22
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Effects of exogenous glucagon-like peptide-2 and distal bowel resection on intestinal and systemic adaptive responses in rats

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Objective

          To determine the effects of exogenous glucagon-like peptide-2 (GLP-2), with or without massive distal bowel resection, on adaptation of jejunal mucosa, enteric neurons, gut hormones and tissue reserves in rats.

          Background

          GLP-2 is a gut hormone known to be trophic for small bowel mucosa, and to mimic intestinal adaptation in short bowel syndrome (SBS). However, the effects of exogenous GLP-2 and SBS on enteric neurons are unclear.

          Methods

          Sprague Dawley rats were randomized to four treatments: Transected Bowel (TB) (n = 8), TB + GLP-2 (2.5 nmol/kg/h, n = 8), SBS (n = 5), or SBS + GLP-2 (2.5 nmol/kg/h, n = 9). SBS groups underwent a 60% jejunoileal resection with cecectomy and jejunocolic anastomosis. All rats were maintained on parenteral nutrition for 7 d. Parameters measured included gut morphometry, qPCR for hexose transporter (SGLT-1, GLUT-2, GLUT-5) and GLP-2 receptor mRNA, whole mount immunohistochemistry for neurons (HuC/D, VIP, nNOS), plasma glucose, gut hormones, and body composition.

          Results

          Resection increased the proportion of nNOS immunopositive myenteric neurons, intestinal muscularis propria thickness and crypt cell proliferation, which were not recapitulated by GLP-2 therapy. Exogenous GLP-2 increased jejunal mucosal surface area without affecting enteric VIP or nNOS neuronal immunopositivity, attenuated resection-induced reductions in jejunal hexose transporter abundance (SGLT-1, GLUT-2), increased plasma amylin and decreased peptide YY concentrations. Exogenous GLP-2 attenuated resection-induced increases in blood glucose and body fat loss.

          Conclusions

          Exogenous GLP-2 stimulates jejunal adaptation independent of enteric neuronal VIP or nNOS changes, and has divergent effects on plasma amylin and peptide YY concentrations. The novel ability of exogenous GLP-2 to modulate resection-induced changes in peripheral glucose and lipid reserves may be important in understanding the whole-body response following intestinal resection, and is worthy of further study.

          Related collections

          Most cited references60

          • Record: found
          • Abstract: found
          • Article: not found

          Intestinal adaptation following resection.

          Intestinal adaptation is a natural compensatory process that occurs following extensive intestinal resection, whereby structural and functional changes in the intestine improve nutrient and fluid absorption in the remnant bowel. In animal studies, postresection structural adaptations include bowel lengthening and thickening and increases in villus height and crypt depth. Functional changes include increased nutrient transporter expression, accelerated crypt cell differentiation, and slowed transit time. In adult humans, data regarding adaptive changes are sparse, and the mechanisms underlying intestinal adaptation remain to be fully elucidated. Several factors influence the degree of intestinal adaptation that occurs post resection, including site and extent of resection, luminal stimulation with enteral nutrients, and intestinotrophic factors. Two intestinotrophic growth factors, the glucagon-like peptide 2 analog teduglutide and recombinant growth hormone (somatropin), are now approved for clinical use in patients with short bowel syndrome (SBS). Both agents enhance fluid absorption and decrease requirements for parenteral nutrition (PN) and/or intravenous fluid. Intestinal adaptation has been thought to be limited to the first 1-2 years following resection in humans. However, recent data suggest that a significant proportion of adult patients with SBS can achieve enteral autonomy, even after many years of PN dependence, particularly with trophic stimulation.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Glucagon-like peptides GLP-1 and GLP-2, predicted products of the glucagon gene, are secreted separately from pig small intestine but not pancreas.

