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Zheng S, Polidori D, Wang Y, Geist B, Lin‐Schmidt X, Furman JL, Nelson S, Nawrocki AR, Hinke SA. A long-acting GDF15 analog causes robust, sustained weight loss and reduction of food intake in an obese nonhuman primate model. Clin Transl Sci 2023; 16:1431-1444. [PMID: 37154518 PMCID: PMC10432867 DOI: 10.1111/cts.13543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/28/2023] [Accepted: 04/27/2023] [Indexed: 05/10/2023] Open
Abstract
Growth Differentiation Factor-15 (GDF15) is a circulating polypeptide linked to cellular stress and metabolic adaptation. GDF15's half-life is ~3 h and activates the glial cell line-derived neurotrophic factor family receptor alpha-like (GFRAL) receptor expressed in the area postrema. To characterize sustained GFRAL agonism on food intake (FI) and body weight (BW), we tested a half-life extended analog of GDF15 (Compound H [CpdH]) suitable for reduced dosing frequency in obese cynomolgus monkeys. Animals were chronically treated once weekly (q.w.) with CpdH or long-acting GLP-1 analog dulaglutide. Mechanism-based longitudinal exposure-response modeling characterized effects of CpdH and dulaglutide on FI and BW. The novel model accounts for both acute, exposure-dependent effects reducing FI and compensatory changes in energy expenditure (EE) and FI occurring over time with weight loss. CpdH had linear, dose-proportional pharmacokinetics (terminal half-life ~8 days) and treatment caused exposure-dependent reductions in FI and BW. The 1.6 mg/kg CpdH reduced mean FI by 57.5% at 1 week and sustained FI reductions of 31.5% from weeks 9-12, resulting in peak reduction in BW of 16 ± 5%. Dulaglutide had more modest effects on FI and peak BW loss was 3.8 ± 4.0%. Longitudinal modeling of both the FI and BW profiles suggested reductions in BW observed with both CpdH and dulaglutide were fully explained by exposure-dependent reductions in FI without increase in EE. Upon verification of the pharmacokinetic/pharmacodynamic relationship established in monkeys and humans for dulaglutide, we predicted that CpdH could reach double digit BW loss in humans. In summary, a long-acting GDF15 analog led to sustained reductions in FI in overweight monkeys and holds potential for effective clinical obesity pharmacotherapy.
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Affiliation(s)
- Songmao Zheng
- Janssen Research & DevelopmentSpring HousePennsylvaniaUSA
- Present address:
AdageneSan DiegoCaliforniaUSA
| | | | - Yuanping Wang
- Janssen Research & DevelopmentSpring HousePennsylvaniaUSA
| | - Brian Geist
- Janssen Research & DevelopmentSpring HousePennsylvaniaUSA
| | | | | | | | | | - Simon A. Hinke
- Janssen Research & DevelopmentSpring HousePennsylvaniaUSA
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2
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Du F, Hinke SA, Cavanaugh C, Polidori D, Wallace N, Kirchner T, Jennis M, Lang W, Kuo GH, Gaul MD, Lenhard J, Demarest K, Ajami NJ, Liang Y, Hornby PJ. Potent Sodium/Glucose Cotransporter SGLT1/2 Dual Inhibition Improves Glycemic Control Without Marked Gastrointestinal Adaptation or Colonic Microbiota Changes in Rodents. J Pharmacol Exp Ther 2018; 365:676-687. [PMID: 29674332 DOI: 10.1124/jpet.118.248575] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 03/22/2018] [Indexed: 02/06/2023] Open
Abstract
The sodium/glucose cotransporters (SGLT1 and SGLT2) transport glucose across the intestinal brush border and kidney tubule. Dual SGLT1/2 inhibition could reduce hyperglycemia more than SGLT2-selective inhibition in patients with type 2 diabetes. However, questions remain about altered gastrointestinal (GI) luminal glucose and tolerability, and this was evaluated in slc5a1-/- mice or with a potent dual inhibitor (compound 8; SGLT1 Ki = 1.5 ± 0.5 nM 100-fold greater potency than phlorizin; SGLT2 Ki = 0.4 ± 0.2 nM). 13C6-glucose uptake was quantified in slc5a1-/- mice and in isolated rat jejunum. Urinary glucose excretion (UGE), blood glucose (Sprague-Dawley rats), glucagon-like peptide 1 (GLP-1), and hemoglobin A1c (HbA1c) levels (Zucker diabetic fatty rats) were measured. Intestinal adaptation and rRNA gene sequencing was analyzed in C57Bl/6 mice. The blood 13C6-glucose area under the curve (AUC) was reduced in the absence of SGLT1 by 75% (245 ± 6 vs. 64 ± 6 mg/dl⋅h in wild-type vs. slc5a1-/- mice) and compound 8 inhibited its transport up to 50% in isolated rat jejunum. Compound 8 reduced glucose excursion more than SGLT2-selective inhibition (e.g., AUC = 129 ± 3 vs. 249 ± 5 mg/dl⋅h for 1 mg/kg compound 8 vs. dapagliflozin) with similar UGE but a lower renal glucose excretion threshold. In Zucker diabetic fatty rats, compound 8 decreased HbA1c and increased total GLP-1 without changes in jejunum SGLT1 expression, mucosal weight, or villus length. Overall, compound 8 (1 mg/kg for 6 days) did not increase cecal glucose concentrations or bacterial diversity in C57BL/6 mice. In conclusion, potent dual SGLT1/2 inhibition lowers blood glucose by reducing intestinal glucose absorption and the renal glucose threshold but minimally impacts the intestinal mucosa or luminal microbiota in chow-fed rodents.
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Affiliation(s)
- Fuyong Du
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Simon A Hinke
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Cassandre Cavanaugh
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - David Polidori
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Nathanial Wallace
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Thomas Kirchner
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Matthew Jennis
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Wensheng Lang
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Gee-Hong Kuo
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Micheal D Gaul
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - James Lenhard
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Keith Demarest
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Nadim J Ajami
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Yin Liang
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
| | - Pamela J Hornby
- Cardiovascular and Metabolism Discovery (F.D., S.A.H., C.C., N.W., T.K., M.J., G.-H.K., M.D.G., J.L., K.D., Y.L., P.J.H.) and Analytical Sciences (W.L.), Janssen R&D LLC, Spring House, Pennsylvania; Cardiovascular and Metabolism Experimental and Translational Medicine, Janssen R&D LLC, San Diego, California (D.P.); and Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas (N.J.A.)
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3
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Hinke SA, Cieniewicz AM, Kirchner T, D'Aquino K, Nanjunda R, Aligo J, Perkinson R, Cooper P, Boayke K, Chiu ML, Jarantow S, Lacy ER, Liang Y, Johnson DL, Whaley JM, Lingham RB, Kihm AJ. Unique pharmacology of a novel allosteric agonist/sensitizer insulin receptor monoclonal antibody. Mol Metab 2018; 10:87-99. [PMID: 29453154 PMCID: PMC5985231 DOI: 10.1016/j.molmet.2018.01.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/02/2018] [Accepted: 01/17/2018] [Indexed: 12/12/2022] Open
Abstract
Objective Insulin resistance is a key feature of Type 2 Diabetes (T2D), and improving insulin sensitivity is important for disease management. Allosteric modulation of the insulin receptor (IR) with monoclonal antibodies (mAbs) can enhance insulin sensitivity and restore glycemic control in animal models of T2D. Methods A novel human mAb, IRAB-A, was identified by phage screening using competition binding and surface plasmon resonance assays with the IR extracellular domain. Cell based assays demonstrated agonist and sensitizer effects of IRAB-A on IR and Akt phosphorylation, as well as glucose uptake. Lean and diet-induced obese mice were used to characterize single-dose in vivo pharmacological effects of IRAB-A; multiple-dose IRAB-A effects were tested in obese mice. Results In vitro studies indicate that IRAB-A exhibits sensitizer and agonist properties distinct from insulin on the IR and is translated to downstream signaling and function; IRAB-A bound specifically and allosterically to the IR and stabilized insulin binding. A single dose of IRAB-A given to lean mice rapidly reduced fed blood glucose for approximately 2 weeks, with concomitant reduced insulin levels suggesting improved insulin sensitivity. Phosphorylated IR (pIR) from skeletal muscle and liver were increased by IRAB-A; however, phosphorylated Akt (pAkt) levels were only elevated in skeletal muscle and not liver vs. control; immunochemistry analysis (IHC) confirmed the long-lived persistence of IRAB-A in skeletal muscle and liver. Studies in diet-induced obese (DIO) mice with IRAB-A reduced fed blood glucose and insulinemia yet impaired glucose tolerance and led to protracted insulinemia during a meal challenge. Conclusion Collectively, the data suggest IRAB-A acts allosterically on the insulin receptor acting non-competitively with insulin to both activate the receptor and enhance insulin signaling. While IRAB-A produced a decrease in blood glucose in lean mice, the data in DIO mice indicated an exacerbation of insulin resistance; these data were unexpected and suggested the interplay of complex unknown pharmacology. Taken together, this work suggests that IRAB-A may be an important tool to explore insulin receptor signaling and pharmacology. A novel anti-insulin receptor monoclonal antibody (IRAB-A) was identified that has both agonist and sensitizing activities. IRAB-A increases the receptor's affinity for insulin by binding to an allosteric site and does not compete with insulin. Mice injected once with IRAB-A show improved glycemia and reduced insulinemia, indicative of enhanced insulin sensitivity. In diet induced obese mice, the insulin sensitizing effect of IRAB-A appears to depend on the degree of insulin resistance. Chronic treatment of obese mice showed mixed effects on glucose homeostasis under normal fed or meal challenged conditions.
