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Lin YF, Shen WD. Pancreatic signal pathways potentially used as targets for treatment of diabetes. Shijie Huaren Xiaohua Zazhi 2014; 22:3600-3607. [DOI: 10.11569/wcjd.v22.i24.3600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The pancreas is the main place where pathological changes of diabetes occur, and inflammation and oxidative stress can interfere with various cell signaling pathways, causing pancreatic lesions and diabetes. Therefore, the pancreas is an important target for the treatment of diabetes. This paper will discuss pancreatic signaling pathways potentially used as targets for the treatment of diabetes in terms of promotion of insulin secretion, inhibition of glucagon secretion, and suppression of islet beta cell apoptosis. The research of these signaling pathways is important for elucidating the pathogenesis of diabetes and developing more safe and effective new drugs. ATP sensitive potassium channel and glucagon like peptide-1 (GLP-1) receptor signaling pathways are associated with insulin secretion and have been widely used as therapeutic targets. The signaling pathway mediated by G protein coupled receptors is a hot spot of diabetes research in recent years, and other signaling pathways are being studied.
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Ito R, Tsujihata Y, Matsuda-Nagasumi K, Mori I, Negoro N, Takeuchi K. TAK-875, a GPR40/FFAR1 agonist, in combination with metformin prevents progression of diabetes and β-cell dysfunction in Zucker diabetic fatty rats. Br J Pharmacol 2014; 170:568-80. [PMID: 23848179 DOI: 10.1111/bph.12297] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 06/20/2013] [Accepted: 07/03/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE TAK-875, a selective GPCR40/free fatty acid receptor 1 agonist, improves glycaemic control by increasing glucose-dependent insulin secretion. Metformin is a first-line drug for treatment of type 2 diabetes that improves peripheral insulin resistance. Based on complementary mechanism of action, combining these agents is expected to enhance glycaemic control. Here, we evaluated the chronic effects of TAK-875 monotherapy and combination therapy with metformin in diabetic rats. EXPERIMENTAL APPROACH Long-term effects on glycaemic control and β-cell function were evaluated using Zucker diabetic fatty (ZDF) rats, which develop diabetes with hyperlipidaemia and progressive β-cell dysfunction. KEY RESULTS Single doses of TAK-875 (3-10 mg·kg(-1) ) and metformin (50-150 mg·kg(-1) ) significantly improved both postprandial and fasting hyperglycaemia, and additive improvements were observed in their combination. Six-week treatment with TAK-875 (10 mg·kg(-1) , b.i.d.) significantly decreased glycosylated Hb (GHb) by 1.7%, and the effect was additively enhanced by combination with metformin (50 mg·kg(-1) , q.d.; GHb: -2.4%). This improvement in glycaemic control in the combination group was accompanied by significant 3.2-fold increase in fasting plasma insulin levels. Pancreatic insulin content was maintained at a level comparable to that in normal rats by combination treatment (vehicle: 26, combination: 67.1; normal lean: 69.1 ng·mg(-1) pancreas) without affecting pancreatic glucagon content. Immunohistochemical analyses revealed normal morphology, enhanced pancreas duodenum homeobox-1 expression and increased PCNA-positive cells in islets of the combination group. CONCLUSION AND IMPLICATIONS Our results indicate that combination therapy with TAK-875 and metformin could be a valuable strategy for glycaemic control and β-cell preservation in type 2 diabetes.
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Affiliation(s)
- R Ito
- Cardiovascular and Metabolic Drug Discovery Unit, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
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Dranse HJ, Kelly MEM, Hudson BD. Drugs or diet?--Developing novel therapeutic strategies targeting the free fatty acid family of GPCRs. Br J Pharmacol 2014; 170:696-711. [PMID: 23937426 DOI: 10.1111/bph.12327] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 02/07/2023] Open
Abstract
Free fatty acids (FFAs) are metabolic intermediates that may be obtained through the diet, synthesized endogenously, or produced via fermentation of carbohydrates by gut microbiota. In addition to serving as an important source of energy, FFAs are known to produce a variety of both beneficial and detrimental effects on metabolic and inflammatory processes. While historically, FFAs were believed to produce these effects only through intracellular targets such as peroxisome proliferator-activated receptors, it has now become clear that FFAs are also agonists for several GPCRs, including a family of four receptors now termed FFA1-4. Increasing evidence suggests that FFA1-4 mediate many of the beneficial properties of FFAs and not surprisingly, this has generated significant interest in the potential of these receptors as therapeutic targets for the treatment of a variety of metabolic and inflammatory disorders. In addition to the traditional strategy of developing small-molecule therapeutics targeting these receptors, there has also been some consideration given to alternate therapeutic approaches, specifically by manipulating endogenous FFA concentrations through alteration of either dietary intake, or production by gut microbiota. In this review, the current state of knowledge for FFA1-4 will be discussed, together with their potential as therapeutic targets in the treatment of metabolic and inflammatory disorders. In particular, the evidence in support of small molecule versus dietary and microbiota-based therapeutic approaches will be considered to provide insight into the development of novel multifaceted strategies targeting the FFA receptors for the treatment of metabolic and inflammatory disorders.
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Affiliation(s)
- H J Dranse
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
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McKillop AM, Moran BM, Abdel-Wahab YHA, Flatt PR. Evaluation of the insulin releasing and antihyperglycaemic activities of GPR55 lipid agonists using clonal beta-cells, isolated pancreatic islets and mice. Br J Pharmacol 2014; 170:978-90. [PMID: 23992544 DOI: 10.1111/bph.12356] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND AND PURPOSE G-protein coupled receptor (GPR)55 is a novel lipid sensing receptor activated by both cannabinoid endogenous ligands (endocannabinoids) and other non-cannabinoid lipid transmitters. This study assessed the effects of various GPR55 agonists on glucose homeostasis. EXPERIMENTAL APPROACH Insulin secretion and changes in intracellular Ca(2) (+) and cAMP in response to glucose and a range of GPR55 agonists [endogenous ligands (OEA, PEA), chemically synthetic cannabidiol (CBD) analogues (Abn-CBD, 0-1602), an analogue of rimonabant (AM-251) and antagonist (CBD)] were investigated in clonal BRIN-BD11 cells and mouse pancreatic islets. Cytotoxicity was assessed by LDH release, cellular localization by double-staining immunohistochemistry and in vivo effects assessed in mice. KEY RESULTS The most potent and selective GPR55 agonist was the synthetic CBD analogue, Abn-CBD (pEC50 10.33), maximum stimulation of 67% at 10(-4) mol·L(-1) (P < 0.001) in BRIN-BD11 cells. AM-251 (pEC50 7.0), OEA (pEC50 7.0), 0-1602 (pEC50 7.3) and PEA (pEC50 6.0) stimulated insulin secretion. Results were corroborated by islet studies, with no cytotoxic effects. Concentration-dependent insulin secretion by GPR55 agonists was glucose-sensitive and accompanied by elevations of [Ca(2) (+) ]i (P < 0.01-P < 0.001) and cAMP (P < 0.05-P < 0.01). GPR55 agonists exhibited insulinotropic and glucose lowering activity in vivo. GPR55 was expressed on BRIN-BD11 cells and confined to islet beta cells with no distribution on alpha cells. CONCLUSION AND IMPLICATIONS These results demonstrate GPR55 is distributed in pancreatic beta cells and is a strong activator of insulin secretion, with glucose-lowering effects in vivo. Development of agents agonizing the GPR55 receptor may have therapeutic potential in the treatment of type 2 diabetes.
