007, USA
| | - Rolf F Kletzien
- Metabolic Solutions Development Company, Kalamazoo, MI 49007, USA
| | - Shawn C Burgess
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Brian N Finck
- Division of Geriatrics and Nutritional Sciences, Center for Human Nutrition, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Chen Z, Vigueira PA, Chambers KT, Hall AM, Mitra MS, Qi N, McDonald WG, Colca JR, Kletzien RF, Finck BN. Insulin resistance and metabolic derangements in obese mice are ameliorated by a novel peroxisome proliferator-activated receptor γ-sparing thiazolidinedione. J Biol Chem 2012; 287:23537-48. [PMID: 22621923 PMCID: PMC3390629 DOI: 10.1074/jbc.m112.363960] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/22/2012] [Indexed: 11/06/2022] Open
Abstract
Currently approved thiazolidinediones (TZDs) are effective insulin-sensitizing drugs that may have efficacy for treatment of a variety of metabolic and inflammatory diseases, but their use is limited by side effects that are mediated through ectopic activation of the peroxisome proliferator-activated receptor γ (PPARγ). Emerging evidence suggests that the potent anti-diabetic efficacy of TZDs can be separated from the ability to serve as ligands for PPARγ. A novel TZD analog (MSDC-0602) with very low affinity for binding and activation of PPARγ was evaluated for its effects on insulin resistance in obese mice. MSDC-0602 treatment markedly improved several measures of multiorgan insulin sensitivity, adipose tissue inflammation, and hepatic metabolic derangements, including suppressing hepatic lipogenesis and gluconeogenesis. These beneficial effects were mediated at least in part via direct actions on hepatocytes and were preserved in hepatocytes from liver-specific PPARγ(-/-) mice, indicating that PPARγ was not required to suppress these pathways. In conclusion, the beneficial pharmacology exhibited by MSDC-0602 on insulin sensitivity suggests that PPARγ-sparing TZDs are effective for treatment of type 2 diabetes with reduced risk of PPARγ-mediated side effects.
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Affiliation(s)
- Zhouji Chen
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Patrick A. Vigueira
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Kari T. Chambers
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Angela M. Hall
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Mayurranjan S. Mitra
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Nathan Qi
- the Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, and
| | | | - Jerry R. Colca
- Metabolic Solutions Development Company, Kalamazoo, Michigan 49007
| | - Rolf F. Kletzien
- Metabolic Solutions Development Company, Kalamazoo, Michigan 49007
| | - Brian N. Finck
- From the Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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Geisler SA, Felisberto-Junior AM, Tavoni TM, Carrara MA, Curi R, Bazotte RB. Participation of the liver gluconeogenesis in the glibenclamide-induced hypoglycaemia in rats. Cell Biochem Funct 2011; 29:81-6. [DOI: 10.1002/cbf.1722] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 12/11/2010] [Accepted: 12/13/2010] [Indexed: 11/09/2022]
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Derlacz RA, Hyc K, Usarek M, Jagielski AK, Drozak J, Jarzyna R. PPAR-gamma-independent inhibitory effect of rosiglitazone on glucose synthesis in primary cultured rabbit kidney-cortex tubules. Biochem Cell Biol 2008; 86:396-404. [PMID: 18923541 DOI: 10.1139/o08-105] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Therapeutic effect of rosiglitazone has been reported to result from an improvement of insulin sensitivity and inhibition of glucose synthesis. As the latter process occurs in both liver and kidney cortex the aim of this study was to elucidate the rosiglitazone action on glucose formation in both tissues. Primary cultured cells of both liver and kidney cortex grown in defined medium were use throughout. To identify the mechanism responsible for drug-induced changes, intracellular gluconeogenic intermediates and enzyme activities were determined. In contrast to hepatocytes, the administration of a 10 micromol/L concentration of rosiglitazone to renal tubules resulted in about a 70% decrease in the rate of gluconeogenesis, accompanied by an approximately 75% decrease in alanine utilization and a 35% increase in lactate synthesis. The effect of rosiglitazone was not abolished by GW9662, the PPAR-gamma irreversible antagonist, indicating that this action is not dependent on PPAR-gamma activation. In view of rosiglitazone-induced changes in gluconeogenic intermediates and a diminished incorporation of 14CO2 into pyruvate, it is likely that the drug causes a decline in flux through pyruvate carboxylase and (or) phosphoenolpyruvate carboxykinase. It is likely that the hypoglycemic action of rosiglitazone is PPAR-gamma independent and results mainly from its inhibitory effects on renal gluconeogenesis.
