1
|
Chen Y, Wijekoon S, Matsumoto A, Luo J, Kiriazis H, Masterman E, Yildiz G, Cross J, Parslow A, Chooi R, Sadoshima J, Greening D, Weeks K, McMullen J. Distinct functional and molecular profiles between physiological and pathological atrial enlargement offer potential new therapeutic opportunities for atrial fibrillation. Clin Sci (Lond) 2024; 138:941-962. [PMID: 39018488 PMCID: PMC11292366 DOI: 10.1042/cs20240178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 07/17/2024] [Accepted: 07/17/2024] [Indexed: 07/19/2024]
Abstract
Atrial fibrillation (AF) remains challenging to prevent and treat. A key feature of AF is atrial enlargement. However, not all atrial enlargement progresses to AF. Atrial enlargement in response to physiological stimuli such as exercise is typically benign and reversible. Understanding the differences in atrial function and molecular profile underpinning pathological and physiological atrial remodelling will be critical for identifying new strategies for AF. The discovery of molecular mechanisms responsible for pathological and physiological ventricular hypertrophy has uncovered new drug targets for heart failure. Studies in the atria have been limited in comparison. Here, we characterised mouse atria from (1) a pathological model (cardiomyocyte-specific transgenic (Tg) that develops dilated cardiomyopathy [DCM] and AF due to reduced protective signalling [PI3K]; DCM-dnPI3K), and (2) a physiological model (cardiomyocyte-specific Tg with an enlarged heart due to increased insulin-like growth factor 1 receptor; IGF1R). Both models presented with an increase in atrial mass, but displayed distinct functional, cellular, histological and molecular phenotypes. Atrial enlargement in the DCM-dnPI3K Tg, but not IGF1R Tg, was associated with atrial dysfunction, fibrosis and a heart failure gene expression pattern. Atrial proteomics identified protein networks related to cardiac contractility, sarcomere assembly, metabolism, mitochondria, and extracellular matrix which were differentially regulated in the models; many co-identified in atrial proteomics data sets from human AF. In summary, physiological and pathological atrial enlargement are associated with distinct features, and the proteomic dataset provides a resource to study potential new regulators of atrial biology and function, drug targets and biomarkers for AF.
Collapse
MESH Headings
- Atrial Fibrillation/physiopathology
- Atrial Fibrillation/metabolism
- Atrial Fibrillation/genetics
- Animals
- Heart Atria/metabolism
- Heart Atria/physiopathology
- Heart Atria/pathology
- Mice, Transgenic
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Atrial Remodeling
- Receptor, IGF Type 1/metabolism
- Receptor, IGF Type 1/genetics
- Cardiomyopathy, Dilated/physiopathology
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Disease Models, Animal
- Fibrosis
- Mice
- Humans
- Signal Transduction
- Phosphatidylinositol 3-Kinases/metabolism
- Heart Failure/physiopathology
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
Collapse
Affiliation(s)
- Yi Ching Chen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Diabetes, Central Clinical School, Monash University, Clayton, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, Victoria, Australia
| | - Seka Wijekoon
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Aya Matsumoto
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Jieting Luo
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Helen Kiriazis
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Emma Masterman
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Gunes Yildiz
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Jonathon Cross
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Adam C. Parslow
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, Victoria, Australia
| | - Roger Chooi
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, NJ, U.S.A
| | - David W. Greening
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, Victoria, Australia
| | - Kate L. Weeks
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Diabetes, Central Clinical School, Monash University, Clayton, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Julie R. McMullen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Diabetes, Central Clinical School, Monash University, Clayton, Victoria, Australia
- Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, Victoria, Australia
- Monash Alfred Baker Centre for Cardiovascular Research, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
2
|
Büttner J, Blüthner E, Greif S, Kühl A, Elezkurtaj S, Ulrich J, Maasberg S, Jochum C, Tacke F, Pape UF. Predictive Potential of Biomarkers of Intestinal Barrier Function for Therapeutic Management with Teduglutide in Patients with Short Bowel Syndrome. Nutrients 2023; 15:4220. [PMID: 37836505 PMCID: PMC10574292 DOI: 10.3390/nu15194220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/12/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
INTRODUCTION The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide. METHODS Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test. RESULTS The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support. CONCLUSIONS Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.
Collapse
Affiliation(s)
- Janine Büttner
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Elisabeth Blüthner
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
- Berlin Institute of Health (BIH), 10178 Berlin, Germany
| | - Sophie Greif
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Anja Kühl
- iPATH.Berlin, Core Unit der Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt, Campus Benjamin Franklin, 12203 Berlin, Germany;
| | - Sefer Elezkurtaj
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Pathology, Campus Mitte, 10117 Berlin, Germany;
| | - Jan Ulrich
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
| | - Sebastian Maasberg
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
| | - Christoph Jochum
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Frank Tacke
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
| | - Ulrich-Frank Pape
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Department of Hepatology and Gastroenterology, Campus Charité Mitte and Campus Virchow Klinikum, 10117 Berlin, Germany; (E.B.); (S.G.); (C.J.); (F.T.)
- Department of Internal Medicine and Gastroenterology, Asklepios Klinik St. Georg, 20099 Hamburg, Germany; (J.U.); (S.M.)
| |
Collapse
|
3
|
Maurya NS, Kushwah S, Kushwaha S, Chawade A, Mani A. Prognostic model development for classification of colorectal adenocarcinoma by using machine learning model based on feature selection technique boruta. Sci Rep 2023; 13:6413. [PMID: 37076536 PMCID: PMC10115869 DOI: 10.1038/s41598-023-33327-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
Colorectal cancer (CRC) is the third most prevalent cancer type and accounts for nearly one million deaths worldwide. The CRC mRNA gene expression datasets from TCGA and GEO (GSE144259, GSE50760, and GSE87096) were analyzed to find the significant differentially expressed genes (DEGs). These significant genes were further processed for feature selection through boruta and the confirmed features of importance (genes) were subsequently used for ML-based prognostic classification model development. These genes were analyzed for survival and correlation analysis between final genes and infiltrated immunocytes. A total of 770 CRC samples were included having 78 normal and 692 tumor tissue samples. 170 significant DEGs were identified after DESeq2 analysis along with the topconfects R package. The 33 confirmed features of importance-based RF prognostic classification model have given accuracy, precision, recall, and f1-score of 100% with 0% standard deviation. The overall survival analysis had finalized GLP2R and VSTM2A genes that were significantly downregulated in tumor samples and had a strong correlation with immunocyte infiltration. The involvement of these genes in CRC prognosis was further confirmed on the basis of their biological function and literature analysis. The current findings indicate that GLP2R and VSTM2A may play a significant role in CRC progression and immune response suppression.
Collapse
Affiliation(s)
- Neha Shree Maurya
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India
| | - Shikha Kushwah
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India
| | - Sandeep Kushwaha
- National Institute of Animal Biotechnology, Hyderabad, 500032, India
| | - Aakash Chawade
- Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53, Alnarp, Sweden.
| | - Ashutosh Mani
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, India.
| |
Collapse
|
4
|
Pinho RM, Garas LC, Huang BC, Weimer BC, Maga EA. Malnourishment affects gene expression along the length of the small intestine. Front Nutr 2022; 9:894640. [PMID: 36118759 PMCID: PMC9478944 DOI: 10.3389/fnut.2022.894640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Malnourishment is a risk factor for childhood mortality, jeopardizing the health of children by aggravating pneumonia/acute respiratory infections and diarrheal diseases. Malnourishment causes morphophysiological changes resulting in stunting and wasting that have long-lasting consequences such as cognitive deficit and metabolic dysfunction. Using a pig model of malnutrition, the interplay between the phenotypic data displayed by the malnourished animals, the gene expression pattern along the intestinal tract, microbiota composition of the intestinal contents, and hepatic metabolite concentrations from the same animals were correlated using a multi-omics approach. Samples from the duodenum, jejunum, and ileum of malnourished (protein and calorie-restricted diet) and full-fed (no dietary restrictions) piglets were subjected to RNA-seq. Gene co-expression analysis and phenotypic correlations were made with WGCNA, while the integration of transcriptome with microbiota composition and the hepatic metabolite profile was done using mixOmics. Malnourishment caused changes in tissue gene expression that influenced energetic balance, cell proliferation, nutrient absorption, and response to stress. Repression of antioxidant genes, including glutathione peroxidase, in coordination with induction of metal ion transporters corresponded to the hepatic metabolite changes. These data indicate oxidative stress in the intestine of malnourished animals. Furthermore, several of the phenotypes displayed by these animals could be explained by changes in gene expression.
Collapse
Affiliation(s)
- Raquel M. Pinho
- Department of Animal Science, University of California, Davis, Davis, CA, United States
- *Correspondence: Raquel M. Pinho
| | - Lydia C. Garas
- Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - B. Carol Huang
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Bart C. Weimer
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Elizabeth A. Maga
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| |
Collapse
|
5
|
Martchenko SE, Prescott D, Martchenko A, Sweeney ME, Philpott DJ, Brubaker PL. Diurnal changes in the murine small intestine are disrupted by obesogenic Western Diet feeding and microbial dysbiosis. Sci Rep 2021; 11:20571. [PMID: 34663882 PMCID: PMC8523685 DOI: 10.1038/s41598-021-98986-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 09/01/2021] [Indexed: 02/07/2023] Open
Abstract
Intestinal functions demonstrate circadian rhythms thought to be entrained, in part, by an organisms’ intrinsic feeding and fasting periods as well as by the intestinal microbiome. Circadian disruption as a result of ill-timed nutrient exposure and obesogenic feeding poses an increased risk to disease. As such, the aim of this study was to assess the relationships between dietary timing, composition, and the microbiome with regard to rhythmic small intestinal structure and mucosal immunity. Rodent chow (RC)-mice exhibited time-dependent increases in small intestinal weight, villus height, and crypt depth as well as an increased proportion of CD8αα+ cells and concomitant decrease in CD8αβ+ cells at the onset of the feeding period (p < 0.05–0.001). Western diet (WD)-animals displayed disrupted time-dependent patterns in intestinal structure and lymphocyte populations (p < 0.05–0.01). Antibiotic-induced microbial depletion abrogated the time- and diet-dependent patterns in both RC- and WD-mice (p < 0.05–0.001). However, although germ-free-mice displayed altered rhythms, fecal microbial transfer from RC-mice was generally unsuccessful in restoring structural and immune changes in these animals. This study shows that adaptive changes in the small intestine at the onset of the feeding and fasting periods are disrupted by WD-feeding, and that these changes are dependent, in part, on the intestinal microbiome.
Collapse
Affiliation(s)
- Sarah E Martchenko
- Departments of Physiology, University of Toronto, Rm 3366 Medical Sciences Building, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - David Prescott
- Department of Immunology, University of Toronto, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Alexandre Martchenko
- Departments of Physiology, University of Toronto, Rm 3366 Medical Sciences Building, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Maegan E Sweeney
- Departments of Physiology, University of Toronto, Rm 3366 Medical Sciences Building, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Dana J Philpott
- Department of Immunology, University of Toronto, Toronto, ON, Canada
| | - Patricia L Brubaker
- Departments of Physiology, University of Toronto, Rm 3366 Medical Sciences Building, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada. .,Department of Medicine, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
6
|
Altered intestinal epithelial nutrient transport: an underappreciated factor in obesity modulated by diet and microbiota. Biochem J 2021; 478:975-995. [PMID: 33661278 DOI: 10.1042/bcj20200902] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/31/2022]
Abstract
Dietary nutrients absorbed in the proximal small intestine and assimilated in different tissues have a profound effect on overall energy homeostasis, determined by a balance between body's energy intake and expenditure. In obesity, altered intestinal absorption and consequently tissue assimilation of nutrients may disturb the energy balance leading to metabolic abnormalities at the cellular level. The absorption of nutrients such as sugars, amino acids and fatty acids released from food digestion require high-capacity transporter proteins expressed in the intestinal epithelial absorptive cells. Furthermore, nutrient sensing by specific transporters/receptors expressed in the epithelial enteroendocrine cells triggers release of gut hormones involved in regulating energy homeostasis via their effects on appetite and food intake. Therefore, the intestinal epithelial cells play a pivotal role in the pathophysiology of obesity and associated complications. Over the past decade, gut microbiota has emerged as a key factor contributing to obesity via its effects on digestion and absorption of nutrients in the small intestine, and energy harvest from dietary fiber, undigested component of food, in the large intestine. Various mechanisms of microbiota effects on obesity have been implicated. However, the impact of obesity-associated microbiota on the intestinal nutrient transporters needs extensive investigation. This review marshals the limited studies addressing the altered structure and function of the gut epithelium in obesity with special emphasis on nutrient transporters and role of diet and microbiota. The review also discusses the thoughts and controversies and research gaps in this field.
Collapse
|
7
|
Maruta K, Takajo T, Akiba Y, Said H, Irie E, Kato I, Kuwahara A, Kaunitz JD. GLP-2 Acutely Prevents Endotoxin-Related Increased Intestinal Paracellular Permeability in Rats. Dig Dis Sci 2020; 65:2605-2618. [PMID: 32006214 PMCID: PMC7392813 DOI: 10.1007/s10620-020-06097-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/20/2020] [Indexed: 01/15/2023]
Abstract
BACKGROUND Circulating endotoxin (lipopolysaccharide, LPS) increases the gut paracellular permeability. We hypothesized that glucagon-like peptide-2 (GLP-2) acutely reduces LPS-related increased intestinal paracellular permeability by a mechanism unrelated to its intestinotrophic effect. METHODS We assessed small intestinal paracellular permeability in vivo by measuring the appearance of intraduodenally perfused FITC-dextran 4000 (FD4) into the portal vein (PV) in rats 1-24 h after LPS treatment (5 mg/kg, ip). We also examined the effect of a stable GLP-2 analog teduglutide (TDG) on FD4 permeability. RESULTS FD4 movement into the PV was increased 6 h, but not 1 or 3 h after LPS treatment, with increased PV GLP-2 levels and increased mRNA expressions of proinflammatory cytokines and proglucagon in the ileal mucosa. Co-treatment with a GLP-2 receptor antagonist enhanced PV FD4 concentrations. PV FD4 concentrations 24 h after LPS were higher than FD4 concentrations 6 h after LPS, reduced by exogenous GLP-2 treatment given 6 or 12 h after LPS treatment. FD4 uptake measured 6 h after LPS was reduced by TDG 3 or 6 h after LPS treatment. TDG-associated reduced FD4 uptake was reversed by the VPAC1 antagonist PG97-269 or L-NAME, not by EGF or IGF1 receptor inhibitors. CONCLUSIONS Systemic LPS releases endogenous GLP-2, reducing LPS-related increased permeability. The therapeutic window of exogenous GLP-2 administration is at minimum within 6-12 h after LPS treatment. Exogenous GLP-2 treatment is of value in the prevention of increased paracellular permeability associated with endotoxemia.
