1
|
Zhu W, Tanday N, Lafferty RA, Flatt PR, Irwin N. Novel enzyme-resistant pancreatic polypeptide analogs evoke pancreatic beta-cell rest, enhance islet cell turnover, and inhibit food intake in mice. Biofactors 2024. [PMID: 38635341 DOI: 10.1002/biof.2059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/02/2024] [Indexed: 04/20/2024]
Abstract
Pancreatic polypeptide (PP) is a postprandial hormone secreted from pancreatic islets that activates neuropeptide Y4 receptors (NPY4Rs). PP is known to induce satiety but effects at the level of the endocrine pancreas are less well characterized. In addition, rapid metabolism of PP by dipeptidyl peptidase-4 (DPP-4) limits the investigation of the effects of the native peptide. Therefore, in the present study, five novel amino acid substituted and/or fatty acid derivatized PP analogs were synthesized, namely [P3]PP, [K13Pal]PP, [P3,K13Pal]PP, [N-Pal]PP, and [N-Pal,P3]PP, and their impact on pancreatic beta-cell function, as well as appetite regulation and glucose homeostasis investigated. All PP analogs displayed increased resistance to DPP-4 degradation. In addition, all peptides inhibited alanine-induced insulin secretion from BRIN-BD11 beta cells. Native PP and related analogs (10-8 and 10-6 M), and especially [P3]PP and [K13Pal]PP, significantly protected against cytokine-induced beta-cell apoptosis and promoted cellular proliferation, with effects dependent on the NPY4R for all peptides barring [N-Pal,P3]PP. In mice, all peptides, except [N-Pal]PP and [N-Pal,P3]PP, evoked a dose-dependent (25, 75, and 200 nmol/kg) suppression of appetite, with native PP and [P3]PP further augmenting glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) induced reductions of food intake. The PP peptides had no obvious detrimental effect on glucose tolerance and they did not noticeably impair the glucose-regulatory actions of GLP-1 or CCK. In conclusion, Pro3 amino acid substitution of PP, either alone or together with mid-chain acylation, creates PP analogs with benefits on beta-cell rest, islet cell turnover, and energy regulation that may be applicable to the treatment of diabetes and obesity.
Collapse
Affiliation(s)
- Wuyun Zhu
- Diabetes Research Centre, Schools of Biomedical Sciences and Pharmacy & Pharmaceutical Sciences, Ulster University, Coleraine, UK
| | - Neil Tanday
- Diabetes Research Centre, Schools of Biomedical Sciences and Pharmacy & Pharmaceutical Sciences, Ulster University, Coleraine, UK
| | - Ryan A Lafferty
- Diabetes Research Centre, Schools of Biomedical Sciences and Pharmacy & Pharmaceutical Sciences, Ulster University, Coleraine, UK
| | - Peter R Flatt
- Diabetes Research Centre, Schools of Biomedical Sciences and Pharmacy & Pharmaceutical Sciences, Ulster University, Coleraine, UK
| | - Nigel Irwin
- Diabetes Research Centre, Schools of Biomedical Sciences and Pharmacy & Pharmaceutical Sciences, Ulster University, Coleraine, UK
| |
Collapse
|
2
|
Gleixner J, Kopanchuk S, Grätz L, Tahk MJ, Laasfeld T, Veikšina S, Höring C, Gattor AO, Humphrys LJ, Müller C, Archipowa N, Köckenberger J, Heinrich MR, Kutta RJ, Rinken A, Keller M. Illuminating Neuropeptide Y Y 4 Receptor Binding: Fluorescent Cyclic Peptides with Subnanomolar Binding Affinity as Novel Molecular Tools. ACS Pharmacol Transl Sci 2024; 7:1142-1168. [PMID: 38633582 PMCID: PMC11019746 DOI: 10.1021/acsptsci.4c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 04/19/2024]
Abstract
The neuropeptide Y (NPY) Y4 receptor (Y4R), a member of the family of NPY receptors, is physiologically activated by the linear 36-amino acid peptide pancreatic polypeptide (PP). The Y4R is involved in the regulation of various biological processes, most importantly pancreatic secretion, gastrointestinal motility, and regulation of food intake. So far, Y4R binding affinities have been mostly studied in radiochemical binding assays. Except for a few fluorescently labeled PP derivatives, fluorescence-tagged Y4R ligands with high affinity have not been reported. Here, we introduce differently fluorescence-labeled (Sulfo-Cy5, Cy3B, Py-1, Py-5) Y4R ligands derived from recently reported cyclic hexapeptides showing picomolar Y4R binding affinity. With pKi values of 9.22-9.71 (radioligand competition binding assay), all fluorescent ligands (16-19) showed excellent Y4R affinity. Y4R saturation binding, binding kinetics, and competition binding with reference ligands were studied using different fluorescence-based methods: flow cytometry (Sulfo-Cy5, Cy3B, and Py-1 label), fluorescence anisotropy (Cy3B label), and NanoBRET (Cy3B label) binding assays. These experiments confirmed the high binding affinity to Y4R (equilibrium pKd: 9.02-9.9) and proved the applicability of the probes for fluorescence-based Y4R competition binding studies and imaging techniques such as single-receptor molecule tracking.
Collapse
Affiliation(s)
- Jakob Gleixner
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Sergei Kopanchuk
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Lukas Grätz
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Maris-Johanna Tahk
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Tõnis Laasfeld
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Santa Veikšina
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Carina Höring
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Albert O. Gattor
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Laura J. Humphrys
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Christoph Müller
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Nataliya Archipowa
- Institute
of Biophysics and Physical Biochemistry, Faculty of Biology and Preclinical
Medicine, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| | - Johannes Köckenberger
- Department
of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Markus R. Heinrich
- Department
of Chemistry and Pharmacy, Molecular and Clinical Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, D-91058 Erlangen, Germany
| | - Roger Jan Kutta
- Institute
of Physical and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Ago Rinken
- Institute
of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Max Keller
- Institute
of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany
| |
Collapse
|
3
|
Röring RJ, Debisarun PA, Botey-Bataller J, Suen TK, Bulut Ö, Kilic G, Koeken VA, Sarlea A, Bahrar H, Dijkstra H, Lemmers H, Gössling KL, Rüchel N, Ostermann PN, Müller L, Schaal H, Adams O, Borkhardt A, Ariyurek Y, de Meijer EJ, Kloet SL, ten Oever J, Placek K, Li Y, Netea MG. MMR vaccination induces trained immunity via functional and metabolic reprogramming of γδ T cells. J Clin Invest 2024; 134:e170848. [PMID: 38290093 PMCID: PMC10977989 DOI: 10.1172/jci170848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 01/26/2024] [Indexed: 02/01/2024] Open
Abstract
The measles, mumps, and rubella (MMR) vaccine protects against all-cause mortality in children, but the immunological mechanisms mediating these effects are poorly known. We systematically investigated whether MMR can induce long-term functional changes in innate immune cells, a process termed trained immunity, that could at least partially mediate this heterologous protection. In a randomized, placebo-controlled trial, 39 healthy adults received either the MMR vaccine or a placebo. Using single-cell RNA-Seq, we found that MMR caused transcriptomic changes in CD14+ monocytes and NK cells, but most profoundly in γδ T cells. Monocyte function was not altered by MMR vaccination. In contrast, the function of γδ T cells was markedly enhanced by MMR vaccination, with higher production of TNF and IFN-γ, as well as upregulation of cellular metabolic pathways. In conclusion, we describe a trained immunity program characterized by modulation of γδ T cell function induced by MMR vaccination.
Collapse
Affiliation(s)
- Rutger J. Röring
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Priya A. Debisarun
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Javier Botey-Bataller
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Computational Biology for Individualised Medicine, Centre for Individualised Infection Medicine (CiiM) and
- TWINCORE, a joint venture between the Helmholtz-Centre for Infection Research (HZI) and Hannover Medical School (MHH), Hannover, Germany
| | - Tsz Kin Suen
- Department of Immunology and Metabolism, Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
| | - Özlem Bulut
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Gizem Kilic
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Valerie A.C.M. Koeken
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Computational Biology for Individualised Medicine, Centre for Individualised Infection Medicine (CiiM) and
- TWINCORE, a joint venture between the Helmholtz-Centre for Infection Research (HZI) and Hannover Medical School (MHH), Hannover, Germany
| | - Andrei Sarlea
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
| | - Harsh Bahrar
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Helga Dijkstra
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Heidi Lemmers
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Nadine Rüchel
- Department for Pediatric Oncology, Hematology and Clinical Immunology and
| | - Philipp N. Ostermann
- Institute of Virology, University Hospital Duesseldorf, Medical Faculty, Heinrich Heine University Duesseldorf, Dusseldorf, Germany
| | - Lisa Müller
- Institute of Virology, University Hospital Duesseldorf, Medical Faculty, Heinrich Heine University Duesseldorf, Dusseldorf, Germany
| | - Heiner Schaal
- Institute of Virology, University Hospital Duesseldorf, Medical Faculty, Heinrich Heine University Duesseldorf, Dusseldorf, Germany
| | - Ortwin Adams
- Institute of Virology, University Hospital Duesseldorf, Medical Faculty, Heinrich Heine University Duesseldorf, Dusseldorf, Germany
| | - Arndt Borkhardt
- Department for Pediatric Oncology, Hematology and Clinical Immunology and
| | - Yavuz Ariyurek
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Emile J. de Meijer
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Susan L. Kloet
- Leiden Genome Technology Center, Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Jaap ten Oever
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Katarzyna Placek
- TWINCORE, a joint venture between the Helmholtz-Centre for Infection Research (HZI) and Hannover Medical School (MHH), Hannover, Germany
| | - Yang Li
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Computational Biology for Individualised Medicine, Centre for Individualised Infection Medicine (CiiM) and
- TWINCORE, a joint venture between the Helmholtz-Centre for Infection Research (HZI) and Hannover Medical School (MHH), Hannover, Germany
| | - Mihai G. Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases and
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
- Department of Immunology and Metabolism, Life and Medical Sciences (LIMES) Institute, University of Bonn, Bonn, Germany
| |
Collapse
|
4
|
Gleixner J, Gattor AO, Humphrys LJ, Brunner T, Keller M. [ 3H]UR-JG102-A Radiolabeled Cyclic Peptide with High Affinity and Excellent Selectivity for the Neuropeptide Y Y 4 Receptor. J Med Chem 2023; 66:13788-13808. [PMID: 37773891 DOI: 10.1021/acs.jmedchem.3c01224] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
The family of human neuropeptide Y receptors (YRs) comprises four subtypes (Y1R, Y2R, Y4R, and Y5R) that are involved in the regulation of numerous physiological processes. Until now, Y4R binding studies have been predominantly performed in hypotonic sodium-free buffers using 125I-labeled derivatives of the endogenous YR agonists pancreatic polypeptide or peptide YY. A few tritium-labeled Y4R ligands have been reported; however, when used in buffers containing sodium at a physiological concentration, their Y4R affinities are insufficient. Based on the cyclic hexapeptide UR-AK86C, we developed a new tritium-labeled Y4R radioligand ([3H]UR-JG102, [3H]20). In sodium-free buffer, [3H]20 exhibits a very low Y4R dissociation constant (Kd 0.012 nM). In sodium-containing buffer (137 mM Na+), the Y4R affinity is lower (Kd 0.11 nM) but still considerably higher compared to previously reported tritiated Y4R ligands. Therefore, [3H]20 represents a useful tool compound for the determination of Y4R binding affinities under physiological-like conditions.