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Affiliation(s)
- A M McKillop
- Biomedical Sciences Research Institute, SAAD Centre for Pharmacy & Diabetes, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Northern Ireland
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Tsujihata Y. [Discovery and development of a selective GPR40/FFAR1 agonist, fasiglifam, for treatment of type 2 diabetes mellitus]. Nihon Yakurigaku Zasshi 2014; 144:59-63. [PMID: 25109517 DOI: 10.1254/fpj.144.59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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Potentiation of insulin secretion and improvement of glucose intolerance by combining a novel G protein-coupled receptor 40 agonist DS-1558 with glucagon-like peptide-1 receptor agonists. Eur J Pharmacol 2014; 737:194-201. [PMID: 24858371 DOI: 10.1016/j.ejphar.2014.05.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/14/2014] [Accepted: 05/14/2014] [Indexed: 11/21/2022]
Abstract
G protein-coupled receptor 40 (GPR40) is a Gq-coupled receptor for free fatty acids predominantly expressed in pancreatic β-cells. In recent years, GPR40 agonists have been investigated for use as novel therapeutic agents in the treatment of type 2 diabetes. We discovered a novel small molecule GPR40 agonist, (3S)-3-ethoxy-3-(4-{[(1R)-4-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl]oxy}phenyl)propanoic acid (DS-1558). The GPR40-mediated effects of DS-1558 on glucose-stimulated insulin secretion were evaluated in isolated islets from GPR40 knock-out and wild-type (littermate) mice. The GPR40-mediated effects on glucose tolerance and insulin secretion were also confirmed by an oral glucose tolerance test in these mice. Furthermore, oral administration of DS-1558 (0.03, 0.1 and 0.3mg/kg) significantly and dose-dependently improved hyperglycemia and increased insulin secretion during the oral glucose tolerance test in Zucker fatty rats, the model of insulin resistance and glucose intolerance. Next, we examined the combination effects of DS-1558 with glucagon like peptide-1 (GLP-1). DS-1558 not only increased the glucose-stimulated insulin secretion by GLP-1 but also potentiated the maximum insulinogenic effects of GLP-1 after an intravenous glucose injection in normal Sprague Dawley rats. Furthermore, the glucose lowering effects of exendin-4, a GLP-1 receptor agonist, were markedly potentiated by the DS-1558 (3mg/kg) add-on in diabetic db/db mice during an intraperitoneal glucose tolerance test. In conclusion, our results indicate that add-on GPR40 agonists to GLP-1 related agents might be a potential treatment compared to single administration of these compounds. Therefore the combinations of these agents are a novel therapeutic option for type 2 diabetes.
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Defossa E, Wagner M. Recent developments in the discovery of FFA1 receptor agonists as novel oral treatment for type 2 diabetes mellitus. Bioorg Med Chem Lett 2014; 24:2991-3000. [PMID: 24881568 DOI: 10.1016/j.bmcl.2014.05.019] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/30/2014] [Accepted: 05/05/2014] [Indexed: 12/12/2022]
Abstract
Despite the availability of established medication for treatment of type 2 diabetes mellitus (T2DM) there still remains a significant unmet need for new effective, oral antidiabetic agents that improve glycemic control while maintaining an excellent safety profile. In this regard the FFA1 receptor has emerged as an attractive target in recent years. Activation of the FFA1 receptor has been shown to not only amplify glucose induced insulin secretion from pancreatic beta cells but also to stimulate incretin secretion from intestinal endocrine cells. The current review highlights on the latest developments and clinical data from evolving research on the potential of FFA1 agonists as effective treatment for T2DM.
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Affiliation(s)
- Elisabeth Defossa
- Lead Generation to Candidate Realization, Sanofi Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt, Germany.
| | - Michael Wagner
- Diabetes Division, Sanofi Deutschland GmbH, Industriepark Hoechst, 65926 Frankfurt, Germany.
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Shen X, Yang L, Yan S, Wei W, Liang L, Zheng H, Cai X. The effect of FFAR1 on pioglitazone-mediated attenuation of palmitic acid-induced oxidative stress and apoptosis in βTC6 cells. Metabolism 2014; 63:335-51. [PMID: 24360748 DOI: 10.1016/j.metabol.2013.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/24/2013] [Accepted: 11/04/2013] [Indexed: 01/27/2023]
Abstract
OBJECTIVE We sought to determine whether free fatty acid receptor 1 (FFAR1), a receptor for free fatty acids on the β-cell membrane, can mediate the pioglitazone (PIO)-attenuating effect on lipoapoptosis in β cells and its relationship to oxidative stress. METHODS The glucose-sensitive mouse beta pancreatic cell line βTC6 was used to investigate the effect of FFAR1 on PIO-attenuating palmitic acid (PA)-induced oxidative stress and apoptosis. RESULTS (1) PIO reduced PA-induced lipoapoptosis in β cells and upregulated the expression of FFAR1 at the mRNA and protein levels in a dose- and time-dependent manner. Silencing of FFAR1 expression was shown to weaken the protective effect of PIO on PA-induced lipoapoptosis in βTC6 cells; while lentiviral-mediated overexpression of FFAR1 was shown to enhance the protective effect of PIO against lipoapoptosis in β cells. (2) Downregulation of FFAR1 expression reduced the attenuating effect of PIO on the expression of NAPDH oxidase subunit p47(phox), Bax, cleaved caspase 3, and the production of reactive oxygen specific (ROS) induced by lipotoxicity, thereby preventing the upregulation of the expression of bcl-2. Inducing the overexpression of FFAR1 enhanced the anti-oxidative stress effect of PIO. Similarly, these effects of FFAR1 on PIO were reproduced under conditions of oxidative stress and apoptosis in βTC6 cells that were induced by H2O2. (3) PIO was found to increase the expression of PLCγ, ERK1/2, and PPARγ in lipotoxic β cells. Silencing FFAR1 expression reduced the PIO-mediated increases in the expression of above proteins; while inducing FFAR1 overexpression showed the opposite effect. Use of an inhibitor of PLCγ, ERK1/2, PPARγ was shown to restrict the protective effect of PIO on oxidative stress and lipoapoptosis of β cells. CONCLUSIONS FFAR1 can mediate PIO suppression of β-cell lipoapoptosis through anti-oxidative stress, which may be related to the activation of the PLCγ-ERK1/2-PPARγ pathway.