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Affiliation(s)
- Rafal A Derlacz
- Department of Metabolic Regulation, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02-096, Poland.
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Gastaldelli A, Miyazaki Y, Mahankali A, Berria R, Pettiti M, Buzzigoli E, Ferrannini E, DeFronzo RA. The effect of pioglitazone on the liver: role of adiponectin. Diabetes Care 2006; 29:2275-81. [PMID: 17003306 DOI: 10.2337/dc05-2445] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Diabetic hyperglycemia results from insulin resistance of peripheral tissues and glucose overproduction due to increased gluconeogenesis (GNG). Thiazolidinediones (TZDs) improve peripheral insulin sensitivity, but the effect on the liver is less clear. The goal of this study was to examine the effect of TZDs on GNG. RESEARCH DESIGN AND METHODS Twenty sulfonylurea-treated type 2 diabetic subjects were randomly assigned (double-blind study) to receive pioglitazone (PIO group; 45 mg/day) or placebo (Plc group) for 4 months to assess endogenous glucose production (EGP) (3-(3)H-glucose infusion), GNG (D2O technique), and insulin sensitivity by two-step hyperinsulinemic-euglycemic clamp (240 and 960 pmol/min per m2). RESULTS Fasting plasma glucose (FPG) (10.0 +/- 0.8 to 7.7 +/- 0.7 mmol/l) and HbA1c (9.0 +/- 0.4 to 7.3 +/- 0.6%) decreased in the PIO and increased in Plc group (P < 0.05 PIO vs. Plc). Insulin sensitivity increased approximately 40% during high insulin clamp after pioglitazone (P < 0.01) and remained unchanged in the Plc group (P < 0.05 PIO vs. Plc). EGP did not change, while GNG decreased in the PIO group (9.6 +/- 0.7 to 8.7 +/- 0.6 micromol x min(-1) x kg(ffm)(-1)) and increased in the Plc group (8.0 +/- 0.5 to 9.6 +/- 0.8) (P < 0.05 PIO vs. Plc). Change in FPG correlated with change in GNG flux (r = 0.63, P < 0.003) and in insulin sensitivity (r = 0.59, P < 0.01). Plasma adiponectin increased after pioglitazone (P < 0.001) and correlated with delta FPG (r = -0.54, P < 0.03), delta GNG flux (r = -0.47, P < 0.05), and delta insulin sensitivity (r = 0.65, P < 0.005). Plasma free fatty acids decreased after pioglitazone and correlated with delta GNG flux (r = 0.54, P < 0.02). From stepwise regression analysis, the strongest determinant of change in FPG was change in GNG flux. CONCLUSIONS Pioglitazone improves FPG, primarily by reducing GNG flux in type 2 diabetic subjects.
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Affiliation(s)
- Amalia Gastaldelli
- Stable Isotope Lab, Institute of Clinical Physiology-CNR, via Moruzzi 1, 56100 Pisa, Italy.
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Bavirti S, Tayek JA. Low-dose oral glyburide reduces glucose production rates in patients with impaired fasting glucose. Metabolism 2003; 52:407-12. [PMID: 12701050 DOI: 10.1053/meta.2003.50068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Impaired fasting glucose (IFG) is commonly seen in the US population. Approximately 20% of patients with IFG can progress to develop type 2 diabetes mellitus (DM-2) within 1 year. In the recent diabetes prevention study, lifestyle changes reduced the progression to only 8% per year, and metformin reduced the progression from IFG to DM-2 from 20% to 11% per year. Sulfonylurea therapy in DM-2 increases beta-cell function and fails to accelerate the 4% loss in function observed per year. Low-dose sulfonylurea therapy for IFG may be an effective treatment to delay the onset of type 2 diabetes if the treatment does not cause hypoglycemia. A very low dose of glyburide (20 microg/kg body weight) was given orally to 15 nondiabetic volunteers in an attempt to describe its effects on glucose production rates (GPR), blood glucose concentrations, and conterregulatory hormone profile. Six of the volunteers had IFG (mean +/- SEM, 115 +/- 1.8 mg/dL), and 9 had a normal fasting glucose (NFG) (94 +/- 2.3 mg/dL). Fasting blood glucose (FBG) decreased more in IFG after glyburide when compared with the NFG group (29% +/- 2.4% v 17% +/- 3.5%, P <.05). Patients with IFG had a larger insulin response to glyburide than those with NFG (17.7 +/-3 v 10.7 +/- 2.9 microU/mL; P <.05). The IFG patients also had a greater decrease in GPR (19% +/- 4%) than seen with the normals (12% +/- 3%, P <.05). The steeper decrease in GPR may have been due to a greater insulin response to oral glyburide in those with IFG. Low-dose glyburide increases insulin's effect on the liver.