Collapse
Affiliation(s)
- Jakob Gleixner
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Albert O Gattor
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Laura J Humphrys
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Thomas Brunner
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| |
Collapse
|
5
|
Caballero-Mateos AM, Ruiz-Rodríguez AJ, Roa-Colomo A, García-Márquez J, Vidal-Vílchez B. β-Endorphins are not responsible for delayed gastric emptying of digestible solids after exercise in professional cyclists. A preliminary study. GASTROENTEROLOGIA Y HEPATOLOGIA 2023; 46:419-424. [PMID: 35964812 DOI: 10.1016/j.gastrohep.2022.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/07/2022] [Accepted: 08/05/2022] [Indexed: 05/24/2023]
Abstract
OBJECTIVE It has been reported that professional cyclists had an accelerated solid gastric emptying which decreased by increasing the exercise intensity. That could be explained by a predominance of stress-dependent motility inhibitors such gastrointestinal hormones, neurotransmitters and or the predominance of the gastric inhibitory vagal motor circuit. The aim of this preliminary study was to evaluate the role of β-endorphins, inhibitors of gastric motility, in these findings. METHODS Gastric emptying of solids marked with Tc99 while resting and plasmatic levels of β-endorphins were evaluated in 27 healthy controls and 19 professional cyclists (day 1). Besides, gastric emptying of solids was also assessed in cyclists when they reached 50% (day 1) and 75% (day 2) of the maximum oxygen consumption (low and high, respectively), during exercise on the cycle-ergometer. The third day, naloxone was administered in cyclists in order to block the β-endorphins receptors and gastric emptying was measured when they reached 75% of the maximum oxygen consumption. RESULTS Basal β-endorphin levels were lower in cyclists vs controls (p<0.05) and they increased with the exercise intensity (p<0.001). There were no significant differences in gastric emptying of solids with or without naloxone when 75% of the maximum oxygen consumption was reached. CONCLUSIONS The inhibitory effect of the exercise in the gastric emptying of solids does not seem to be secondary to the action of β-endorphins, that leaves the gastric inhibitory vagal motor circuit a more likely predominant role.
Collapse
Affiliation(s)
| | | | - Amparo Roa-Colomo
- Servicio de Aparato Digestivo, Hospital Clínico San Cecilio, Granada, Spain
| | | | | |
Collapse
|
6
|
Verbeure W, Rotondo A, Janssen P, Carbone F, Tack J. Supraphysiological effects of pancreatic polypeptide on gastric motor function and nutrient tolerance in humans. Physiol Rep 2021; 9:e15002. [PMID: 34435472 PMCID: PMC8387790 DOI: 10.14814/phy2.15002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/24/2022] Open
Abstract
Pancreatic polypeptide (PP) is known to affect food intake. In this exploratory study, we set out to investigate its supraphysiological effect on food tolerance, gastric accommodation, and emptying. In 12 healthy volunteers, 0, 3, or 10 pmol*kg-1 *min-1 PP was administered intravenously (PP0, PP3 or PP10). Thirty minutes thereafter, nutrient drink infusion (60 ml*min-1 ) through a nasogastric feeding tube was started until maximum satiation. Gastric accommodation was assessed by measuring the intragastric pressure (IGP; nasogastric manometry). In a separate test, the effect of PP0 or PP10 on gastric emptying was tested in 10 healthy volunteers and assessed using the 13 C breath test. Results are presented as mean ± SEM, and p < 0.05 was considered significant. For the IGP test, PP increased ingested nutrient volume: 886 ± 93, 1059 ± 124, and 1025 ± 125 ml for PP0, PP3, and PP10, respectively (p = 0.048). In all groups, Nadir IGP values were reached upon food intake (transformed values: 1.5 ± 0.2, 1.7 ± 0.3, and 1.6 ± 0.3 mmHg for PP0, PP3, and PP10, respectively; NS) to return to baseline thereafter. For the gastric emptying study, volunteers ingested a similar nutrient volume: 802 ± 119 and 1089 ± 128 ml (p = 0.016), and gastric half-emptying time was 281 ± 52 and 249 ± 37 min for PP0 and PP10, respectively (NS). No significant correlation between tolerated nutrient volume and IGP drop (R² < 0.01; p = 0.88 for PP0 vs. PP3 and R² =0.07; p = 0.40 for PP0 vs. PP10, respectively) or gastric half-emptying time (R² = 0.12; p = 0.32) was found. A supraphysiological PP dose enhances food tolerance; however, this effect is not mediated through gastric motility. CLINICAL TRIAL REGISTRY NUMBER: NCT03854708 is obtained from clinicaltrials.gov.
Collapse
Affiliation(s)
- Wout Verbeure
- Translational Research Center for Gastrointestinal DisordersKULeuvenBelgium
| | - Alessandra Rotondo
- Translational Research Center for Gastrointestinal DisordersKULeuvenBelgium
| | - Pieter Janssen
- Translational Research Center for Gastrointestinal DisordersKULeuvenBelgium
| | - Florencia Carbone
- Translational Research Center for Gastrointestinal DisordersKULeuvenBelgium
| | - Jan Tack
- Translational Research Center for Gastrointestinal DisordersKULeuvenBelgium
| |
Collapse
|
7
|
Pancreatic Ppy-expressing γ-cells display mixed phenotypic traits and the adaptive plasticity to engage insulin production. Nat Commun 2021; 12:4458. [PMID: 34294685 PMCID: PMC8298494 DOI: 10.1038/s41467-021-24788-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 07/08/2021] [Indexed: 02/06/2023] Open
Abstract
The cellular identity of pancreatic polypeptide (Ppy)-expressing γ-cells, one of the rarest pancreatic islet cell-type, remains elusive. Within islets, glucagon and somatostatin, released respectively from α- and δ-cells, modulate the secretion of insulin by β-cells. Dysregulation of insulin production raises blood glucose levels, leading to diabetes onset. Here, we present the genetic signature of human and mouse γ-cells. Using different approaches, we identified a set of genes and pathways defining their functional identity. We found that the γ-cell population is heterogeneous, with subsets of cells producing another hormone in addition to Ppy. These bihormonal cells share identity markers typical of the other islet cell-types. In mice, Ppy gene inactivation or conditional γ-cell ablation did not alter glycemia nor body weight. Interestingly, upon β-cell injury induction, γ-cells exhibited gene expression changes and some of them engaged insulin production, like α- and δ-cells. In conclusion, we provide a comprehensive characterization of γ-cells and highlight their plasticity and therapeutic potential.
Collapse
|
8
|
Ng XW, Chung YH, Piston DW. Intercellular Communication in the Islet of Langerhans in Health and Disease. Compr Physiol 2021; 11:2191-2225. [PMID: 34190340 DOI: 10.1002/cphy.c200026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Blood glucose homeostasis requires proper function of pancreatic islets, which secrete insulin, glucagon, and somatostatin from the β-, α-, and δ-cells, respectively. Each islet cell type is equipped with intrinsic mechanisms for glucose sensing and secretory actions, but these intrinsic mechanisms alone cannot explain the observed secretory profiles from intact islets. Regulation of secretion involves interconnected mechanisms among and between islet cell types. Islet cells lose their normal functional signatures and secretory behaviors upon dispersal as compared to intact islets and in vivo. In dispersed islet cells, the glucose response of insulin secretion is attenuated from that seen from whole islets, coordinated oscillations in membrane potential and intracellular Ca2+ activity, as well as the two-phase insulin secretion profile, are missing, and glucagon secretion displays higher basal secretion profile and a reverse glucose-dependent response from that of intact islets. These observations highlight the critical roles of intercellular communication within the pancreatic islet, and how these communication pathways are crucial for proper hormonal and nonhormonal secretion and glucose homeostasis. Further, misregulated secretions of islet secretory products that arise from defective intercellular islet communication are implicated in diabetes. Intercellular communication within the islet environment comprises multiple mechanisms, including electrical synapses from gap junctional coupling, paracrine interactions among neighboring cells, and direct cell-to-cell contacts in the form of juxtacrine signaling. In this article, we describe the various mechanisms that contribute to proper islet function for each islet cell type and how intercellular islet communications are coordinated among the same and different islet cell types. © 2021 American Physiological Society. Compr Physiol 11:2191-2225, 2021.
Collapse
Affiliation(s)
- Xue W Ng
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - Yong H Chung
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - David W Piston
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| |
Collapse
|
9
|
Montégut L, Lopez-Otin C, Magnan C, Kroemer G. Old Paradoxes and New Opportunities for Appetite Control in Obesity. Trends Endocrinol Metab 2021; 32:264-294. [PMID: 33707095 DOI: 10.1016/j.tem.2021.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022]
Abstract
Human obesity is accompanied by alterations in the blood concentrations of multiple circulating appetite regulators. Paradoxically, most of the appetite-inhibitory hormones are elevated in nonsyndromic obesity, while most of the appetite stimulatory hormones are reduced, perhaps reflecting vain attempts of regulation by inefficient feedback circuitries. In this context, it is important to understand which appetite regulators exhibit a convergent rather than paradoxical behavior and hence are likely to contribute to the maintenance of the obese state. Pharmacological interventions in obesity should preferentially consist of the supplementation of deficient appetite inhibitors or the neutralization of excessive appetite stimulators. Here, we critically analyze the current literature on appetite-regulatory peptide hormones. We propose a short-list of appetite modulators that may constitute the best candidates for therapeutic interventions.
Collapse
Affiliation(s)
- Léa Montégut
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France
| | - Carlos Lopez-Otin
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, 33006, Oviedo, Spain
| | | | - Guido Kroemer
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue Contre le Cancer, Université de Paris, Sorbonne Université, INSERM U1138, Institut Universitaire de France, Paris, France; Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France; Unité de Biologie Fonctionnelle et Adaptative, Sorbonne Paris Cité, CNRS UMR8251, Université Paris Diderot, Paris, France; Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-, HP, Paris, France; Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China; Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden.
| |
Collapse
|
10
|
Cong GZ, Ghosh KK, Mishra S, Gulyás M, Kovács T, Máthé D, Padmanabhan P, Gulyás B. Targeted pancreatic beta cell imaging for early diagnosis. Eur J Cell Biol 2020; 99:151110. [PMID: 33070042 DOI: 10.1016/j.ejcb.2020.151110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 06/29/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022] Open
Abstract
Pancreatic beta cells are important in blood glucose level regulation. As type 1 and 2 diabetes are getting prevalent worldwide, we need to explore new methods for early detection of beta cell-related afflictions. Using bioimaging techniques to measure beta cell mass is crucial because a decrease in beta cell density is seen in diseases such as diabetes and thus can be a new way of diagnosis for such diseases. We also need to appraise beta cell purity in transplanted islets for type 1 diabetes patients. Sufficient amount of functional beta cells must also be determined before being transplanted to the patients. In this review, indirect imaging of beta cells will be discussed. This includes membrane protein on pancreatic beta cells whereby specific probes are designed for different imaging modalities mainly magnetic resonance imaging, positron emission tomography and fluorescence imaging. Direct imaging of insulin is also explored though probes synthesized for such function are relatively fewer. The path for successful pancreatic beta cell imaging is fraught with challenges like non-specific binding, lack of beta cell-restricted targets, the requirement of probes to cross multiple lipid layers to bind to intracellular insulin. Hence, there is an urgent need to develop new imaging techniques and innovative probing constructs in the entire imaging chain of bioengineering to provide early detection of beta cell-related pathology.
