651
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Kojima M, Hamamoto A, Sato T. Ghrelin O-acyltransferase (GOAT), a specific enzyme that modifies ghrelin with a medium-chain fatty acid. J Biochem 2016; 160:189-194. [PMID: 27489223 DOI: 10.1093/jb/mvw046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/01/2016] [Indexed: 11/14/2022] Open
Abstract
In the gastric peptide hormone ghrelin, serine 3 (threonine 3 in frogs) is modified, primarily by n-octanoic acid; this modification is essential for ghrelin's activity. The enzyme that transfers n-octanoic acid to Ser3 of ghrelin is ghrelin O-acyltransferase (GOAT). GOAT, the only enzyme known to catalyze acyl modification of ghrelin, specifically modifies serine (or threonine) at the third position and does not modify other serine residues in ghrelin peptides. GOAT prefers n-hexanoyl-CoA over n-octanoyl-CoA as the acyl donor, although in the stomach the n-octanoyl form is the predominant form of acyl-modified ghrelin. GOAT is a promising target for drug development to treat metabolic diseases and eating disorders.
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Affiliation(s)
- Masayasu Kojima
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
| | - Akie Hamamoto
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
| | - Takahiro Sato
- Molecular Genetics, Institute of Life Science, Kurume University, Kurume, Fukuoka, Japan
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652
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Castellano JM, Tena-Sempere M. Metabolic control of female puberty: potential therapeutic targets. Expert Opin Ther Targets 2016; 20:1181-93. [PMID: 27409160 DOI: 10.1080/14728222.2016.1212015] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The onset of puberty in females is highly sensitive to the nutritional status and the amount of energy reserves of the organism. This metabolic information is sensed and transmitted to hypothalamic GnRH neurons, considered to be ultimately responsible for triggering puberty through the coordinated action of different peripheral hormones, central neurotransmitters, and molecular mediators. AREAS COVERED This article will review and discuss (i) the relevant actions of the adipose hormone leptin, as a stimulatory/permissive signal, and the gut hormone ghrelin, as an inhibitory factor, in the metabolic control of female puberty; (ii) the crucial role of the hypothalamic kisspeptin neurons, recently emerged as essential gatekeepers of puberty, in transmitting this metabolic information to GnRH neurons; and (iii) the potential involvement of key cellular energy sensors, such as mTOR, as molecular mediators in this setting. EXPERT OPINION The thorough characterization of the physiological roles of the above elements in the metabolic control of female puberty, along with the discovery of novel factors, pathways, and mechanisms involved, will promote our understanding of the complex networks connecting metabolism and puberty and, ultimately, will aid in the design of target-specific treatments for female pubertal disorders linked to conditions of metabolic stress.
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Affiliation(s)
- Juan M Castellano
- a Department of Cell Biology, Physiology and Immunology , University of Córdoba , Córdoba , Spain.,b CIBER Fisiopatología de la Obesidad y Nutrición , Instituto de Salud Carlos III , Córdoba , Spain.,c Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Hospital Universitario Reina Sofia , Córdoba , Spain
| | - Manuel Tena-Sempere
- a Department of Cell Biology, Physiology and Immunology , University of Córdoba , Córdoba , Spain.,b CIBER Fisiopatología de la Obesidad y Nutrición , Instituto de Salud Carlos III , Córdoba , Spain.,c Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/Hospital Universitario Reina Sofia , Córdoba , Spain.,d FiDiPro Program, Department of Physiology , University of Turku , Turku , Finland
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653
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Sun N, Wang H, Wang L. Protective effects of ghrelin against oxidative stress, inducible nitric oxide synthase and inflammation in a mouse model of myocardial ischemia/reperfusion injury via the HMGB1 and TLR4/NF-κB pathway. Mol Med Rep 2016; 14:2764-70. [DOI: 10.3892/mmr.2016.5535] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 06/20/2016] [Indexed: 11/06/2022] Open
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654
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Affiliation(s)
- Edmund T. Rolls
- Oxford Centre for Computational Neuroscience, Oxford, United Kingdom;
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655
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Abstract
Ghrelin is a growth hormone-releasing polypeptide that was first isolated from the rat stomach in 1999. High expression of growth hormone secretagogue receptor, the ghrelin receptor, in the heart, kidney, and blood vessels provides evidence of ghrelin activity in blood pressure regulation. Circulating ghrelin concentrations are reported to be inversely correlated with blood pressure, and the acute and chronic effects of ghrelin in decreasing blood pressure have been reported in animals with normal blood pressure, healthy individuals, animals and patients with heart failure, and animals with hypertension. The mechanism by which ghrelin regulates blood pressure appears to be related to modulation of the autonomic nervous system, direct vasodilatory activities, and kidney diuresis. Thus, modulation of the signaling pathway through ghrelin may provide a novel concept for treating hypertension. In this review, we discuss the current evidence and potential mechanisms of ghrelin activity in blood pressure regulation.