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Affiliation(s)
- Ximei Shen
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China; Department of Endocrinology, The First Clinical Medical College of Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Liyong Yang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China.
| | - Sunjie Yan
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Wenfeng Wei
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Liyu Liang
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Huanhuan Zheng
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
| | - Xiuhui Cai
- Endocrinology Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian, China
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59
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Watterson KR, Hudson BD, Ulven T, Milligan G. Treatment of type 2 diabetes by free Fatty Acid receptor agonists. Front Endocrinol (Lausanne) 2014; 5:137. [PMID: 25221541 PMCID: PMC4147718 DOI: 10.3389/fendo.2014.00137] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/07/2014] [Indexed: 12/11/2022] Open
Abstract
Dietary free fatty acids (FFAs), such as ω-3 fatty acids, regulate metabolic and anti-inflammatory processes, with many of these effects attributed to FFAs interacting with a family of G protein-coupled receptors. Selective synthetic ligands for free fatty acid receptors (FFA1-4) have consequently been developed as potential treatments for type 2 diabetes (T2D). In particular, clinical studies show that Fasiglifam, an agonist of the long-chain FFA receptor, FFA1, improved glycemic control and reduced HbA1c levels in T2D patients, with a reduced risk of hypoglycemia. However, this ligand was removed from clinical trials due to potential liver toxicity and determining if this is a target or a ligand-specific feature is now of major importance. Pre-clinical studies also show that FFA4 agonism increases insulin sensitivity, induces weight loss, and reduces inflammation and the metabolic and anti-inflammatory effects of short chain fatty acids (SCFAs) are linked with FFA2 and FFA3 activation. In this review, we therefore show that FFA receptor agonism is a potential clinical target for T2D treatment and discuss ongoing drug development programs within industry and academia aimed at improving the safety and effectiveness of these potential treatments.
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Affiliation(s)
- Kenneth R. Watterson
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Brian D. Hudson
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Trond Ulven
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Graeme Milligan
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- *Correspondence: Graeme Milligan, Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK e-mail:
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60
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Huang H, Dai MH, Tao YX. Physiology and Therapeutics of the Free Fatty Acid Receptor GPR40. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 121:67-94. [DOI: 10.1016/b978-0-12-800101-1.00003-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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61
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Kaku K. Fasiglifam as a new potential treatment option for patients with type 2 diabetes. Expert Opin Pharmacother 2013; 14:2591-600. [DOI: 10.1517/14656566.2013.851668] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kristinsson H, Smith DM, Bergsten P, Sargsyan E. FFAR1 is involved in both the acute and chronic effects of palmitate on insulin secretion. Endocrinology 2013; 154:4078-88. [PMID: 24035997 DOI: 10.1210/en.2013-1352] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Free fatty acids (FFAs) have pleiotropic effects on the pancreatic β-cell. Although acute exposure to FFAs stimulates glucose-stimulated insulin secretion (GSIS), prolonged exposure impairs GSIS and causes apoptosis. FFAs exert their effects both via intracellular metabolism and interaction with the FFA receptor 1 (FFAR1/GPR40). Here we studied the role of FFAR1 in acute and long-term effects of palmitate on GSIS and insulin content in isolated human islets by using the FFAR1 agonist TAK-875 and the antagonist ANT203. Acute palmitate exposure potentiated GSIS approximately 3-fold, whereas addition of the antagonist decreased this potentiation to approximately 2-fold. In the absence of palmitate, the agonist caused a 40% increase in GSIS. Treatment with palmitate for 7 days decreased GSIS to 70% and insulin content to 25% of control level. These negative effects of long-term exposure to palmitate were ameliorated by FFAR1 inhibition and further aggravated by additional stimulation of the receptor. In the absence of extracellularly applied palmitate, long-term treatment with the agonist caused a modest increase in GSIS. The protective effect of FFAR1 inhibition was verified by using FFAR1-deficient MIN6 cells. Improved β-cell function by the antagonist was paralleled by the decreased apoptosis and lowered oxidation of palmitate, which may represent the potential mechanisms of protection. We conclude that FFAR1 in the pancreatic β-cell plays a substantial role not only in acute potentiation of GSIS by palmitate but also in the negative long-term effects of palmitate on GSIS and insulin content.
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Affiliation(s)
- Hjalti Kristinsson
- PhD, Department of Medical Cell Biology, Uppsala University, Box 571, SE-751 23 Uppsala, Sweden.
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63
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Yabuki C, Komatsu H, Tsujihata Y, Maeda R, Ito R, Matsuda-Nagasumi K, Sakuma K, Miyawaki K, Kikuchi N, Takeuchi K, Habata Y, Mori M. A novel antidiabetic drug, fasiglifam/TAK-875, acts as an ago-allosteric modulator of FFAR1. PLoS One 2013; 8:e76280. [PMID: 24130766 PMCID: PMC3794927 DOI: 10.1371/journal.pone.0076280] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/22/2013] [Indexed: 01/23/2023] Open
Abstract
Selective free fatty acid receptor 1 (FFAR1)/GPR40 agonist fasiglifam (TAK-875), an antidiabetic drug under phase 3 development, potentiates insulin secretion in a glucose-dependent manner by activating FFAR1 expressed in pancreatic β cells. Although fasiglifam significantly improved glycemic control in type 2 diabetes patients with a minimum risk of hypoglycemia in a phase 2 study, the precise mechanisms of its potent pharmacological effects are not fully understood. Here we demonstrate that fasiglifam acts as an ago-allosteric modulator with a partial agonistic activity for FFAR1. In both Ca2+ influx and insulin secretion assays using cell lines and mouse islets, fasiglifam showed positive cooperativity with the FFAR1 ligand γ-linolenic acid (γ-LA). Augmentation of glucose-induced insulin secretion by fasiglifam, γ-LA, or their combination was completely abolished in pancreatic islets of FFAR1-knockout mice. In diabetic rats, the insulinotropic effect of fasiglifam was suppressed by pharmacological reduction of plasma free fatty acid (FFA) levels using a lipolysis inhibitor, suggesting that fasiglifam potentiates insulin release in conjunction with plasma FFAs in vivo. Point mutations of FFAR1 differentially affected Ca2+ influx activities of fasiglifam and γ-LA, further indicating that these agonists may bind to distinct binding sites. Our results strongly suggest that fasiglifam is an ago-allosteric modulator of FFAR1 that exerts its effects by acting cooperatively with endogenous plasma FFAs in human patients as well as diabetic animals. These findings contribute to our understanding of fasiglifam as an attractive antidiabetic drug with a novel mechanism of action.