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Affiliation(s)
- Simon A Hinke
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA.
| | - Anne M Cieniewicz
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Thomas Kirchner
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Katharine D'Aquino
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Rupesh Nanjunda
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Jason Aligo
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Robert Perkinson
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Philip Cooper
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Ken Boayke
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Mark L Chiu
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Steve Jarantow
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Eilyn R Lacy
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Yin Liang
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Dana L Johnson
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Jean M Whaley
- Cardiovascular and Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Russell B Lingham
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA
| | - Anthony J Kihm
- Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development LLC, 1400 McKean Road, Spring House PA 19477, USA.
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4
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Cieniewicz AM, Kirchner T, Hinke SA, Nanjunda R, D'Aquino K, Boayke K, Cooper PR, Perkinson R, Chiu ML, Jarantow S, Johnson DL, Whaley JM, Lacy ER, Lingham RB, Liang Y, Kihm AJ. Novel Monoclonal Antibody Is an Allosteric Insulin Receptor Antagonist That Induces Insulin Resistance. Diabetes 2017; 66:206-217. [PMID: 27797911 DOI: 10.2337/db16-0633] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/21/2016] [Indexed: 11/13/2022]
Abstract
A hallmark of type 2 diabetes is impaired insulin receptor (IR) signaling that results in dysregulation of glucose homeostasis. Understanding the molecular origins and progression of diabetes and developing therapeutics depend on experimental models of hyperglycemia, hyperinsulinemia, and insulin resistance. We present a novel monoclonal antibody, IRAB-B, that is a specific, potent IR antagonist that creates rapid and long-lasting insulin resistance. IRAB-B binds to the IR with nanomolar affinity and in the presence of insulin efficiently blocks receptor phosphorylation within minutes and is sustained for at least 3 days in vitro. We further confirm that IRAB-B antagonizes downstream signaling and metabolic function. In mice, a single dose of IRAB-B induces rapid onset of hyperglycemia within 6 h, and severe hyperglycemia persists for 2 weeks. IRAB-B hyperglycemia is normalized in mice treated with exendin-4, suggesting that this model can be effectively treated with a GLP-1 receptor agonist. Finally, a comparison of IRAB-B with the IR antagonist S961 shows distinct antagonism in vitro and in vivo. IRAB-B appears to be a powerful tool to generate both acute and chronic insulin resistance in mammalian models to elucidate diabetic pathogenesis and evaluate therapeutics.
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Affiliation(s)
- Anne M Cieniewicz
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Thomas Kirchner
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Simon A Hinke
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Rupesh Nanjunda
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Katharine D'Aquino
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Ken Boayke
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Philip R Cooper
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Robert Perkinson
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Mark L Chiu
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Stephen Jarantow
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Dana L Johnson
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Jean M Whaley
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Eilyn R Lacy
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Russell B Lingham
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Yin Liang
- Cardiovascular & Metabolism Therapeutic Area, Janssen Pharmaceutical Research & Development, Spring House, PA
| | - Anthony J Kihm
- Biologics Research, Janssen BioTherapeutics, Janssen Pharmaceutical Research & Development, Spring House, PA
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5
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Rives ML, Shaw M, Zhu B, Hinke SA, Wickenden AD. State-Dependent Allosteric Inhibition of the Human SLC13A5 Citrate Transporter by Hydroxysuccinic Acids, PF-06649298 and PF-06761281. Mol Pharmacol 2016; 90:766-774. [PMID: 27754898 DOI: 10.1124/mol.116.106575] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/13/2016] [Indexed: 01/16/2023] Open
Abstract
In the liver, citrate is a key metabolic intermediate involved in the regulation of glycolysis and lipid synthesis and reduced expression of the hepatic citrate SLC13A5 transporter has been shown to improve metabolic outcomes in various animal models. Although inhibition of hepatic extracellular citrate uptake through SLC13A5 has been suggested as a potential therapeutic approach for Type-2 diabetes and/or fatty liver disease, so far, only a few SLC13A5 inhibitors have been identified. Moreover, their mechanism of action still remains unclear, potentially limiting their utility for in vivo proof-of-concept studies. In this study, we characterized the pharmacology of the recently identified hydroxysuccinic acid SLC13A5 inhibitors, PF-06649298 and PF-06761281, using a combination of 14C-citrate uptake, a membrane potential assay and electrophysiology. In contrast to their previously proposed mechanism of action, our data suggest that both PF-06649298 and PF-06761281 are allosteric, state-dependent SLC13A5 inhibitors, with low-affinity substrate activity in the absence of citrate. As allosteric state-dependent modulators, the inhibitory potency of both compounds is highly dependent on the ambient citrate concentration and our detailed mechanism of action studies therefore, may be of value in interpreting the in vivo effects of these compounds.
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Affiliation(s)
- Marie-Laure Rives
- Molecular and Cellular Pharmacology, Discovery Sciences, Janssen R&D, LLC., San Diego, California (M.-L.R., M.S., A.D.W.) and Cardiovascular and Metabolism Discovery, Janssen R&D, LLC., Springhouse, Pennsylvania, (B.Z., S.A.H.)
| | - Morena Shaw
- Molecular and Cellular Pharmacology, Discovery Sciences, Janssen R&D, LLC., San Diego, California (M.-L.R., M.S., A.D.W.) and Cardiovascular and Metabolism Discovery, Janssen R&D, LLC., Springhouse, Pennsylvania, (B.Z., S.A.H.)
| | - Bin Zhu
- Molecular and Cellular Pharmacology, Discovery Sciences, Janssen R&D, LLC., San Diego, California (M.-L.R., M.S., A.D.W.) and Cardiovascular and Metabolism Discovery, Janssen R&D, LLC., Springhouse, Pennsylvania, (B.Z., S.A.H.)
| | - Simon A Hinke
- Molecular and Cellular Pharmacology, Discovery Sciences, Janssen R&D, LLC., San Diego, California (M.-L.R., M.S., A.D.W.) and Cardiovascular and Metabolism Discovery, Janssen R&D, LLC., Springhouse, Pennsylvania, (B.Z., S.A.H.)
| | - Alan D Wickenden
- Molecular and Cellular Pharmacology, Discovery Sciences, Janssen R&D, LLC., San Diego, California (M.-L.R., M.S., A.D.W.) and Cardiovascular and Metabolism Discovery, Janssen R&D, LLC., Springhouse, Pennsylvania, (B.Z., S.A.H.)