Collapse
Affiliation(s)
- Koji Maruta
- Department of Medicine, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Takeshi Takajo
- Department of Medicine, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Yasutada Akiba
- Greater Los Angeles Veterans Affairs Healthcare System, West Los Angeles VA Medical Center, Bldg. 114, Suite 217, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA,Brentwood Biomedical Research Institute, Los Angeles, CA, USA
| | - Hyder Said
- Department of Medicine, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Emi Irie
- Greater Los Angeles Veterans Affairs Healthcare System, West Los Angeles VA Medical Center, Bldg. 114, Suite 217, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA
| | - Ikuo Kato
- Department of Medical Biochemistry, Kobe Pharmaceutical University, Kobe, Japan
| | - Atsukazu Kuwahara
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Japan
| | - Jonathan D. Kaunitz
- Greater Los Angeles Veterans Affairs Healthcare System, West Los Angeles VA Medical Center, Bldg. 114, Suite 217, 11301 Wilshire Blvd., Los Angeles, CA 90073, USA,Department of Medicine, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA,Department of Surgery, School of Medicine, University of California Los Angeles, Los Angeles, CA, USA,Brentwood Biomedical Research Institute, Los Angeles, CA, USA
| |
Collapse
|
8
|
Fesler Z, Mitova E, Brubaker PL. GLP-2, EGF, and the Intestinal Epithelial IGF-1 Receptor Interactions in the Regulation of Crypt Cell Proliferation. Endocrinology 2020; 161:5799206. [PMID: 32147716 PMCID: PMC7098877 DOI: 10.1210/endocr/bqaa040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/28/2020] [Indexed: 12/13/2022]
Abstract
Glucagon-like peptide-2 (GLP-2) is an intestinotrophic hormone that promotes intestinal growth and proliferation through downstream mediators, including epidermal growth factor (EGF) and insulin-like growth factor-1 (IGF-1). EGF synergistically enhances the proliferative actions of IGF-1 in intestinal cell lines, and both of these factors are known to be essential for the trophic effects of GLP-2 in vivo. However, whether EGF and IGF-1 interact to mediate the proliferative actions of GLP-2 in vivo remains unknown. Normal and knockout (KO) mice lacking the intestinal epithelial IGF-1 receptor (IE-IGF-1R) were therefore treated chronically with EGF and/or long-acting human hGly2GLP-2, followed by determination of intestinal growth parameters. Intestines from control and IE-IGF-1R KO mice were also used to generate organoids (which lack the GLP-2 receptor) and were treated with EGF and/or IGF-1. Combination treatment with EGF and hGly2GLP-2 increased small intestinal weight and crypt-villus height in C57Bl/6 mice in an additive manner, whereas only hGly2GLP-2 treatment increased crypt cell proliferation. However, although combination treatment also increased small intestinal weight and crypt-villus height in IE-IGF-1R KO mice, the proliferative responses to hGly2GLP-2 alone or with EGF were diminished in these animals. Finally, IGF-1 treatment of organoids undergoing EGF withdrawal was not additive to the effect of EGF replacement on proliferation, but could restore normal proliferation in the absence of EGF. Together, these findings demonstrate that the intestinal proliferative effects of hGly2GLP-2 are augmented by exogenous EGF in a manner that is partially dependent upon IE-IGF-1R signaling.
Collapse
Affiliation(s)
- Zivit Fesler
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Emilia Mitova
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Patricia L Brubaker
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
- Correspondence: Dr Patricia L. Brubaker, Rm. 3366 Medical Sciences Building, University of Toronto, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada. E-mail:
| |
Collapse
|
9
|
Lu Y, Kweon SS, Tanikawa C, Jia WH, Xiang YB, Cai Q, Zeng C, Schmit SL, Shin A, Matsuo K, Jee SH, Kim DH, Kim J, Wen W, Shi J, Guo X, Li B, Wang N, Zhang B, Li X, Shin MH, Li HL, Ren Z, Oh JH, Oze I, Ahn YO, Jung KJ, Conti DV, Schumacher FR, Rennert G, Jenkins MA, Campbell PT, Hoffmeister M, Casey G, Gruber SB, Gao J, Gao YT, Pan ZZ, Kamatani Y, Zeng YX, Shu XO, Long J, Matsuda K, Zheng W. Large-Scale Genome-Wide Association Study of East Asians Identifies Loci Associated With Risk for Colorectal Cancer. Gastroenterology 2019; 156:1455-1466. [PMID: 30529582 PMCID: PMC6441622 DOI: 10.1053/j.gastro.2018.11.066] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/26/2018] [Accepted: 11/30/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Genome-wide association studies (GWASs) have associated approximately 50 loci with risk of colorectal cancer (CRC)-nearly one third of these loci were initially associated with CRC in studies conducted in East Asian populations. We conducted a GWAS of East Asians to identify CRC risk loci and evaluate the generalizability of findings from GWASs of European populations to Asian populations. METHODS We analyzed genetic data from 22,775 patients with CRC (cases) and 47,731 individuals without cancer (controls) from 14 studies in the Asia Colorectal Cancer Consortium. First, we performed a meta-analysis of 7 GWASs (10,625 cases and 34,595 controls) and identified 46,554 promising risk variants for replication by adding them to the Multi-Ethnic Global Array (MEGA) for genotype analysis in 6445 cases and 7175 controls. These data were analyzed, along with data from an additional 5705 cases and 5961 controls genotyped using the OncoArray. We also obtained data from 57,976 cases and 67,242 controls of European descent. Variants at identified risk loci were functionally annotated and evaluated in correlation with gene expression levels. RESULTS A meta-analyses of all samples from people of Asian descent identified 13 loci and 1 new variant at a known locus (10q24.2) associated with risk of CRC at the genome-wide significance level of P < 5 × 10-8. We did not perform experiments to replicate these associations in additional individuals of Asian ancestry. However, the lead risk variant in 6 of these loci was also significantly associated with risk of CRC in European descendants. A strong association (44%-75% increase in risk per allele) was found for 2 low-frequency variants: rs201395236 at 1q44 (minor allele frequency, 1.34%) and rs77969132 at 12p11.21 (minor allele frequency, 1.53%). For 8 of the 13 associated loci, the variants with the highest levels of significant association were located inside or near the protein-coding genes L1TD1, EFCAB2, PPP1R21, SLCO2A1, HLA-G, NOTCH4, DENND5B, and GNAS. For other intergenic loci, we provided evidence for the possible involvement of the genes ALDH7A1, PRICKLE1, KLF5, WWOX, and GLP2R. We replicated findings for 41 of 52 previously reported risk loci. CONCLUSIONS We showed that most of the risk loci previously associated with CRC risk in individuals of European descent were also associated with CRC risk in East Asians. Furthermore, we identified 13 loci significantly associated with risk for CRC in Asians. Many of these loci contained genes that regulate the immune response, Wnt signaling to β-catenin, prostaglandin E2 catabolism, and cell pluripotency and proliferation. Further analyses of these genes and their variants is warranted, particularly for the 8 loci for which the lead CRC risk variants were not replicated in persons of European descent.
Collapse
Affiliation(s)
- Yingchang Lu
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Sun-Seog Kweon
- Department of Preventive Medicine, Chonnam National University Medical School, Gwangju, South Korea; Jeonnam Regional Cancer Center, Chonnam National University Hwasun Hospital, Hwasun, South Korea
| | - Chizu Tanikawa
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Wei-Hua Jia
- State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, Guangzhou, China
| | - Yong-Bing Xiang
- State Key Laboratory of Oncogenes and Related Genes and Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qiuyin Cai
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Chenjie Zeng
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Stephanie L Schmit
- Department of Cancer Epidemiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Aesun Shin
- Department of Preventive Medicine, Seoul National University College of Medicine, Seoul National University Cancer Research Institute, Seoul, Korea
| | - Keitaro Matsuo
- Division of Molecular and Clinical Epidemiology, Aichi Cancer Center Research Institute, Nagoya, Japan; Department of Epidemiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sun Ha Jee
- Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea
| | - Dong-Hyun Kim
- Department of Social and Preventive Medicine, Hallym University College of Medicine, Okcheon-dong, Korea
| | - Jeongseon Kim
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Gyeonggi-do, South Korea
| | - Wanqing Wen
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jiajun Shi
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Xingyi Guo
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Bingshan Li
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Nan Wang
- General Surgery Department, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Ben Zhang
- Department of Epidemiology and Biostatistics First Affiliated Hospital, Army Medical University, Shapingba District, Chongqing, China
| | - Xinxiang Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Min-Ho Shin
- Department of Preventive Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Hong-Lan Li
- State Key Laboratory of Oncogenes and Related Genes and Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zefang Ren
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jae Hwan Oh
- Center for Colorectal Cancer, National Cancer Center Hospital, National Cancer Center, Gyeonggi-do, South Korea
| | - Isao Oze
- Division of Molecular and Clinical Epidemiology, Aichi Cancer Center Research Institute, Nagoya, Japan
| | - Yoon-Ok Ahn
- Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, South Korea
| | - Keum Ji Jung
- Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea
| | - David V Conti
- Department of Preventive Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Fredrick R Schumacher
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio
| | - Gad Rennert
- Clalit Health Services National Israeli Cancer Control Center, Haifa, Israel; Department of Community Medicine and Epidemiology, Carmel Medical Center, Haifa, Israel; Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Mark A Jenkins
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Peter T Campbell
- Behavioral and Epidemiology Research Group, American Cancer Society, Atlanta, Georgia
| | - Michael Hoffmeister
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Graham Casey
- Center for Public Health Genomics, University of Virginia, Charlottesville, Virginia
| | - Stephen B Gruber
- Department of Preventive Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California; Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Jing Gao
- State Key Laboratory of Oncogenes and Related Genes and Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu-Tang Gao
- State Key Laboratory of Oncogenes and Related Genes and Department of Epidemiology, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhi-Zhong Pan
- State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, Guangzhou, China
| | - Yoichiro Kamatani
- Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan; Kyoto-McGill International Collaborative School in Genomic Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yi-Xin Zeng
- State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, Guangzhou, China
| | - Xiao-Ou Shu
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jirong Long
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Koichi Matsuda
- Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
| | - Wei Zheng
- Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt Epidemiology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.
| |
Collapse
|
10
|
Mu J, Chen Q, Zhu L, Wu Y, Liu S, Zhao Y, Ma T. Influence of gut microbiota and intestinal barrier on enterogenic infection after liver transplantation. Curr Med Res Opin 2019; 35:241-248. [PMID: 29701490 DOI: 10.1080/03007995.2018.1470085] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Liver transplantation is currently a standard therapy for patients with end-stage liver diseases and hepatocellular carcinoma. Given that liver transplantation has undergone a thriving development in these decades, the survival rates after liver transplantation have markedly improved as a result of the critical advancement in surgical techniques, immunosuppressive therapies, and post-operative care. However, infection remains a fatal complication after liver transplantation surgery. In particular, enterogenic infection represents a major complication in liver transplant recipients. This article gives an overview of infection cases after liver transplantation and focuses on the discussion of enterogenic infection in terms of its pathophysiology, risk factor, outcome, and treatment.
Collapse
Affiliation(s)
- Jingzhou Mu
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Qiuyu Chen
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Liang Zhu
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Yunhong Wu
- b College of Public Health , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Suping Liu
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Yufei Zhao
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| | - Tonghui Ma
- a College of Basic Medicine , Dalian Medical University , Dalian , Liaoning Province , PR China
| |
Collapse
|
11
|
Abstract
Enteroendocrine cells (EECs) are sensory cells of the gastrointestinal tract. Most EECs reside in the mucosal lining of the stomach or intestine and sense food in the gut lumen. Food signals stimulate the release of hormones into the paracellular space where they either act locally or are taken up into the blood and circulate to distant organs. It recently was recognized that many EECs possess basal processes known as neuropods that not only contain hormones but also connect to nerves. This review describes how neuropods contribute to EEC function beyond typical hormonal actions. For example, gastrointestinal hormones not only act on distant organs, but, through neuropods, some act locally to stimulate other mucosal cells such as intestinal stem cells, enterocytes, or other EECs. With the recent discovery that EECs communicate directly with enteric nerves, EECs not only have the ability to sense food and bacteria in the gastrointestinal tract, but can communicate these signals directly to the nervous system.
Collapse
|
12
|
Orhan A, Gögenur I, Kissow H. The Intestinotrophic Effects of Glucagon-Like Peptide-2 in Relation to Intestinal Neoplasia. J Clin Endocrinol Metab 2018; 103:2827-2837. [PMID: 29741675 DOI: 10.1210/jc.2018-00655] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 05/01/2018] [Indexed: 02/07/2023]
Abstract
CONTEXT Glucagon-like peptide-2 (GLP-2) is a gastrointestinal hormone with intestinotrophic and antiapoptotic effects. The hormone's therapeutic potential in intestinal diseases and relation to intestinal neoplasia has raised great interest among researchers. This article reviews and discusses published experimental and clinical studies concerning the growth-stimulating and antiapoptotic effects of GLP-2 in relation to intestinal neoplasia. EVIDENCE ACQUISITION The data used in this narrative review were collected through literature research in PubMed using English keywords. All studies to date examining GLP-2's relation to intestinal neoplasms have been reviewed in this article, as the studies on the matter are sparse. EVIDENCE SYNTHESIS GLP-2 has been found to stimulate intestinal growth through secondary mediators and through the involvement of Akt phosphorylation. Studies on rodents have shown that exogenously administered GLP-2 increases the growth and incidence of adenomas in the colon, suggesting that GLP-2 may play an important role in the progression of intestinal tumors. Clinical studies have found that exogenous GLP-2 treatment is well tolerated for up to 30 months, but the tolerability for even longer periods of treatment has not been examined. CONCLUSION Exogenous GLP-2 is currently available as teduglutide for the treatment of short bowel syndrome. However, the association between exogenous GLP-2 treatment and intestinal neoplasia in humans has not been fully identified. This leads to a cause for concern regarding the later risk of the development or progression of intestinal tumors with long-term GLP-2 treatment. Therefore, further research regarding GLP-2's potential relation to intestinal cancers is needed.