            We developed specific antibodies and RIAs for glucagon-like peptides 1 and 2 (GLP-1 and GLP-2), two predicted products of the glucagon gene, and studied the occurrence, nature, and secretion of immunoreactive GLP-1 and GLP-2 in pig pancreas and small intestine. Immunoreactive GLP-1 and GLP-2 were identified in glucagon-producing cells of the pancreatic islets, and in glicentin-producing cells of the small intestine. Immunoreactive GLP-1 and 2 in intestinal extracts corresponded in molecular size to peptides synthesized according to the predicted structure. By reverse phase HPLC, intestinal and synthetic GLP-1 behaved similarly, whereas synthetic and intestinal GLP-2 differed. Pancreatic extracts contained a large peptide with both GLP-1 and GLP-2 immunoreactivity. Secretion was studied using isolated perfused pig pancreas during arginine stimulation, and isolated perfused pig ileum during either luminal glucose stimulation or vascular administration of the neuropeptide, gastrin-releasing peptide (GRP). Immunoreactive GLP-1 and GLP-2 were secreted in parallel with pancreatic glucagon and intestinal glicentin. The molecular forms of secreted immunoreactive GLP-1 and 2 corresponded to those identified in the tissue extracts.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              GLP-2 receptor localizes to enteric neurons and endocrine cells expressing vasoactive peptides and mediates increased blood flow.

              Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive hormone that exerts diverse actions in the gastrointestinal tract, including enhancing epithelial cell survival and proliferation, mucosal blood flow, and nutrient uptake and suppressing gastric motility and secretion. These actions are mediated by the G-protein-coupled receptor, GLP-2R. Cellular localization of the GLP-2R and the nature of its signaling network in the gut, however, are poorly defined. Thus, our aim was to establish cellular localization of GLP-2R and functional connection to vascular action of GLP-2 in the gut. Intestinal cellular GLP-2R localization was determined with real-time, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) of laser capture microdissected subtissue and fluorescence in situ hybridization and also with double and/or triple immunostaining of human and pig tissue using a validated GLP-2R polyclonal antibody. Superior mesenteric arterial blood flow and intestinal eNOS expression and phosphorylation were measured in TPN-fed pigs acutely (4 h) infused with GLP-2. We show that the porcine GLP-2R mRNA was expressed in the villus epithelium and myenteric plexus. GLP-2R protein was co-localized by confocal immunohistochemistry with serotonin in enteroendocrine cells and also with endothelial nitric oxide synthase (eNOS)-expressing and vasoactive intestinal polypeptide-positive enteric neurons. In neonatal pigs, GLP-2 infusion dose-dependently stimulated intestinal blood flow and coordinately upregulated the expression of intestinal eNOS mRNA, protein, and phosphorylation (eNOS-Ser1117). We conclude that the GLP-2-induced stimulation of blood flow is mediated by vasoactive neurotransmitters that are colocalized with GLP-2R in 2 functionally distinct cell types within the gastrointestinal tract.
                Bookmark

                Author and article information

                Contributors
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: SoftwareRole: ValidationRole: VisualizationRole: Writing – original draftRole: Writing – review & editing
                Role: Data curationRole: InvestigationRole: MethodologyRole: Project administrationRole: SoftwareRole: Validation
                Role: Data curationRole: InvestigationRole: MethodologyRole: Project administration
                Role: Data curationRole: Formal analysisRole: InvestigationRole: MethodologyRole: ValidationRole: Writing – review & editing
                Role: Formal analysisRole: InvestigationRole: MethodologyRole: ResourcesRole: ValidationRole: Writing – review & editing
                Role: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: SupervisionRole: Writing – original draftRole: Writing – review & editing
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: Project administrationRole: ResourcesRole: SupervisionRole: ValidationRole: Writing – original draftRole: Writing – review & editing
                Role: ConceptualizationRole: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: Project administrationRole: ResourcesRole: SupervisionRole: ValidationRole: VisualizationRole: Writing – original draftRole: Writing – review & editing
                Role: Editor
                Journal
                PLoS One
                PLoS ONE
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, CA USA )
                1932-6203
                24 July 2017
                2017
                : 12
                : 7
                : e0181453
                Affiliations
                [1 ] Department of Surgery, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
                [2 ] Department of Biomedical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, The Panum Institute, Copenhagen, Denmark
                [3 ] Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
                [4 ] Department of Surgery, Sidra Medical and Research Center and Weil Cornell Medical College, Doha, Qatar
                University of Texas Medical Branch, UNITED STATES
                Author notes