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6
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Nystoriak MA, Nieves-Cintrón M, Nygren PJ, Hinke SA, Nichols CB, Chen CY, Puglisi JL, Izu LT, Bers DM, Dell'acqua ML, Scott JD, Santana LF, Navedo MF. AKAP150 contributes to enhanced vascular tone by facilitating large-conductance Ca2+-activated K+ channel remodeling in hyperglycemia and diabetes mellitus. Circ Res 2013; 114:607-15. [PMID: 24323672 DOI: 10.1161/circresaha.114.302168] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RATIONALE Increased contractility of arterial myocytes and enhanced vascular tone during hyperglycemia and diabetes mellitus may arise from impaired large-conductance Ca(2+)-activated K(+) (BKCa) channel function. The scaffolding protein A-kinase anchoring protein 150 (AKAP150) is a key regulator of calcineurin (CaN), a phosphatase known to modulate the expression of the regulatory BKCa β1 subunit. Whether AKAP150 mediates BKCa channel suppression during hyperglycemia and diabetes mellitus is unknown. OBJECTIVE To test the hypothesis that AKAP150-dependent CaN signaling mediates BKCa β1 downregulation and impaired vascular BKCa channel function during hyperglycemia and diabetes mellitus. METHODS AND RESULTS We found that AKAP150 is an important determinant of BKCa channel remodeling, CaN/nuclear factor of activated T-cells c3 (NFATc3) activation, and resistance artery constriction in hyperglycemic animals on high-fat diet. Genetic ablation of AKAP150 protected against these alterations, including augmented vasoconstriction. d-glucose-dependent suppression of BKCa channel β1 subunits required Ca(2+) influx via voltage-gated L-type Ca(2+) channels and mobilization of a CaN/NFATc3 signaling pathway. Remarkably, high-fat diet mice expressing a mutant AKAP150 unable to anchor CaN resisted activation of NFATc3 and downregulation of BKCa β1 subunits and attenuated high-fat diet-induced elevation in arterial blood pressure. CONCLUSIONS Our results support a model whereby subcellular anchoring of CaN by AKAP150 is a key molecular determinant of vascular BKCa channel remodeling, which contributes to vasoconstriction during diabetes mellitus.
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MESH Headings
- A Kinase Anchor Proteins/genetics
- A Kinase Anchor Proteins/metabolism
- Animals
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Dietary Fats/pharmacology
- Gene Knock-In Techniques
- Hyperglycemia/genetics
- Hyperglycemia/metabolism
- Hyperglycemia/physiopathology
- Hypertension/genetics
- Hypertension/metabolism
- Hypertension/physiopathology
- Large-Conductance Calcium-Activated Potassium Channel beta Subunits/genetics
- Large-Conductance Calcium-Activated Potassium Channel beta Subunits/metabolism
- Large-Conductance Calcium-Activated Potassium Channels/genetics
- Large-Conductance Calcium-Activated Potassium Channels/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- NFATC Transcription Factors/metabolism
- Peptides/pharmacology
- Signal Transduction/physiology
- Toxins, Biological/pharmacology
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
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Affiliation(s)
- Matthew A Nystoriak
- From the Department of Pharmacology, University of California, Davis (M.A.N., M.N.-C., C.B.N., C.-Y.C., J.L.P., L.T.I., D.M.B., M.F.N.); Department of Pharmacology, University of Colorado, Denver (M.L.D.); Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, WA (P.J.N., S.A.H., J.D.S.); and Department of Physiology and Biophysics, University of Washington, Seattle (L.F.S.)
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7
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Hinke SA, Navedo MF, Ulman A, Whiting JL, Nygren PJ, Tian G, Jimenez-Caliani AJ, Langeberg LK, Cirulli V, Tengholm A, Dell'Acqua ML, Santana LF, Scott JD. Anchored phosphatases modulate glucose homeostasis. EMBO J 2012; 31:3991-4004. [PMID: 22940692 PMCID: PMC3474922 DOI: 10.1038/emboj.2012.244] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 07/23/2012] [Indexed: 02/07/2023] Open
Abstract
AKAP150 knockout- and mutant knock-in alleles reveal an unexpected role of the adaptor in anchoring phosphatase 2B for efficient insulin secretion from pancreatic β-cells and thus glucose homeostasis. Endocrine release of insulin principally controls glucose homeostasis. Nutrient-induced exocytosis of insulin granules from pancreatic β-cells involves ion channels and mobilization of Ca2+ and cyclic AMP (cAMP) signalling pathways. Whole-animal physiology, islet studies and live-β-cell imaging approaches reveal that ablation of the kinase/phosphatase anchoring protein AKAP150 impairs insulin secretion in mice. Loss of AKAP150 impacts L-type Ca2+ currents, and attenuates cytoplasmic accumulation of Ca2+ and cAMP in β-cells. Yet surprisingly AKAP150 null animals display improved glucose handling and heightened insulin sensitivity in skeletal muscle. More refined analyses of AKAP150 knock-in mice unable to anchor protein kinase A or protein phosphatase 2B uncover an unexpected observation that tethering of phosphatases to a seven-residue sequence of the anchoring protein is the predominant molecular event underlying these metabolic phenotypes. Thus anchored signalling events that facilitate insulin secretion and glucose homeostasis may be set by AKAP150 associated phosphatase activity.
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Affiliation(s)
- Simon A Hinke
- Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
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8
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Nystoriak MA, Nieves-Cintrón M, Hinke SA, Scott JD, Santana LF, Navedo MF. AKAP150 is required for NFATc3‐induced vascular BKCa channel suppression during diabetic hypertension. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.872.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Nieves M, Hirenallur-S DK, Hinke SA, Scott JD, Santana LF. AKAP150‐dependent changes in K
v
channel expression in ventricular myocytes following myocardial infarction. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1053.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Luis F Santana
- Physiology & BiophysicsUniversity of WashingtonSeattleWA
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10
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11
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Hinke SA. Diamyd, an alum-formulated recombinant human GAD65 for the prevention of autoimmune diabetes. Curr Opin Mol Ther 2008; 10:516-525. [PMID: 18830927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Diamyd Medical AB is developing Diamyd (GAD-65), an alum formulation of a full-length recombinant human glutamic acid decarboxylase 65 for subcutaneous injection, for the potential prevention and treatment of type 1 diabetes (T1DM) or latent autoimmune diabetes (LADA) in adults. Phase II clinical trials indicated that Diamyd was safe and well tolerated in patients with T1DM or LADA. Diamyd is currently in phase II/III and III clinical trials for T1DM.
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Affiliation(s)
- Simon A Hinke
- University of Washington, Department of Pharmacology, Seattle, WA 98195, USA.
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12
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Abstract
The movement of signal transduction enzymes in and out of multi-protein complexes coordinates the spatial and temporal resolution of cellular events. Anchoring and scaffolding proteins are key to this process because they sequester protein kinases and phosphatases with a subset of their preferred substrates. The protein kinase A-anchoring family of proteins (AKAPs), which target the cAMP-dependent protein kinase (PKA) and other enzymes to defined subcellular microenvironments, represent a well studied group of these signal-organizing molecules. In this report we demonstrate that the Rab27a GTPase effector protein MyRIP is a member of the AKAP family. The zebrafish homolog of MyRIP (Ze-AKAP2) was initially detected in a two-hybrid screen for AKAPs. A combination of biochemical, cell-based, and immunofluorescence approaches demonstrate that the mouse MyRIP ortholog targets the type II PKA holoenzyme via an atypical mechanism to a specific perinuclear region of insulin-secreting cells. Similar approaches show that MyRIP interacts with the Sec6 and Sec8 components of the exocyst complex, an evolutionarily conserved protein unit that controls protein trafficking and exocytosis. These data indicate that MyRIP functions as a scaffolding protein that links PKA to components of the exocytosis machinery.
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Affiliation(s)
- April S. Goehring
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239
| | - Benjamin S. Pedroja
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239
| | - Simon A. Hinke
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239
| | - Lorene K. Langeberg
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239
| | - John D. Scott
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239
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13
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Affiliation(s)
- Simon A Hinke
- Vollum Institute, Oregon Health and Science University (MRB322/L-474), 3181 Southwest Sam Jackson Park Road, Portland, OR 97239, USA.