Collapse
Affiliation(s)
- Adile Orhan
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Ismail Gögenur
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Koege, Denmark
| | - Hannelouise Kissow
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
- NNF Center of Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| |
Collapse
|
13
|
Brubaker PL. Glucagon‐like Peptide‐2 and the Regulation of Intestinal Growth and Function. Compr Physiol 2018; 8:1185-1210. [DOI: 10.1002/cphy.c170055] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
14
|
Hytting-Andreasen R, Balk-Møller E, Hartmann B, Pedersen J, Windeløv JA, Holst JJ, Kissow H. Endogenous glucagon-like peptide- 1 and 2 are essential for regeneration after acute intestinal injury in mice. PLoS One 2018; 13:e0198046. [PMID: 29864142 PMCID: PMC5986149 DOI: 10.1371/journal.pone.0198046] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/12/2018] [Indexed: 12/15/2022] Open
Abstract
Objective Mucositis is a side effect of chemotherapy seen in the digestive tract, with symptoms including pain, diarrhoea, inflammation and ulcerations. Our aim was to investigate whether endogenous glucagon-like peptide -1 and -2 (GLP-1 and GLP-2) are implicated in intestinal healing after chemotherapy-induced mucositis. Design We used a transgenic mouse model Tg(GCG.DTR)(Tg) expressing the human diphtheria toxin receptor in the proglucagon-producing cells. Injections with diphtheria toxin ablated the GLP-1 and GLP-2 producing L-cells in Tg mice with no effect in wild-type (WT) mice. Mice were injected with 5-fluorouracil or saline and received vehicle, exendin-4, teduglutide (gly2-GLP-2), or exendin-4/teduglutide in combination. The endpoints were body weight change, small intestinal weight, morphology, histological scoring of mucositis and myeloperoxidase levels. Results Ablation of L-cells led to impaired GLP-2 secretion; increased loss of body weight; lower small intestinal weight; lower crypt depth, villus height and mucosal area; and increased the mucositis severity score in mice given 5-fluorouracil. WT mice showed compensatory hyperproliferation as a sign of regeneration in the recovery phase. Co-treatment with exendin-4 and teduglutide rescued the body weight of the Tg mice and led to a hyperproliferation in the small intestine, whereas single treatment was less effective. Conclusion The ablation of L-cells leads to severe mucositis and insufficient intestinal healing, shown by severe body weight loss and lack of compensatory hyperproliferation in the recovery phase. Co-treatment with exendin-4 and teduglutide could prevent this. Because both peptides were needed, we can conclude that both GLP-1 and GLP-2 are essential for intestinal healing in mice.
Collapse
Affiliation(s)
- Rasmus Hytting-Andreasen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Emilie Balk-Møller
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Johanne Agerlin Windeløv
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jens Juul Holst
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Hannelouise Kissow
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center of Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| |
Collapse
|
15
|
Khan D, Vasu S, Moffett RC, Irwin N, Flatt PR. Differential expression of glucagon-like peptide-2 (GLP-2) is involved in pancreatic islet cell adaptations to stress and beta-cell survival. Peptides 2017; 95:68-75. [PMID: 28746825 DOI: 10.1016/j.peptides.2017.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 12/12/2022]
Abstract
Recent studies have confirmed that locally released proglucagon derived gene products, other than glucagon, have a major influence on pancreatic endocrine function. We assessed the impact of glucagon-like peptide-2 (GLP-2) on beta-cell secretory function, proliferation and apoptosis, as well as glucose tolerance, feeding behaviour and islet adaptions to chemically-induced insulin deficiency and resistance. The GLP-2 receptor was evidenced on cultured rodent and human beta-cells, rodent alpha-cells and isolated mouse islets. GLP-2 had no effect on insulin secretion from beta-cells, or isolated mouse islets. In vivo, GLP-2 administration significantly (P<0.05 to P<0.01) decreased food intake in mice. Conversely, GLP-2 had no discernible effects on glucose disposal or insulin secretion. As expected, streptozotocin treatment decreased and hydrocortisone increased beta-cell mass in mice. GLP-2 was visualised in mouse islets and intestinal L-cells. Islet GLP-2 co-localisation with glucagon was significantly decreased (P<0.01) by both streptozotocin and hydrocortisone. In contrast, both interventions increased (P<0.05) co-localisation of GLP-2 with somatostatin. Interestingly, GLP-2 positive cells were reduced (P<0.05) in the intestines of streptozotocin, but not hydrocortisone, treated mice. Further in vitro investigations revealed that GLP-2 protected rodent and human 1.1B4 beta-cells against streptozotocin induced DNA damage. Furthermore, GLP-2 augmented (P<0.05) BRIN BD11 beta-cell proliferation, but was less efficacious in 1.1B4 cells. These data highlight the involvement of GLP-2 receptor signalling in the adaptations to pancreatic islet cell stress.
Collapse
Affiliation(s)
- Dawood Khan
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Srividya Vasu
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - R Charlotte Moffett
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - Nigel Irwin
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK.
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| |
Collapse
|
16
|
Said H, Akiba Y, Narimatsu K, Maruta K, Kuri A, Iwamoto KI, Kuwahara A, Kaunitz JD. FFA3 Activation Stimulates Duodenal Bicarbonate Secretion and Prevents NSAID-Induced Enteropathy via the GLP-2 Pathway in Rats. Dig Dis Sci 2017; 62:1944-1952. [PMID: 28523577 PMCID: PMC5511769 DOI: 10.1007/s10620-017-4600-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/29/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with enteropathy in humans and experimental animals, a cause of considerable morbidity. Unlike foregut NSAID-associated mucosal lesions, most treatments for this condition are of little efficacy. We propose that the endogenously released intestinotrophic hormone glucagon-like peptide-2 (GLP-2) prevents the development of NSAID-induced enteropathy. Since the short-chain fatty acid receptor FFA3 is expressed on enteroendocrine L cells and on enteric nerves in the gastrointestinal tract, we further hypothesized that activation of FFA3 on L cells protects the mucosa from injury via GLP-2 release with enhanced duodenal HCO3- secretion. We thus investigated the effects of synthetic selective FFA3 agonists with consequent GLP-2 release on NSAID-induced enteropathy. METHODS We measured duodenal HCO3- secretion in isoflurane-anesthetized rats in a duodenal loop perfused with the selective FFA3 agonists MQC or AR420626 (AR) while measuring released GLP-2 in the portal vein (PV). Intestinal injury was produced by indomethacin (IND, 10 mg/kg, sc) with or without MQC (1-10 mg/kg, ig) or AR (0.01-0.1 mg/kg, ig or ip) treatment. RESULTS Luminal perfusion with MQC or AR (0.1-10 µM) dose-dependently augmented duodenal HCO3- secretion accompanied by increased GLP-2 concentrations in the PV. The effect of FFA3 agonists was inhibited by co-perfusion of the selective FFA3 antagonist CF3-MQC (30 µM). AR-induced augmented HCO3- secretion was reduced by iv injection of the GLP-2 receptor antagonist GLP-2(3-33) (3 nmol/kg), or by pretreatment with the cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 (1 mg/kg, ip). IND-induced small intestinal ulcers were dose-dependently inhibited by intragastric administration of MQC or AR. GLP-2(3-33) (1 mg/kg, ip) or CF3-MQC (1 mg/kg, ig) reversed AR-associated reduction in IND-induced enteropathy. In contrast, ip injection of AR had no effect on enteropathy. CONCLUSION These results suggest that luminal FFA3 activation enhances mucosal defenses and prevents NSAID-induced enteropathy via the GLP-2 pathway. The selective FFA3 agonist may be a potential therapeutic candidate for NSAID-induced enteropathy.
Collapse
Affiliation(s)
- Hyder Said
- College of Arts and Sciences, University of California, Los Angeles, CA, USA
| | - Yasutada Akiba
- Greater Los Angeles Veterans Affairs Healthcare System, 11301 Wilshire Boulevard, Bldg 115, Suite 217, Los Angeles, CA, 90073, USA
- Department of Medicine, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
- Brentwood Biomedical Research Institute, Los Angeles, CA, USA
| | - Kazuyuki Narimatsu
- Department of Medicine, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
| | - Koji Maruta
- Department of Medicine, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
| | - Ayaka Kuri
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
| | - Ken-Ichi Iwamoto
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
| | - Atsukazu Kuwahara
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
| | - Jonathan D Kaunitz
- Greater Los Angeles Veterans Affairs Healthcare System, 11301 Wilshire Boulevard, Bldg 115, Suite 217, Los Angeles, CA, 90073, USA.
- Department of Medicine, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA.
- Brentwood Biomedical Research Institute, Los Angeles, CA, USA.
- Department of Surgery, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA.
| |
Collapse
|
17
|
Shawe-Taylor M, Kumar JD, Holden W, Dodd S, Varga A, Giger O, Varro A, Dockray GJ. Glucagon-like petide-2 acts on colon cancer myofibroblasts to stimulate proliferation, migration and invasion of both myofibroblasts and cancer cells via the IGF pathway. Peptides 2017; 91:49-57. [PMID: 28363795 DOI: 10.1016/j.peptides.2017.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 01/17/2023]
Abstract
Glucagon-like peptide (GLP)-2 stimulates intestinal epithelial proliferation by acting, in part, via IGF release from sub-epithelial myofibroblasts. The response of myofibroblasts to GLP-2 remains incompletely understood. We studied the action of GLP-2 on myofibroblasts from colon cancer and adjacent tissue, and the effects of conditioned medium from these cells on epithelial cell proliferation, migration and invasion. GLP-2 stimulated proliferation, migration and invasion of myofibroblasts and the proliferative and invasive responses of cancer-associated myofibroblasts were greater than those of myofibroblasts from adjacent tissue. The responses were inhibited by an IGF receptor inhibitor, AG1024. Conditioned medium from GLP-2 treated myofibroblasts increased proliferation, migration and invasion of SW480, HT29, LoVo epithelial cells and these responses were inhibited by AG1024; GLP-2 alone had no effect on these cells. In addition, when myofibroblasts and epithelial cells were co-cultured in Ibidi chambers there was mutual stimulation of migration in response to GLP-2. The latter increased both IGF-1 and IGF-2 transcript abundance in myofibroblasts. Moreover, a number of IGF binding proteins (IGFBP-4, -5, -7) were identified in myofibroblast medium; in the presence of GLP-2 there was increased abundance of the cleavage products of IGBBP-4 and IGFBP-5 suggesting activation of a degradation mechanism that might increase IGF bioavailability. The data suggest that GLP-2 stimulates cancer myofibroblast proliferation, migration and invasion; GLP-2 acts indirectly on epithelial cells partly via increased IGF expression in myofibroblasts and partly, perhaps, by increased bioavailability through degradation of IGFBPs.
Collapse
Affiliation(s)
- Marianne Shawe-Taylor
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - J Dinesh Kumar
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Whitney Holden
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Steven Dodd
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Akos Varga
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Olivier Giger
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Andrea Varro
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Graham J Dockray
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
| |
Collapse
|
18
|
Lim DW, Levesque CL, Vine DF, Muto M, Koepke JR, Nation PN, Wizzard PR, Li J, Bigam DL, Brubaker PL, Turner JM, Wales PW. Synergy of glucagon-like peptide-2 and epidermal growth factor coadministration on intestinal adaptation in neonatal piglets with short bowel syndrome. Am J Physiol Gastrointest Liver Physiol 2017; 312:G390-G404. [PMID: 28104586 DOI: 10.1152/ajpgi.00281.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 01/06/2017] [Accepted: 01/16/2017] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) treatment enhance intestinal adaptation. To determine whether these growth factors exert synergistic effects on intestinal growth and function, GLP-2 and EGF-containing media (EGF-cm) were administered, alone and in combination, in neonatal piglet models of short bowel syndrome (SBS). Neonatal Landrace-Large White piglets were block randomized to 75% midintestinal [jejunoileal (JI) group] or distal intestinal [jejunocolic (JC) group] resection or sham control, with 7-day infusion of saline (control), intravenous human GLP-2 (11 nmol·kg-1·day-1) alone, enteral EGF-cm (80 μg·kg-1·day-1) alone, or GLP-2 and EGF-cm in combination. Adaptation was assessed by intestinal length, histopathology, Üssing chamber analysis, and real-time quantitative PCR of intestinal growth factors. Combined EGF-cm and GLP-2 treatment increased intestinal length in all three surgical models (P < 0.01). EGF-cm alone selectively increased bowel weight per length and jejunal villus height in the JI group only. The JC group demonstrated increased intestinal weight and villus height (P < 0.01) when given either GLP-2 alone or in combination with EGF-cm, with no effect of EGF-cm alone. Jejunal permeability of mannitol and polyethylene glycol decreased with combination therapy in both SBS groups (P < 0.05). No difference was observed in fat absorption or body weight gain. IGF-1 mRNA was differentially expressed in JI vs. JC piglets with treatment. Combined treatment with GLP-2 and EGF-cm induced intestinal lengthening and decreased permeability, in addition to the trophic effects of GLP-2 alone. Our findings demonstrate the benefits of novel combination GLP-2 and EGF treatment for neonatal SBS, especially in the JC model representing most human infants with SBS.NEW & NOTEWORTHY Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) are intestinotrophic, with demonstrated benefit in both animal models and human studies of short bowel syndrome (SBS). The current research shows that over and above known trophic effects, the combination of GLP-2 and EGF synergistically lengthens the bowel in neonatal piglet models of SBS. Most notable benefit occurred with resection of the terminal ileum, the common clinical anatomy seen in neonatal SBS and associated with least de novo lengthening postsurgery.