Collapse
Affiliation(s)
- Goh Zheng Cong
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Krishna Kanta Ghosh
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Sachin Mishra
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
| | - Miklós Gulyás
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Dag Hammarskölds väg 20, Uppsala Se-751 85, Sweden
| | - Tibor Kovács
- Institute of Radiochemistry and Radioecology, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary
| | - Domokos Máthé
- Department of Biophysics and Radiation Biology, Semmelweis University Faculty of Medicine, Tűzoltó u. 37-47, Budapest H-1094, Hungary
| | - Parasuraman Padmanabhan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore.
| | - Balázs Gulyás
- Lee Kong Chian School of Medicine, Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore.
| |
Collapse
|
11
|
Lasschuijt M, Mars M, de Graaf C, Smeets PAM. How oro-sensory exposure and eating rate affect satiation and associated endocrine responses-a randomized trial. Am J Clin Nutr 2020; 111:1137-1149. [PMID: 32320002 PMCID: PMC7266691 DOI: 10.1093/ajcn/nqaa067] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/16/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Longer oral processing decreases food intake. This can be attributed to greater oro-sensory exposure (OSE) and a lower eating rate (ER). How these factors contribute to food intake, and the underlying physiological mechanisms, remain unclear. OBJECTIVES We aimed to determine the independent and simultaneous effects of OSE and ER on satiation and associated endocrine responses. METHODS Forty participants in study 1 [mean ± SD age: 24 ± 4 y; BMI (in kg/m2): 22 ± 2] and 20 in study 2 (mean ± SD age: 23 ± 3 y; BMI: 23 ± 2) participated in a 2 × 2 randomized trial. In both studies, participants ate chocolate custard with added caramel sauce (low OSE) or caramel fudge (high OSE) and with short (fast ER) or long breaks (slow ER) in between bites, until fullness. In study 2, endocrine responses were measured during the meal. RESULTS In study 1, participants ate (mean ± SEM) 42 ± 15 g less in the slow- than in the fast-ER condition, only within the high-OSE condition (P = 0.04). In study 2, participants ate 66 ± 21 g less in the high- than in the low-OSE condition and there were no intake differences between slow and fast ER (P = 0.35). Eight minutes after starting to eat, insulin concentrations increased by 42%-65% in all treatments compared with the control. At the end of the meal, insulin concentrations were 81% higher in the high-OSE, slow-ER than in the low-OSE, fast-ER condition (P = 0.049). Pancreatic polypeptide (PP) increased by 62%, 5 min after meal onset in the low-OSE, fast-ER condition (P = 0.005). Ghrelin concentrations did not change. CONCLUSIONS Greater OSE increases insulin responsiveness. In contrast, PP responses are stronger when OSE is reduced and ER is fast. Insulin and PP responses may mediate the independent effects of OSE and ER on food intake. These may be beneficial eating strategies, particularly for type 2 diabetic patients, to control food intake and maintain glucose homeostasis.This trial was registered at trialregister.nl as NL6544.
Collapse
Affiliation(s)
- Marlou Lasschuijt
- Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, Netherlands,Address correspondence to ML (e-mail: )
| | - Monica Mars
- Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, Netherlands
| | - Cees de Graaf
- Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, Netherlands
| | - Paul A M Smeets
- Division of Human Nutrition and Health, Wageningen University & Research, Wageningen, Netherlands,Image Sciences Institute, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
12
|
Veedfald S, Vedtofte L, Skov-Jeppesen K, Deacon CF, Hartmann B, Vilsbøll T, Knop FK, Christensen MB, Holst JJ. Glucose-Dependent Insulinotropic Polypeptide Is a Pancreatic Polypeptide Secretagogue in Humans. J Clin Endocrinol Metab 2020; 105:5607542. [PMID: 31665480 DOI: 10.1210/clinem/dgz097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/05/2019] [Indexed: 02/13/2023]
Abstract
BACKGROUND Glucose-dependent insulinotropic polypeptide (GIP) has been suggested to stimulate the secretion of pancreatic polypeptide (PP), an islet hormone thought to regulate gut motility, appetite, and glycemia. OBJECTIVE To determine whether human GIP1-42 (hGIP) stimulates PP secretion. METHOD As glycemia modulates the secretion of PP, we measured plasma PP concentrations from 2 studies in healthy men (n = 10) and in patients with type 2 diabetes (T2D) (n = 12), where hGIP1-42 had been administered intravenously during fasting glycemia, hyperglycemia (12 mmol/L), and insulin-induced hypoglycemia (targets: 2.5 mmol/L [healthy]; 3.5 mmol/L [T2D]). Porcine GIP1-42 (pGIP) was also infused intra-arterially in isolated porcine pancreata (n = 4). RESULTS Mean fasting plasma glucose concentrations were approximately 5 mmol/L (healthy) and approximately 8 mmol/L (T2D). At fasting glycemia, PP concentrations were higher during intravenous hGIP1-42 infusion compared with saline in healthy men (mean [standard error of the mean, SEM], net incremental areas under the curves (iAUCs)[0-30min], 403 [116] vs -6 [57] pmol/L × min; P = 0.004) and in patients with T2D (905 [177] vs -96 [86] pmol/L × min; P = 0.009). During hyperglycemic clamping, mean [SEM] PP concentrations were significantly higher during hGIP1-42 infusion compared with saline in patients with T2D (771 [160] vs -183 [117] pmol/L × min; P = 0.001), but not in healthy individuals (-8 [86] vs -57 [53] pmol/L × min; P = 0.69). When plasma glucose levels were declining in response to exogenous insulin, mean [SEM] PP concentrations were higher during hGIP1-42 infusion compared with saline in healthy individuals (294 [88] vs -82 [53] pmol/L × min; P = 0.0025), but not significantly higher in patients with T2D (586 [314] vs -120 [53]; P = 0.070). At target hypoglycemia, PP levels surged in both groups during both hGIP1-42 and saline infusions. In isolated pancreata, pGIP1-42 increased mean [SEM] PP output in the pancreatic venous effluent (baseline vs infusion, 24[5] vs 79 [16] pmol/min x min; P = 0.044). CONCLUSION GIP1-42 increases plasma PP secretion in healthy individuals, patients with T2D, and isolated porcine pancreata. Hyperglycemia blunts the stimulatory effect of hGIP1-42 in healthy individuals, but not in patients with T2D.
Collapse
Affiliation(s)
- Simon Veedfald
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise Vedtofte
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Kirsa Skov-Jeppesen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Carolyn F Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Tina Vilsbøll
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel B Christensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| |
Collapse
|
13
|
Miron I, Dumitrascu DL. GASTROINTESTINAL MOTILITY DISORDERS IN OBESITY. ACTA ENDOCRINOLOGICA-BUCHAREST 2019; 15:497-504. [PMID: 32377248 DOI: 10.4183/aeb.2019.497] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The gastrointestinal (GI) motility, which is important for the digestion and absorption, may be altered in obesity. The aim of this review is to present the GI motility changes occurring in obesity, as well as their underlying mechanisms. We have conducted a systematic review of the published literature concerning GI motility and obesity and have described recent published data on the changes throughout the entire GI tract. Most recent discoveries include evidence supporting the increase of gastroesophageal reflux disease in obesity and inhibition of gastric motility. Intestinal transit of the distal small bowel generally slows down, ensuring enough time for digestion and absorption. Constipation is more frequent in obese patients than in those with a normal weight. The gut-brain axis plays an important role in the pathophysiology of GI motility disorders in obesity. This bidirectional communication is achieved by way of neurons, hormones, metabolites derived from intestinal microbiota and cytokines. The molecular mechanisms of GI motility changes in obesity are complex. Current data offer a starting point for further research needed to clarify the association of obesity with GI motility disorders.
Collapse
Affiliation(s)
- I Miron
- "Iuliu Hatieganu" University of Medicine and Pharmacy, 3 Medical Clinic, Cluj-Napoca, Romania
| | - D L Dumitrascu
- "Iuliu Hatieganu" Dept of Internal Medicine, Cluj-Napoca, Romania
| |
Collapse
|
14
|
Kumar N, Bazerbachi F, Rustagi T, McCarty TR, Thompson CC, Galvao Neto MP, Zundel N, Wilson EB, Gostout CJ, Abu Dayyeh BK. The Influence of the Orbera Intragastric Balloon Filling Volumes on Weight Loss, Tolerability, and Adverse Events: a Systematic Review and Meta-Analysis. Obes Surg 2018; 27:2272-2278. [PMID: 28285471 DOI: 10.1007/s11695-017-2636-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The Orbera intragastric balloon (IGB) has been approved by the US Food and Drug Administration for use in patients with a body mass index (BMI) between 30 and 40 kg/m2 and is in wide use worldwide as a primary and bridge obesity management tool. The balloon filling volume (BFV) ranges between 400 and 700 mL of saline. Our objective was to determine whether there is an association between BFV and clinically relevant endpoints, namely weight loss outcomes, balloon tolerability, and adverse events. METHODS A systematic review of studies investigating the use of the Orbera IGB system for obesity treatment was performed. Data was examined using random effects modelling and meta-regression analyses. RESULTS Forty-four studies (n = 5549 patients) reported BFV and % total body weight loss (TBWL) at 6 months. Pooled %TBWL at 6 months was 13.2% [95% CI 12.3-14.0]. A funnel plot demonstrated a low risk of publication bias. Meta-regression showed no statistically significant association between filling volume and %TBWL at 6 months (p = 0.268). Higher BFV was associated with lower rates of esophagitis (slope = -0.008, p < 0.001) and prosthesis migration (slope = -0.015, p < 0.001). There was no association between BFV and early removal (p = 0.1), gastroesophageal reflux symptom (p = 0.64), or ulcer rates (p = 0.09). CONCLUSIONS No association was observed between Orbera IGB filling volume and weight loss outcomes. Higher volumes appear to be associated with lower migration and esophagitis rates; thus, a balloon filling volume of 600-650 mL is recommended.