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14
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Hinke SA, Martens GA, Cai Y, Finsi J, Heimberg H, Pipeleers D, Van de Casteele M. Methyl succinate antagonises biguanide-induced AMPK-activation and death of pancreatic beta-cells through restoration of mitochondrial electron transfer. Br J Pharmacol 2007; 150:1031-43. [PMID: 17339833 PMCID: PMC2013909 DOI: 10.1038/sj.bjp.0707189] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Two mechanisms have been proposed to explain the insulin-sensitising properties of metformin in peripheral tissues: (a) inhibition of electron transport chain complex I, and (b) activation of the AMP activated protein kinase (AMPK). However the relationship between these mechanisms and their contribution to beta-cell death and dysfunction in vitro, are currently unclear. EXPERIMENTAL APPROACH The effects of biguanides (metformin and phenformin) were tested on MIN6 beta-cells and primary FACS-purified rat beta-cells. Cell metabolism was assessed biochemically and by FACS analysis, and correlated with AMPK phosphorylation state and cell viability, with or without fuel substrates. KEY RESULTS In MIN6 cells, metformin reduced mitochondrial complex I activity by up to 44% and a 25% net reduction in mitochondrial reducing potential. In rat beta-cells, metformin caused NAD(P)H accumulation above maximal glucose-inducible levels, mimicking the effect of rotenone. Drug exposure caused phosphorylation of AMPK on Thr(172) in MIN6 cell extracts, indicative of kinase activation. Methyl succinate, a complex II substrate, appeared to bypass metformin blockade of complex I. This resulted in reduced phosphorylation of AMPK, establishing a link between biguanide-induced mitochondrial inhibition and AMPK activation. Corresponding assessment of cell death indicated that methyl succinate decreased biguanide toxicity to beta-cells in vitro. CONCLUSIONS AND IMPLICATIONS AMPK activation can partly be attributed to metformin's inhibitory action on mitochondrial complex I. Anaplerotic fuel metabolism via complex II rescued beta-cells from metformin-associated toxicity. We propose that utilisation of anaplerotic nutrients may reconcile in vitro and in vivo effects of metformin on the pancreatic beta-cell.
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Affiliation(s)
- S A Hinke
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - G A Martens
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - Y Cai
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - J Finsi
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - H Heimberg
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - D Pipeleers
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
| | - M Van de Casteele
- Diabetes Research Center and Juvenile Diabetes Research Center for Beta Cell Therapy in Europe, Brussels Free University (VUB) Laarbeeklaan 103, Brussels, Belgium
- Author for correspondence:
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15
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Cai Y, Martens GA, Hinke SA, Heimberg H, Pipeleers D, Van de Casteele M. Increased oxygen radical formation and mitochondrial dysfunction mediate beta cell apoptosis under conditions of AMP-activated protein kinase stimulation. Free Radic Biol Med 2007; 42:64-78. [PMID: 17157194 DOI: 10.1016/j.freeradbiomed.2006.09.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 08/16/2006] [Accepted: 09/19/2006] [Indexed: 12/22/2022]
Abstract
AMP-activated protein kinase influences cellular metabolism, glucose-regulated gene expression, and insulin secretion of pancreatic beta cells. Its sustained activation by culture at low glucose concentrations or in the presence of 5-aminoimidazole-4-carboxamide riboside (AICAR) was shown to trigger apoptosis in beta cells. This study shows that both low glucose- and AICAR-induced apoptosis are associated with increased formation of mitochondrial superoxide-derived radicals and decreased mitochondrial activity. Mitochondrial dysfunction was reflected by an increased oxidized state of the mitochondrial flavins (FMN/FAD) but not of NAD(P)H. It was accompanied by suppression of glucose oxidation and glucose-induced insulin secretion, while palmitate oxidation appeared unaffected. When the cellular accumulation of superoxide-derived radicals was quenched by the ROS scavengers vitamin E, N-acetylcysteine, or the SOD-mimetic compound MnTBAP, apoptosis was significantly inhibited. Both low glucose and AICAR also elevated the expression of BH3-domain-only Bcl-2 antagonists, and induced caspase-3 activation, causing caspase-dependent truncation of Bcl-2. Overexpression of recombinant human Bcl-2 prevented caspase-3 activation, endogenous Bcl-2 processing, and apoptosis, but did not attenuate oxygen radical formation, AMPK activation, or JNK phosphorylation. We conclude that apoptosis by prolonged AMPK activation in beta cells results from enhanced production of mitochondria-derived oxygen radicals and onset of the intrinsic mitochondrial apoptosis pathway, followed by caspase activation and Bcl-2 cleavage which may amplify the death signal.
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16
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Hinke SA, Pederson RA, McIntosh CHS. Relative contribution of incretins to the glucose lowering effect of DP IV inhibitors in type 2 diabetes mellitus (T2DM). Adv Exp Med Biol 2006; 575:119-33. [PMID: 16700515 DOI: 10.1007/0-387-32824-6_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Affiliation(s)
- Simon A Hinke
- Department of Metabolism and Endocrinology, Diabetes Research Center, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium.
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17
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Hinke SA, Manhart S, Speck M, Pederson RA, Demuth HU, McIntosh CHS. In depth analysis of the N-terminal bioactive domain of gastric inhibitory polypeptide. Life Sci 2004; 75:1857-70. [PMID: 15302229 DOI: 10.1016/j.lfs.2004.03.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Accepted: 03/29/2004] [Indexed: 11/27/2022]
Abstract
Gastric inhibitory polypeptide/glucose-dependent insulinotropic polypeptide (GIP) is an important gastrointestinal regulator of insulin release and glucose homeostasis following a meal. Strategies have been undertaken to delineate the bioactive domains of GIP with the intention of developing small molecular weight GIP mimetics. The molecular cloning of receptors for GIP and the related hormone GLP-1 (glucagon-like peptide-1) has allowed examination of the characteristics of incretin analogs in transfected cell models. The current report examines the N-terminal bioactive domain of GIP residing in residues 1-14 by alanine scanning mutagenesis and N-terminal substitution/modification. Further studies examined peptide chimeras of GIP and GLP-1 designed to localize bioactive determinants of the two hormones. The alanine scan of the GIP(1-14) sequence established that the peptide was extremely sensitive to structural perturbations. Only replacement of amino acids 2 and 13 with those found in glucagon failed to dramatically reduce receptor binding and activation. Of four GIP(1-14) peptides modified by the introduction of DP IV-resistant groups, a peptide with a reduced bond between Ala2 and Glu3 demonstrated improved receptor potency compared to native GIP(1-14). The peptide chimera studies supported recent results on the importance of a mid-region helix for bioactivity of GIP, and confirmed existence of two separable regions with independent intrinsic receptor binding and activation properties. Furthermore, peptide chimeras showed that binding of GLP-1 also involves both N- and C-terminal domains, but that it apparently contains only a single bioactive domain in its N-terminus. Together, these results should facilitate development of incretin based therapies using rational drug design for potential treatment of diabetes.
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Affiliation(s)
- Simon A Hinke
- Department of Physiology, Faculty of Medicine, University of British Columbia, 2146 Health Sciences Mall, Vancouver, British Columbia, V6T 1Z3, Canada
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18
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Delmeire D, Flamez D, Moens K, Hinke SA, Van Schravendijk C, Pipeleers D, Schuit F. Prior in vitro exposure to GLP-1 with or without GIP can influence the subsequent beta cell responsiveness. Biochem Pharmacol 2004; 68:33-9. [PMID: 15183115 DOI: 10.1016/j.bcp.2004.02.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Accepted: 02/18/2004] [Indexed: 11/21/2022]
Abstract
Glucagon-like peptide-1 (7-36) amide (GLP-1) and glucose-dependent insulinotropic peptide (GIP) potentiate glucose-induced insulin release when present at the time of nutrient stimulation. This study examines whether they can also influence rat beta cell responsiveness to subsequent stimulations. When rat beta cells were cultured for 24 h with 1 nM GLP-1, they progressively desensitized to subsequent GLP-1 stimuli, as evidenced by cellular cAMP production. This GLP-1-induced desensitization did not occur when the incretin was only present during three periods of 1 h at 10 mM glucose that alternated with 6-9 h culture at 3 mM glucose. After these 24h, the beta cells exhibited the same secretory response to glucose (10 mM) and GLP-1 (10 nM at 10 mM glucose), whether GLP-1 was present during the pulses or not. Similarly the presence of 1 nM GIP during these one hour pulses did not influence subsequent secretory responses to glucose and GLP-1. However, when both GLP-1 and GIP, each at 0.5 nM, were added to the one hour pulses, they not only amplified insulin release during the pulses, as was the case with their single addition, but also increased the secretory response to a subsequent stimulation by glucose and GLP-1. These data distinguish between a desensitization effect of a prolonged exposure to GLP-1 and a positive priming effect of a discontinuous exposure to a combination of GLP-1 plus GIP. They may have to be taken into account in drug treatment strategies aiming the mimicking of physiologic patterns in the regulation of insulin release.