Collapse
Affiliation(s)
- David W Lim
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Crystal L Levesque
- Department of Animal Science, South Dakota State University, Brookings, South Dakota
| | - Donna F Vine
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
| | - Mitsuru Muto
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Jacob R Koepke
- Department of Animal Science, South Dakota State University, Brookings, South Dakota
| | - Patrick N Nation
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Pamela R Wizzard
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Julang Li
- Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada
| | - David L Bigam
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Patricia L Brubaker
- Departments of Physiology and Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Justine M Turner
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada; .,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Paul W Wales
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.,Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.,Department of Surgery and Group for the Improvement of Intestinal Function and Treatment, Hospital for Sick Children, Toronto, Ontario, Canada; and
| |
Collapse
|
19
|
Interdependency of EGF and GLP-2 Signaling in Attenuating Mucosal Atrophy in a Mouse Model of Parenteral Nutrition. Cell Mol Gastroenterol Hepatol 2017; 3:447-468. [PMID: 28462383 PMCID: PMC5403977 DOI: 10.1016/j.jcmgh.2016.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/31/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND & AIMS Total parenteral nutrition (TPN), a crucial treatment for patients who cannot receive enteral nutrition, is associated with mucosal atrophy, barrier dysfunction, and infectious complications. Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) improve intestinal epithelial cell (IEC) responses and attenuate mucosal atrophy in several TPN models. However, it remains unclear whether these 2 factors use distinct or overlapping signaling pathways to improve IEC responses. We investigated the interaction of GLP-2 and EGF signaling in a mouse TPN model and in patients deprived of enteral nutrition. METHODS Adult C57BL/6J, IEC-Egfrknock out (KO) and IEC-pik3r1KO mice receiving TPN or enteral nutrition were treated with EGF or GLP-2 alone or in combination with reciprocal receptor inhibitors, GLP-2(3-33) or gefitinib. Jejunum was collected and mucosal atrophy and IEC responses were assessed by histologic, gene, and protein expression analyses. In patients undergoing planned looped ileostomies, fed and unfed ileum was analyzed. RESULTS Enteral nutrient deprivation reduced endogenous EGF and GLP-2 signaling in mice and human beings. In the mouse TPN model, exogenous EGF or GLP-2 attenuated mucosal atrophy and restored IEC proliferation. The beneficial effects of EGF and GLP-2 were decreased upon Gefitinib treatment and in TPN-treated IEC-EgfrKO mice, showing epidermal growth factor-receptor dependency for these IEC responses. By contrast, in TPN-treated IEC-pi3kr1KO mice, the beneficial actions of EGF were lost, although GLP-2 still attenuated mucosal atrophy. CONCLUSIONS Upon enteral nutrient deprivation, exogenous GLP-2 and EGF show strong interdependency for improving IEC responses. Understanding the differential requirements for phosphatidylinositol 3-kinase/phosphoAKT (Ser473) signaling may help improve future therapies to prevent mucosal atrophy.
Collapse
Key Words
- EGF
- EGF, epidermal growth factor
- EGFR
- EGFR, epidermal growth factor receptor
- GLP-2
- GLP-2 (3-33), glucagon-like peptide 2 antagonist
- GLP-2, glucagon-like peptide 2
- GLP2R, glucagon-like peptide 2 receptor
- IEC, intestinal epithelial cell
- IGF-1, insulin-like growth factor 1
- ISC, intestinal stem cell
- IV, intravenous
- KO, knock out
- Lgr5, leucine-rich repeat-containing G-protein–coupled receptor 5
- Mucosal Atrophy
- PCNA, proliferating cell nuclear antigen
- PCR, polymerase chain reaction
- PI3K
- PI3K, phosphatidylinositol 3-kinase
- PI3KR1, phosphatidylinositol 3-kinase p85a
- SBS, short-bowel syndrome
- TNF, tumor necrosis factor
- TPN, total parenteral nutrition
- TUNEL, terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling
- Total Parenteral Nutrition
- WT, wild-type
- bp, base pair
- mRNA, messenger RNA
Collapse
|
20
|
Lee J, Koehler J, Yusta B, Bahrami J, Matthews D, Rafii M, Pencharz PB, Drucker DJ. Enteroendocrine-derived glucagon-like peptide-2 controls intestinal amino acid transport. Mol Metab 2017; 6:245-255. [PMID: 28271031 PMCID: PMC5324020 DOI: 10.1016/j.molmet.2017.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/11/2017] [Indexed: 12/28/2022] Open
Abstract
Objective Glucagon-like peptide-2 (GLP-2) is co-secreted with GLP-1 from gut endocrine cells, and both peptides act as growth factors to expand the surface area of the mucosal epithelium. Notably, GLP-2 also enhances glucose and lipid transport in enterocytes; however, its actions on control of amino acid (AA) transport remain unclear. Here we examined the mechanisms linking gain and loss of GLP-2 receptor (GLP-2R) signaling to control of intestinal amino acid absorption in mice. Methods Absorption, transport, and clearance of essential AAs, specifically lysine, were measured in vivo by Liquid Chromatography triple quadrupole Mass Spectrometry (LC-MS/MS) and ex vivo with Ussing chambers using intestinal preparations from Glp2r+/+ and Glp2r−/− mice. Immunoblotting determined jejunal levels of protein components of signaling pathways (PI3K-AKT, and mTORC1-pS6-p4E-BP1) following administration of GLP-2, protein gavage, and rapamycin to fasted Glp2r+/+ and Glp2r−/− mice. Expression of AA transporters from full thickness jejunum and 4F2hc from brush border membrane vesicles (BBMVs) was measured by real-time PCR and immunoblotting, respectively. Results Acute administration of GLP-2 increased basal AA absorption in vivo and augmented basal lysine transport ex vivo. GLP-2-stimulated lysine transport was attenuated by co-incubation with wortmannin, rapamycin, or tetrodotoxin ex vivo. Phosphorylation of mTORC1 effector proteins S6 and 4E-BP1 was significantly increased in wild-type mice in response to GLP-2 alone, or when co-administered with protein gavage, and abolished following oral gavage of rapamycin. In contrast, activation of GLP-1R signaling did not enhance S6 phosphorylation. Disruption of GLP-2 action in Glp2r−/− mice reduced lysine transport ex vivo and attenuated the phosphorylation of S6 and 4E-BP1 in response to oral protein. Moreover, the expression of cationic AA transporter slc7a9 in response to refeeding, and the abundance of 4F2hc in BBMVs following protein gavage, was significantly attenuated in Glp2r−/− mice. Conclusions These findings reveal an important role for GLP-2R signaling in the physiological and pharmacological control of enteral amino acid sensing and assimilation, defining an enteroendocrine cell-enterocyte axis for optimal energy absorption. GLP-2 promotes intestinal amino acid absorption in vivo. Intestinal amino acid absorption is reduced in Glp2r−/− mice. GLP-2 stimulates amino acid transport independently of blood flow. GLP-2, but not GLP-1, activates the mTORC1 signaling pathway. Amino acid transport by GLP-2 requires the enteric nervous system and mTORC1.
Collapse
Key Words
- 4E-BP1, eukaryotic translation initiation factor 4E (eIF4e)-binding protein 1
- AA, amino acid
- Amino acid absorption
- BBMV, brush border membrane vesicles
- EAA, essential amino acid
- EECs, enteroendocrine cells
- ENS, enteric nervous system
- GLP-1
- GLP-1, Glucagon-like peptide-1
- GLP-2
- GLP-2, glucagon-like peptide-2
- GLP-2R, GLP-2 receptor
- Gut peptides
- LC-MS/MS, liquid chromatography triple quadrupole mass spectrometry
- PGDP, proglucagon-derived peptides
- Rapamycin
- S6K1, 70 kDa ribosomal protein S6 kinase 1
- mTORC1, mechanistic target of rapamycin complex 1
Collapse
Affiliation(s)
- Jennifer Lee
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jacqueline Koehler
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Bernardo Yusta
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jasmine Bahrami
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Dianne Matthews
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Mahroukh Rafii
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Paul B Pencharz
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Daniel J Drucker
- Department of Medicine, University of Toronto, Canada; Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, ON M5G 1X5, Canada.
| |
Collapse
|
21
|
Rubin DC, Levin MS. Mechanisms of intestinal adaptation. Best Pract Res Clin Gastroenterol 2016; 30:237-48. [PMID: 27086888 PMCID: PMC4874810 DOI: 10.1016/j.bpg.2016.03.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/03/2016] [Accepted: 03/05/2016] [Indexed: 01/31/2023]
Abstract
Following loss of functional small bowel surface area due to surgical resection for therapy of Crohn's disease, ischemia, trauma or other disorders, the remnant gut undergoes a morphometric and functional compensatory adaptive response which has been best characterized in preclinical models. Increased crypt cell proliferation results in increased villus height, crypt depth and villus hyperplasia, accompanied by increased nutrient, fluid and electrolyte absorption. Clinical observations suggest that functional adaptation occurs in humans. In the immediate postoperative period, patients with substantial small bowel resection have massive fluid and electrolyte loss with reduced nutrient absorption. For many patients, the adaptive response permits partial or complete weaning from parenteral nutrition (PN), within two years following resection. However, others have life-long PN dependence. An understanding of the molecular mechanisms that regulate the gut adaptive response is critical for developing novel therapies for short bowel syndrome. Herein we present a summary of key studies that seek to elucidate the mechanisms that regulate post-resection adaptation, focusing on stem and crypt cell proliferation, epithelial differentiation, apoptosis, enterocyte function and the role of growth factors and the enteric nervous system.
Collapse
Affiliation(s)
- Deborah C Rubin
- Departments of Medicine and Developmental Biology, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, Box 8124, Saint Louis, MO, 63141, USA.
| | - Marc S Levin
- Veteran's Administration, St. Louis Health Care System and Department of Medicine, Divisions of Gastroenterology and VA Medicine, Washington University in St. Louis School of Medicine, 660 South Euclid Avenue, Box 8124, Saint Louis, MO, 63141, USA.
| |
Collapse
|
22
|
Lim DW, Wales PW, Turner JM, Bigam DL, Brubaker PL. On the horizon: trophic peptide growth factors as therapy for neonatal short bowel syndrome. Expert Opin Ther Targets 2016; 20:819-30. [DOI: 10.1517/14728222.2016.1146695] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- David W. Lim
- Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Paul W. Wales
- Department of Surgery, University of Toronto & Hospital for Sick Children, Toronto, ON, Canada
| | - Justine M. Turner
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - David L. Bigam
- Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Patricia L. Brubaker
- Departments of Physiology and Medicine, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
23
|
Connor EE, Evock-Clover CM, Walker MP, Elsasser TH, Kahl S. COMPARATIVE GUT PHYSIOLOGY SYMPOSIUM: Comparative physiology of glucagon-like peptide-2: Implications and applications for production and health of ruminants. J Anim Sci 2016; 93:492-501. [PMID: 26020740 DOI: 10.2527/jas.2014-8577] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Glucagon-like peptide-2 (GLP-2) is a 33-amino acid peptide derived from proteolytic cleavage of proglucagon by prohormone convertase 1/3 in enteroendocrine L cells. Studies conducted in humans, in rodent models, and in vitro indicate that GLP-2 is secreted in response to the presence of molecules in the intestinal lumen, including fatty acids, carbohydrates, amino acids, and bile acids, which are detected by luminal chemosensors. The physiological actions of GLP-2 are mediated by its G protein-coupled receptor expressed primarily in the intestinal tract on enteric neurons, enteroendocrine cells, and myofibroblasts. The biological activity of GLP-2 is further regulated by dipeptidyl peptidase IV, which rapidly cleaves the N-terminus of GLP-2 that is responsible for GLP-2 receptor activation. Within the gut, GLP-2 increases nutrient absorption, crypt cell proliferation, and mesenteric blood flow and decreases gut permeability and motility, epithelial cell apoptosis, and inflammation. Outside the gut, GLP-2 reduces bone resorption, can suppress appetite, and is cytoprotective in the lung. Thus, GLP-2 has been studied intensively as a therapeutic to improve intestinal function of humans during parenteral nutrition and following small bowel resection and, more recently, as a treatment for osteoporosis and obesity-related disorders and to reduce cellular damage associated with inflammation of the gut and lungs. Recent studies demonstrate that many biological actions and properties of GLP-2 in ruminants are similar to those in nonruminants, including the potential to reduce intestinal nitro-oxidative stress in calves caused by parasitic diseases such as coccidiosis. Because of its beneficial impacts on nutrient absorption, gut healing, and normal gut development, GLP-2 therapy offers significant opportunities to improve calf health and production efficiency. However, GLP-2 therapies require an extended time course to achieve desired physiological responses, as well as daily administration because of the hormone's short half-life. Thus, practical means of administration and alternative strategies to enhance basal GLP-2 secretion (e.g., through specific feed additives), which are more likely to achieve consumer acceptance, are needed. Opportunities to address these challenges are discussed.
Collapse
|
24
|
Schall KA, Holoyda KA, Grant CN, Levin DE, Torres ER, Maxwell A, Pollack HA, Moats RA, Frey MR, Darehzereshki A, Al Alam D, Lien C, Grikscheit TC. Adult zebrafish intestine resection: a novel model of short bowel syndrome, adaptation, and intestinal stem cell regeneration. Am J Physiol Gastrointest Liver Physiol 2015; 309:G135-45. [PMID: 26089336 PMCID: PMC4525108 DOI: 10.1152/ajpgi.00311.2014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 05/28/2015] [Indexed: 01/31/2023]
Abstract
Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation.