Collapse
Affiliation(s)
- Nitin Kumar
- Department of Gastroenterology, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Tarun Rustagi
- Department of Gastroenterology, Mayo Clinic, Rochester, MN, USA
| | - Thomas R McCarty
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | | | | | - Natan Zundel
- Department of Surgery, Florida International University, Miami, FL, USA
| | - Erik B Wilson
- Department of Surgery, University of Texas, Houston, TX, USA
| | | | | |
Collapse
|
15
|
Kar P, Jones KL, Plummer MP, Ali Abdelhamid Y, Giersch EJ, Summers MJ, Hatzinikolas S, Heller S, Horowitz M, Deane AM. Antecedent Hypoglycemia Does Not Attenuate the Acceleration of Gastric Emptying by Hypoglycemia. J Clin Endocrinol Metab 2017; 102:3953-3960. [PMID: 28973430 PMCID: PMC5673277 DOI: 10.1210/jc.2017-00051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 07/21/2017] [Indexed: 02/07/2023]
Abstract
Context Acute hypoglycemia accelerates gastric emptying and increases cardiac contractility. However, antecedent hypoglycemia attenuates counterregulatory hormonal responses to subsequent hypoglycemia. Objective To determine the effect of antecedent hypoglycemia on gastric and cardiac responses to subsequent hypoglycemia in health. Design A prospective, single-blind, randomized, crossover study (performed at the Royal Adelaide Hospital, Adelaide, South Australia, Australia). Patients Ten healthy young men 18 to 35 years of age were studied for 36 hours on two occasions. Interventions Participants were randomly assigned to either antecedent hypoglycemia [three 45-minute periods of strict hypoglycemia (2.8 mmol/L] or control [three 45-minute periods of strict euglycemia (6 mmol/L)] during the initial 12-hour period. Participants were monitored overnight, and the following morning blood glucose was clamped at 2.8 mmol/L for 60 minutes and then at 6 mmol/L for 120 minutes. At least 6 weeks later participants returned for the alternative intervention. Gastric emptying and cardiac fractional shortening were measured with scintigraphy and two-dimensional echocardiography, respectively, on the morning of all 4 study days. Results A single, acute episode of hypoglycemia accelerated gastric emptying (P = 0.01) and augmented fractional shortening (P < 0.01). Gastric emptying was unaffected by antecedent hypoglycemia (P = 0.74) whereas fractional shortening showed a trend to attenuation (P = 0.06). The adrenaline response was diminished (P < 0.05) by antecedent hypoglycemia. Conclusions In health, the acceleration of gastric emptying during hypoglycemia is unaffected by antecedent hypoglycemia, whereas the increase in cardiac contractility may be attenuated.
Collapse
Affiliation(s)
- Palash Kar
- Discipline of Acute Care Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia 5000, Australia
| | - Karen L. Jones
- National Health and Medical Research Council Centre of Research Excellence in the Translation of Nutritional Science into Good Health, University of Adelaide, Adelaide, South Australia 5005, Australia
- Discipline of Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Mark P. Plummer
- Discipline of Acute Care Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia 5000, Australia
| | - Yasmine Ali Abdelhamid
- Discipline of Acute Care Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia 5000, Australia
| | - Emma J. Giersch
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia 5000, Australia
| | - Matthew J. Summers
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia 5000, Australia
| | - Seva Hatzinikolas
- National Health and Medical Research Council Centre of Research Excellence in the Translation of Nutritional Science into Good Health, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Simon Heller
- Academic Unit of Diabetes, Endocrinology and Metabolism, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Michael Horowitz
- National Health and Medical Research Council Centre of Research Excellence in the Translation of Nutritional Science into Good Health, University of Adelaide, Adelaide, South Australia 5005, Australia
- Discipline of Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Adam M. Deane
- Discipline of Acute Care Medicine, University of Adelaide, Adelaide, South Australia 5005, Australia
- Intensive Care Unit, The Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| |
Collapse
|
16
|
Guarino D, Nannipieri M, Iervasi G, Taddei S, Bruno RM. The Role of the Autonomic Nervous System in the Pathophysiology of Obesity. Front Physiol 2017; 8:665. [PMID: 28966594 PMCID: PMC5606212 DOI: 10.3389/fphys.2017.00665] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 08/22/2017] [Indexed: 12/18/2022] Open
Abstract
Obesity is reaching epidemic proportions globally and represents a major cause of comorbidities, mostly related to cardiovascular disease. The autonomic nervous system (ANS) dysfunction has a two-way relationship with obesity. Indeed, alterations of the ANS might be involved in the pathogenesis of obesity, acting on different pathways. On the other hand, the excess weight induces ANS dysfunction, which may be involved in the haemodynamic and metabolic alterations that increase the cardiovascular risk of obese individuals, i.e., hypertension, insulin resistance and dyslipidemia. This article will review current evidence about the role of the ANS in short-term and long-term regulation of energy homeostasis. Furthermore, an increased sympathetic activity has been demonstrated in obese patients, particularly in the muscle vasculature and in the kidneys, possibily contributing to increased cardiovascular risk. Selective leptin resistance, obstructive sleep apnea syndrome, hyperinsulinemia and low ghrelin levels are possible mechanisms underlying sympathetic activation in obesity. Weight loss is able to reverse metabolic and autonomic alterations associated with obesity. Given the crucial role of autonomic dysfunction in the pathophysiology of obesity and its cardiovascular complications, vagal nerve modulation and sympathetic inhibition may serve as therapeutic targets in this condition.
Collapse
Affiliation(s)
- Daniela Guarino
- Department of Clinical and Experimental Medicine, University of PisaPisa, Italy.,Institute of Clinical Physiology of CNRPisa, Italy.,Scuola Superiore Sant'AnnaPisa, Italy
| | - Monica Nannipieri
- Department of Clinical and Experimental Medicine, University of PisaPisa, Italy
| | | | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of PisaPisa, Italy
| | - Rosa Maria Bruno
- Department of Clinical and Experimental Medicine, University of PisaPisa, Italy
| |
Collapse
|
17
|
Bunt JC, Blackstone R, Thearle MS, Vinales KL, Votruba S, Krakoff J. Changes in glycemia, insulin and gut hormone responses to a slowly ingested solid low-carbohydrate mixed meal after laparoscopic gastric bypass or band surgery. Int J Obes (Lond) 2017; 41:706-713. [PMID: 28119531 DOI: 10.1038/ijo.2017.22] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 12/22/2016] [Accepted: 01/11/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To evaluate early changes in glycemia, insulin physiology and gut hormone responses to an easily tolerated and slowly ingested solid, low-carbohydrate mixed meal test (MMT) following laparoscopic adjustable gastric banding (LAGB) or Roux-en-Y gastric bypass (RYGB) surgery. SUBJECTS/METHODS This was a prospective non-randomized study. Plasma glucose, insulin and c-peptide (to estimate hepatic insulin extraction; %HIE), incretins (GIP, aGLP-1) and pancreatic polypeptide (PP) responses to the MMT were measured at 4-8 weeks before and after surgery in obese, metabolically healthy patients (RYGB=10F or LAGB =7F/1M). Supplementary clamp data on basal endogenous glucose production (EGP) and peripheral insulin action (Rd=rate of glucose disposal) and metabolic clearance rates of insulin (MCR-INS) were available in five of the RYGB patients. Repeated measures were appropriately accounted for in the analyses. RESULTS Following LAGB surgery, C-peptide and insulin MMT profiles (P=0.004 and P=0.0005, respectively) were lower with no change in %HIE (P=0.98). In contrast, in RYGB subjects, both fasting glucose and insulin (Δ=-0.66 mmol l-1, P⩽0.05 and Δ=-44.4 pmol l-1, P⩽0.05, respectively) decreased, and MMT glucose (P<0.0001) and insulin (P=0.001) but not c-peptide (P= 0.69) decreased. Estimated %HIE increased at fasting (Δ=8.4%, P⩽0.05) and during MMT (P=0.0005). Early (0-20 min) prandial glucose (0.27±0.26 versus 0.006±0.21 mmol l-1, P⩽0.05) and insulin (63(48, 66) versus 18(12, 24) pmol l-1, P⩽0.05) responses increased after RYGB. RYGB altered the trajectory of prandial aGLP-1 responses (treatment × trajectory P=0.02), and PP was lower (P<0.0001). Clamp data in a subset of RYGB patients showed early improvement in basal EGP (P=0.001), and MCR-INS (P=0.015). CONCLUSION RYGB results in distinctly different changes in plasma glucose, insulin and gut hormone response patterns to a solid, slowly ingested low-carbohydrate MMT versus LAGB. Altered nutrient delivery, along with indirect evidence for changes in hepatic and peripheral insulin physiology, are consistent with the greater early improvement in glycemia observed after RYGB versus LAGB surgery.
Collapse
Affiliation(s)
- J C Bunt
- Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, NIDDK, NIH, DHHS, Phoenix, AZ, USA
| | - R Blackstone
- Scottsdale Healthcare Bariatric Center, Scottsdale, AZ, USA.,Department of Surgery, University of Arizona College of Medicine, Phoenix, AZ, USA
| | - M S Thearle
- Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, NIDDK, NIH, DHHS, Phoenix, AZ, USA
| | - K L Vinales
- Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, NIDDK, NIH, DHHS, Phoenix, AZ, USA
| | - S Votruba
- Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, NIDDK, NIH, DHHS, Phoenix, AZ, USA
| | - J Krakoff
- Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, NIDDK, NIH, DHHS, Phoenix, AZ, USA
| |
Collapse
|
18
|
Amato A, Baldassano S, Caldara GF, Mulè F. Pancreatic polypeptide stimulates mouse gastric motor activity through peripheral neural mechanisms. Neurogastroenterol Motil 2017; 29. [PMID: 27381051 DOI: 10.1111/nmo.12901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/10/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Pancreatic polypeptide (PP) is supposed to be one of the major endogenous agonists of the neuropeptide Y4 receptor. Pancreatic polypeptide can influence gastrointestinal motility, acting mainly through vagal mechanisms, but whether PP acts directly on the stomach has not been explored yet. The aims of this study were to investigate the effects of PP on mouse gastric emptying, on spontaneous tone of whole stomach in vitro and to examine the mechanism of action. METHODS Gastric emptying was measured by red phenol method after i.p. PP administration (1-3 nmol per mouse). Responses induced by PP (1-300 mmol L-1 ) on gastric endoluminal pressure were analyzed in vitro in the presence of different drugs. Gastric genic expression of Y4 receptor was verified by RT-PCR. KEY RESULTS Pancreatic polypeptide dose-dependently increased non-nutrient liquid gastric emptying rate. In vitro, PP produced a concentration-dependent contraction that was abolished by tetrodotoxin, a neural blocker of Na+ voltage-dependent channels. The contractile response was significantly reduced by atropine, a muscarinic receptor antagonist, and by SR48968, an NK2 receptor antagonist, while it was potentiated by neostigmine, an inhibitor of acetylcholinesterase. The joint application of atropine and SR48968 fully abolished PP contractile effect. Reverse transcriptase-polymerase chain reaction analysis revealed the presence of Y4 receptor mRNA in mouse stomach with a greater expression in antrum than in fundus. CONCLUSIONS & INFERENCES The present findings demonstrate that exogenous PP stimulates mouse gastric motor activity, by acting directly on the stomach. This effect appears due to the activation of enteric excitatory neurons releasing acetylcholine and tachykinins.