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19
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Hinke SA, Hellemans K, Schuit FC. Plasticity of the beta cell insulin secretory competence: preparing the pancreatic beta cell for the next meal. J Physiol 2004; 558:369-80. [PMID: 15181163 PMCID: PMC1664983 DOI: 10.1113/jphysiol.2004.064881] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
It is well established that the acute rise in plasma glucose and in the incretin hormones glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (7-36) amide (GLP-1), as occurs during a meal, is of pivotal importance in regulating the minute-to-minute output of insulin from pancreatic beta cells. In addition to this well studied acute effect, both glucose and incretin hormones have been recently observed to determine the future secretory responsiveness of the cells. Such plasticity of the insulin secretory competence would imply that glucose and incretins not only act during the present meal, but also help to prepare the beta cells to function during the subsequent meal. Evidence supporting this hypothesis is growing as a result of physiological studies of cultured beta cells (either primary cells or beta cell lines), as well as from an increasing number of large-scale gene expression studies, exploring transcriptional and post-transcriptional events in genes regulated by glucose and incretins. On the basis of this hypothesis, one can speculate that genetic or environmental disturbances of plasticity of the insulin secretory competence is one aspect of beta cell dysfunction that can contribute to the aetiology of type 2 diabetes.
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Affiliation(s)
- Simon A Hinke
- Diabetes Research Center, Vrije Universiteit Brussel, Belgium
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20
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Hansotia T, Baggio LL, Delmeire D, Hinke SA, Yamada Y, Tsukiyama K, Seino Y, Holst JJ, Schuit F, Drucker DJ. Double incretin receptor knockout (DIRKO) mice reveal an essential role for the enteroinsular axis in transducing the glucoregulatory actions of DPP-IV inhibitors. Diabetes 2004; 53:1326-35. [PMID: 15111503 DOI: 10.2337/diabetes.53.5.1326] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are gut-derived incretins that potentiate glucose clearance following nutrient ingestion. Elimination of incretin receptor action in GIPR(-/-) or GLP-1R(-/-) mice produces only modest impairment in glucose homeostasis, perhaps due to compensatory upregulation of the remaining incretin. We have now studied glucose homeostasis in double incretin receptor knockout (DIRKO) mice. DIRKO mice exhibit normal body weight and fail to exhibit an improved glycemic response after exogenous administration of GIP or the GLP-1R agonist exendin-4. Plasma glucagon and the hypoglycemic response to exogenous insulin were normal in DIRKO mice. Glycemic excursion was abnormally increased and levels of glucose-stimulated insulin secretion were decreased following oral but not intraperitoneal glucose challenge in DIRKO compared with GIPR(-/-) or GLP-1R(-/-) mice. Similarly, glucose-stimulated insulin secretion and the response to forskolin were well preserved in perifused DIRKO islets. Although the dipeptidyl peptidase-IV (DPP-IV) inhibitors valine pyrrolidide (Val-Pyr) and SYR106124 lowered glucose and increased plasma insulin in wild-type and single incretin receptor knockout mice, the glucose-lowering actions of DPP-IV inhibitors were eliminated in DIRKO mice. These findings demonstrate that glucose-stimulated insulin secretion is maintained despite complete absence of both incretin receptors, and they delineate a critical role for incretin receptors as essential downstream targets for the acute glucoregulatory actions of DPP-IV inhibitors.
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Affiliation(s)
- Tanya Hansotia
- Banting and Best Diabetes Centre, Department of Medicine, Toronto General Hospital, University of Toronto, 200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
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21
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Hinke SA, Manhart S, Kühn-Wache K, Nian C, Demuth HU, Pederson RA, McIntosh CHS. [Ser2]- and [SerP2] incretin analogs: comparison of dipeptidyl peptidase IV resistance and biological activities in vitro and in vivo. J Biol Chem 2003; 279:3998-4006. [PMID: 14610075 DOI: 10.1074/jbc.m311304200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP; also known as gastric inhibitory polypeptide) are incretin hormones that reduce postprandial glycemic excursions via enhancing insulin release but are rapidly inactivated by enzymatic N-terminal truncation. As such, efforts have been made to improve their plasma stability by synthetic modification or by inhibition of the responsible protease, dipeptidyl peptidase (DP) IV. Here we report a parallel comparison of synthetic GIP and GLP-1 with their Ser2- and Ser(P)2-substituted analogs, examining receptor binding and activation, metabolic stability, and biological effects in vivo. Both incretins and their Ser2-substituted analogs showed similar EC50s (0.16-0.52 nm) and IC50s (4.3-8.1 nm) at their respective cloned receptors. Although both phosphoserine 2-modified (Ser(PO3H2); Ser(P)) peptides were able to stimulate maximal cAMP production and fully displace receptor-bound tracer, they showed significantly right-shifted concentration-response curves and binding affinities. Ser2-substituted analogs were moderately resistant to DP IV cleavage, whereas [Ser(P)2]GIP and [Ser(P)2] GLP-1 showed complete resistance to purified DP IV. It was shown that the Ser(P) forms were dephosphorylated in serum and thus in vivo act as precursor forms of Ser2-substituted analogs. When injected subcutaneously into conscious Wistar rats, all peptides reduced glycemic excursions (rank potency: [Ser(P)2]incretins > or = [Ser2] incretins > native hormones). Insulin determinations indicated that the reductions in postprandial glycemia were at least in part insulin-mediated. Thus it has been shown that despite having low in vitro bioactivity using receptor-transfected cells, in vivo potency of [Ser(P)2] incretins was comparable with or greater than that of native or [Ser2]peptides. Hence, Ser(P)2-modified incretins present as novel glucose-lowering agents.
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Affiliation(s)
- Simon A Hinke
- Department of Physiology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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22
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Delmeire D, Flamez D, Hinke SA, Cali JJ, Pipeleers D, Schuit F. Type VIII adenylyl cyclase in rat beta cells: coincidence signal detector/generator for glucose and GLP-1. Diabetologia 2003; 46:1383-93. [PMID: 13680124 DOI: 10.1007/s00125-003-1203-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2002] [Revised: 06/02/2003] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS The secretory function of pancreatic beta cells is synergistically stimulated by two signalling pathways which mediate the effects of nutrients and hormones such as glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) or glucagon. These hormones are known to activate adenylyl cyclase in beta cells. We examined the type of adenylyl cyclase that is associated with this synergistic interaction. METHODS Insulin release, cAMP production, adenylyl cyclase activity, mRNA and protein expression were measured in fluorescence-activated cell sorter-purified rat beta cells and in the rat beta-cell lines RINm5F, INS-1 832/13 and INS-1 832/2. RESULTS In primary beta cells, glucagon and GLP-1 synergistically potentiate the stimulatory effect of 20 mmol/l glucose on insulin release and cAMP production. Both effects are abrogated in the presence of the L-type Ca(2+)-channel blocker verapamil. The cAMP-producing activity of adenylyl cyclase in membranes from RINm5F cells is synergistically increased by Ca(2+)-calmodulin and recombinant GTP(gamma)S-activated G(s alpha)-protein subunits. This type of regulation is characteristic for type I and type VIII AC isoforms. Consistent with this functional data, AC mRNA analysis shows abundant expression of type VI AC, four splice variants of type VIII AC and low expression level of type I AC in beta cells. Type VIII AC expression at the protein level was observed using immunoblots of RINm5F cell extracts. CONCLUSION/INTERPRETATION This study identifies type VIII AC in insulin-secreting cells as one of the potential molecular targets for synergism between GLP-1 receptor mediated and glucose-mediated signalling.