Collapse
Affiliation(s)
- K. A. Schall
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - K. A. Holoyda
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - C. N. Grant
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - D. E. Levin
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - E. R. Torres
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - A. Maxwell
- 2Developmental Biology and Regenerative Medicine Program, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - H. A. Pollack
- 3Department of Radiology, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - R. A. Moats
- 3Department of Radiology, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - M. R. Frey
- 2Developmental Biology and Regenerative Medicine Program, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California; ,4Department of Pediatrics and Department of Biochemistry and Molecular Biology, Keck School of Medicine at University of Southern California, Los Angeles, California; and
| | - A. Darehzereshki
- 2Developmental Biology and Regenerative Medicine Program, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - D. Al Alam
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| | - C. Lien
- 2Developmental Biology and Regenerative Medicine Program, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California; ,5Department of Cardiothoracic Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California
| | - T. C. Grikscheit
- 1Division of Pediatric Surgery, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California; ,2Developmental Biology and Regenerative Medicine Program, The Saban Research Institute, Children's Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, California;
| |
Collapse
|
25
|
Pedersen J, Pedersen NB, Brix SW, Grunddal KV, Rosenkilde MM, Hartmann B, Ørskov C, Poulsen SS, Holst JJ. The glucagon-like peptide 2 receptor is expressed in enteric neurons and not in the epithelium of the intestine. Peptides 2015; 67:20-8. [PMID: 25748021 DOI: 10.1016/j.peptides.2015.02.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 02/26/2015] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide 2 (GLP-2) is a potent intestinotrophic growth factor with therapeutic potential in the treatment of intestinal deficiencies. It has recently been approved for the treatment of short bowel syndrome. The effects of GLP-2 are mediated by specific binding of the hormone to the GLP-2 receptor (GLP-2R) which was cloned in 1999. However, consensus about the exact receptor localization in the intestine has never been established. By physical, chemical and enzymatic tissue fragmentation, we were able to divide rat jejunum into different compartments consisting of: (1) epithelium alone, (2) mucosa with lamina propria and epithelium, (3) the external muscle coat including myenteric plexus, (4) a compartment enriched for the myenteric plexus and (5) intestine without epithelium. Expression of Glp2r; chromogranin A; tubulin, beta 3; actin, gamma 2, smooth muscle, enteric and glial fibrillary acidic protein in these isolated tissue fractions was quantified with qRT-PCR. Expression of the Glp2r was confined to compartments containing enteric neurons and receptor expression was absent in the epithelium. Our findings provide evidence for the expression of the GLP-2R in intestinal compartments rich in enteric neurons and, importantly they exclude significant expression in the epithelium of rat jejunal mucosa.
Collapse
Affiliation(s)
- Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Nis B Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Sophie W Brix
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Kaare Villum Grunddal
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Mette M Rosenkilde
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Steen S Poulsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| |
Collapse
|
26
|
Sangild PT, Ney DM, Sigalet DL, Vegge A, Burrin D. Animal models of gastrointestinal and liver diseases. Animal models of infant short bowel syndrome: translational relevance and challenges. Am J Physiol Gastrointest Liver Physiol 2014; 307:G1147-68. [PMID: 25342047 PMCID: PMC4269678 DOI: 10.1152/ajpgi.00088.2014] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal failure (IF), due to short bowel syndrome (SBS), results from surgical resection of a major portion of the intestine, leading to reduced nutrient absorption and need for parenteral nutrition (PN). The incidence is highest in infants and relates to preterm birth, necrotizing enterocolitis, atresia, gastroschisis, volvulus, and aganglionosis. Patient outcomes have improved, but there is a need to develop new therapies for SBS and to understand intestinal adaptation after different diseases, resection types, and nutritional and pharmacological interventions. Animal studies are needed to carefully evaluate the cellular mechanisms, safety, and translational relevance of new procedures. Distal intestinal resection, without a functioning colon, results in the most severe complications and adaptation may depend on the age at resection (preterm, term, young, adult). Clinically relevant therapies have recently been suggested from studies in preterm and term PN-dependent SBS piglets, with or without a functional colon. Studies in rats and mice have specifically addressed the fundamental physiological processes underlying adaptation at the cellular level, such as regulation of mucosal proliferation, apoptosis, transport, and digestive enzyme expression, and easily allow exogenous or genetic manipulation of growth factors and their receptors (e.g., glucagon-like peptide 2, growth hormone, insulin-like growth factor 1, epidermal growth factor, keratinocyte growth factor). The greater size of rats, and especially young pigs, is an advantage for testing surgical procedures and nutritional interventions (e.g., PN, milk diets, long-/short-chain lipids, pre- and probiotics). Conversely, newborn pigs (preterm or term) and weanling rats provide better insights into the developmental aspects of treatment for SBS in infants owing to their immature intestines. The review shows that a balance among practical, economical, experimental, and ethical constraints will determine the choice of SBS model for each clinical or basic research question.
Collapse
Affiliation(s)
- Per T. Sangild
- 1Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark; ,2Department of Paediatrics and Adolescent Medicine, Rigshospitalet, Copenhagen, Denmark;
| | - Denise M. Ney
- 3Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin;
| | | | - Andreas Vegge
- 1Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark; ,5Diabetes Pharmacology, Novo Nordisk, Måløv, Denmark; and
| | - Douglas Burrin
- 6USDA-ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
27
|
Enteral nutrition in the management of pediatric intestinal failure. J Pediatr 2014; 165:1085-90. [PMID: 25242686 PMCID: PMC4253063 DOI: 10.1016/j.jpeds.2014.08.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/16/2014] [Accepted: 08/07/2014] [Indexed: 12/28/2022]
|
28
|
Dash S, Xiao C, Morgantini C, Connelly PW, Patterson BW, Lewis GF. Glucagon-like peptide-2 regulates release of chylomicrons from the intestine. Gastroenterology 2014; 147:1275-1284.e4. [PMID: 25173752 PMCID: PMC4316201 DOI: 10.1053/j.gastro.2014.08.037] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/19/2014] [Accepted: 08/22/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS The intestine efficiently incorporates and rapidly secretes dietary fat as chylomicrons (lipoprotein particles comprising triglycerides, phospholipids, cholesterol, and proteins) that contain the apolipoprotein isoform apoB-48. The gut can store lipids for many hours after their ingestion, and release them in chylomicrons in response to oral glucose, sham feeding, or unidentified stimuli. The gut hormone glucagon-like peptide-2 (GLP-2) facilitates intestinal absorption of lipids, but its role in chylomicron secretion in human beings is unknown. METHODS We performed a randomized, single-blind, cross-over study, with 2 study visits 4 weeks apart, to assess the effects of GLP-2 administration on triglyceride-rich lipoprotein (TRL) apoB-48 in 6 healthy men compared with placebo. Subjects underwent constant intraduodenal feeding, with a pancreatic clamp and primed constant infusion of deuterated leucine. In a separate randomized, single-blind, cross-over validation study, 6 additional healthy men ingested a high-fat meal containing retinyl palmitate and were given either GLP-2 or placebo 7 hours later with measurement of TRL triglyceride, TRL retinyl palmitate, and TRL apoB-48 levels. RESULTS GLP-2 administration resulted in a rapid (within 30 minutes) and transient increase in the concentration of TRL apoB-48, compared with placebo (P = .03). Mathematic modeling of stable isotope enrichment and the mass of the TRL apoB-48 suggested that the increase resulted from the release of stored, presynthesized apoB-48 from the gut. In the validation study, administration of GLP-2 at 7 hours after the meal, in the absence of additional food intake, robustly increased levels of TRL triglycerides (P = .007), TRL retinyl palmitate (P = .002), and TRL apoB-48 (P = .04) compared with placebo. CONCLUSIONS Administration of GLP-2 to men causes the release of chylomicrons that comprise previously synthesized and stored apoB-48 and lipids. This transiently increases TRL apoB-48 levels compared with placebo. Clinical trials number at www.clinicaltrials.gov: NCT 01958775.
Collapse
Affiliation(s)
- Satya Dash
- Department of Medicine, Department of Physiology, Banting and Best Diabetes Centre, Canada
,Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Changting Xiao
- Department of Medicine, Department of Physiology, Banting and Best Diabetes Centre, Canada
,Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Cecilia Morgantini
- Department of Medicine, Department of Physiology, Banting and Best Diabetes Centre, Canada
,Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Philip W. Connelly
- Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
,Keenan Research Centre for Biomedical Science of St. Michael’s Hospital, Toronto, Ontario, Canada
| | - Bruce W. Patterson
- Center for Human Nutrition, Department of Internal Medicine, Division of Geriatrics and Nutritional Science, Washington University School of Medicine, St. Louis, Missouri
| | - Gary F. Lewis
- Department of Medicine, Department of Physiology, Banting and Best Diabetes Centre, Canada
,Division of Endocrinology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
29
|
Mah AT, Van Landeghem L, Gavin HE, Magness ST, Lund PK. Impact of diet-induced obesity on intestinal stem cells: hyperproliferation but impaired intrinsic function that requires insulin/IGF1. Endocrinology 2014; 155:3302-14. [PMID: 24914941 PMCID: PMC4138564 DOI: 10.1210/en.2014-1112] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nutrient intake regulates intestinal epithelial mass and crypt proliferation. Recent findings in model organisms and rodents indicate nutrient restriction impacts intestinal stem cells (ISC). Little is known about the impact of diet-induced obesity (DIO), a model of excess nutrient intake on ISC. We used a Sox9-EGFP reporter mouse to test the hypothesis that an adaptive response to DIO or associated hyperinsulinemia involves expansion and hyperproliferation of ISC. The Sox9-EGFP reporter mouse allows study and isolation of ISC, progenitors, and differentiated lineages based on different Sox9-EGFP expression levels. Sox9-EGFP mice were fed a high-fat diet for 20 weeks to induce DIO and compared with littermates fed low-fat rodent chow. Histology, fluorescence activated cell sorting, and mRNA analyses measured impact of DIO on jejunal crypt-villus morphometry, numbers, and proliferation of different Sox9-EGFP cell populations and gene expression. An in vitro culture assay directly assessed functional capacity of isolated ISC. DIO mice exhibited significant increases in body weight, plasma glucose, insulin, and insulin-like growth factor 1 (IGF1) levels and intestinal Igf1 mRNA. DIO mice had increased villus height and crypt density but decreased intestinal length and decreased numbers of Paneth and goblet cells. In vivo, DIO resulted in a selective expansion of Sox9-EGFP(Low) ISC and percentage of ISC in S-phase. ISC expansion significantly correlated with plasma insulin levels. In vitro, isolated ISC from DIO mice formed fewer enteroids in standard 3D Matrigel culture compared to controls, indicating impaired ISC function. This decreased enteroid formation in isolated ISC from DIO mice was rescued by exogenous insulin, IGF1, or both. We conclude that DIO induces specific increases in ISC and ISC hyperproliferation in vivo. However, isolated ISC from DIO mice have impaired intrinsic survival and growth in vitro that can be rescued by exogenous insulin or IGF1.
Collapse
Affiliation(s)
- Amanda T Mah
- Departments of Nutrition (A.T.M.), Cell Biology and Physiology (L.V.L., S.T.M., P.K.L.), and Chemistry (H.E.G.), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | | | | | | | | |
Collapse
|
30
|
Guan X. The CNS glucagon-like peptide-2 receptor in the control of energy balance and glucose homeostasis. Am J Physiol Regul Integr Comp Physiol 2014; 307:R585-96. [PMID: 24990862 DOI: 10.1152/ajpregu.00096.2014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The gut-brain axis plays a key role in the control of energy balance and glucose homeostasis. In response to luminal stimulation of macronutrients and microbiota-derived metabolites (secondary bile acids and short chain fatty acids), glucagon-like peptides (GLP-1 and -2) are cosecreted from endocrine L cells in the gut and coreleased from preproglucagonergic neurons in the brain stem. Glucagon-like peptides are proposed as key mediators for bariatric surgery-improved glycemic control and energy balance. Little is known about the GLP-2 receptor (Glp2r)-mediated physiological roles in the control of food intake and glucose homeostasis, yet Glp1r has been studied extensively. This review will highlight the physiological relevance of the central nervous system (CNS) Glp2r in the control of energy balance and glucose homeostasis and focuses on cellular mechanisms underlying the CNS Glp2r-mediated neural circuitry and intracellular PI3K signaling pathway. New evidence (obtained from Glp2r tissue-specific KO mice) indicates that the Glp2r in POMC neurons is essential for suppressing feeding behavior, gastrointestinal motility, and hepatic glucose production. Mice with Glp2r deletion selectively in POMC neurons exhibit hyperphagic behavior, accelerated gastric emptying, glucose intolerance, and hepatic insulin resistance. GLP-2 differentially modulates postsynaptic membrane excitability of hypothalamic POMC neurons in Glp2r- and PI3K-dependent manners. GLP-2 activates the PI3K-Akt-FoxO1 signaling pathway in POMC neurons by Glp2r-p85α interaction. Intracerebroventricular GLP-2 augments glucose tolerance, suppresses glucose production, and enhances insulin sensitivity, which require PI3K (p110α) activation in POMC neurons. Thus, the CNS Glp2r plays a physiological role in the control of food intake and glucose homeostasis. This review will also discuss key questions for future studies.