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Affiliation(s)
- Chiori Yabuki
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
- * E-mail:
| | - Hidetoshi Komatsu
- Central Nervous System Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Yoshiyuki Tsujihata
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Risa Maeda
- Central Nervous System Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Ryo Ito
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kae Matsuda-Nagasumi
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kensuke Sakuma
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kazumasa Miyawaki
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Naoya Kikuchi
- Central Nervous System Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Koji Takeuchi
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Yugo Habata
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Masaaki Mori
- Cardiovascular and Metabolic Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
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64
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Ezcurra M, Reimann F, Gribble FM, Emery E. Molecular mechanisms of incretin hormone secretion. Curr Opin Pharmacol 2013; 13:922-7. [PMID: 24035446 PMCID: PMC3838618 DOI: 10.1016/j.coph.2013.08.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/14/2013] [Accepted: 08/26/2013] [Indexed: 01/06/2023]
Abstract
Incretin peptides (glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)) are secreted from enteroendocrine cells in the intestinal epithelium, and help to coordinate metabolic responses to food ingestion. A number of molecular mechanisms have recently been defined that underlie carbohydrate, lipid and protein sensing in gut endocrine cells. Knockout mice lacking sodium glucose tranporter-1 (SGLT-1) or the short chain fatty acid sensing receptor FFAR2 (GPR43), for example, have highlighted the importance of these molecules in incretin secretion. This review outlines our current understanding of sensory pathways in incretin secreting cells and highlights the therapeutic potential of targeting them for the development of novel therapies for obesity and diabetes.
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Affiliation(s)
- Marina Ezcurra
- Cambridge Institute for Medical Research, Wellcome Trust, MRC Building, Addenbrooke's Hospital, Box 139, Hills Road, Cambridge CB2 0XY, UK
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65
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Song WJ, Mondal P, Li Y, Lee SE, Hussain MA. Pancreatic β-cell response to increased metabolic demand and to pharmacologic secretagogues requires EPAC2A. Diabetes 2013; 62:2796-807. [PMID: 23578994 PMCID: PMC3717830 DOI: 10.2337/db12-1394] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Incretin hormone action on β-cells stimulates in parallel two different intracellular cyclic AMP-dependent signaling branches mediated by protein kinase A and exchange protein activated by cAMP islet/brain isoform 2A (EPAC2A). Both pathways contribute toward potentiation of glucose-stimulated insulin secretion (GSIS). However, the overall functional role of EPAC2A in β-cells as it relates to in vivo glucose homeostasis remains incompletely understood. Therefore, we have examined in vivo GSIS in global EPAC2A knockout mice. Additionally, we have conducted in vitro studies of GSIS and calcium dynamics in isolated EPAC2A-deficient islets. EPAC2A deficiency does not impact GSIS in mice under basal conditions. However, when mice are exposed to diet-induced insulin resistance, pharmacologic secretagogue stimulation of β-cells with an incretin hormone glucagon-like peptide-1 analog or with a fatty acid receptor 1/G protein-coupled receptor 40 selective activator, EPAC2A is required for the increased β-cell response to secretory demand. Under these circumstances, EPAC2A is required for potentiating the early dynamic increase in islet calcium levels after glucose stimulation, which is reflected in potentiated first-phase insulin secretion. These studies broaden our understanding of EPAC2A function and highlight its significance during increased secretory demand or drive on β-cells. Our findings advance the rationale for developing EPAC2A-selective pharmacologic activators for β-cell-targeted pharmacotherapy in type 2 diabetes.
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Affiliation(s)
- Woo-Jin Song
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
| | - Prosenjit Mondal
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
| | - Yuanyuan Li
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
| | - Suh Eun Lee
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
| | - Mehboob A. Hussain
- Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, Maryland
- Corresponding author: Mehboob A. Hussain,
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Tanaka H, Yoshida S, Oshima H, Minoura H, Negoro K, Yamazaki T, Sakuda S, Iwasaki F, Matsui T, Shibasaki M. Chronic treatment with novel GPR40 agonists improve whole-body glucose metabolism based on the glucose-dependent insulin secretion. J Pharmacol Exp Ther 2013; 346:443-52. [PMID: 23853170 DOI: 10.1124/jpet.113.206466] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
GPR40 is a free fatty acid receptor that has been shown to regulate glucose-dependent insulin secretion. This study aimed to discover novel GPR40 agonists and investigate the whole-body effect on glucose metabolism of GPR40 activation using these novel GPR40 agonists. To identify novel GPR40-specific agonists, we conducted high-throughput chemical compound screening and evaluated glucose-dependent insulin secretion. To investigate the whole-body effect on glucose metabolism of GPR40 activation, we conducted repeat administration of the novel GPR40 agonists to diabetic model ob/ob mice and evaluated metabolic parameters. To characterize the effect of the novel GPR40 agonists more deeply, we conducted an insulin tolerance test and a euglycemic-hyperinsulinemic clamp test. As a result, we discovered the novel GPR40-specific agonists, including AS2034178 [bis{2-[(4-{[4'-(2-hydroxyethoxy)-2'-methyl[1,1'-biphenyl]-3-yl]methoxy}phenyl)methyl]-3,5-dioxo-1,2,4-oxadiazolidin-4-ide} tetrahydrate], and found that its exhibited glucose-dependent insulin secretion enhancement both in vitro and in vivo. In addition, the compounds also decreased plasma glucose and HbA1c levels after repeat administration to ob/ob mice, with favorable oral absorption and pharmacokinetics. Repeat administration of AS2034178 enhanced insulin sensitivity in an insulin tolerance test and a euglycemic-hyperinsulinemic clamp test. These results indicate that improvement of glucose-dependent insulin secretion leads the improvement of whole-body glucose metabolism chronically. In conclusion, AS2034178 and other GPR40 agonists may become useful therapeutics in the treatment of type 2 diabetes mellitus.