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Affiliation(s)
- Surekha Bavirti
- Department of Internal Medicine, Harbor-UCLA Medical Center, Torrance, USA
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Abstract
Type 2 diabetes is characterized by two fundamental biological defects: a reduced glucose-dependent insulin secretion and an increased resistance to the action of insulin at the level of various target tissues. While the use of agents to improve the insulin secretory activity of the islets of Langerhans has witnessed the flourishing of several new drugs over the years, a much greater difficulty has been experienced in the search for insulin-sensitizing drugs. The aim of this article is to critically review this topic, and to emphasize the importance of providing alternative strategies for the management of Type 2 diabetes.
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Affiliation(s)
- R Perfetti
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
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13
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Raman P, Judd RL. Role of glucose and insulin in thiazolidinedione-induced alterations in hepatic gluconeogenesis. Eur J Pharmacol 2000; 409:19-29. [PMID: 11099696 DOI: 10.1016/s0014-2999(00)00806-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Previous studies from our laboratory as well as from others have suggested that the thiazolidinediones have the capacity to act as insulinomimetic agents, especially in the liver. In order to further characterize this insulinomimetic action, we evaluated the effect of troglitazone, a representative thiazolidinedione, on lactate- and glucagon-stimulated gluconeogenesis, in the presence or absence of insulin (10 nM) in isolated rat hepatocytes. The antigluconeogenic effect of troglitazone under basal (lactate-stimulated) conditions was found to be due to an elevation in the fructose 2,6-bisphosphate content, which was, however, not mediated by an activation of 6-phosphofructo 2-kinase. Troglitazone (125 and 250 microM) in the absence of insulin, produced a dose-dependent reduction in glucagon-stimulated gluconeogenesis, thereby suggesting an insulinomimetic effect. In addition, troglitazone (125 and 250 microM), in combination with insulin, produced an additive inhibition of gluconeogenesis during glucagon-stimulated conditions. However, unlike insulin, the metabolic mechanism responsible for these effects (in the presence or absence of insulin) does not involve fructose 2,6-bisphosphate.
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Affiliation(s)
- P Raman
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, AL 36849-5518, USA
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14
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Chapter 19. Recent advances in therapeutic approaches to type 2 diabetes. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2000. [DOI: 10.1016/s0065-7743(00)35020-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Abstract
Thiazolidinediones (TZDs) are a new class of oral antidiabetic agents. They selectively enhance or partially mimic certain actions of insulin, causing a slowly generated antihyperglycaemic effect in Type 2 (noninsulin dependent) diabetic patients. This is often accompanied by a reduction in circulating concentrations of insulin, triglycerides and nonesterified fatty acids. TZDs act additively with other types of oral antidiabetic agents (suphonylureas, metformin and acarbose) and reduce the insulin dosage required in insulin-treated patients. The glucose-lowering effect of TZDs is attributed to increased peripheral glucose disposal and decreased hepatic glucose output. This is achieved substantively by the activation of a specific nuclear receptor - the peroxisome proliferator-activated receptor-gamma (PPARgamma), which increases transcription of certain insulin-sensitive genes. To date one TZD, troglitazone, has been introduced into clinical use (in Japan, USA and UK in 1997). This was suspended after 2 months in the UK pending further investigation of adverse effects on liver function. TZDs have been shown to improve insulin sensitivity in a range of insulin-resistant states including obesity, impaired glucose tolerance (IGT) and polycystic ovary syndrome (PCOS). In Type 2 diabetes, the TZDs offer a new type of oral therapy to reduce insulin resistance and assist glycaemic control.
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Affiliation(s)
- C Day
- Diabetes Research Group, Life and Health Sciences, Aston University, Birmingham, UK
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