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656
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Kunath N, Müller NCJ, Tonon M, Konrad BN, Pawlowski M, Kopczak A, Elbau I, Uhr M, Kühn S, Repantis D, Ohla K, Müller TD, Fernández G, Tschöp M, Czisch M, Steiger A, Dresler M. Ghrelin modulates encoding-related brain function without enhancing memory formation in humans. Neuroimage 2016; 142:465-473. [PMID: 27402596 DOI: 10.1016/j.neuroimage.2016.07.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/07/2016] [Accepted: 07/06/2016] [Indexed: 01/24/2023] Open
Abstract
Ghrelin regulates energy homeostasis in various species and enhances memory in rodent models. In humans, the role of ghrelin in cognitive processes has yet to be characterized. Here we show in a double-blind randomized crossover design that acute administration of ghrelin alters encoding-related brain activity, however does not enhance memory formation in humans. Twenty-one healthy young male participants had to memorize food- and non-food-related words presented on a background of a virtual navigational route while undergoing fMRI recordings. After acute ghrelin administration, we observed decreased post-encoding resting state fMRI connectivity between the caudate nucleus and the insula, amygdala, and orbitofrontal cortex. In addition, brain activity related to subsequent memory performance was modulated by ghrelin. On the next day, however, no differences were found in free word recall or cued location-word association recall between conditions; and ghrelin's effects on brain activity or functional connectivity were unrelated to memory performance. Further, ghrelin had no effect on a cognitive test battery comprising tests for working memory, fluid reasoning, creativity, mental speed, and attention. In conclusion, in contrast to studies with animal models, we did not find any evidence for the potential of ghrelin acting as a short-term cognitive enhancer in humans.
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Affiliation(s)
- N Kunath
- Max Planck Institute of Psychiatry, Munich, Germany
| | - N C J Müller
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - M Tonon
- Max Planck Institute of Psychiatry, Munich, Germany
| | - B N Konrad
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - M Pawlowski
- Max Planck Institute of Psychiatry, Munich, Germany
| | - A Kopczak
- Max Planck Institute of Psychiatry, Munich, Germany
| | - I Elbau
- Max Planck Institute of Psychiatry, Munich, Germany
| | - M Uhr
- Max Planck Institute of Psychiatry, Munich, Germany
| | - S Kühn
- Max Planck Institute for Human Development, Berlin, Germany
| | - D Repantis
- Charité - Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, CBF, Berlin, Germany
| | - K Ohla
- German Institute for Human Nutrition, Potsdam-Rehbrücke, Germany
| | - T D Müller
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Munich, Germany; Department of Medicine, Technische Universität München, Munich, Germany
| | - G Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - M Tschöp
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Munich, Germany; Department of Medicine, Technische Universität München, Munich, Germany
| | - M Czisch
- Max Planck Institute of Psychiatry, Munich, Germany
| | - A Steiger
- Max Planck Institute of Psychiatry, Munich, Germany
| | - M Dresler
- Max Planck Institute of Psychiatry, Munich, Germany; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.