Collapse
Affiliation(s)
- Xinfu Guan
- U.S. Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics; and Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
31
|
Inoue T, Higashiyama M, Kaji I, Rudenkyy S, Higuchi K, Guth PH, Engel E, Kaunitz JD, Akiba Y. Dipeptidyl peptidase IV inhibition prevents the formation and promotes the healing of indomethacin-induced intestinal ulcers in rats. Dig Dis Sci 2014; 59:1286-95. [PMID: 24379150 PMCID: PMC4196264 DOI: 10.1007/s10620-013-3001-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/11/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUNDS AND AIMS We studied the intestinotrophic hormone glucagon-like peptide-2 (GLP-2) as a possible therapy for non-steroidal anti-inflammatory drug (NSAID)-induced intestinal ulcers. Luminal nutrients release endogenous GLP-2 from enteroendocrine L cells. Since GLP-2 is degraded by dipeptidyl peptidase IV (DPPIV), we hypothesized that DPPIV inhibition combined with luminal administration of nutrients potentiates the effects of endogenous GLP-2 on intestinal injury. METHODS Intestinal injury was induced by indomethacin (10 mg/kg, sc) in fed rats. The long-acting DPPIV inhibitor K579 was given intragastrically (ig) or intraperitoneally (ip) before or after indomethacin treatment. L-Alanine (L-Ala) and inosine 5'-monophosphate (IMP) were co-administered ig after the treatment. RESULTS Indomethacin treatment induced intestinal ulcers that gradually healed after treatment. Pretreatment with ig or ip K579 given at 1 mg/kg reduced total ulcer length, whereas K579 at 3 mg/kg had no effect. Exogenous GLP-2 also reduced intestinal ulcers. The preventive effect of K579 was dose-dependently inhibited by a GLP-2 receptor antagonist. Daily treatment with K579 (1 mg/kg), GLP-2, or L-Ala + IMP after indomethacin treatment reduced total ulcer length. Co-administration (ig) of K579 and L-Ala + IMP further accelerated intestinal ulcer healing. CONCLUSION DPPIV inhibition and exogenous GLP-2 prevented the formation and promoted the healing of indomethacin-induced intestinal ulcers, although high-dose DPPIV inhibition reversed the preventive effect. Umami receptor agonists also enhanced the healing effects of the DPPIV inhibitor. The combination of DPPIV inhibition and luminal nutrient-induced GLP-2 release may be a useful therapeutic tool for the treatment of NSAIDs-induced intestinal ulcers.
Collapse
Affiliation(s)
- Takuya Inoue
- Department of Medicine, School of Medicine, University of California, Los Angeles
- The Second Department of Internal Medicine, Osaka Medical College, Osaka, Japan
| | - Masaaki Higashiyama
- Department of Medicine, School of Medicine, University of California, Los Angeles
| | - Izumi Kaji
- Department of Medicine, School of Medicine, University of California, Los Angeles
| | - Sergiy Rudenkyy
- Greater Los Angles Veterans Affairs Healthcare System, University of California, Los Angeles
| | - Kazuhide Higuchi
- The Second Department of Internal Medicine, Osaka Medical College, Osaka, Japan
| | - Paul H. Guth
- Greater Los Angles Veterans Affairs Healthcare System, University of California, Los Angeles
| | - Eli Engel
- Department of Biomathematics, University of California, Los Angeles
| | - Jonathan D Kaunitz
- Greater Los Angles Veterans Affairs Healthcare System, University of California, Los Angeles
- Department of Medicine, School of Medicine, University of California, Los Angeles
- Brentwood Biomedical Research Institute, Los Angeles, CA 90073, USA
| | - Yasutada Akiba
- Greater Los Angles Veterans Affairs Healthcare System, University of California, Los Angeles
- Department of Medicine, School of Medicine, University of California, Los Angeles
- Brentwood Biomedical Research Institute, Los Angeles, CA 90073, USA
| |
Collapse
|
32
|
Dong CX, Zhao W, Solomon C, Rowland KJ, Ackerley C, Robine S, Holzenberger M, Gonska T, Brubaker PL. The intestinal epithelial insulin-like growth factor-1 receptor links glucagon-like peptide-2 action to gut barrier function. Endocrinology 2014; 155:370-9. [PMID: 24265452 DOI: 10.1210/en.2013-1871] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glucagon-like peptide-2 (GLP-2) is an intestinal growth-promoting hormone used to treat short bowel syndrome. GLP-2 promotes intestinal growth through a mechanism that involves both IGF-1 and the intestinal-epithelial IGF-1 receptor (IE-IGF-1R). GLP-2 also enhances intestinal barrier function, but through an unknown mechanism. We therefore hypothesized that GLP-2-enhanced barrier function requires the IE-IGF-1R and is mediated through alterations in expression and localization of tight junction proteins. Conditional IE-IGF-1R-null and control mice were treated with vehicle or degradation-resistant Gly(2)-GLP-2 for 10 days; some animals also received irinotecan to induce enteritis. Mice were then examined for gastrointestinal permeability to 4-kDa fluorescein isothiocyanate-dextran, jejunal resistance using Ussing chambers, tight junction structure by electron microscopy, and expression and localization of tight junction proteins by immunoblot and immunohistofluorescence, respectively. GLP-2 treatment decreased permeability to 4-kDa fluorescein isothiocyanate-dextran and increased jejunal resistance (P <.05-.01), effects that were lost in IE-IGF-1R-null mice. Electron microscopy did not reveal major structural changes in the tight junctions in any group of animals. However, the tight junctional proteins claudin-3 and -7 were upregulated by GLP-2 in control (P <.05-.01) but not null mice, whereas IE-IGF-1R deletion induced a shift in occludin localization from apical to intracellular domains; no changes were observed in expression or distribution of claudin-15 and zona occludins-1. Finally, in irinotecan-induced enteritis, GLP-2 normalized epithelial barrier function in control (P < .05) but not knockout animals. In conclusion, the effects of GLP-2 on intestinal barrier function are dependent on the IE-IGF-1R and involve modulation of key components of the tight junctional complex.
Collapse
Affiliation(s)
- Charlotte X Dong
- Departments of Physiology (C.X.D., W.Z., C.S., K.J.R., P.L.B.), Pediatrics (T.G.), and Medicine (P.L.B.), University of Toronto, Toronto, Ontario M5S 1A8 Canada; Department of Paediatric Laboratory Medicine (C.A.), and Physiology and Experimental Medicine, Research Institute (T.G.), The Hospital for Sick Children, Toronto M5G 1X8, Canada; Centre National de la Recherche Scientifique (S.R.), Institut Curie, Paris, 75248 France; and Inserm (M.H.), Hôpital St-Antoine, Paris, 75005 France
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Drucker DJ, Yusta B. Physiology and pharmacology of the enteroendocrine hormone glucagon-like peptide-2. Annu Rev Physiol 2013; 76:561-83. [PMID: 24161075 DOI: 10.1146/annurev-physiol-021113-170317] [Citation(s) in RCA: 225] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Glucagon-like peptide-2 (GLP-2) is a 33-amino-acid proglucagon-derived peptide secreted from enteroendocrine L cells. GLP-2 circulates at low basal levels in the fasting period, and plasma levels rise rapidly after food ingestion. Renal clearance and enzymatic inactivation control the elimination of bioactive GLP-2. GLP-2 increases mesenteric blood flow and activates proabsorptive pathways in the gut, facilitating nutrient absorption. GLP-2 also enhances gut barrier function and induces proliferative and cytoprotective pathways in the small bowel. The actions of GLP-2 are transduced via a single G protein-coupled receptor (GLP-2R), expressed predominantly within the gastrointestinal tract. Disruption of GLP-2R signaling increases susceptibility to gut injury and impairs the adaptive mucosal response to refeeding. Sustained augmentation of GLP-2R signaling reduces the requirement for parenteral nutrition in human subjects with short-bowel syndrome. Hence GLP-2 integrates nutrient-derived signals to optimize mucosal integrity and energy absorption.
Collapse
Affiliation(s)
- Daniel J Drucker
- Department of Medicine, Mount Sinai Hospital, Lunenfeld Tanenbaum Research Institute, University of Toronto, Toronto, Ontario, Canada M5G 1X5; ,
| | | |
Collapse
|
34
|
Shi X, Zhou F, Li X, Chang B, Li D, Wang Y, Tong Q, Xu Y, Fukuda M, Zhao JJ, Li D, Burrin DG, Chan L, Guan X. Central GLP-2 enhances hepatic insulin sensitivity via activating PI3K signaling in POMC neurons. Cell Metab 2013; 18:86-98. [PMID: 23823479 PMCID: PMC3752162 DOI: 10.1016/j.cmet.2013.06.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 05/09/2013] [Accepted: 06/18/2013] [Indexed: 12/23/2022]
Abstract
Glucagon-like peptides (GLP-1/GLP-2) are coproduced and highlighted as key modulators to improve glucose homeostasis and insulin sensitivity after bariatric surgery. However, it is unknown if CNS GLP-2 plays any physiological role in the control of glucose homeostasis and insulin sensitivity. We show that mice lacking GLP-2 receptor (GLP-2R) in POMC neurons display glucose intolerance and hepatic insulin resistance. GLP-2R activation in POMC neurons is required for GLP-2 to enhance insulin-mediated suppression of hepatic glucose production (HGP) and gluconeogenesis. GLP-2 directly modulates excitability of POMC neurons in GLP-2R- and PI3K-dependent manners. GLP-2 initiates GLP-2R-p85α interaction and facilitates PI3K-Akt-dependent FoxO1 nuclear exclusion in POMC neurons. Central GLP-2 suppresses basal HGP and enhances insulin sensitivity, which are abolished in POMC-p110α KO mice. Thus, CNS GLP-2 plays a key physiological role in the control of HGP through activating PI3K-dependent modulation of membrane excitability and nuclear transcription of POMC neurons in the brain.
Collapse
Affiliation(s)
- Xuemei Shi
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Fuguo Zhou
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xiaojie Li
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Benny Chang
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Depei Li
- Department of Critical Care, the University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yi Wang
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qingchun Tong
- Institute of Molecular Medicine, the University of Texas Health Science Center at Houston, TX 77030, USA
| | - Yong Xu
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Makoto Fukuda
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jean J. Zhao
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Defa Li
- State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100083, China
| | - Douglas G. Burrin
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lawrence Chan
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xinfu Guan
- USDA/ARS Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- To whom correspondence and reprint should be addressed. Dr. Xinfu Guan can be reached at , 713-798-9322 (phone), or 713-798-7101(fax). His mailing address: Children’s Nutrition Research Center, 1100 Bates St., Houston, TX 77030
| |
Collapse
|
35
|
Glucagon-like peptide 2 in colon carcinogenesis: Possible target for anti-cancer therapy? Pharmacol Ther 2013; 139:87-94. [DOI: 10.1016/j.pharmthera.2013.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 03/21/2013] [Indexed: 12/18/2022]
|
36
|
Mu JZ, Chen QY, Sun CY, Wu YH, Zhu L. Current status of research on enterogenic infection following liver transplantation. Shijie Huaren Xiaohua Zazhi 2013; 21:1055-1061. [DOI: 10.11569/wcjd.v21.i12.1055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Since the introduction of the Milan criteria in 1996, liver transplantation has become a standard therapy for end-stage liver diseases and hepatocellular carcinoma. In recent years, liver transplantation has developed greatly. Survival rates after liver transplantation have markedly improved as a result of improved operative techniques, use of immunosuppressants, etc. But infection, especially enterogenic infection, is still the most disturbing complication in patients undergoing liver transplantation. This article gives an overview of infection after liver transplantation and focuses on the discussion of enterogenic infection in terms of its pathophysiology, risk factors, outcome, diagnosis and treatment.
Collapse
|
37
|
Baldassano S, Amato A, Cappello F, Rappa F, Mulè F. Glucagon-like peptide-2 and mouse intestinal adaptation to a high-fat diet. J Endocrinol 2013; 217:11-20. [PMID: 23308022 DOI: 10.1530/joe-12-0500] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Endogenous glucagon-like peptide-2 (GLP2) is a key mediator of refeeding-induced and resection-induced intestinal adaptive growth. This study investigated the potential role of GLP2 in mediating the mucosal responses to a chronic high-fat diet (HFD). In this view, the murine small intestine adaptive response to a HFD was analyzed and a possible involvement of endogenous GLP2 was verified using GLP2 (3-33) as GLP2 receptor (GLP2R) antagonist. In comparison with animals fed a standard diet, mice fed a HFD for 14 weeks exhibited an increase in crypt-villus mean height (duodenum, 27.5±3.0%; jejunum, 36.5±2.9%; P<0.01), in the cell number per villus (duodenum, 28.4±2.2%; jejunum, 32.0±2.9%; P<0.01), and in Ki67-positive cell number per crypt. No change in the percent of caspase-3-positive cell in the villus-crypt was observed. The chronic exposure to a HFD also caused a significant increase in GLP2 plasma levels and in GLP2R intestinal expression. Daily administration of GLP2 (3-33) (30-60 ng) for 4 weeks did not modify the crypt-villus height in control mice. In HFD-fed mice, chronic treatment with GLP2 (3-33) reduced the increase in crypt-villus height and in the cell number per villus through reduction of cell proliferation and increase in apoptosis. This study provides the first experimental evidence for a role of endogenous GLP2 in the intestinal adaptation to HFD in obese mice and for a dysregulation of the GLP2/GLP2R system after a prolonged HFD.
Collapse
Affiliation(s)
- Sara Baldassano
- Laboratorio di Fisiologia generale, Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari (STEMBIO), Università di Palermo, 90128 Palermo, Italy
| | | | | | | | | |
Collapse
|
38
|
Janssen P, Rotondo A, Mulé F, Tack J. Review article: a comparison of glucagon-like peptides 1 and 2. Aliment Pharmacol Ther 2013; 37:18-36. [PMID: 23121085 DOI: 10.1111/apt.12092] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/09/2012] [Accepted: 09/29/2012] [Indexed: 12/18/2022]
Abstract
BACKGROUND Recent advancements in understanding the roles and functions of glucagon-like peptide 1 (GLP-1) and 2 (GLP-2) have provided a basis for targeting these peptides in therapeutic strategies. AIM To summarise the preclinical and clinical research supporting the discovery of new therapeutic molecules targeting GLP-1 and GLP-2. METHODS This review is based on a comprehensive PubMed search, representing literature published during the past 30 years related to GLP-1 and GLP-2. RESULTS Although produced and secreted together primarily from L cells of the intestine in response to ingestion of nutrients, GLP-1 and GLP-2 exhibit distinctive biological functions that are governed by the expression of their respective receptors, GLP-1R and GLP-2R. Through widespread expression in the pancreas, intestine, nervous tissue, et cetera, GLP-1Rs facilitates an incretin effect along with effects on appetite and satiety. GLP-1 analogues resistant to degradation by dipeptidyl peptidase-IV and inhibitors of dipeptidyl peptidase-IV have been developed to aid treatment of diabetes and obesity. The GLP-2R is expressed almost exclusively in the stomach and bowel. The most apparent role for GLP-2 is its promotion of growth and function of intestinal mucosa, which has been targeted for therapies that promote repair and adaptive growth. These are used as treatments for intestinal failure and related conditions. CONCLUSIONS Our growing understanding of the biology and function of GLP-1, GLP-2 and corresponding receptors has fostered further discovery of fundamental biological function as well as new categories of potent therapeutic medicines.