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Affiliation(s)
- Hirotsugu Tanaka
- Pharmacology Research Laboratories, Drug Discovery Research, Astellas Pharma Inc, Tsukuba, Japan.
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67
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Xiong Y, Swaminath G, Cao Q, Yang L, Guo Q, Salomonis H, Lu J, Houze JB, Dransfield PJ, Wang Y, Liu JJ, Wong S, Schwandner R, Steger F, Baribault H, Liu L, Coberly S, Miao L, Zhang J, Lin DCH, Schwarz M. Activation of FFA1 mediates GLP-1 secretion in mice. Evidence for allosterism at FFA1. Mol Cell Endocrinol 2013; 369:119-29. [PMID: 23403053 DOI: 10.1016/j.mce.2013.01.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 01/03/2013] [Accepted: 01/14/2013] [Indexed: 01/04/2023]
Abstract
FFA1 (GPR40) and GPR120 are G-protein-coupled receptors activated by long-chain fatty acids. FFA1 is expressed in pancreatic β-cells, where it regulates glucose-dependent insulin secretion, and GPR120 has been implicated in mediating GLP-1 secretion. We show here that FFA1 co-localizes with GLP-1 in enteroendocrine cells and plays a critical role in glucose management by mediating GLP-1 secretion in vivo. Corn oil induces GLP-1 secretion in wild type mice and in GPR120-/- mice, but not in FFA1-/- mice. α-Linolenic acid, an endogenous ligand of FFA1, induces GLP-1 secretion in GLUTag cells and in primary fetal mouse intestinal cells. Synthetic partial FFA1 agonists do not stimulate GLP-1 secretion in mice, but partial and full agonists combined function cooperatively to enhance receptor activation and GLP-1 secretion both in vitro and in vivo. We conclude that allosterism at FFA1 can contribute to postprandial glucose management by stimulating insulin secretion via an extrapancreatic mechanism of action, and that GPR120 in GLP-1 secretion requires further investigation.
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Affiliation(s)
- Yumei Xiong
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, CA 94080, USA
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Abstract
INTRODUCTION Many oral antidiabetic drugs (OADs) are available for patients with type 2 diabetes mellitus (T2DM). However, it is recognized that additional therapies are needed and several new compounds are in advanced stages of development. PURPOSE This narrative review considers the essential features of a successful OAD, the main classes of OADs that are currently used, and the therapies that may be available in the upcoming years. RESULTS AND CONCLUSIONS The first OADs (sulfonylureas and biguanides) were discovered by chance. Although effective in reducing blood glucose levels, early sulfonylureas were associated with significant off-target effects, and the biguanide phenformin was discontinued due to adverse events. Although metformin is in the same drug class, it has a better safety profile and is now recommended as first-line treatment, except when contraindicated. Nonetheless, many patients require additional glucose control (even on metformin) with an agent that has a complementary mechanism of action. Developments in bench science have facilitated the selection of agents for specific therapeutic targets, with the thiazolidinediones providing an interesting example. This OAD class initially appeared encouraging, yet in clinical practice was associated with safety concerns. As a result, newer agents, such as dipeptidyl peptidase-4 inhibitors, are undergoing more rigorous safety evaluations than OADs of previous generations. Promising compounds with novel mechanisms of action include the sodium-glucose co-transporter 2 inhibitors, the G-protein-coupled receptor agonists, and the balanced dual peroxisome proliferator-activated receptor-α/γ agonists. There is optimism that in the next few years, novel classes of OADs that are currently under development will offer additional blood glucose control options via complementary mechanisms of action. However, history has shown that compounds of the same class can have different safety profiles and treatment effects. Therefore, high-quality clinical trial evidence is needed for every compound.
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Affiliation(s)
- Robert M Guthrie
- Emergency Medicine, Ohio State University, 6408 Phoenix Park Dr., Dublin, OH 43016, USA.
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Ou HY, Wu HT, Hung HC, Yang YC, Wu JS, Chang CJ. Multiple mechanisms of GW-9508, a selective G protein-coupled receptor 40 agonist, in the regulation of glucose homeostasis and insulin sensitivity. Am J Physiol Endocrinol Metab 2013; 304:E668-76. [PMID: 23341496 DOI: 10.1152/ajpendo.00419.2012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Activation of G protein-coupled receptor 40 (GPR40) by agonists increases insulin release in isolated islets, whereas it is inconclusive whether GPR40 antagonists decrease blood glucose and increase insulin sensitivity. Although some clinical trials indicated that administration of a GPR40 agonist shows benefits in the regulation of blood glucose homeostasis, the pharmacological mechanisms of this receptor in the improvement of glycemic control remain unclear. Therefore, we used a selective GPR40 agonist, GW-9508, to clarify the role of GPR40 in the regulation of blood glucose. Bolus intraperitoneal injection of GW-9508 in mice showed a slight decrease in blood glucose, with an increase in plasma insulin levels under glucose stimuli. However, long-term treatment with low doses of GW-9508 in high-fat diet-induced (HFD) diabetic mice decreased blood glucose with decreased plasma insulin significantly and improved glucose intolerance and insulin resistance. Using small interfering ribonucleic acid to delete GPR40 in HepG2 cells, we demonstrated that GW-9508 reversed palmitate-induced insulin signaling impairment through a GPR40-dependent pathway. We also found that GW-9508 activates the Akt/GSK-3β pathway to increase glycogen levels in HepG2 cells. Furthermore, administration of GW-9508 decreased the hepatic expression of fetuin-A in HFD mice significantly and regulated high-glucose- or palmitate-induced fetuin-A expression to increase insulin sensitivity through a GPR40/PLC/PKC pathway in HepG2 cells. Taken together, GW-9508 exerts a partial agonist effect to regulate blood glucose through multiple mechanisms. Investigation of chemicals that act on GPR40 might be a new strategy for the treatment of diabetes.