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657
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Sirotkin AV, Harrath AH, Grossmann R. Comparison of the effects of human and chicken ghrelin on chicken ovarian hormone release. Comp Biochem Physiol B Biochem Mol Biol 2016; 201:59-63. [PMID: 27378405 DOI: 10.1016/j.cbpb.2016.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 06/20/2016] [Accepted: 06/27/2016] [Indexed: 11/26/2022]
Abstract
The aim of the present experiments was to examine the species-specific and cell-specific effects of ghrelin on chicken ovarian hormone release. For this purpose, we compared the effects of chicken and human ghrelin on the release of estradiol (E), testosterone (T), progesterone (P) and arginine-vasotocin (AVT) by cultured fragments of chicken ovarian follicles and on the release of T and AVT by cultured ovarian granulosa cells. In cultured chicken ovarian fragments, both human and chicken ghrelin promoted E release. T output was stimulated by chicken ghrelin but not by human ghrelin. No effect of either human or chicken ghrelin on P release was observed. Human ghrelin promoted but chicken ghrelin suppressed AVT release by chicken ovarian fragments. In cultured ovarian granulosa cells, human ghrelin inhibited while chicken ghrelin stimulated T release. Both human and chicken ghrelin suppressed AVT output by chicken granulosa cells. These data confirm the involvement of ghrelin in the control of ovarian secretory activity and demonstrate that the effect of ghrelin is species-specific. The similarity of avian ghrelin on avian ovarian granulosa cells and ovarian fragments (containing both granulosa and theca cells) suggests that ghrelin can influence chicken ovarian hormones primarily by acting on granulosa cells.
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Affiliation(s)
- Alexander V Sirotkin
- Dept. of Zoology and Anthropology, Constantine the Philosopher University, 949 74 Nitra, Slovakia; Dept. of Genetics and Reproduction, Research Institute of Animal Production, 949 59 Lužianky, Slovakia; King Saud University, Zoology Department, College of Science, Riyadh, Saudi Arabia.
| | - Abdel Halim Harrath
- King Saud University, Zoology Department, College of Science, Riyadh, Saudi Arabia.
| | - Roland Grossmann
- Dept. of Functional Genomics & Bioregulation, Friedrich Loeffler Institute, Mariensee, Neustadt, Germany.
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658
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Razzoli M, Bartolomucci A. The Dichotomous Effect of Chronic Stress on Obesity. Trends Endocrinol Metab 2016; 27:504-515. [PMID: 27162125 PMCID: PMC4912918 DOI: 10.1016/j.tem.2016.04.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 11/22/2022]
Abstract
Obesity and metabolic diseases are linked to chronic stress and low socioeconomic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive thermogenesis and brown adipose tissue (BAT) function support a dichotomous relation to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperphagia and unchanged BAT function; stress results in weight loss and/or obesity resistance in the presence of hypophagia, or when hyperphagia is associated with BAT recruitment and enhanced thermogenesis. Mechanistically dissecting the bidirectional effects of stress on metabolic outcomes might open new avenues for innovative pharmacotherapies for the treatment of obesity-associated diseases.
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Affiliation(s)
- Maria Razzoli
- Department of Integrative Biology and Physiology University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Alessandro Bartolomucci
- Department of Integrative Biology and Physiology University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA.
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659
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Cornejo MP, Hentges ST, Maliqueo M, Coirini H, Becu-Villalobos D, Elias CF. Neuroendocrine Regulation of Metabolism. J Neuroendocrinol 2016; 28:10.1111/jne.12395. [PMID: 27114114 PMCID: PMC4956544 DOI: 10.1111/jne.12395] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/31/2016] [Accepted: 04/21/2016] [Indexed: 12/29/2022]
Abstract
Given the current environment in most developed countries, it is a challenge to maintain a good balance between calories consumed and calories burned, although maintenance of metabolic balance is key to good health. Therefore, understanding how metabolic regulation is achieved and how the dysregulation of metabolism affects health is an area of intense research. Most studies focus on the hypothalamus, which is a brain area that acts as a key regulator of metabolism. Among the nuclei that comprise the hypothalamus, the arcuate nucleus is one of the major mediators in the regulation of food intake. The regulation of energy balance is also a key factor ensuring the maintenance of any species as a result of the dependence of reproduction on energy stores. Adequate levels of energy reserves are necessary for the proper functioning of the hypothalamic-pituitary-gonadal axis. This review discusses valuable data presented in the 2015 edition of the International Workshop of Neuroendocrinology concerning the fundamental nature of the hormonal regulation of the hypothalamus and the impact on energy balance and reproduction.