Collapse
Affiliation(s)
- P Janssen
- Translational Research Center for Gastrointestinal Disorders, University of Leuven, Belgium
| | | | | | | |
Collapse
|
39
|
Dong CX, Brubaker PL. Ghrelin, the proglucagon-derived peptides and peptide YY in nutrient homeostasis. Nat Rev Gastroenterol Hepatol 2012; 9:705-15. [PMID: 23026903 DOI: 10.1038/nrgastro.2012.185] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Dysregulation of nutrient homeostasis is implicated in the current epidemics of obesity and type 2 diabetes mellitus. The maintenance of homeostasis in the setting of repeated cycles of feeding and fasting occurs through complex interactions between metabolic, hormonal and neural factors. Although pancreatic islets, the liver, muscle, adipocytes and the central nervous system are all key players in this network, the gastrointestinal tract is the first tissue exposed to ingested nutrients and thus has an important role. This Review focuses on several of the endocrine hormones released by the gastrointestinal tract prior to or during nutrient ingestion that have key roles in maintaining energy balance. These hormones include the gastric orexigenic hormone, ghrelin, and the distal L cell anorexigenic and metabolic hormones, glucagon-like peptide (GLP)-1, GLP-2, oxyntomodulin and peptide YY. Each of these hormones exerts a distinct set of biological actions to maintain nutrient homeostasis, the properties of which are currently, or might soon be, exploited in the clinic for the treatment of obesity and type 2 diabetes mellitus.
Collapse
Affiliation(s)
- Charlotte X Dong
- Department of Physiology, Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | | |
Collapse
|
40
|
Guan X, Shi X, Li X, Chang B, Wang Y, Li D, Chan L. GLP-2 receptor in POMC neurons suppresses feeding behavior and gastric motility. Am J Physiol Endocrinol Metab 2012; 303:E853-64. [PMID: 22829581 PMCID: PMC3469617 DOI: 10.1152/ajpendo.00245.2012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Glucagon-like peptides (GLP-1/2) are cosecreted from endocrine L cells in the gut and preproglucagonergic neurons in the brain. Peripheral GLP-2 action is essential for maintaining intestinal homeostasis, improving absorption efficiency and blood flow, promoting immune defense, and producing efficacy in treatment of gastrointestinal diseases. However, it is unknown if CNS GLP-2 plays a physiological role in the control of energy homeostasis. Since GLP-1/2 are cotranslated from preproglucagongene and coproduced by prohormone convertase-1, it is challenging to knockout GLP-2 only. Instead, our laboratory has generated a Glp2r-floxed mouse line to dissect cell-specific GLP-2 receptor GLP-2R) action in the regulation of energy balance. Our objective was to determine if GLP-2R in the hypothalamus modulates feeding behavior and gastric emptying. We show that Glp2r mRNA and protein are highly expressed in the arcuate nucleus and dorsomedial nucleus of the mouse hypothalamus. Using the Cre-LoxP system, we generated mice that lack Glp2r expression in POMC neurons (KO; mainly in the hypothalamus). The KO mice showed hyperphagic behavior (such as increases in food intake and meal frequency), accelerated gastric emptying (assessed by [(13)C]octanoic acid breath test), and late-onset obesity, yet there was no decrease in basal metabolic rate. Infusion of GLP-2 (2.5 nmol into the 4th ventricle) suppressed food intake and gastric emptying, while GLP-2-mediated effects were abolished in the melanocortin receptor-4 (MC4R) KO mice. We conclude that Glp2r deletion in POMC neurons enhances feeding behavior and gastric motility, whereas icv GLP-2R activation suppresses food intake and gastric emptying through the MC4R signaling pathway. This study indicates that CNS GLP-2R plays a physiological role in the control of feeding behavior and gastric emptying and that this is mediated probably through the melanocortin system.
Collapse
MESH Headings
- Animals
- Arcuate Nucleus of Hypothalamus/physiology
- Dorsomedial Hypothalamic Nucleus/physiology
- Feeding Behavior/physiology
- Female
- Gastrointestinal Motility/genetics
- Gastrointestinal Motility/physiology
- Glucagon-Like Peptide 2/pharmacology
- Glucagon-Like Peptide-2 Receptor
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Neurons/physiology
- Pro-Opiomelanocortin/physiology
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/physiology
- Receptors, Glucagon/biosynthesis
- Receptors, Glucagon/genetics
- Receptors, Glucagon/physiology
- Signal Transduction/physiology
Collapse
Affiliation(s)
- Xinfu Guan
- Department of Pediatrics, US Department of Agriculture/Agricultural Research Service Children’s Nutrition Research Center, TX 77030, USA.
| | | | | | | | | | | | | |
Collapse
|
41
|
Yusta B, Holland D, Waschek JA, Drucker DJ. Intestinotrophic glucagon-like peptide-2 (GLP-2) activates intestinal gene expression and growth factor-dependent pathways independent of the vasoactive intestinal peptide gene in mice. Endocrinology 2012; 153:2623-32. [PMID: 22535770 PMCID: PMC3359603 DOI: 10.1210/en.2012-1069] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The enteroendocrine and enteric nervous systems convey signals through an overlapping network of regulatory peptides that act either as circulating hormones or as localized neurotransmitters within the gastrointestinal tract. Because recent studies invoke an important role for vasoactive intestinal peptide (VIP) as a downstream mediator of glucagon-like peptide-2 (GLP-2) action in the gut, we examined the importance of the VIP-GLP-2 interaction through analysis of Vip(-/-) mice. Unexpectedly, we detected abnormal villous architecture, expansion of the crypt compartment, increased crypt cell proliferation, enhanced Igf1 and Kgf gene expression, and reduced expression of Paneth cell products in the Vip(-/-) small bowel. These abnormalities were not reproduced by antagonizing VIP action in wild-type mice, and VIP administration did not reverse the intestinal phenotype of Vip(-/-) mice. Exogenous administration of GLP-2 induced the expression of ErbB ligands and immediate-early genes to similar levels in Vip(+/+) vs. Vip(-/-) mice. Moreover, GLP-2 significantly increased crypt cell proliferation and small bowel growth to comparable levels in Vip(+/+) vs. Vip(-/-) mice. Unexpectedly, exogenous GLP-2 administration had no therapeutic effect in mice with dextran sulfate-induced colitis; the severity of colonic injury and weight loss was modestly reduced in female but not male Vip(-/-) mice. Taken together, these findings extend our understanding of the complex intestinal phenotype arising from loss of the Vip gene. Furthermore, although VIP action may be important for the antiinflammatory actions of GLP-2, the Vip gene is not required for induction of a gene expression program linked to small bowel growth after enhancement of GLP-2 receptor signaling.
Collapse
Affiliation(s)
- Bernardo Yusta
- Department of Medicine, Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, University of Toronto, Toronto, Ontario, Canada M5G 1X5
| | | | | | | |
Collapse
|
42
|
Hitch MC, Leinicke JA, Wakeman D, Guo J, Erwin CR, Rowland KJ, Merrick EC, Heuckeroth RO, Warner BW. Ret heterozygous mice have enhanced intestinal adaptation after massive small bowel resection. Am J Physiol Gastrointest Liver Physiol 2012; 302:G1143-50. [PMID: 22421622 PMCID: PMC3362098 DOI: 10.1152/ajpgi.00296.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal adaptation is an important compensatory response to massive small bowel resection (SBR) and occurs because of a proliferative stimulus to crypt enterocytes by poorly understood mechanisms. Recent studies suggest the enteric nervous system (ENS) influences enterocyte proliferation. We, therefore, sought to determine whether ENS dysfunction alters resection-induced adaptation responses. Ret+/- mice with abnormal ENS function and wild-type (WT) littermates underwent sham surgery or 50% SBR. After 7 days, ileal morphology, enterocyte proliferation, apoptosis, and selected signaling proteins were characterized. Crypt depth and villus height were equivalent at baseline in WT and Ret+/- mice. In contrast after SBR, Ret+/- mice had longer villi (Ret+/- 426.7 ± 46.0 μm vs. WT 306.5 ± 7.7 μm, P < 0.001) and deeper crypts (Ret+/- 119 ± 3.4 μm vs. WT 82.4 ± 3.1 μm, P < 0.001) than WT. Crypt enterocyte proliferation was higher in Ret+/- (48.8 ± 1.3%) than WT (39.9 ± 2.1%; P < 0.001) after resection, but apoptosis rates were similar. Remnant bowel of Ret+/- mice also had higher levels of glucagon-like peptide 2 (6.2-fold, P = 0.005) and amphiregulin (4.6-fold, P < 0.001) mRNA after SBR, but serum glucagon-like peptide 2 protein levels were equal in WT and Ret+/- mice, and there was no evidence of increased c-Fos nuclear localization in submucosal neurons. Western blot confirmed higher crypt epidermal growth factor receptor (EGFR) protein levels (1.44-fold; P < 0.001) and more phosphorylated EGFR (2-fold; P = 0.003) in Ret+/- than WT mice after SBR. These data suggest that Ret heterozygosity enhances intestinal adaptation after massive SBR, likely via enhanced EGFR signaling. Reducing Ret activity or altering ENS function may provide a novel strategy to enhance adaptation attenuating morbidity in patients with short bowel syndrome.
Collapse
Affiliation(s)
- Meredith C. Hitch
- 1Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition, and
| | - Jennifer A. Leinicke
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| | - Derek Wakeman
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| | - Jun Guo
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| | - Chris R. Erwin
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| | - Kathryn J. Rowland
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| | - Ellen C. Merrick
- 1Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition, and
| | - Robert O. Heuckeroth
- 1Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition, and ,3Department of Developmental, Regenerative and Stem Cell Biology, Washington University School of Medicine, St. Louis, Missouri
| | - Brad W. Warner
- 2Department of Surgery, Division of Pediatric Surgery, Washington University School of Medicine, St. Louis Children's Hospital, and
| |
Collapse
|
43
|
Jeppesen PB. Teduglutide, a novel glucagon-like peptide 2 analog, in the treatment of patients with short bowel syndrome. Therap Adv Gastroenterol 2012; 5:159-71. [PMID: 22570676 PMCID: PMC3342570 DOI: 10.1177/1756283x11436318] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Short bowel syndrome results from surgical resection, congenital defect or disease-associated loss of absorption. Parenteral support (PS) is lifesaving in patients with short bowel syndrome and intestinal failure who are unable to compensate for their malabsorption by metabolic or pharmacologic adaptation. Together, the symptoms of short bowel syndrome and the inconvenience and complications in relation to PS (e.g. catheter-related blood steam infections, central thrombosis and intestinal failure associated liver disease) may impair the quality of life of patients. The aim of treatment is to maximize intestinal absorption, minimize the inconvenience of diarrhea, and avoid, reduce or eliminate the need for PS to achieve the best possible quality of life for the patient. Conventional treatments include dietary manipulations, oral rehydration solutions, and antidiarrheal and antisecretory treatments. However, the evidence base for these interventions is limited and treatments that improve the structural and functional integrity of the remaining intestine are needed. Teduglutide, an analog of glucagon-like peptide 2, improves intestinal rehabilitation by promoting mucosal growth and possibly by restoring gastric emptying and secretion, thereby reducing intestinal losses and promoting intestinal absorption. In a 3-week, phase II balance study, teduglutide reduced diarrhea by around 700 g/day and fecal energy losses by around 0.8 MJ/day. In two randomized, placebo-controlled, 24-week, phase III studies, similar findings were obtained when evaluating the fluid composite effect, which is the sum of the beneficial effects of teduglutide - reduction in the need for PS, increase in urine production and reduction in oral fluid intake. The fluid composite effect reflects the increase in intestinal fluid absorption (and the concomitant reduction in diarrhea) and may be used in studies in which metabolic balance assessments are not performed. In studies of up to 24 weeks' duration, teduglutide appears to be safe and well tolerated. Treatment with teduglutide was associated with enhancement or restoration of the structural and functional integrity of the remaining intestine with significant intestinotrophic and proabsorptive effects, facilitating a reduction in diarrhea and an equivalent reduction in the need for PS in patients with short bowel syndrome and intestinal failure.
Collapse
Affiliation(s)
- Palle Bekker Jeppesen
- Department of Medicine CA-2121, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| |
Collapse
|
44
|
Trivedi S, Wiber SC, El-Zimaity HM, Brubaker PL. Glucagon-like peptide-2 increases dysplasia in rodent models of colon cancer. Am J Physiol Gastrointest Liver Physiol 2012; 302:G840-9. [PMID: 22323126 DOI: 10.1152/ajpgi.00505.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The intestinal hormone, glucagon-like peptide-2 (GLP-2), enhances intestinal growth and reduces inflammation in rodent models. Hence, a degradation-resistant GLP-2 analog is under investigation for treatment of Crohn's disease. However, GLP-2 increases colonic dysplasia in murine azoxymethane (AOM)-induced colon cancer. Considering the increased colon cancer risk associated with chronic colitis, we have therefore examined the effects of long-acting hGly(2)GLP-2, as well as of endogenous GLP-2 using the antagonist hGLP-2(3-33) in two novel models of inflammation-associated colon cancer: rats fed the carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and a high-fat diet (HFD) for one or three cycles, and mice with chronic dextran sodium-sulfate (DSS)-induced colitis administered AOM. hGly(2)GLP-2 treatment of one-cycle PhIP/HFD rats increased the number of colonic aberrant crypt foci by 72 ± 11% (P < 0.01). Fifty-one weeks after three PhIP/HFD cycles, hGly(2)GLP-2-treated rats had a 22% incidence of colon cancer, compared with 0% in vehicle-treated rats. AOM-DSS mice treated with vehicle or hGly(2)GLP-2 had high-grade dysplasia/colon cancer incidences of 56 and 64%, respectively, compared with 46% in hGLP-2(3-33)-treated AOM-DSS animals (P < 0.05). Unexpectedly, hGLP-2(3-33) also reduced the colitis damage score by 32.0 ± 8.4% (P < 0.05). All high-grade dysplastic/cancerous tumors had nuclear localization of β-catenin although β-catenin mRNA transcript and protein levels did not differ between treatment groups. GLP-2 receptor mRNA expression also was not different. However, hGLP-2(3-33)-treated mice had markedly reduced numbers of doublecortin-and-calmodulin-kinase-like-1-positive stem cells, by 73.7 ± 8.6% (P < 0.05). In conclusion, the results of this study indicate a role for hGly(2)GLP-2 and endogenous GLP-2 as potential cancer promoters in rodents.