Collapse
Affiliation(s)
- A Amato
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - S Baldassano
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - G F Caldara
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| | - F Mulè
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Università di Palermo, Palermo, Italy
| |
Collapse
|
19
|
Ting CH, Chen YC, Liaw WJ, Lin HC, Chen CY. Peripheral injection of pancreatic polypeptide enhances colonic transit without eliciting anxiety or altering colonic secretion in rats. Neuropeptides 2016; 55:67-71. [PMID: 26601891 DOI: 10.1016/j.npep.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 10/10/2015] [Accepted: 10/11/2015] [Indexed: 12/11/2022]
Abstract
Pancreatic polypeptide (PP) is a negative regulator of energy homeostasis that suppresses food intake and lowers body weight. Similar to other gastrointestinal-derived peptides, PP also modulates gastrointestinal motility and may be involved in the regulation of anxiety. Previous studies revealed that PP suppresses gastric emptying but increases colonic motility in mice. In our present study, we assessed the effect of PP on anxiety as well as colonic motility and secretory function. Intracerebroventricular and intravenous routes of PP were administered in conscious rats. Our results showed that intracerebroventricular administration of PP did not affect anxiety in the open field test. Intravenous injection of PP accelerated colonic transit, but did not significantly change fecal amount and fecal fluid composition. On the other hand, intracerebroventricular injection of PP did not alter colonic transit, fecal amount, or fluid composition. In conclusion, peripheral, but not central PP administration enhances colonic motility without eliciting anxiety or altering colonic secretion.
Collapse
Affiliation(s)
- Ching-Heng Ting
- Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ying-Chieh Chen
- Division of Digestive Medicine, Taipei City Hospital Yangming Branch, Taipei, Taiwan
| | - Wen-Jinn Liaw
- Department of Anesthesiology, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan; Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
| | - Han-Chieh Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
| |
Collapse
|
20
|
Khandekar N, Berning BA, Sainsbury A, Lin S. The role of pancreatic polypeptide in the regulation of energy homeostasis. Mol Cell Endocrinol 2015; 418 Pt 1:33-41. [PMID: 26123585 DOI: 10.1016/j.mce.2015.06.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/16/2015] [Accepted: 06/03/2015] [Indexed: 12/13/2022]
Abstract
Imbalances in normal regulation of food intake can cause obesity and related disorders. Inadequate therapies for such disorders necessitate better understanding of mechanisms that regulate energy homeostasis. Pancreatic polypeptide (PP), a robust anorexigenic hormone, effectively modulates food intake and energy homeostasis, thus potentially aiding anti-obesity therapeutics. Intra-gastric and intra-intestinal infusion of nutrients stimulate PP secretion from the gastrointestinal tract, leading to vagal stimulation that mediates complex actions via the neuropeptide Y4 receptor in arcuate nucleus of the hypothalamus, subsequently activating key hypothalamic nuclei and dorsal vagal complex of the brainstem to influence energy homeostasis and body composition. Novel studies indicate affinity of PP for the relatively underexplored neuropeptide y6 receptor, mediating actions via the suprachiasmatic nucleus and pathways involving vasoactive intestinal polypeptide and insulin like growth factor 1. This review highlights detailed mechanisms by which PP mediates its actions on energy balance through various areas in the brain.
Collapse
Affiliation(s)
- Neeta Khandekar
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
| | - Britt A Berning
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
| | - Amanda Sainsbury
- The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Shu Lin
- Neurological Diseases Division, Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| |
Collapse
|
21
|
Veedfald S, Plamboeck A, Hartmann B, Svendsen LB, Vilsbøll T, Knop FK, Holst JJ. Pancreatic polypeptide responses to isoglycemic oral and intravenous glucose in humans with and without intact vagal innervation. Peptides 2015. [PMID: 26218807 DOI: 10.1016/j.peptides.2015.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Secretion of pancreatic polypeptide (PP) from the pancreatic PP cells is controlled partly by vagal mechanisms. Release is stimulated by cephalic stimulation and enteral but not parenteral nutrients. Ambient glucose levels modulate circulating PP levels as hypoglycemia stimulates while hyperglycemia inhibits secretion. The glucose sensing mechanism has yet to be determined but may involve a vagal pathway. To investigate the role of enteral stimuli with or without intact vagal innervation, while controlling for the glucose excursion caused by the OGTT, we measured PP plasma levels by an in-house radioimmunoassay in truncally vagotomized (n=15) and control individuals (n=10). All participants were studied by a 50-g oral glucose tolerance test (OGTT) with or without dipeptidyl peptidase 4 (DPP-4) inhibition (DPP-4i) and a subsequent isoglycemic intravenous glucose infusion (IGII). We included measurements from the DPP-4i day to determine the potential effect of DPP-4-cleaved peptides on PP secretion. In both vagotomized and controls, oral glucose elicited PP secretion. In controls, but not in the vagotomized participants, intravenous glucose significantly inhibited PP secretion suggesting a vagal glucose sensing mechanism dependent on intact vagal innervation. DPP-4i did not alter PP secretion in either group.
Collapse
Affiliation(s)
- Simon Veedfald
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Denmark; The NNF Center for Basic Metabolic Research and The Department of Biomedical Sciences, University of Copenhagen, Denmark; Department of Surgical Gastroenterology C, Rigshospitalet, University of Copenhagen, Denmark
| | - Astrid Plamboeck
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Denmark; The NNF Center for Basic Metabolic Research and The Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Bolette Hartmann
- The NNF Center for Basic Metabolic Research and The Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Lars B Svendsen
- Department of Surgical Gastroenterology C, Rigshospitalet, University of Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Denmark
| | - Filip K Knop
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Denmark; The NNF Center for Basic Metabolic Research and The Department of Biomedical Sciences, University of Copenhagen, Denmark
| | - Jens J Holst
- The NNF Center for Basic Metabolic Research and The Department of Biomedical Sciences, University of Copenhagen, Denmark.
| |
Collapse
|
22
|
Gonzalez-Anton C, Lopez-Millan B, Rico MC, Sanchez-Rodriguez E, Ruiz-Lopez MD, Gil A, Mesa MD. An enriched, cereal-based bread affects appetite ratings and glycemic, insulinemic, and gastrointestinal hormone responses in healthy adults in a randomized, controlled trial. J Nutr 2015; 145:231-8. [PMID: 25644342 DOI: 10.3945/jn.114.200386] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Bread can contribute to the regulation of appetite. OBJECTIVE The objective of this study was to investigate the appetite ratings and postprandial glucose, insulin, and gastrointestinal hormone responses related to hunger and satiety after the intake of a cereal-based bread. METHODS A randomized, controlled crossover trial was conducted in 30 healthy adults (17 men and 13 women) aged 19-32 y with body mass index of 19.2-28.5. Each volunteer consumed the cereal-based bread and the control bread 2 times, with a 1-wk wash-out period, over a total of 4 sessions. The cereal-based bread contained a variety of cereal flours (wheat, oat, and spelt) and consisted of 22% dried fruits (figs, apricots, raisins, and prunes). It was also enriched with both fiber (7% from wheat cross-linked maltodextrins and pea) and protein (10-11% from wheat gluten and hydrolyzed wheat proteins). The control bread consisted of white bread with margarine and jam to control for energy density, fat, and sugar content. We measured appetite ratings using standardized visual analogue scales and glucose, insulin, and gastrointestinal hormone responses over a postprandial time of 4 h after the ingestion of each bread. Linear mixed-effects models were used to compare the areas under the curve (AUCs) for different variables. RESULTS Consuming the cereal-based bread decreased prospective consumption more than consumption of the control bread (-5.3 ± 0.6 m · min and -4.4 ± 0.6 m · min, respectively; P = 0.02) and increased satiety more (6.2 ± 0.7 m · min and 5.2 ± 0.6 m · min, respectively; P = 0.04), although subsequent ad libitum energy intake 4 h later did not differ. Postprandial blood glucose, insulin, ghrelin, glucagon-like peptide 1 and gastric inhibitory polypeptide AUCs were lower after the ingestion of the cereal-based bread, whereas the pancreatic polypeptide AUC was higher than with the control bread (P < 0.05). CONCLUSIONS Consumption of the cereal-based bread contributed to appetite control by reducing hunger and enhancing satiety. In addition, consumption of this bread improved glycemic, insulinemic, and gastrointestinal hormone responses in healthy adults. This trial was registered at clinicaltrials.gov as NCT02090049.
Collapse
Affiliation(s)
| | | | - Maria C Rico
- Departments of Biochemistry and Molecular Biology II
| | | | - Maria D Ruiz-Lopez
- Nutrition and Food Sciences, Jose Mataix Institute of Nutrition and Food Technology, University of Granada, Granada, Spain
| | - Angel Gil
- Departments of Biochemistry and Molecular Biology II
| | - Maria D Mesa
- Departments of Biochemistry and Molecular Biology II
| |
Collapse
|
23
|
Verschueren S, Janssen P, Van Oudenhove L, Hultin L, Tack J. Effect of pancreatic polypeptide on gastric accommodation and gastric emptying in conscious rats. Am J Physiol Gastrointest Liver Physiol 2014; 307:G122-8. [PMID: 24742985 DOI: 10.1152/ajpgi.00043.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pancreatic polypeptide (PP) is an anorexigenic hormone released from pancreatic F cells upon food intake. We aimed to determine the effect of PP on gastric accommodation and gastric emptying in conscious Wistar HAN rats to investigate whether effects on motor function could contribute to its anorexigenic effects. Intragastric pressure (IGP) was measured through a chronically implanted gastric fistula during the infusion of a nutrient meal (Nutridrink; 0.5 ml/min). Rats were treated with PP (0, 33 and 100 pmol·kg(-1)·min(-1)) in combination with N(G)-nitro-L-arginine methyl ester (L-NAME; 180 mg·kg(-1)·h(-1)), atropine (3 mg·kg(-1)·h(-1)), or vehicle. Furthermore, the effect of PP was tested after subdiaphragmal vagotomy of the stomach. Gastric emptying of a noncaloric and a caloric meal after treatment with 100 pmol·kg(-1)·min(-1) PP or vehicle was compared using X-rays. PP significantly increased IGP during nutrient infusion compared with vehicle (P < 0.01). L-NAME and atropine significantly increased IGP during nutrient infusion compared with vehicle treatment (P < 0.005 and 0.01, respectively). The effect of PP on IGP during nutrient infusion was abolished in the presence of L-NAME and in the presence of atropine. In vagotomized rats, PP increased IGP compared with intact controls (P < 0.05). PP significantly delayed gastric emptying of both a noncaloric (P < 0.05) and a caloric (P < 0.005) meal. PP inhibits gastric accommodation and delays gastric emptying, probably through inhibition of nitric oxide release. These results indicate that, besides the well-known centrally mediated effects, PP might decrease food intake through peripheral mechanisms.