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Affiliation(s)
- Maria P. Cornejo
- Laboratory of Neurophysiology, Multidisciplinary Institute of Cell Biology [IMBICE, dependent on the Argentine Research Council (CONICET), Scientific Research Commission, Province of Buenos Aires (CIC-PBA) and National University of La Plata (UNLP)], La Plata, Argentina
| | - Shane T. Hentges
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Manuel Maliqueo
- Endocrinology and Metabolism Laboratory, Department of Medicine West Division, School of Medicine University of Chile, Santiago de Chile, Chile
| | - Hector Coirini
- Laboratory of Neurobiology, Institute of Biology and Experimental Medicine [(IBYME), dependent on CONICET] and Department of Human Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Damasia Becu-Villalobos
- Laboratory of Pituitary Regulation, Institute of Biology and Experimental Medicine [(IBYME), dependent on CONICET], Buenos Aires, Argentina
| | - Carol F. Elias
- Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
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660
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Tamboli RA, Sidani RM, Garcia AE, Antoun J, Isbell JM, Albaugh VL, Abumrad NN. Jejunal administration of glucose enhances acyl ghrelin suppression in obese humans. Am J Physiol Endocrinol Metab 2016; 311:E252-9. [PMID: 27279247 PMCID: PMC4967145 DOI: 10.1152/ajpendo.00082.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/26/2016] [Indexed: 01/03/2023]
Abstract
Ghrelin is a gastric hormone that stimulates hunger and worsens glucose metabolism. Circulating ghrelin is decreased after Roux-en-Y gastric bypass (RYGB) surgery; however, the mechanism(s) underlying this change is unknown. We tested the hypothesis that jejunal nutrient exposure plays a significant role in ghrelin suppression after RYGB. Feeding tubes were placed in the stomach or jejunum in 13 obese subjects to simulate pre-RYGB or post-RYGB glucose exposure to the gastrointestinal (GI) tract, respectively, without the confounding effects of caloric restriction, weight loss, and surgical stress. On separate study days, the plasma glucose curves obtained with either gastric or jejunal administration of glucose were replicated with intravenous (iv) infusions of glucose. These "isoglycemic clamps" enabled us to determine the contribution of the GI tract and postabsorptive plasma glucose to acyl ghrelin suppression. Plasma acyl ghrelin levels were suppressed to a greater degree with jejunal glucose administration compared with gastric glucose administration (P < 0.05). Jejunal administration of glucose also resulted in a greater suppression of acyl ghrelin than the corresponding isoglycemic glucose infusion (P ≤ 0.01). However, gastric and isoglycemic iv glucose infusions resulted in similar degrees of acyl ghrelin suppression (P > 0.05). Direct exposure of the proximal jejunum to glucose increases acyl ghrelin suppression independent of circulating glucose levels. The enhanced suppression of acyl ghrelin after RYGB may be due to a nutrient-initiated signal in the jejunum that regulates ghrelin secretion.
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Affiliation(s)
- Robyn A Tamboli
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Reem M Sidani
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Anna E Garcia
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Joseph Antoun
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - James M Isbell
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Vance L Albaugh
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Naji N Abumrad
- Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee
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661
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Affiliation(s)
| | - William Snape
- California Pacific Medical Center, San Francisco, California
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662
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González-Domínguez MI, Lazo-de-la-Vega-Monroy ML, Zaina S, Sabanero M, Daza-Benítez L, Malacara JM, Barbosa-Sabanero G. Association of cord blood des-acyl ghrelin with birth weight, and placental GHS-R1 receptor expression in SGA, AGA, and LGA newborns. Endocrine 2016; 53:182-91. [PMID: 26754660 DOI: 10.1007/s12020-015-0833-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/14/2015] [Indexed: 11/29/2022]
Abstract
Although ghrelin in cord blood has been associated to birth weight, its role in fetal and postnatal growth has not been elucidated. The aim of this study was to analyze total ghrelin, acyl ghrelin (AG), and des-acyl ghrelin (DAG) in cord blood of newborns with idiopathic birth weight alterations, and to evaluate protein expression of placental GHS-R1, in order to investigate their correlation with birth weight and placental weight. We performed a cross-sectional comparative study in umbilical cord blood and placentas from healthy mothers of SGA, AGA, and LGA (small, adequate and large for gestational age) term newborns (n = 20 per group). Cord blood total ghrelin, AG, and DAG were measured by ELISA, and placental GHS-R1 expression was evaluated by Western blot. Cord blood DAG was higher in SGA compared to AGA newborns (902.1 ± 109.1 and 597.4 ± 58.2 pg/ml, respectively, p = 0.01) while LGA and AGA showed similar values (627.2 ± 76.4 pg/ml for LGA, p = 0.80). DAG negatively correlated with birthweight (r = -0.31, p = 0.02) and placental weight (r = -0.33, p = 0.02). No differences in AG or total ghrelin were found. GHS-R1 protein in placenta was not differentially expressed among SGA, AGA, and LGA. Our results suggest a role of DAG in intrauterine growth. Further studies are needed in order to elucidate the mechanisms by which DAG participates in fetal growth.