Collapse
Affiliation(s)
- Shivangi Trivedi
- Department of 1Physiology, University of Toronto, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
45
|
Murali SG, Brinkman AS, Solverson P, Pun W, Pintar JE, Ney DM. Exogenous GLP-2 and IGF-I induce a differential intestinal response in IGF binding protein-3 and -5 double knockout mice. Am J Physiol Gastrointest Liver Physiol 2012; 302:G794-804. [PMID: 22281475 PMCID: PMC3355561 DOI: 10.1152/ajpgi.00372.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) action is dependent on intestinal expression of IGF-I, and IGF-I action is modulated by IGF binding proteins (IGFBP). Our objective was to evaluate whether the intestinal response to GLP-2 or IGF-I is dependent on expression of IGFBP-3 and -5. Male, adult mice in six treatment groups, three wild-type (WT) and three double IGFBP-3/-5 knockout (KO), received twice daily intraperitoneal injections of GLP-2 (0.5 μg/g body wt), IGF-I (4 μg/g body wt), or PBS (vehicle) for 7 days. IGFBP-3/-5 KO mice showed a phenotype of lower plasma IGF-I concentration, but greater body weight and relative mass of visceral organs, compared with WT mice (P < 0.001). WT mice showed jejunal growth with either IGF-I or GLP-2 treatment. In KO mice, IGF-I did not stimulate jejunal growth, crypt mitosis, sucrase activity, and IGF-I receptor (IGF-IR) expression, suggesting that the intestinotrophic actions of IGF-I are dependent on expression of IGFBP-3 and -5. In KO mice, GLP-2 induced significant increases in jejunal mucosal cellularity, crypt mitosis, villus height, and crypt depth that was associated with increased expression of the ErbB ligand epiregulin and decreased expression of IGF-I and IGF-IR. This suggests that in KO mice, GLP-2 action in jejunal mucosa is independent of the IGF-I system and linked with ErbB ligands. In summary, the intestinotrophic actions of IGF-I, but not GLP-2, in mucosa are dependent on IGFBP-3 and -5. These findings support the role of multiple downstream mediators for the mucosal growth induced by GLP-2.
Collapse
Affiliation(s)
| | - Adam S. Brinkman
- Departments of 1Nutritional Sciences and ,2Surgery, School of Medicine and Public Health, University
of Wisconsin-Madison, Madison, Wisconsin;
| | | | - Wing Pun
- Departments of 1Nutritional Sciences and
| | - John E. Pintar
- 3Department of Neuroscience and Cell Biology, Robert Wood
Johnson Medical School, University of Medicine and Dentistry of New Jersey,
Piscataway, New Jersey
| | | |
Collapse
|
46
|
Lee SJ, Lee J, Li KK, Holland D, Maughan H, Guttman DS, Yusta B, Drucker DJ. Disruption of the murine Glp2r impairs Paneth cell function and increases susceptibility to small bowel enteritis. Endocrinology 2012; 153:1141-51. [PMID: 22253424 PMCID: PMC3606134 DOI: 10.1210/en.2011-1954] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Exogenous glucagon-like peptide-2 receptor (GLP-2R) activation elicits proliferative and cytoprotective responses in the gastrointestinal mucosa and ameliorates experimental small and large bowel gut injury. Nevertheless, the essential physiological role(s) of the endogenous GLP-2R remain poorly understood. We studied the importance of the GLP-2R for gut growth, epithelial cell lineage allocation, the response to mucosal injury, and host-bacterial interactions in Glp2r(-/-) and littermate control Glp2r(+/+) mice. Glp2r(-/-) mice exhibit normal somatic growth and preserved small and large bowel responses to IGF-I and keratinocyte growth factor. However, Glp2r(-/-) mice failed to up-regulate intestinal epithelial c-fos expression in response to acute GLP-2 administration and do not exhibit changes in small bowel conductance or small or large bowel growth after administration of GLP-2R agonists. The crypt and villus compartment and the numbers and localization of Paneth, enteroendocrine, and goblet cells were comparable in Glp2r(+/+) vs. Glp2r(-/-) mice. Although the severity and extent of colonic mucosal injury in response to 3% oral dextran sulfate was similar across Glp2r genotypes, Glp2r(-/-) mice exhibited significantly increased morbidity and mortality and increased bacterial translocation after induction of enteritis with indomethacin and enhanced mucosal injury in response to irinotecan. Moreover, bacterial colonization of the small bowel was significantly increased, expression of Paneth cell antimicrobial gene products was reduced, and mucosal bactericidal activity was impaired in Glp2r(-/-) mice. Although the Glp2r is dispensable for gut development and the response to colonic injury, Glp2r(-/-) mice exhibit enhanced sensitivity to small bowel injury, and abnormal host-bacterial interactions in the small bowel.
Collapse
Affiliation(s)
- Seung-Jun Lee
- Department of Medicine, Mt. Sinai Hospital, Samuel Lunenfeld Research Institute, 600 University Avenue, TCP5-1004, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Nørholk LM, Holst JJ, Jeppesen PB. Treatment of adult short bowel syndrome patients with teduglutide. Expert Opin Pharmacother 2012; 13:235-43. [PMID: 22224470 DOI: 10.1517/14656566.2012.644787] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Parenteral support is lifesaving in short bowel syndrome patients with intestinal failure (SBS-IF), who are unable to compensate for their malabsorption by metabolic or pharmacologic adaptation. Mutually, the symptoms of SBS-IF and the inconveniences and complications in relation to parenteral support may cause impairment of the quality of life of SBS-IF patients. Conventional treatments include dietary manipulations, oral rehydration solutions, antidiarrheal and antisecretory treatments. However, the evidence base for these interventions is limited, and treatments improving structural and functional integrity of the remaining intestine are desired. Teduglutide , an analog of glucagon-like peptide 2, improves intestinal rehabilitation by promoting mucosal growth and possibly by inhibiting gastric emptying and secretion, which in turn reduces intestinal losses and promotes intestinal absorption. AREAS COVERED This paper reviews the following findings: in a 3-week, Phase II balance study, teduglutide reduced diarrhea by ∼ 700 g/day and fecal energy losses by ∼ 0.8 MJ/day, and in a randomized, placebo-controlled, 24-week, Phase III study, corresponding reductions in the need for parenteral support were obtained. EXPERT OPINION Teduglutide seems to be safe and well-tolerated and demonstrates restoration of structural and functional integrity of the remaining intestine with significant intestinotrophic and proabsorptive effects, facilitating a reduction in diarrhea and an equivalent reduction in the need for parenteral support in SBS-IF patients.
Collapse
Affiliation(s)
- Lærke Marijke Nørholk
- Department of Medicine CA-2121, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| | | | | |
Collapse
|
48
|
Rowland KJ, Trivedi S, Lee D, Wan K, Kulkarni RN, Holzenberger M, Brubaker PL. Loss of glucagon-like peptide-2-induced proliferation following intestinal epithelial insulin-like growth factor-1-receptor deletion. Gastroenterology 2011; 141:2166-2175.e7. [PMID: 21925122 DOI: 10.1053/j.gastro.2011.09.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 08/18/2011] [Accepted: 09/01/2011] [Indexed: 01/16/2023]
Abstract
BACKGROUND & AIMS Glucagon-like peptide-2 (GLP-2) is an intestinal hormone that promotes growth of the gastrointestinal tract. Although insulin-like growth factor (IGF)-1 and the IGF-1 receptor (IGF-1R) are required for GLP-2-induced proliferation of crypt cells, little is known about localization of the IGF-1R which mediates the intestinotropic actions of GLP-2. METHODS We examined intestinal growth and proliferative responses in mice with conditional deletion of IGF-1R from intestinal epithelial cells (IE-igf1rKO) after acute administration (30-90 min) of GLP-2, in response to 24-hour fasting and re-feeding (to induce GLP-2-dependent adaptation), and after chronic exposure (10 days) to GLP-2. RESULTS IE-igf1rKO mice had normal small intestinal weight, morphometric parameters, proliferative indices, and distribution of differentiated epithelial cell lineages. Acute administration of GLP-2 increased nuclear translocation of β-catenin in non-Paneth crypt cells and stimulated the crypt-cell proliferative marker c-Myc in control but not IE-igf1rKO mice. Small intestinal weight, crypt depth, villus height, and crypt-cell proliferation were decreased in control and IE-igf1rKO mice after 24-hour fasting. Although re-feeding control mice restored all of these parameters, re-fed IE-igf1rKO mice had reductions in adaptive regrowth of the villi and crypt-cell proliferation. Control mice that were given chronic GLP-2 had increases in small intestinal weight, mucosal cross-sectional area, crypt depth, villus height, and crypt-cell proliferation. However, the GLP-2-induced increase in crypt-cell proliferation was not observed in IE-igf1rKO mice, and growth of the crypt-villus axis was reduced. CONCLUSIONS The proliferative responses of the intestinal epithelium to exogenous GLP-2 administration and conditions of GLP-2-dependent adaptive re-growth require the intestinal epithelial IGF-1R.
Collapse
Affiliation(s)
- Katherine J Rowland
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
49
|
Rowland KJ, Brubaker PL. The "cryptic" mechanism of action of glucagon-like peptide-2. Am J Physiol Gastrointest Liver Physiol 2011; 301:G1-8. [PMID: 21527727 DOI: 10.1152/ajpgi.00039.2011] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) is a peptide hormone with multiple beneficial effects on the intestine, including expansion of the mucosal surface area through stimulation of crypt cell proliferation, as well as enhancement of nutrient digestion and absorption. Recent advances in clinical trials involving GLP-2 necessitate elucidation of the exact signaling pathways by which GLP-2 acts. In particular, the GLP-2 receptor has been localized to several intestinal cell types that do not include the proliferating crypt cells, and the actions of GLP-2 have thus been linked to a complex network of indirect mediators that induce diverse signaling pathways. The intestinotropic actions of GLP-2 on the colon have been shown to be mediated through the actions of keratinocyte growth factor and insulin-like growth factor (IGF)-2, whereas small intestinal growth has been linked to IGF-1, IGF-2, and ErbB ligands, as well as the IGF-1 receptor and ErbB. The cellular source of these mediators remains unclear, but it likely includes the intestinal subepithelial myofibroblasts. Conversely, the anti-inflammatory and blood flow effects of GLP-2 are dependent on vasoactive intestinal polypeptide released from submucosal enteric neurons and nitric oxide, respectively. Finally, recent studies have suggested that GLP-2 not only modulates intestinal stem cell behavior but may also promote carcinogenesis in models of sporadic colon cancer. Further consideration of the molecular cross-talk and downstream signaling pathways mediating the intestinotropic effects of GLP-2 is clearly warranted.
Collapse
|
50
|
Shi X, Li X, Wang Y, Zhang K, Zhou F, Chan L, Li D, Guan X. Glucagon-like peptide-2-stimulated protein synthesis through the PI 3-kinase-dependent Akt-mTOR signaling pathway. Am J Physiol Endocrinol Metab 2011; 300:E554-63. [PMID: 21177288 PMCID: PMC3279303 DOI: 10.1152/ajpendo.00620.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive neuropeptide that exerts diverse actions in the gastrointestinal tract, including enhancing mucosal cell survival and proliferation. GLP-2 stimulates mucosal growth in vivo with an increased rate of protein synthesis. However, it was unclear whether GLP-2 can directly stimulate protein synthesis. The objective was to test critically whether GLP-2 receptor (GLP-2R) activation directly stimulates protein synthesis through a PI 3-kinase-dependent Akt-mTOR signaling pathway. HEK 293 cells (transfected with human GLP-2R cDNA) were treated with human GLP-2 with/without pretreatment of PI 3-kinase inhibitor (LY-294002) or mTOR inhibitor (rapamycin). Results show that 1) GLP-2 specifically bound to GLP-2R overexpressed in the HEK cells with K(a) = 0.22 nM and B(max) = 321 fmol/μg protein; 2) GLP-2-stimulated protein synthesis was dependent on the amount of GLP-2R cDNA and the dosage of GLP-2 and reached the plateau among 0.2-2 nM GLP-2; 3) GLP-2-stimulated protein synthesis was abolished by the PI 3-kinase inhibitor and mTOR inhibitor; and 4) GLP-2-mediated stimulation of phosphorylation on Akt and mTOR was dependent on the amount of GLP-2R cDNA transfected and the dosage of GLP-2. In addition, GLP-2-mediated action and signaling in regulation of protein synthesis were confirmed in mouse hippocampal neurons (expressing native GLP-2R). GLP-2 directly stimulated protein synthesis of primary cultured neurons in dosage-dependent, PI 3-kinase-dependent, and rapamycin-sensitive manners, which linked with activation of Akt-mTOR signaling pathway as well. We conclude that GLP-2R activation directly stimulates protein synthesis by activating the PI 3-kinase-dependent Akt-mTOR signaling pathway. GLP-2-stimulated protein synthesis may be physiologically relevant to maintaining neuronal long-term potentiation and providing secondary mediators (namely neuropeptides or growth factors).
Collapse
Affiliation(s)
- Xuemei Shi
- USDA/ARS Children's Nutrition Research Center, Dept. of Pediatrics, Baylor College of Medicine, 1100 Bates St., Houston, TX 77030, USA
| | | | | | | | | | | | | | | |
Collapse
|