Collapse
Affiliation(s)
- Sofie Verschueren
- Translational Research Center for Gastrointestinal Disorders, Leuven, Belgium; and
| | - Pieter Janssen
- Translational Research Center for Gastrointestinal Disorders, Leuven, Belgium; and
| | - Lukas Van Oudenhove
- Translational Research Center for Gastrointestinal Disorders, Leuven, Belgium; and
| | | | - Jan Tack
- Translational Research Center for Gastrointestinal Disorders, Leuven, Belgium; and
| |
Collapse
|
24
|
The role of gastrointestinal hormones in the pathogenesis of obesity and type 2 diabetes. GASTROENTEROLOGY REVIEW 2014; 9:69-76. [PMID: 25061485 PMCID: PMC4108747 DOI: 10.5114/pg.2014.42498] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/05/2012] [Accepted: 04/10/2012] [Indexed: 12/25/2022]
Abstract
Obesity, influencing the increase of incidence of type 2 diabetes, cardiovascular complications and cancer is a growing medical problem worldwide. The feelings of hunger and satiety are stimulated by the “gut-brain axis”, where a crucial role is played by gastrointestinal hormones: glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide, pancreatic polypeptide, peptide YY, oxyntomodulin, cholecystokinin and ghrelin. These hormones affect not only the functioning of the digestive tract, but also might have effects on insulin secretion and are mediators which affect brain areas involved in the regulation of food intake. The effect of their actions can be antagonistic as well as an additive or synergistic, and their secretion is dependent on many factors, such as dietary nutrients or the energy state of the body. Changes in circulating gut hormones concentrations result in activation of various pathways primarily within the hypothalamus and brain stem areas, which modulate feeding behaviour and a number of metabolic processes.
Collapse
|
25
|
A blood-based predictor for neocortical Aβ burden in Alzheimer's disease: results from the AIBL study. Mol Psychiatry 2014; 19:519-26. [PMID: 23628985 DOI: 10.1038/mp.2013.40] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 01/30/2013] [Accepted: 03/06/2013] [Indexed: 12/28/2022]
Abstract
Dementia is a global epidemic with Alzheimer's disease (AD) being the leading cause. Early identification of patients at risk of developing AD is now becoming an international priority. Neocortical Aβ (extracellular β-amyloid) burden (NAB), as assessed by positron emission tomography (PET), represents one such marker for early identification. These scans are expensive and are not widely available, thus, there is a need for cheaper and more widely accessible alternatives. Addressing this need, a blood biomarker-based signature having efficacy for the prediction of NAB and which can be easily adapted for population screening is described. Blood data (176 analytes measured in plasma) and Pittsburgh Compound B (PiB)-PET measurements from 273 participants from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study were utilised. Univariate analysis was conducted to assess the difference of plasma measures between high and low NAB groups, and cross-validated machine-learning models were generated for predicting NAB. These models were applied to 817 non-imaged AIBL subjects and 82 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) for validation. Five analytes showed significant difference between subjects with high compared to low NAB. A machine-learning model (based on nine markers) achieved sensitivity and specificity of 80 and 82%, respectively, for predicting NAB. Validation using the ADNI cohort yielded similar results (sensitivity 79% and specificity 76%). These results show that a panel of blood-based biomarkers is able to accurately predict NAB, supporting the hypothesis for a relationship between a blood-based signature and Aβ accumulation, therefore, providing a platform for developing a population-based screen.
Collapse
|
26
|
Abstract
Obesity is a complex disease that results from increased energy intake and decreased energy expenditure. The gastrointestinal system plays a key role in the pathogenesis of obesity and facilitates caloric imbalance. Changes in gastrointestinal hormones and the inhibition of mechanisms that curtail caloric intake result in weight gain. It is not clear if the gastrointestinal role in obesity is a cause or an effect of this disease. Obesity is often associated with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Obesity is also associated with gastrointestinal disorders, which are more frequent and present earlier than T2DM and CVD. Diseases such as gastroesophageal reflux disease (GERD), cholelithiasis, or nonalcoholic steatohepatitis are directly related to body weight and abdominal adiposity. Our objective is to assess the role of each gastrointestinal organ in obesity and the gastrointestinal morbidity resulting in those organs from the effects of obesity.
Collapse
Affiliation(s)
- Andres Acosta
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | | |
Collapse
|
27
|
Troke RC, Tan TM, Bloom SR. The future role of gut hormones in the treatment of obesity. Ther Adv Chronic Dis 2014; 5:4-14. [PMID: 24381724 PMCID: PMC3871274 DOI: 10.1177/2040622313506730] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The obesity pandemic presents a significant burden, both in terms of healthcare and economic outcomes, and current medical therapies are inadequate to deal with this challenge. Bariatric surgery is currently the only therapy available for obesity which results in long-term, sustained weight loss. The favourable effects of this surgery are thought, at least in part, to be mediated via the changes of gut hormones such as GLP-1, PYY, PP and oxyntomodulin seen following the procedure. These hormones have subsequently become attractive novel targets for the development of obesity therapies. Here, we review the development of these gut peptides as current and emerging therapies in the treatment of obesity.
Collapse
Affiliation(s)
- Rachel C Troke
- Department of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - Tricia M Tan
- Department of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - Steve R Bloom
- Department of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, 6th Floor, Commonwealth Building, London W12 0HS, UK
| |
Collapse
|
28
|
Abstract
Over the past 30 years, it has been established that hormones produced by the gut, pancreas, and adipose tissue are key players in the control of body weight. These hormones act through a complex neuroendocrine system, including the hypothalamus, to regulate metabolism and energy homeostasis. In obesity, this homeostatic balance is disrupted, either through alterations in the levels of these hormones or through resistance to their actions. Alterations in gut hormone secretion following gastric bypass surgery are likely to underlie the dramatic and persistent loss of weight following this procedure, as well as the observed amelioration in type 2 diabetes mellitus. Medications based on the gut hormone GLP-1 are currently in clinical use to treat type 2 diabetes mellitus and have been shown to produce weight loss. Further therapies for obesity based on other gut hormones are currently in development.
Collapse
Affiliation(s)
- Rebecca Scott
- Division of Diabetes, Endocrinology, Metabolism, Hammersmith Hospital, Imperial College London, London, United Kingdom.
| | | | | |
Collapse
|
29
|
Chowdhury S, Wang S, Patterson BW, Reeds DN, Wice BM. The combination of GIP plus xenin-25 indirectly increases pancreatic polypeptide release in humans with and without type 2 diabetes mellitus. ACTA ACUST UNITED AC 2013; 187:42-50. [PMID: 24183983 DOI: 10.1016/j.regpep.2013.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 10/07/2013] [Accepted: 10/23/2013] [Indexed: 12/25/2022]
Abstract
Xenin-25 (Xen) is a 25-amino acid neurotensin-related peptide that activates neurotensin receptor-1 (NTSR1). We previously showed that Xen increases the effect of glucose-dependent insulinotropic polypeptide (GIP) on insulin release 1) in hyperglycemic mice via a cholinergic relay in the periphery independent from the central nervous system and 2) in humans with normal or impaired glucose tolerance, but not type 2 diabetes mellitus (T2DM). Since this blunted response to Xen defines a novel defect in T2DM, it is important to understand how Xen regulates islet physiology. On separate visits, subjects received intravenous graded glucose infusions with vehicle, GIP, Xen, or GIP plus Xen. The pancreatic polypeptide response was used as an indirect measure of cholinergic input to islets. The graded glucose infusion itself had little effect on the pancreatic polypeptide response whereas administration of Xen equally increased the pancreatic polypeptide response in humans with normal glucose tolerance, impaired glucose tolerance, and T2DM. The pancreatic polypeptide response to Xen was similarly amplified by GIP in all 3 groups. Antibody staining of human pancreas showed that NTSR1 is not detectable on islet endocrine cells, sympathetic neurons, blood vessels, or endothelial cells but is expressed at high levels on PGP9.5-positive axons in the exocrine tissue and at low levels on ductal epithelial cells. PGP9.5 positive nerve fibers contacting beta cells in the islet periphery were also observed. Thus, a neural relay, potentially involving muscarinic acetylcholine receptors, indirectly increases the effects of Xen on pancreatic polypeptide release in humans.
Collapse
Affiliation(s)
- Sara Chowdhury
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, MO, United States
| | | | | | | | | |
Collapse
|
30
|
Luttikhold J, de Ruijter FM, van Norren K, Diamant M, Witkamp RF, van Leeuwen PAM, Vermeulen MAR. Review article: the role of gastrointestinal hormones in the treatment of delayed gastric emptying in critically ill patients. Aliment Pharmacol Ther 2013; 38:573-83. [PMID: 23879699 DOI: 10.1111/apt.12421] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 12/27/2012] [Accepted: 07/01/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Delayed gastric emptying limits the administration of enteral nutrition, leading to malnutrition, which is associated with higher mortality and morbidity. Currently available prokinetics have limitations in terms of sustained efficacy and side effects. AIM To summarise the mechanisms of action and to discuss the possible utility of gastrointestinal hormones to prevent or treat delayed gastric emptying in critically ill patients. METHODS We searched PubMed for articles discussing 'delayed gastric emptying', 'enteral nutrition', 'treatment', 'gastrointestinal hormones', 'prokinetic', 'agonist', 'antagonist' and 'critically ill patients'. RESULTS Motilin and ghrelin receptor agonists initiate the migrating motor complex in the stomach, which accelerates gastric emptying. Cholecystokinin, glucagon-like peptide-1 and peptide YY have an inhibiting effect on gastric emptying; therefore, antagonising these gastrointestinal hormones may have therapeutic potential. Other gastrointestinal hormones appear less promising. CONCLUSIONS Manipulation of endogenous secretion, physiological replacement and administration of gastrointestinal hormones in pharmacological doses is likely to have therapeutic potential in the treatment of delayed gastric emptying. Future challenges in this field will include the search for candidates with improved selectivity and favourable kinetic properties.
Collapse
Affiliation(s)
- J Luttikhold
- Department of Surgery, VU University Medical Center, Amsterdam, the Netherlands.
| | | | | | | | | | | | | |
Collapse
|
31
|
Babilon S, Mörl K, Beck-Sickinger AG. Towards improved receptor targeting: anterograde transport, internalization and postendocytic trafficking of neuropeptide Y receptors. Biol Chem 2013; 394:921-36. [DOI: 10.1515/hsz-2013-0123] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 02/22/2013] [Indexed: 01/10/2023]
Abstract
Abstract
The neuropeptide Y system is known to be involved in the regulation of many central physiological and pathophysiological processes, such as energy homeostasis, obesity, cancer, mood disorders and epilepsy. Four Y receptor subtypes have been cloned from human tissue (hY1, hY2, hY4 and hY5) that form a multiligand/multireceptor system together with their three peptidic agonists (NPY, PYY and PP). Addressing this system for medical application requires on the one hand detailed information about the receptor-ligand interaction to design subtype-selective compounds. On the other hand comprehensive knowledge about alternative receptor signaling, as well as desensitization, localization and downregulation is crucial to circumvent the development of undesired side-effects and drug resistance. By bringing such knowledge together, highly potent and long-lasting drugs with minimized side-effects can be engineered. Here, current knowledge about Y receptor export, internalization, recycling, and degradation is summarized, with a focus on the human Y receptor subtypes, and is discussed in terms of its impact on therapeutic application.