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MESH Headings
- Animals
- Blood Glucose/analysis
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/etiology
- Diabetes Mellitus, Type 2/metabolism
- Diet, High-Fat/adverse effects
- Hep G2 Cells
- Humans
- Hyperglycemia/prevention & control
- Hypoglycemic Agents/administration & dosage
- Hypoglycemic Agents/therapeutic use
- Insulin/blood
- Insulin Resistance
- Liver/drug effects
- Liver/metabolism
- Liver Glycogen/metabolism
- Male
- Methylamines/administration & dosage
- Methylamines/therapeutic use
- Mice
- Mice, Inbred C57BL
- Propionates/administration & dosage
- Propionates/therapeutic use
- RNA Interference
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction/drug effects
- alpha-2-HS-Glycoprotein/metabolism
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Affiliation(s)
- Horng-Yih Ou
- Department of Internal Medicine, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan
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70
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Jain S, Ruiz de Azua I, Lu H, White MF, Guettier JM, Wess J. Chronic activation of a designer G(q)-coupled receptor improves β cell function. J Clin Invest 2013; 123:1750-62. [PMID: 23478411 DOI: 10.1172/jci66432] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 01/17/2013] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes (T2D) has emerged as a major threat to human health in most parts of the world. Therapeutic strategies aimed at improving pancreatic β cell function are predicted to prove beneficial for the treatment of T2D. In the present study, we demonstrate that drug-mediated, chronic, and selective activation of β cell G(q) signaling greatly improve β cell function and glucose homeostasis in mice. These beneficial metabolic effects were accompanied by the enhanced expression of many genes critical for β cell function, maintenance, and differentiation. By employing a combination of in vivo and in vitro approaches, we identified a novel β cell pathway through which receptor-activated G(q) leads to the sequential activation of ERK1/2 and IRS2 signaling, thus triggering a series of events that greatly improve β cell function. Importantly, we found that chronic stimulation of a designer G(q)-coupled receptor selectively expressed in β cells prevented both streptozotocin-induced diabetes and the metabolic deficits associated with the consumption of a high-fat diet in mice. Since β cells are endowed with numerous receptors that mediate their cellular effects via activation of G(q)-type G proteins, our findings provide a rational basis for the development of novel antidiabetic drugs targeting this class of receptors.
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Affiliation(s)
- Shalini Jain
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
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71
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Affiliation(s)
- Ananda Basu
- Endocrine Research Unit, Division of Endocrinology and Metabolism, Mayo College of Medicine, Rochester, MN, USA.
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Kaku K, Araki T, Yoshinaka R. Randomized, double-blind, dose-ranging study of TAK-875, a novel GPR40 agonist, in Japanese patients with inadequately controlled type 2 diabetes. Diabetes Care 2013; 36:245-50. [PMID: 23086138 PMCID: PMC3554318 DOI: 10.2337/dc12-0872] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Assessment of the efficacy and safety of TAK-875 (a novel GPR40 agonist) in Japanese patients with type 2 diabetes inadequately controlled by diet/exercise. RESEARCH DESIGN AND METHODS This was a phase II, multicenter, randomized, double-blind, parallel-group, placebo-controlled, 12-week dose-ranging evaluation of TAK-875 (6.25-200 mg once daily) with the primary end point of change in A1C at week 12. A nonblinded group received 1 mg glimepiride once daily as an active control. RESULTS A total of 396 patients were randomized to receive TAK-875 (n = 299), placebo (n = 48), or glimepiride (n = 49). The least square mean changes in A1C at week 12 from baseline were as follows: 0.09% in the placebo group; -0.54, -0.67, -0.88, -1.27, -1.29, and -1.40% in the 6.25-, 12.5-, 25-, 50-, 100-, and 200-mg TAK-875 groups, respectively; and -1.32% in the 1-mg glimepiride group. All TAK-875 groups had statistically significant reductions in A1C compared with placebo (P < 0.0001), and those receiving ≥50 mg TAK-875 achieved reductions in A1C equivalent to those with glimepiride. Results for other glycemic parameters, including improvements during a meal tolerance test, mirrored these positive findings with TAK-875. There were no significant differences in incidence of adverse events among the groups and no dose-dependent changes in tolerability. Hypoglycemic episodes were reported in 0.7% of patients in the TAK-875 groups and in 4.1% of the glimepiride group. CONCLUSIONS TAK-875 produced clinically and statistically significant improvements in glycemic control in patients with type 2 diabetes inadequately controlled by diet and exercise, and it was well tolerated with a lower propensity to cause hypoglycemia.
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Affiliation(s)
- Kohei Kaku
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, Okayama, Japan.
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73
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Wauquier F, Philippe C, Léotoing L, Mercier S, Davicco MJ, Lebecque P, Guicheux J, Pilet P, Miot-Noirault E, Poitout V, Alquier T, Coxam V, Wittrant Y. The free fatty acid receptor G protein-coupled receptor 40 (GPR40) protects from bone loss through inhibition of osteoclast differentiation. J Biol Chem 2013; 288:6542-51. [PMID: 23335512 DOI: 10.1074/jbc.m112.429084] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mechanisms linking fat intake to bone loss remain unclear. By demonstrating the expression of the free fatty acid receptor G-coupled protein receptor 40 (GPR40) in bone cells, we hypothesized that this receptor may play a role in mediating the effects of fatty acids on bone remodeling. Using micro-CT analysis, we showed that GPR40(-/-) mice exhibit osteoporotic features suggesting a positive role of GPR40 on bone density. In primary cultures of bone marrow, we showed that GW9508, a GRP40 agonist, abolished bone-resorbing cell differentiation. This alteration of the receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation occurred via the inhibition of the nuclear factor κB (NF-κB) signaling pathway as demonstrated by decrease in gene reporter activity, inhibitor of κB kinase (IKKα/β) activation, inhibitor of κB (IkBα) phosphorylation, and nuclear factor of activated T cells 1 (NFATc1) expression. The GPR40-dependent effect of GW9508 was confirmed using shRNA interference in osteoclast precursors and GPR40(-/-) primary cell cultures. In addition, in vivo administration of GW9508 counteracted ovariectomy-induced bone loss in wild-type but not GPR40(-/-) mice, enlightening the obligatory role of the GPR40 receptor. Then, in a context of growing prevalence of metabolic and age-related bone disorders, our results demonstrate for the first time in translational approaches that GPR40 is a relevant target for the design of new nutritional and therapeutic strategies to counter bone complications.