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Affiliation(s)
- D Delmeire
- Molecular Pharmacology Unit, Diabetes Research Center, Faculty of Medicine, Vrije Universiteit Brussel, 1090 Brussels, Belgium
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Hinke SA, Lynn F, Ehses J, Pamir N, Manhart S, Kühn-Wache K, Rosche F, Demuth HU, Pederson RA, McIntosh CHS. Glucose-dependent insulinotropic polypeptide (GIP): development of DP IV-resistant analogues with therapeutic potential. Adv Exp Med Biol 2003; 524:293-301. [PMID: 12675251 DOI: 10.1007/0-306-47920-6_35] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- Simon A Hinke
- Department of Physiology, University of British Columbia, Vancouver, Canada
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24
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Pamir N, Lynn FC, Buchan AMJ, Ehses J, Hinke SA, Pospisilik JA, Miyawaki K, Yamada Y, Seino Y, McIntosh CHS, Pederson RA. Glucose-dependent insulinotropic polypeptide receptor null mice exhibit compensatory changes in the enteroinsular axis. Am J Physiol Endocrinol Metab 2003; 284:E931-9. [PMID: 12540373 DOI: 10.1152/ajpendo.00270.2002] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The incretins glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are gut hormones that act via the enteroinsular axis to potentiate insulin secretion from the pancreas in a glucose-dependent manner. Both GLP-1 receptor and GIP receptor knockout mice (GLP-1R(-/-) and GIPR(-/-), respectively) have been generated to investigate the physiological importance of this axis. Although reduced GIP action is a component of type 2 diabetes, GIPR-deficient mice exhibit only moderately impaired glucose tolerance. The present study was directed at investigating possible compensatory mechanisms that take place within the enteroinsular axis in the absence of GIP action. Although serum total GLP-1 levels in GIPR knockout mice were unaltered, insulin responses to GLP-1 from pancreas perfusions and static islet incubations were significantly greater (40-60%) in GIPR(-/-) than in wild-type (GIPR(+/+)) mice. Furthermore, GLP-1-induced cAMP production was also elevated twofold in the islets of the knockout animals. Pancreatic insulin content and gene expression were reduced in GIPR(-/-) mice compared with GIPR(+/+) mice. Paradoxically, immunocytochemical studies showed a significant increase in beta-cell area in the GIPR-null mice but with less intense staining for insulin. In conclusion, GIPR(-/-) mice exhibit altered islet structure and topography and increased islet sensitivity to GLP-1 despite a decrease in pancreatic insulin content and gene expression.
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Affiliation(s)
- Nathalie Pamir
- Department of Physiology, University of British Columbia, 2146 Health Sciences Mall, Vancouver, British Columbia, Canada, V6T 1Z3
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25
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Manhart S, Hinke SA, McIntosh CHS, Pederson RA, Demuth HU. Structure-function analysis of a series of novel GIP analogues containing different helical length linkers. Biochemistry 2003; 42:3081-8. [PMID: 12627975 DOI: 10.1021/bi026868e] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP1-42) is a potent glucose-lowering intestinal peptide hormone. The equipotent GIP1-30NH2 was structurally modified by linking N- and C-terminal fragments with several different linkers. Substitution of the middle region of GIP by a flexible aminohexanoic linker resulted in greatly reduced binding affinity and reduction or complete loss of bioactivity. Connection of the bioactive domains GIP1-14 and GIP19-30NH2 by EKEK or AAAA linkers resulted in peptide agonists with approximately 3-4-fold increased bioactivity as compared to GIP1-30NH2. Conformational analysis by CD spectroscopy of GIP fragments and analogues suggests a helical region in the C-terminal (19-30) portion of GIP. It was demonstrated that stabilization of this C-terminal helical region by the introduction of helical linkers favored binding and activation of the GIP receptor. Our results suggest an important contribution of a direct interaction of the first 14 amino acids with the GIP receptor, an appropriate relative orientation of N- and C-terminal parts of GIP, and the presence of helical linkers to be essential for bioactivity.
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Affiliation(s)
- Susanne Manhart
- Department of Peptide Chemistry, probiodrug AG, Weinbergweg 22, 06120 Halle/Saale, Germany
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26
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Hinke SA, Gelling R, Manhart S, Lynn F, Pederson RA, Kühn-Wache K, Rosche F, Demuth HU, Coy D, McIntosh CHS. Structure-activity relationships of glucose-dependent insulinotropic polypeptide (GIP). Biol Chem 2003; 384:403-7. [PMID: 12715891 DOI: 10.1515/bc.2003.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Six GIP(1-NH2) analogs were synthesized with modifications (de-protonation, N-methylation, reversed chirality, and substitution) at positions 1, 3, and 4 of the N-terminus, and additionally, a cyclized GIP derivative was synthesized. The relationship between altered structure to biological activity was assessed by measuring receptor binding affinity and ability to stimulate adenylyl cyclase in CHO-K1 cells transfected with the wild-type GIP receptor (wtGIPR). These structure-activity relationship studies demonstrate the importance of the GIP N-terminus and highlight structural constraints that can be introduced in GIP analogs. These analogs may be useful starting points for design of peptides with enhanced in vivo bioactivity.
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Affiliation(s)
- Simon A Hinke
- Department of Physiology, University of British Columbia, Vancouver, B.C., Canada V6T 1Z3
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27
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Lynn FC, Thompson SA, Pospisilik JA, Ehses JA, Hinke SA, Pamir N, McIntosh CHS, Pederson RA. A novel pathway for regulation of glucose-dependent insulinotropic polypeptide (GIP) receptor expression in beta cells. FASEB J 2003; 17:91-3. [PMID: 12475913 DOI: 10.1096/fj.02-0243fje] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is secreted postprandially and acts in concert with glucose to stimulate insulin secretion from the pancreas. Here, we describe a novel pathway for the regulation of GIP receptor (GIPR) expression within clonal beta-cell lines, pancreatic islets, and in vivo. High (25 mM) glucose was able to significantly reduce GIPR mRNA levels in INS(832/13) cells after only 6 h. In contrast, palmitic acid (2 mM) and WY 14643 (100 microM) stimulated approximate doublings of GIPR expression in INS(832/13) cells under low (5.5 mM), but not high (25 mM), glucose conditions, suggesting that fat can regulate GIPR expression via PPARalpha in a glucose-dependent manner. Both MK-886, an antagonist of PPARalpha, and a dominant negative form of PPARalpha transfected into INS(832/13) cells caused a significant reduction in GIPR expression in low, but not high, glucose conditions. Finally, in hyperglycemic clamped rats, there was a 70% reduction in GIPR expression in the islets and a 71% reduction in GIP-stimulated insulin secretion from the perfused pancreas. Thus, evidence is presented that the GIPR is controlled at normoglycemia by the fatty acid load on the islet; however, when exposed to hyperglycemic conditions, the GIPR is down-regulated, which may contribute to the decreased responsiveness to GIP that is observed in type 2 diabetes.