Collapse
|
32
|
Abstract
The alarming prevalence of obesity has led to a better understanding of the molecular mechanisms controlling energy homeostasis. Regulation of energy intake and expenditure is more complex than previously thought, being influenced by signals from many peripheral tissues. In this sense, a wide variety of peripheral signals derived from different organs contributes to the regulation of body weight and energy expenditure. Besides the well-known role of insulin and adipokines, such as leptin and adiponectin, in the regulation of energy homeostasis, signals from other tissues not previously thought to play a role in body weight regulation have emerged in recent years. The role of fibroblast growth factor 21 (FGF21), insulin-like growth factor 1 (IGF-I), and sex hormone-binding globulin (SHBG) produced by the liver in the regulation of body weight and insulin sensitivity has been recently described. Moreover, molecules expressed by skeletal muscle such as myostatin have also been involved in adipose tissue regulation. Better known is the involvement of ghrelin, cholecystokinin, glucagon-like peptide 1 (GLP-1) and PYY(3-36), produced by the gut, in energy homeostasis. Even the kidney, through the production of renin, appears to regulate body weight, with mice lacking this hormone exhibiting resistance to diet-induced obesity. In addition, the skeleton has recently emerged as an endocrine organ, with effects on body weight control and glucose homeostasis through the actions of bone-derived factors such as osteocalcin and osteopontin. The comprehension of these signals will help in a better understanding of the aetiopathology of obesity, contributing to the potential development of new therapeutic targets aimed at tackling excess body fat accumulation.
Collapse
|
33
|
Abstract
PURPOSE OF REVIEW The obesity epidemic over the world has called to attention different ways to manage this development. As bariatric surgery today is the only manner by which rapid and sustained weight control can be achieved, new ways of treating obesity are under investigation. This review focuses on today's knowledge on satiety signaling as a means to combat obesity. RECENT FINDINGS The combined knowledge achieved from obesity surgery with gastric bypass and duodenal switch together with the pharmacological treatment of type 2 diabetes have given us some clues of how to manage obesity. The basis for our understanding is the present research focusing on the gut peptide hormones that are released in response to food intake, and the paucity of satiety signaling seems to prevail in obesity. This means that obese patients experience less activation of higher brain centers in association with a meal and therefore compensate with increased meal size or frequent food intake. SUMMARY Altered satiety signaling primarily emanating from the gastrointestinal tract seems to lead to the development of obesity and type 2 diabetes. Pharmacological tools that enhance the gut hormone signaling are in focus for the upcoming venues of treatment.
Collapse
|
34
|
Hussain SS, Bloom SR. The regulation of food intake by the gut-brain axis: implications for obesity. Int J Obes (Lond) 2012; 37:625-33. [PMID: 22710925 DOI: 10.1038/ijo.2012.93] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Our understanding of the regulation of appetite has improved considerably over the last few decades. Recent work, stimulated by efforts aimed at curbing the current obesity epidemic, has unravelled some of the complex pathways regulating energy homeostasis. Key factors to this progress have been the discovery of leptin and the neuronal circuitry involved in mediating its effects, as well as the identification of gut hormones that have important physiological roles relating to energy homeostasis. Despite these advances in research, there are currently no effective treatments for the growing problem of obesity. In this article, we summarise the regulatory pathways controlling appetite with a special focus on gut hormones. We detail how recent findings have contributed to our knowledge regarding the pathogenesis and treatment of common obesity. A number of barriers still need to be overcome to develop safe and effective anti-obesity treatments. We outline problems highlighted by historical failures and discuss the potential of augmenting natural satiety signals, such as gut hormones, to treat obesity.
Collapse
Affiliation(s)
- S S Hussain
- Department of Diabetes, Endocrinology and Metabolism, Hammersmith Hospital, Imperial College London, London, UK
| | | |
Collapse
|
35
|
Banerjee A, Onyuksel H. Human pancreatic polypeptide in a phospholipid-based micellar formulation. Pharm Res 2012; 29:1698-711. [PMID: 22399387 DOI: 10.1007/s11095-012-0718-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/20/2012] [Indexed: 01/24/2023]
Abstract
PURPOSE Pancreatic polypeptide (PP) has important glucoregulatory functions and thereby holds significance in the treatment of diabetes and obesity. However, short plasma half-life and aggregation propensity of PP in aqueous solution, limits its therapeutic application. To address these issues, we prepared and characterized a formulation of PP in sterically stabilized micelles (SSM) that protects and stabilizes PP in its active conformation. METHODS PP-SSM was prepared by incubating PP with SSM dispersion in buffer. Peptide-micelle association and freeze-drying efficacy of the formulation was characterized in phosphate buffers with or without sodium chloride using dynamic light scattering, fluorescence spectroscopy and circular dichroism. The degradation kinetics of PP-SSM in presence of proteolytic enzyme was determined using HPLC and bioactivity of the formulation was evaluated by in vitro cAMP inhibition study. RESULTS PP self-associated with SSM and this interaction was influenced by presence/absence of sodium chloride in the buffer. The formulation was effectively lyophilized, demonstrating feasibility for its long-term storage. The stability of peptide against proteolytic degradation was significantly improved and PP in SSM retained its bioactivity in vitro. CONCLUSIONS Self-association of PP with phospholipid micelles addressed the delivery issues of the peptide. This nanomedicine should be further developed for the treatment of diabetes.
Collapse
Affiliation(s)
- Amrita Banerjee
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois 60612, USA
| | | |
Collapse
|
36
|
Barone Lumaga R, Azzali D, Fogliano V, Scalfi L, Vitaglione P. Sugar and dietary fibre composition influence, by different hormonal response, the satiating capacity of a fruit-based and a β-glucan-enriched beverage. Food Funct 2011; 3:67-75. [PMID: 22057424 DOI: 10.1039/c1fo10065c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In this study the satiating capacity of three beverages containing 3 g barley β-glucan, or 2.5 g dietary fibre (DF) from fruit, or without DF (control) was evaluated. Fourteen healthy volunteers were randomized to have isocaloric breakfasts including one of the beverages in different occasions. Appetite ratings over 3 h post-breakfast and energy intakes at ad libitum lunch, blood glucose, insulin, ghrelin, PYY, GLP-1, GIP, and PP concentrations, and 24 h food intake, were assessed. The bevaerages containing DF increased fullness and satiety over 3 h post-breakfast, but only the β-glucan-enriched vs. the control significantly reduced energy intakes by 18% at lunch and 40% over the rest of the day. Blood ghrelin and PP responses were differently modulated by beverages. The fruit-based and the β-glucan-enriched beverage suppressed by 8.9% and 8.1% ghrelin response over the 3 h and the first hour post-breakfast, respectively, while only the latter increased PP response by 34.6%, compared to the control. A sucrose-sweetened beverage providing 3 g barley β-glucans can control food intake by modulating PP response and it can even reduce 24 h energy intake. Ghrelin suppression by fruit dietary fibre and mixed sugars was not sufficient to significantly reduce food intake compared to the control.
Collapse
Affiliation(s)
- Roberta Barone Lumaga
- Department of Food Science, University of Naples, via Università 100, 80055 Portici, NA, Italy
| | | | | | | | | |
Collapse
|
37
|
Sam AH, Troke RC, Tan TM, Bewick GA. The role of the gut/brain axis in modulating food intake. Neuropharmacology 2011; 63:46-56. [PMID: 22037149 DOI: 10.1016/j.neuropharm.2011.10.008] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 09/28/2011] [Accepted: 10/13/2011] [Indexed: 12/12/2022]
Abstract
Peptide hormones released from the gastrointestinal tract communicate information about the current state of energy balance to the brain. These hormones regulate appetite and energy expenditure via the vagus nerve or by acting on key brain regions implicated in energy homeostasis such as the hypothalamus and brainstem. This review gives an overview of the main gut hormones implicated in the regulation of food intake. Research in this area has provided novel targets for the pharmacological treatment of obesity. This article is part of a Special Issue entitled 'Central Control Food Intake'
Collapse
Affiliation(s)
- Amir H Sam
- Section of Investigative Medicine, Imperial College London, London W12 0NN, UK
| | | | | | | |
Collapse
|
38
|
The neuropeptide Y system: Pathophysiological and therapeutic implications in obesity and cancer. Pharmacol Ther 2011; 131:91-113. [DOI: 10.1016/j.pharmthera.2011.03.011] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 03/07/2011] [Indexed: 12/28/2022]
|
39
|
Woods M, Lan Z, Li J, Wheeler MB, Wang H, Wang R. Antidiabetic effects of duodenojejunal bypass in an experimental model of diabetes induced by a high-fat diet. Br J Surg 2011; 98:686-96. [DOI: 10.1002/bjs.7400] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2010] [Indexed: 11/08/2022]
Abstract
Abstract
Background
Obese patients with type II diabetes who undergo bariatric surgery revert to normal blood glucose and insulin levels, and develop a dramatic increase in insulin sensitivity. However, the mechanisms involved are unknown. This study characterized pancreatic islet and duodenojejunal enteroendocrine cells in normal mice and those with diabetes induced by a high-fat diet (HFD) following duodenojejunal bypass (DJB).
Methods
C57BL/6J mice, fed for 8 weeks either a normal diet (n = 10) or a HFD (n = 10) resulting in a hyperglycaemic state, underwent DJB (connection of the distal end of the jejunum to the distal stomach and direction of biliopancreatic secretions to the distal jejunum). Metabolic and immunohistological analyses were carried out on the pancreas and gastrointestinal tract.
Results
A significant decrease in fasting blood glucose was observed in normal-DJB and HFD-DJB mice 1 week after the operation, with improved glucose tolerance at 4 weeks. There were no changes in pancreatic β-cell mass, but an increase in the ratio of α-cell to β-cell mass was observed in the DJB groups. Furthermore, the number of cells expressing Pdx-1, glucagon-like peptide 1, pancreatic polypeptide and synaptophysin was increased in the bypassed duodenum and/or gastrojejunum of the DJB groups.
Conclusion
Both normal and obese diabetic mice that underwent DJB displayed improved glucose tolerance and a reduction in fasting blood glucose, which mimicked findings in obese diabetic patients following bariatric surgery. The present data suggest that an increase in specific enteroendocrine cell populations may play a critical role in normalizing glucose homeostasis.