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Affiliation(s)
- Fabien Wauquier
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1019, Unité de Nutrition Humaine, Centre de Recherche en Nutrition Humaine Auvergne, F-63009 Clermont-Ferrand, France
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Hara T, Kimura I, Inoue D, Ichimura A, Hirasawa A. Free Fatty Acid Receptors and Their Role in Regulation of Energy Metabolism. Rev Physiol Biochem Pharmacol 2013; 164:77-116. [DOI: 10.1007/112_2013_13] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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75
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Tonack S, Tang C, Offermanns S. Endogenous metabolites as ligands for G protein-coupled receptors modulating risk factors for metabolic and cardiovascular disease. Am J Physiol Heart Circ Physiol 2012; 304:H501-13. [PMID: 23241321 DOI: 10.1152/ajpheart.00641.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During the last decade, several G protein-coupled receptors activated by endogenous metabolites have been described. These receptors respond to fatty acids, mono- and disaccharides, amino acids, or various intermediates and products of metabolism, including ketone bodies, lactate, succinate, or bile acids. Receptors of endogenous metabolites are expressed in taste cells, the gastrointestinal tract, adipose tissue, endocrine glands, immune cells, or the kidney and are therefore in a position to sense food intake in the gastrointestinal tract or to link metabolite levels to the appropriate responses of metabolic organs. Some of the receptors appear to provide a link between metabolic and neuronal or immune functions. Given that many of these metabolic processes are dysregulated under pathological conditions, including diabetes, dyslipidemia, and obesity, receptors of endogenous metabolites have also been recognized as potential drug targets to prevent and/or treat metabolic and cardiovascular diseases. This review describes G protein-coupled receptors activated by endogenous metabolites and summarizes their physiological, pathophysiological, and potential pharmacological roles.
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Affiliation(s)
- Sarah Tonack
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
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76
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Cuny T, Guerci B, Cariou B. New avenues for the pharmacological management of type 2 diabetes: An update. ANNALES D'ENDOCRINOLOGIE 2012; 73:459-68. [DOI: 10.1016/j.ando.2012.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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77
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Luo J, Swaminath G, Brown SP, Zhang J, Guo Q, Chen M, Nguyen K, Tran T, Miao L, Dransfield PJ, Vimolratana M, Houze JB, Wong S, Toteva M, Shan B, Li F, Zhuang R, Lin DCH. A potent class of GPR40 full agonists engages the enteroinsular axis to promote glucose control in rodents. PLoS One 2012; 7:e46300. [PMID: 23056280 PMCID: PMC3467217 DOI: 10.1371/journal.pone.0046300] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 08/29/2012] [Indexed: 12/20/2022] Open
Abstract
Type 2 diabetes is characterized by impaired glucose homeostasis due to defects in insulin secretion, insulin resistance and the incretin response. GPR40 (FFAR1 or FFA1) is a G-protein-coupled receptor (GPCR), primarily expressed in insulin-producing pancreatic β-cells and incretin-producing enteroendocrine cells of the small intestine. Several GPR40 agonists, including AMG 837 and TAK-875, have been disclosed, but no GPR40 synthetic agonists have been reported that engage both the insulinogenic and incretinogenic axes. In this report we provide a molecular explanation and describe the discovery of a unique and potent class of GPR40 full agonists that engages the enteroinsular axis to promote dramatic improvement in glucose control in rodents. GPR40 full agonists AM-1638 and AM-6226 stimulate GLP-1 and GIP secretion from intestinal enteroendocrine cells and increase GSIS from pancreatic islets, leading to enhanced glucose control in the high fat fed, streptozotocin treated and NONcNZO10/LtJ mouse models of type 2 diabetes. The improvement in hyperglycemia by AM-1638 was reduced in the presence of the GLP-1 receptor antagonist Ex(9–39)NH2.
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Affiliation(s)
- Jian Luo
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Gayathri Swaminath
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Sean P. Brown
- Department of Therapeutic Discovery, Amgen Inc., South San Francisco, California, United States of America
| | - Jane Zhang
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Qi Guo
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Michael Chen
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Kathy Nguyen
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Thanhvien Tran
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Lynn Miao
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Paul J. Dransfield
- Department of Therapeutic Discovery, Amgen Inc., South San Francisco, California, United States of America
| | - Marc Vimolratana
- Department of Therapeutic Discovery, Amgen Inc., South San Francisco, California, United States of America
| | - Jonathan B. Houze
- Department of Therapeutic Discovery, Amgen Inc., South San Francisco, California, United States of America
| | - Simon Wong
- Department of Pharmacokinetics and Drug Metabolism, Amgen Inc., South San Francisco, California, United States of America
| | - Maria Toteva
- Department of Pharmaceutics, Amgen Inc., South San Francisco, California, United States of America
| | - Bei Shan
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Frank Li
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Run Zhuang
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
| | - Daniel C.-H. Lin
- Department of Metabolic Disorders, Amgen Inc., South San Francisco, California, United States of America
- * E-mail:
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78
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Ferdaoussi M, Bergeron V, Kebede M, Mancini A, Alquier T, Poitout V. Free Fatty Acid Receptor 1: A New Drug Target for Type 2 Diabetes? Can J Diabetes 2012. [DOI: 10.1016/j.jcjd.2012.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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79
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Ferdaoussi M, Bergeron V, Zarrouki B, Kolic J, Cantley J, Fielitz J, Olson EN, Prentki M, Biden T, MacDonald PE, Poitout V. G protein-coupled receptor (GPR)40-dependent potentiation of insulin secretion in mouse islets is mediated by protein kinase D1. Diabetologia 2012; 55:2682-2692. [PMID: 22820510 PMCID: PMC3543464 DOI: 10.1007/s00125-012-2650-x] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/18/2012] [Indexed: 10/28/2022]
Abstract
AIMS/HYPOTHESIS Activation of the G protein-coupled receptor (GPR)40 by long-chain fatty acids potentiates glucose-stimulated insulin secretion (GSIS) from pancreatic beta cells, and GPR40 agonists are in clinical development for type 2 diabetes therapy. GPR40 couples to the G protein subunit Gα(q/11) but the signalling cascade activated downstream is unknown. This study aimed to determine the mechanisms of GPR40-dependent potentiation of GSIS by fatty acids. METHODS Insulin secretion in response to glucose, oleate or diacylglycerol (DAG) was assessed in dynamic perifusions and static incubations in islets from wild-type (WT) and Gpr40 (-/-) mice. Depolymerisation of filamentous actin (F-actin) was visualised by phalloidin staining and epifluorescence. Pharmacological and molecular approaches were used to ascertain the roles of protein kinase D (PKD) and protein kinase C delta in GPR40-mediated potentiation of GSIS. RESULTS Oleate potentiates the second phase of GSIS, and this effect is largely dependent upon GPR40. Accordingly, oleate induces rapid F-actin remodelling in WT but not in Gpr40 (-/-) islets. Exogenous DAG potentiates GSIS in both WT and Gpr40 (-/-) islets. Oleate induces PKD phosphorylation at residues Ser-744/748 and Ser-916 in WT but not Gpr40 (-/-) islets. Importantly, oleate-induced F-actin depolymerisation and potentiation of GSIS are lost upon pharmacological inhibition of PKD1 or deletion of Prkd1. CONCLUSIONS/INTERPRETATION We conclude that the signalling cascade downstream of GPR40 activation by fatty acids involves activation of PKD1, F-actin depolymerisation and potentiation of second-phase insulin secretion. These results provide important information on the mechanisms of action of GPR40, a novel drug target for type 2 diabetes.