                Competing Interests: DLS has acted as a speaker for Shire Pharmaceuticals on one occasion after this work was completed. This does not alter our adherence to PLOS ONE policies on sharing data and materials. The remaining authors have declared that no competing interests exist.

                Author information
                http://orcid.org/0000-0003-4670-8795
                Article
                PONE-D-17-04560
                10.1371/journal.pone.0181453
                5524396
                28738080
                18276082-8614-48f5-a06d-3c0d4b29e8fb
                © 2017 Lai et al

                This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                History
                : 4 February 2017
                : 1 July 2017
                Page count
                Figures: 6, Tables: 3, Pages: 20
                Funding
                Funded by: funder-id http://dx.doi.org/10.13039/501100000038, Natural Sciences and Engineering Research Council of Canada;
                Award ID: 355993-2013
                Award Recipient :
                Funded by: Sidra Medical and Research Center
                Award Recipient :
                Funded by: funder-id http://dx.doi.org/10.13039/501100003206, Alberta Children's Hospital Foundation;
                Award ID: Professorship in Pediatric Surgerical Research
                Award Recipient :
                Salary support was provided by the University of Calgary Clinician Investigator Program and the Alberta Graduate Student Scholarship for SWL. Operational funding was provided by a Natural Sciences and Engineering Research Council Discovery Grant (Application ID 355993-2013, http://www.nserc-crsng.gc.ca/index_eng.asp) for PKC, and from the Alberta Children’s Hospital Foundation Professorship in Pediatric Surgical Research and from Sidra Medical and Research Center, as part of the Qatar Foundation, to DLS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
                Categories
                Research Article
                Medicine and Health Sciences
                Surgical and Invasive Medical Procedures
                Surgical Resection
                Medicine and Health Sciences
                Surgical and Invasive Medical Procedures
                Digestive System Procedures
                Intestinal Resection
                Medicine and Health Sciences
                Surgical and Invasive Medical Procedures
                Surgical Resection
                Intestinal Resection
                Biology and Life Sciences
                Cell Biology
                Cellular Types
                Animal Cells
                Neurons
                Biology and Life Sciences
                Neuroscience
                Cellular Neuroscience
                Neurons
                Biology and Life Sciences
                Anatomy
                Body Fluids
                Blood
                Blood Plasma
                Medicine and Health Sciences
                Anatomy
                Body Fluids
                Blood
                Blood Plasma
                Biology and Life Sciences
                Physiology
                Body Fluids
                Blood
                Blood Plasma
                Medicine and Health Sciences
                Physiology
                Body Fluids
                Blood
                Blood Plasma
                Biology and Life Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Jejunum
                Medicine and Health Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Jejunum
                Physical Sciences
                Chemistry
                Chemical Compounds
                Organic Compounds
                Carbohydrates
                Monosaccharides
                Glucose
                Physical Sciences
                Chemistry
                Organic Chemistry
                Organic Compounds
                Carbohydrates
                Monosaccharides
                Glucose
                Biology and Life Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Medicine and Health Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Biology and Life Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Colon
                Medicine and Health Sciences
                Anatomy
                Digestive System
                Gastrointestinal Tract
                Colon
                Custom metadata
                The raw data for these observations, and all the findings from this study, can be found at https://doi.org/10.6084/m9.figshare.4832648.v1.

                Uncategorized
                Uncategorized

                Comments

                Comment on this article