Collapse
Affiliation(s)
- M Woods
- Children's Health Research Institute, University of Western Ontario, London, Canada
| | - Z Lan
- Department of Surgery, University of Western Ontario, London, Canada
- Department of Multi-Organ Transplant Program, London Health Sciences Center, London, Canada
| | - J Li
- Children's Health Research Institute, University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Canada
| | - M B Wheeler
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - H Wang
- Department of Surgery, University of Western Ontario, London, Canada
- Department of Multi-Organ Transplant Program, London Health Sciences Center, London, Canada
| | - R Wang
- Children's Health Research Institute, University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, Canada
- Department of Medicine, University of Western Ontario, London, Canada
| |
Collapse
|
40
|
Brunstrom JM, Brown S, Hinton EC, Rogers PJ, Fay SH. 'Expected satiety' changes hunger and fullness in the inter-meal interval. Appetite 2011; 56:310-5. [PMID: 21219951 DOI: 10.1016/j.appet.2011.01.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 11/30/2010] [Accepted: 01/05/2011] [Indexed: 11/17/2022]
Abstract
Previously, we have shown that foods differ markedly in the satiety that they are expected to confer (compared calorie-for-calorie). In the present study we tested the hypothesis that 'expected satiety' plays a causal role in the satiety that is experienced after a food has been consumed. Before lunch, participants (N=32) were shown the ingredients of a fruit smoothie. Half were shown a small portion of fruit and half were shown a large portion. Participants then assessed the expected satiety of the smoothie and provided appetite ratings, before, and for three hours after its consumption. As anticipated, expected satiety was significantly higher in the 'large portion' condition. Moreover, and consistent with our hypothesis, participants reported significantly less hunger and significantly greater fullness in the large-portion condition. Importantly, this effect endured throughout the test period (for three hours). Together, these findings confirm previous reports indicating that beliefs and expectations can have marked effects on satiety and they show that this effect can persist well into the inter-meal interval. Potential explanations are discussed, including the prospect that satiety is moderated by memories of expected satiety that are encoded around the time that a meal is consumed.
Collapse
Affiliation(s)
- Jeffrey M Brunstrom
- Department of Experimental Psychology, University of Bristol, 12a Priory Road, Bristol BS8 1TU, United Kingdom.
| | | | | | | | | |
Collapse
|
41
|
Zhang L, Riepler SJ, Turner N, Enriquez RF, Lee ICJ, Baldock PA, Herzog H, Sainsbury A. Y2 and Y4 receptor signaling synergistically act on energy expenditure and physical activity. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1618-28. [DOI: 10.1152/ajpregu.00345.2010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neuropeptide Y receptors are critical regulators of energy homeostasis and are well known for their powerful influence on feeding, but their roles in other important aspects of energy homeostasis, such as energy expenditure and their functional interactions in these processes, are largely unknown. Here we show that mice lacking both Y2 and Y4 receptors exhibited a reduction in adiposity, more prominent in intra-abdominal vs. subcutaneous fat, and an increase in lean mass as determined by dual-energy X-ray absorptiometry. These changes were more pronounced than those seen in mice with Y2 or Y4 receptor single deletion, demonstrating the important roles and synergy of Y2 and Y4 signaling in the regulation of body composition. These changes in body composition occurred without significant changes in food intake, but energy expenditure and physical activity were significantly increased in Y4−/− and particularly in Y2−/−Y4−/− but not in Y2−/− mice, suggesting a critical role of Y4 signaling and synergistic interactions with Y2 signaling in the regulation of energy expenditure and physical activity. Y2−/− and Y4−/− mice also exhibited a decrease in respiratory exchange ratio with no further synergistic decrease in Y2−/−Y4−/− mice, suggesting that Y2 and Y4 signaling each play important and independent roles in the regulation of substrate utilization. The synergy between Y2 and Y4 signaling in regulating fat mass may be related to differences in mitochondrial oxidative capacity, since Y2−/−Y4−/− but not Y2−/− or Y4−/− mice showed significant increases in muscle protein levels of peroxisome proliferator-activated receptor (PPAR)γ coactivator (PGC)-1α, and mitochondrial respiratory chain complexes I and III. Taken together, this work demonstrates the critical roles of Y2 and Y4 receptors in the regulation of body composition and energy metabolism, highlighting dual antagonism of Y2 and Y4 receptors as a potentially effective anti-obesity treatment.
Collapse
Affiliation(s)
| | | | - Nigel Turner
- Diabetes and Obesity Program, Garvan Institute of Medical Research, St. Vincent's Hospital, Darlinghurst, Sydney, Australia
- St. Vincent's Hospital Clinical School,
| | | | | | | | - Herbert Herzog
- Neuroscience Research Program and
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Amanda Sainsbury
- Neuroscience Research Program and
- School of Medical Sciences, and
| |
Collapse
|
42
|
Abstract
Food intake and energy expenditure are tightly regulated by the brain, in a homeostatic process that integrates diverse hormonal, neuronal and metabolic signals. The gastrointestinal tract is an important source of such signals, which include several hormones released by specialized enteroendocrine cells. These hormones exert powerful effects on appetite and energy expenditure. This Review addresses the physiological roles of peptide YY, pancreatic polypeptide, islet amyloid polypeptide, glucagon-like peptide 1, glucagon, oxyntomodulin, cholecystokinin and ghrelin and discusses their potential as targets for the development of novel treatments for obesity.
Collapse
Affiliation(s)
- Benjamin C T Field
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
| | | | | |
Collapse
|
43
|
Abstract
Our knowledge of the complex mechanisms underlying energy homeostasis has expanded enormously in recent years. Food intake and body weight are tightly regulated by the hypothalamus, brainstem and reward circuits, on the basis both of cognitive inputs and of diverse humoral and neuronal signals of nutritional status. Several gut hormones, including cholecystokinin, glucagon-like peptide-1, peptide YY, oxyntomodulin, amylin, pancreatic polypeptide and ghrelin, have been shown to play an important role in regulating short-term food intake. These hormones therefore represent potential targets in the development of novel anti-obesity drugs. This review focuses on the role of gut hormones in short- and long-term regulation of food intake, and on the current state of development of gut hormone-based obesity therapies.
Collapse
Affiliation(s)
- Benjamin C T Field
- Department of Investigative Medicine, Imperial College London, Hammersmith Hospital Campus, London, UK
| | | | | |
Collapse
|
44
|
Genome-wide association study suggested copy number variation may be associated with body mass index in the Chinese population. J Hum Genet 2009; 54:199-202. [PMID: 19229253 DOI: 10.1038/jhg.2009.10] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Obesity is a major public health problem characterized with high body mass index (BMI). Copy number variations (CNVs) have been identified to be associated with complex human diseases. The effect of CNVs on obesity is unknown. In this study, we explored the association of CNVs with BMI in 597 Chinese Han subjects using Affymetrix GeneChip Human Mapping 500K Array Set. We found that one CNV at 10q11.22 (from 46.36 Mb to 46.56 Mb) was associated with BMI (the raw P=0.011). The CNV contributed 1.6% of BMI variation, and it covered one important obesity gene-pancreatic polypeptide receptor 1(PPYR1). It was reported that PPYR1 was a key regulator of energy homeostasis. Our findings suggested that CNV might be potentially important for the BMI variation. In addition, our study suggested that CNV might be used as a genetic marker to locate genes associated with BMI in Chinese population.
Collapse
|
45
|
Abstract
The gastrointestinal tract is the largest endocrine organ in the body. It secretes more than 20 different peptide hormones, which serve both a local regulatory function and provide a means by which the gut can regulate appetite and satiety. As the worldwide prevalence of obesity reaches epidemic proportions, the importance of delineating the mechanisms which regulate food intake becomes even more urgent. There is now a substantial body of work in both rodent and human models demonstrating the effects of these peptides on appetite and work is underway to therapeutically manipulate the gut-brain axis for the treatment of obesity. In addition, it may also be possible to use our understanding of the entero-endocrine system to treat calorie-deficient states.
Collapse
Affiliation(s)
- S Hameed
- Department of Investigative Medicine, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
| | | | | |
Collapse
|
46
|
Sanger GJ, Lee K. Hormones of the gut-brain axis as targets for the treatment of upper gastrointestinal disorders. Nat Rev Drug Discov 2008; 7:241-54. [PMID: 18309313 DOI: 10.1038/nrd2444] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The concept of the gut forming the centre of an integrated gut-brain-energy axis - modulating appetite, metabolism and digestion - opens up new paradigms for drugs that can tackle multiple symptoms in complex upper gastrointestinal disorders. These include eating disorders, nausea and vomiting, gastroesophageal reflux disease, gastroparesis, dyspepsia and irritable bowel syndrome. The hormones that modulate gastric motility represent targets for gastric prokinetic drugs, and peptides that modify eating behaviours may be targeted to develop drugs that reduce nausea, a currently poorly treated condition. The gut-brain axis may therefore provide a range of therapeutic opportunities that deliver a more holistic treatment of upper gastrointestinal disorders.
Collapse
Affiliation(s)
- Gareth J Sanger
- Immuno Inflammation Centre of Excellence for Drug Discovery, GlaxoSmithKline, Stevenage, Hertfordshire SG1 2NY, UK.
| | | |
Collapse
|
47
|
Affiliation(s)
- Owais B. Chaudhri
- Department of Metabolic Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom;
| | - Victoria Salem
- Department of Metabolic Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom;
| | - Kevin G. Murphy
- Department of Metabolic Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom;
| | - Stephen R. Bloom
- Department of Metabolic Medicine, Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom;
| |
Collapse
|
48
|
Field BCT, Wren AM, Cooke D, Bloom SR. Gut Hormones as Potential New Targets for Appetite Regulation and the Treatment of Obesity. Drugs 2008; 68:147-63. [DOI: 10.2165/00003495-200868020-00002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
49
|
Abstract
Obesity is a serious public health problem throughout the world, affecting both developed societies and developing countries. The central nervous system has developed a meticulously interconnected circuitry in order to keep us fed and in an adequate nutritional state. One of these consequences is that an energy-dense environment favors the development of obesity. Neuropeptide Y (NPY) is one of the most abundant and widely distributed peptides in the central nervous system of both rodents and humans and has been implicated in a variety of physiological actions. Within the hypothalamus, NPY plays an essential role in the control of food intake and body weight. Centrally administered NPY causes robust increases in food intake and body weight and, with chronic administration, can eventually produce obesity. NPY activates a population of at least six G protein-coupled Y receptors. NPY analogs exhibit varying degrees of affinity and specificity for these Y receptors. There has been renewed speculation that ligands for Y receptors may be of benefit for the treatment of obesity. This review highlights the therapeutic potential of Y(1), Y(2), Y(4), and Y(5) receptor agonists and antagonists as additional intervention to treat human obesity.
Collapse
Affiliation(s)
- M M Kamiji
- Department of Gastroenterology, Faculty of Medicine, University of Sao Paulo, Ribeirão Preto Campus 14048-900, Ribeirão Preto-SP, Brazil
| | | |
Collapse
|
50
|
|