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Affiliation(s)
- M Ferdaoussi
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - V Bergeron
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - B Zarrouki
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - J Kolic
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - J Cantley
- Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, NSW, Australia
| | - J Fielitz
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
- Medical Department, Division of Cardiology, Charité University, Campus Virchow-Klinikum, Berlin, Germany
| | - E N Olson
- Departments of Molecular Biology, Internal Medicine, and Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - M Prentki
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Departments of Nutrition and Biochemistry, University of Montreal, Montreal, QC, Canada
| | - T Biden
- Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, NSW, Australia
| | - P E MacDonald
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - V Poitout
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4.
- Department of Medicine, University of Montreal, Montreal, QC, Canada.
- Departments of Nutrition and Biochemistry, University of Montreal, Montreal, QC, Canada.
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80
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Lau DC, Kieffer T, Light P. Islet Biology Key to Our Understanding of Diabetes. Can J Diabetes 2012. [DOI: 10.1016/j.jcjd.2012.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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81
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Feng XT, Leng J, Xie Z, Li SL, Zhao W, Tang QL. GPR40: a therapeutic target for mediating insulin secretion (review). Int J Mol Med 2012; 30:1261-6. [PMID: 23023155 DOI: 10.3892/ijmm.2012.1142] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/26/2012] [Indexed: 11/05/2022] Open
Abstract
G-protein-coupled receptor 40 (GPR40), known as free fatty acid receptor 1, is mainly expressed in pancreatic β-cells and activated by medium- and long-chain fatty acids. Increasing evidence indicates that the activation of GPR40 in cells causes insulin secretion, and GPR40 has become an attractive therapeutic target for type 2 diabetes. Recently, certain novel GPR40 agonists have been identified that regulate glucose-stimulated insulin secretion, leading to the development of new drugs for the treatment of type 2 diabetes. In this review, we focus on progress in the physiological role of GPR40 and potential drugs targeting GPR40 over the past decade.
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Affiliation(s)
- Xiao-Tao Feng
- Guangxi Scientific Experimental Center of Traditional Chinese Medicine, Guangxi University of Chinese Medicine, Nanning, P.R. China
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Lin DCH, Guo Q, Luo J, Zhang J, Nguyen K, Chen M, Tran T, Dransfield PJ, Brown SP, Houze J, Vimolratana M, Jiao XY, Wang Y, Birdsall NJM, Swaminath G. Identification and pharmacological characterization of multiple allosteric binding sites on the free fatty acid 1 receptor. Mol Pharmacol 2012; 82:843-59. [PMID: 22859723 DOI: 10.1124/mol.112.079640] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Activation of FFA1 (GPR40), a member of G protein-coupling receptor family A, is mediated by medium- and long-chain fatty acids and leads to amplification of glucose-stimulated insulin secretion, suggesting a potential role for free fatty acid 1 (FFA1) as a target for type 2 diabetes. It was assumed previously that there is a single binding site for fatty acids and synthetic FFA1 agonists. However, using members of two chemical series of partial and full agonists that have been identified, radioligand binding interaction studies revealed that the full agonists do not bind to the same site as the partial agonists but exhibit positive heterotropic cooperativity. Analysis of functional data reveals positive functional cooperativity between the full agonists and partial agonists in various functional assays (in vitro and ex vivo) and also in vivo. Furthermore, the endogenous fatty acid docosahexaenoic acid (DHA) shows negative or neutral cooperativity with members of both series of agonists in binding assays but displays positive cooperativity in functional assays. Another synthetic agonist is allosteric with members of both agonist series, but apparently competitive with DHA. Therefore, there appear to be three allosterically linked binding sites on FFA1 with agonists specific for each of these sites. Activation of free fatty acid 1 receptor (FFAR1) by each of these agonists is differentially affected by mutations of two arginine residues, previously found to be important for FFAR1 binding and activation. These ligands with their high potencies and strong positive functional cooperativity with endogenous fatty acids, demonstrated in vitro and in vivo, have the potential to deliver therapeutic benefits.
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Glucose activates free fatty acid receptor 1 gene transcription via phosphatidylinositol-3-kinase-dependent O-GlcNAcylation of pancreas-duodenum homeobox-1. Proc Natl Acad Sci U S A 2012; 109:2376-81. [PMID: 22308370 DOI: 10.1073/pnas.1114350109] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The G protein-coupled free fatty acid receptor-1 (FFA1/GPR40) plays a major role in the regulation of insulin secretion by fatty acids. GPR40 is considered a potential therapeutic target to enhance insulin secretion in type 2 diabetes; however, its mode of regulation is essentially unknown. The aims of this study were to test the hypothesis that glucose regulates GPR40 gene expression in pancreatic β-cells and to determine the mechanisms of this regulation. We observed that glucose stimulates GPR40 gene transcription in pancreatic β-cells via increased binding of pancreas-duodenum homeobox-1 (Pdx-1) to the A-box in the HR2 region of the GPR40 promoter. Mutation of the Pdx-1 binding site within the HR2 abolishes glucose activation of GPR40 promoter activity. The stimulation of GPR40 expression and Pdx-1 binding to the HR2 in response to glucose are mimicked by N-acetyl glucosamine, an intermediate of the hexosamine biosynthesis pathway, and involve PI3K-dependent O-GlcNAcylation of Pdx-1 in the nucleus. We demonstrate that O-GlcNAc transferase (OGT) interacts with the product of the PI3K reaction, phosphatidylinositol 3,4,5-trisphosphate (PIP(3)), in the nucleus. This interaction enables OGT to catalyze O-GlcNAcylation of nuclear proteins, including Pdx-1. We conclude that glucose stimulates GPR40 gene expression at the transcriptional level through Pdx-1 binding to the HR2 region and via a signaling cascade that involves an interaction between OGT and PIP(3) at the nuclear membrane. These observations reveal a unique mechanism by which glucose metabolism regulates the function of transcription factors in the nucleus to induce gene expression.
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