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Affiliation(s)
- Martha I González-Domínguez
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Leon Campus. 20 de Enero No. 929 Col. Obregon, 37320, Leon, Guanajuato, Mexico
| | - Maria-Luisa Lazo-de-la-Vega-Monroy
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Leon Campus. 20 de Enero No. 929 Col. Obregon, 37320, Leon, Guanajuato, Mexico
| | - Silvio Zaina
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Leon Campus. 20 de Enero No. 929 Col. Obregon, 37320, Leon, Guanajuato, Mexico
| | - Myrna Sabanero
- Biology Department, Natural and Exact Sciences Division, University of Guanajuato, Guanajuato Campus, Guanajuato, Mexico
| | | | - Juan Manuel Malacara
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Leon Campus. 20 de Enero No. 929 Col. Obregon, 37320, Leon, Guanajuato, Mexico
| | - Gloria Barbosa-Sabanero
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Leon Campus. 20 de Enero No. 929 Col. Obregon, 37320, Leon, Guanajuato, Mexico.
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663
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Gillard L, Billiauws L, Stan-Iuga B, Ribeiro-Parenti L, Jarry AC, Cavin JB, Cluzeaud F, Mayeur C, Thomas M, Freund JN, Lacorte JM, Le Gall M, Bado A, Joly F, Le Beyec J. Enhanced Ghrelin Levels and Hypothalamic Orexigenic AgRP and NPY Neuropeptide Expression in Models of Jejuno-Colonic Short Bowel Syndrome. Sci Rep 2016; 6:28345. [PMID: 27323884 PMCID: PMC4914859 DOI: 10.1038/srep28345] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/01/2016] [Indexed: 12/20/2022] Open
Abstract
Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations.
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Affiliation(s)
- Laura Gillard
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Lore Billiauws
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
- AP-HP, Hôpital Beaujon, Service de Gastroentérologie et d’Assistance nutritive, Clichy, France
| | - Bogdan Stan-Iuga
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Lara Ribeiro-Parenti
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
- AP-HP, Hôpital Bichat - Claude Bernard, Service de Chirurgie Générale et Digestive, F-75018 Paris, France
| | - Anne-Charlotte Jarry
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Jean-Baptiste Cavin
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Françoise Cluzeaud
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Camille Mayeur
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Muriel Thomas
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Jean-Noël Freund
- INSERM UMR_S1113, Université de Strasbourg, Faculté de Médecine, FMTS, 67081 Strasbourg, France
| | - Jean-Marc Lacorte
- INSERM, UMR_S 1166, Research Institute of Cardiovascular Disease, Metabolism and Nutrition, ICAN, Université Pierre et Marie Curie, Sorbonne Université, F-75013, Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Biochimie Endocrinienne et Oncologique, F-75651, Paris, Cedex
- Université Pierre et Marie Curie, Sorbonne Université, F-75005, Paris, France
| | - Maude Le Gall
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - André Bado
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
| | - Francisca Joly
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
- AP-HP, Hôpital Beaujon, Service de Gastroentérologie et d’Assistance nutritive, Clichy, France
| | - Johanne Le Beyec
- Inserm UMR1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, DHU Unity, AP-HP, F-75890 Paris, France
- AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Biochimie Endocrinienne et Oncologique, F-75651, Paris, Cedex
- Université Pierre et Marie Curie, Sorbonne Université, F-75005, Paris, France
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664
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Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats. Sci Rep 2016; 6:27499. [PMID: 27271793 PMCID: PMC4895129 DOI: 10.1038/srep27499] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/19/2016] [Indexed: 11/08/2022] Open
Abstract
The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways.