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Affiliation(s)
- Francis C Lynn
- Department of Physiology, University of British Columbia, Vancouver Canada, V6T 1Z3
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28
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Demuth HU, Hinke SA, Pederson RA, McIntosh CHS. Rebuttal to Deacon and Holst: "Metformin effects on dipeptidyl peptidase IV degradation of glucagon-like peptide-1" versus "Dipeptidyl peptidase inhibition as an approach to the treatment and prevention of type 2 diabetes: a historical perspective". Biochem Biophys Res Commun 2002; 296:229-32. [PMID: 12163006 DOI: 10.1016/s0006-291x(02)00753-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hans-Ulrich Demuth
- Probiodrug AG, Biocenter, Weinbergweg 22, D-06120 (Saale), Halle, Germany
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29
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Hinke SA, McIntosh CHS, Hoffmann T, Kühn-Wache K, Wagner L, Bär J, Manhart S, Wermann M, Pederson RA, Demuth HU. On combination therapy of diabetes with metformin and dipeptidyl peptidase IV inhibitors. Diabetes Care 2002; 25:1490-1; author reply 1491-2. [PMID: 12145269 DOI: 10.2337/diacare.25.8.1490-b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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30
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Hinke SA, Kühn-Wache K, Hoffmann T, Pederson RA, McIntosh CHS, Demuth HU. Metformin effects on dipeptidylpeptidase IV degradation of glucagon-like peptide-1. Biochem Biophys Res Commun 2002; 291:1302-8. [PMID: 11883961 DOI: 10.1006/bbrc.2002.6607] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There is current interest in the use of inhibitors of dipeptidyl peptidase IV (DP IV) as therapeutic agents to normalize glycemic excursions in type 2 diabetic patients. Data indicating that metformin increases the circulating amount of active glucagon-like peptide-1 (GLP-1) in obese nondiabetic subjects have recently been presented, and it was proposed that metformin might act as a DP IV inhibitor. This possibility has been investigated directly using a number of in vitro methods. Studies were performed on DP IV enzyme from three sources: 20% human serum, purified porcine kidney DP IV, and recombinant human DP IV. Inhibition of DP IV hydrolysis of the substrate Gly-Pro-pNA by metformin was examined spectrophotometrically. Effects of metformin on GLP-1([7-36NH2]) degradation were assessed by mass spectrometry. In addition, surface plasmon resonance was used to establish whether or not metformin had any effect on GLP-1([7-36NH2]) or GLP-1([9-36NH2]) interaction with immobilized porcine or human DP IV. Metformin failed to alter the kinetics of Gly-Pro-pNA hydrolysis or GLP-1 degradation tested according to established methods. Surface plasmon resonance recordings indicated that both GLP-1([7-36NH2]) and GLP-1([9-36NH2]) show micromolar affinity (K(D)) for DP IV, but neither interaction was influenced by metformin. The results conclusively indicate that metformin does not act directly on DP IV, therefore alternative explanations for the purported effect of metformin on circulating active GLP-1 concentrations must be considered.
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Affiliation(s)
- Simon A Hinke
- Probiodrug Research, Biocenter, Weinbergweg 22, D-06120 Halle (Saale), Germany
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31
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Hinke SA, Gelling RW, Pederson RA, Manhart S, Nian C, Demuth HU, McIntosh CHS. Dipeptidyl peptidase IV-resistant [D-Ala(2)]glucose-dependent insulinotropic polypeptide (GIP) improves glucose tolerance in normal and obese diabetic rats. Diabetes 2002; 51:652-61. [PMID: 11872663 DOI: 10.2337/diabetes.51.3.652] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The therapeutic potential of glucose-dependent insulinotropic polypeptide (GIP) for improving glycemic control has largely gone unstudied. A series of synthetic GIP peptides modified at the NH(2)-terminus were screened in vitro for resistance to dipeptidyl peptidase IV (DP IV) degradation and potency to stimulate cyclic AMP and affinity for the transfected rat GIP receptor. In vitro experiments indicated that [D-Ala(2)]GIP possessed the greatest resistance to enzymatic degradation, combined with minimal effects on efficacy at the receptor. Thus, [D-Ala(2)]GIP(1--42) was selected for further testing in the perfused rat pancreas and bioassay in conscious Wistar and Zucker rats. When injected subcutaneously in normal Wistar, Fa/?, or fa/fa Vancouver Diabetic Fatty (VDF) Zucker rats, both GIP and [D-Ala(2)]GIP significantly reduced glycemic excursions during a concurrent oral glucose tolerance test via stimulation of insulin release. The latter peptide displayed greater in vivo effectiveness, likely because of resistance to enzymatic degradation. Hence, despite reduced bioactivity in diabetic models at physiological concentrations, GIP and analogs with improved plasma stability still improve glucose tolerance when given in supraphysiological doses, and thus may prove useful in the treatment of diabetic states.
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Affiliation(s)
- Simon A Hinke
- Department of Physiology, University of British Columbia, Vancouver, Canada
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32
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Hinke SA, Manhart S, Pamir N, Demuth H, W Gelling R, Pederson RA, McIntosh CH. Identification of a bioactive domain in the amino-terminus of glucose-dependent insulinotropic polypeptide (GIP). Biochim Biophys Acta 2001; 1547:143-55. [PMID: 11343800 DOI: 10.1016/s0167-4838(01)00181-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The incretins are a class of hormones released from the small bowel that act on the endocrine pancreas to potentiate insulin secretion in a glucose-dependent manner. Due to the requirement for an elevated glucose concentration for activity, the incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1, have potential in the treatment of non-insulin-dependent diabetes mellitus. A series of synthetic peptide GIP fragments was generated for the purpose of elucidating the bioactive domain of the molecule. Peptides were screened for stimulation of cyclic AMP (cAMP) accumulation in Chinese hamster ovary cells transfected with the rat islet GIP receptor. Of the GIP fragments tested, GIP(1-14) and GIP(19-30) demonstrated the greatest cAMP-stimulating ability over the range of concentrations tested (up to 20 microM). In contrast, GIP fragments corresponding to amino acids 15-42, 15-30, 16-30 and 17-30 all demonstrated weak antagonism of GIP(1-42) activity. Competitive-binding displacement studies indicated that these peptides were low-affinity ligands for the GIP receptor. To examine biological activity in vivo, a bioassay was developed in the anesthetized rat. Intravenous infusion of GIP(1-42) (1 pmol/min/100 g) with a concurrent intraperitoneal glucose load (1 g/kg) significantly reduced circulating blood glucose excursions through stimulation of insulin release. Higher doses of GIP(1-14) and GIP(19-30) (100 pmol/min/100 g) also reduced blood glucose excursions.
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Affiliation(s)
- S A Hinke
- Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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33
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Kühn-Wache K, Manhart S, Hoffmann T, Hinke SA, Gelling R, Pederson RA, McIntosh CH, Demuth HU. Analogs of glucose-dependent insulinotropic polypeptide with increased dipeptidyl peptidase IV resistance. Adv Exp Med Biol 2001; 477:187-95. [PMID: 10849746 DOI: 10.1007/0-306-46826-3_21] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- K Kühn-Wache
- Probiodrug GmbH, Biocenter, Halle, Saale, Germany
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Pospisilik JA, Hinke SA, Pederson RA, Hoffmann T, Rosche F, Schlenzig D, Glund K, Heiser U, McIntosh CH, Demuth H. Metabolism of glucagon by dipeptidyl peptidase IV (CD26). Regul Pept 2001; 96:133-41. [PMID: 11111019 DOI: 10.1016/s0167-0115(00)00170-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Glucagon is a 29-amino acid polypeptide released from pancreatic islet alpha-cells that acts to maintain euglycemia by stimulating hepatic glycogenolysis and gluconeogenesis. Despite its importance, there remains controversy about the mechanisms responsible for glucagon clearance in the body. In the current study, enzymatic metabolism of glucagon was assessed using sensitive mass spectrometric techniques to identify the molecular products. Incubation of glucagon with purified porcine dipeptidyl peptidase IV (DP IV) yielded sequential production of glucagon(3-29) and glucagon(5-29). In human serum, degradation to glucagon(3-29) was rapidly followed by N-terminal cyclization of glucagon, preventing further DP IV-mediated hydrolysis. Bioassay of glucagon, following incubation with purified DP IV or normal rat serum demonstrated a significant loss of hyperglycemic activity, while a similar incubation in DP IV-deficient rat serum did not show any loss of glucagon bioactivity. Degradation, monitored by mass spectrometry and bioassay, was blocked by the specific DP IV inhibitor, isoleucyl thiazolidine. These results identify DP IV as a primary enzyme involved in the degradation and inactivation of glucagon. These findings have important implications for the determination of glucagon levels in human plasma.
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Affiliation(s)
- J A Pospisilik
- Department of Physiology, University of British Columbia, British Columbia, V6T 1Z3, Vancouver, Canada
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35
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Hinke SA, Pauly RP, Ehses J, Kerridge P, Demuth HU, McIntosh CH, Pederson RA. Role of glucose in chronic desensitization of isolated rat islets and mouse insulinoma (betaTC-3) cells to glucose-dependent insulinotropic polypeptide. J Endocrinol 2000; 165:281-91. [PMID: 10810292 DOI: 10.1677/joe.0.1650281] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It is well documented that the release of insulin from isolated perifused islets attenuates over time, despite a continued glucose stimulation. In the current study we have shown that potentiation of insulin release by the intestinal hormone glucose-dependent insulinotropic polypeptide (GIP) is also attenuated after its continuous application. In less than 20 h of maintained stimulus with either hyperglycaemia (11.0 mM glucose) or GIP (10 nM) under hyperglycaemic conditions, insulin release returned to basal values. This was not due to loss of islet viability or reduction in the releasable pool of insulin granules, as 1 mM isobutylmethylxanthine was able to stimulate equivalent insulin release under both conditions. Further examination of chronic GIP desensitization was examined in cultured mouse insulinoma (betaTC-3) cells. GIP-stimulated cAMP production was not greatly affected by the prevailing glucose conditions, suggesting that the glucose dependence of GIP-stimulated insulin release occurs distally to the increase in intracellular cAMP in betaTC-3 cells. The GIP-stimulated cAMP response curve after desensitization was of similar magnitude at all glucose concentrations, but GIP pretreatment did not affect forskolin-stimulated cAMP production. Desensitization of the cAMP response in betaTC-3 cells was shown not to involve induction of dipeptidyl peptidase IV or pertussis toxin-sensitive G-proteins, activation of protein kinase C or protein kinase A, or modulation of phosphodiesterase activity. Homologous desensitization of the insulin-potentiating activity of GIP was found to affect both GIP-stimulated and forskolin-stimulated insulin release, indicating desensitization of distal steps in the stimulus-exocytosis cascade.
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Affiliation(s)
- S A Hinke
- Department of Physiology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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36
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Hinke SA, Pospisilik JA, Demuth HU, Mannhart S, Kühn-Wache K, Hoffmann T, Nishimura E, Pederson RA, McIntosh CH. Dipeptidyl peptidase IV (DPIV/CD26) degradation of glucagon. Characterization of glucagon degradation products and DPIV-resistant analogs. J Biol Chem 2000; 275:3827-34. [PMID: 10660533 DOI: 10.1074/jbc.275.6.3827] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Over the past decade, numerous studies have been targeted at defining structure-activity relationships of glucagon. Recently, we have found that glucagon(1-29) is hydrolyzed by dipeptidyl peptidase IV (DPIV) to produce glucagon(3-29) and glucagon(5-29); in human serum, [pyroglutamyl (pGlu)(3)]glucagon(3-29) is formed from glucagon(3-29), and this prevents further hydrolysis of glucagon by DPIV (H.-U. Demuth, K. Glund, U. Heiser, J. Pospisilik, S. Hinke, T. Hoffmann, F. Rosche, D. Schlenzig, M. Wermann, C. McIntosh, and R. Pederson, manuscript in preparation). In the current study, the biological activity of these peptides was examined in vitro. The amino-terminally truncated peptides all behaved as partial agonists in cyclic AMP stimulation assays, with Chinese hamster ovary K1 cells overexpressing the human glucagon receptor (potency: glucagon(1-29) > [pGlu(3)]glu- cagon(3-29) > glucagon(3-29) > glucagon(5-29) > [Glu(9)]glu- cagon(2-29)). In competition binding experiments, [pGlu(3)]glucagon(3-29) and glucagon(5-29) both demonstrated 5-fold lower affinity for the receptor than glucagon(1-29), whereas glucagon(3-29) exhibited 18-fold lower affinity. Of the peptides tested, only glucagon(5-29) showed antagonist activity, and this was weak compared with the classical glucagon antagonist, [Glu(9)]glucagon(2-29). Hence, DPIV hydrolysis of glucagon yields low affinity agonists of the glucagon receptor. As a corollary to evidence indicating that DPIV degrades glucagon (Demuth, et al., manuscript in preparation), DPIV-resistant analogs were synthesized. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry was used to assess DPIV resistance, and it allowed kinetic analysis of degradation. Of several analogs generated, only [D-Ser(2)] and [Gly(2)]glucagon retained high affinity binding and biological potency, similar to native glucagon in vitro. [D-Ser(2)]Glucagon exhibited enhanced hyperglycemic activity in a bioassay, whereas [Gly(2)]glucagon was not completely resistant to DPIV degradation.
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Affiliation(s)
- S A Hinke
- Department of Physiology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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37
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Wheeler MB, Gelling RW, Hinke SA, Tu B, Pederson RA, Lynn F, Ehses J, McIntosh CH. Characterization of the carboxyl-terminal domain of the rat glucose-dependent insulinotropic polypeptide (GIP) receptor. A role for serines 426 and 427 in regulating the rate of internalization. J Biol Chem 1999; 274:24593-601. [PMID: 10455124 DOI: 10.1074/jbc.274.35.24593] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone involved in the regulation of insulin secretion. In non-insulin-dependent diabetes mellitus insulin responses to GIP are blunted, possibly due to altered signal transduction or reduced receptor number. Site-directed mutagenesis was used to construct truncated GIP receptors to study the importance of the carboxyl-terminal tail (CT) in binding, signaling, and receptor internalization. Receptors truncated at amino acids 425, 418, and 405, expressed in COS-7 or CHO-K1 cells, exhibited similar binding to wild type receptors. GIP-dependent cAMP production with the 405 mutant was decreased in COS-7 cells. Maximal cAMP production in CHO-K1 cells was reduced with all truncated forms. Binding was undetectable with a receptor truncated at amino acid 400; increasing tail length by adding 5 alanines restored binding and signaling. Mutants produced by alanine scanning of residues 394-401, adjacent to transmembrane domain 7, were all functional. CT truncation by 30 or more amino acids, mutation of serines 426/427, singly or combined, or complete CT serine knockout all reduced receptor internalization rate. The majority of the GIP receptor CT is therefore not required for signaling, a minimum chain length of approximately 405 amino acids is needed for receptor expression, and serines 426 and 427 are important for regulating rate of receptor internalization.
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Affiliation(s)
- M B Wheeler
- Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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38
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McIntosh CH, Bremsak I, Lynn FC, Gill R, Hinke SA, Gelling R, Nian C, McKnight G, Jaspers S, Pederson RA. Glucose-dependent insulinotropic polypeptide stimulation of lipolysis in differentiated 3T3-L1 cells: wortmannin-sensitive inhibition by insulin. Endocrinology 1999; 140:398-404. [PMID: 9886851 DOI: 10.1210/endo.140.1.6464] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GIP is an important insulinotropic hormone (incretin) that has also been implicated in fat metabolism. There is controversy regarding the actions of GIP on adipocytes. In the current study, the existence of GIP receptors and effects of GIP on lipolysis were studied in differentiated 3T3-L1 cells. GIP receptor messenger RNA was detected by RT-PCR and RNase protection assay. Receptors were detected in binding studies (IC50 26.7 +/- 0.7 nM). GIP stimulated glycerol release with an EC50 of 3.28 +/- 0.63 nM. GIP (10(-9)-10(-7) M) +/- IBMX increased cAMP production by 1180-2246%. The adenylyl cyclase inhibitor MDL 12330A (10(-4) M) inhibited GIP-induced glycerol production by >90%, and reduced cAMP responses to basal. Preincubation of 3T3-L1 cells with insulin inhibited glycerol responses to GIP, and the inhibitory effect of insulin was blocked by the phosphatidylinositol 3'-kinase inhibitor, wortmannin. It is concluded that GIP stimulates glycerol release in 3T3-L1 cells primarily via stimulation of cAMP production, and that insulin antagonizes GIP-induced lipolysis in a wortmannin-sensitive fashion. It is suggested that effects of GIP on fat metabolism in vivo may depend upon the circulating insulin level, and that meal-released GIP may elevate circulating fatty acids, thus optimizing pancreatic beta-cell responsiveness to stimulation by glucose and GIP.
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Affiliation(s)
- C H McIntosh
- Department of Physiology, University of British Columbia, Vancouver, Canada.
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