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665
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Loncar G, Springer J, Anker M, Doehner W, Lainscak M. Cardiac cachexia: hic et nunc. J Cachexia Sarcopenia Muscle 2016; 7:246-60. [PMID: 27386168 PMCID: PMC4929818 DOI: 10.1002/jcsm.12118] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/18/2016] [Indexed: 12/12/2022] Open
Abstract
Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.
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Affiliation(s)
- Goran Loncar
- Department of Cardiology Clinical Hospital Zvezdara Belgrade Serbia; School of Medicine University of Belgrade Belgrade Serbia
| | - Jochen Springer
- Innovative Clinical Trials, Department of Cardiology and Pneumology University Medical Center Göttingen (UMG) Göttingen Germany
| | - Markus Anker
- Department of Cardiology Charité - Universitätsmedizin Berlin Germany
| | - Wolfram Doehner
- Center for Stroke Research Berlin Charité Universitätsmedizin Berlin Germany
| | - Mitja Lainscak
- Department of Cardiology and Department of Research and Education General Hospital Celje Celje Slovenia; Faculty of Medicine University of Ljubljana Ljubljana Slovenia
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666
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Ritze Y, Schollenberger A, Hamze Sinno M, Bühler N, Böhle M, Bárdos G, Sauer H, Mack I, Enck P, Zipfel S, Meile T, Königsrainer A, Kramer M, Bischoff SC. Gastric ghrelin, GOAT, leptin, and leptinR expression as well as peripheral serotonin are dysregulated in humans with obesity. Neurogastroenterol Motil 2016; 28:806-15. [PMID: 26787056 DOI: 10.1111/nmo.12773] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 12/19/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND Gastrointestinal hormone release and the regulation of appetite and body weight are thought to be dysbalanced in obesity. However, human data investigating the expression of gastrointestinal hormones in the obese are rare. We studied the expression of ghrelin, leptin, and the serotonergic system in stomach tissue and serum of obese and non-obese individuals. METHODS Gastric tissue and serum were collected from 29 adult obese (BMI 48.7 ± 10.6 kg/m(2) ; mean ± SD) who underwent laparoscopic sleeve gastrectomy. Gastric biopsies, surgery specimen or serum was obtained from 35 adult non-obese humans (BMI 22.7 ± 1.9 kg/m(2) ). Ghrelin, ghrelin O-acyl transferase (GOAT), leptin, leptin receptor, and tryptophan hydroxylase 1 (TPH1) mRNA expression were measured by qRT-PCR. Serotonin (5HT) and leptin protein concentration were quantified in tissue extracts and serum; GOAT and ghrelin-positive cells were immunohistologically quantified in tissue. Additionally, 21 blood immune markers were analyzed. KEY RESULTS In gastric tissue, GOAT-positive cells were reduced (p < 0.01), but ghrelin-positive cells and mRNA were increased (both p < 0.05) in obese compared with non-obese individuals. Gastric leptin (p < 0.001) and leptin receptor (p < 0.001) mRNA expression, as well as leptin concentrations in serum (p < 0.001), were increased in obese compared with non-obese individuals. Serum 5HT was reduced (p < 0.05), while tissue 5HT and TPH1 mRNA were reduced only by trend. Interleukin 1 receptor a (IL1Ra), IL-8, IL-12, and monocyte chemoattractant protein 1 (IL1Ra) were increased and IL1Ra correlated negatively with serum leptin. CONCLUSIONS & INFERENCES Our data indicate that obesity causes a dysregulation of gastrointestinal hormones at the tissue level and serum, including a negative correlation with an increased marker of subclinical inflammation.
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Affiliation(s)
- Y Ritze
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany.,Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - A Schollenberger
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - M Hamze Sinno
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - N Bühler
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - M Böhle
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - G Bárdos
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - H Sauer
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
| | - I Mack
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
| | - P Enck
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
| | - S Zipfel
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
| | - T Meile
- Department of General and Transplant Surgery and Comprehensive Cancer Center, University of Tübingen, Tübingen, Germany
| | - A Königsrainer
- Department of General and Transplant Surgery and Comprehensive Cancer Center, University of Tübingen, Tübingen, Germany
| | - M Kramer
- Arabella Clinic, München, Germany
| | - S C Bischoff
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
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667
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Tong J, Davis HW, Gastaldelli A, D'Alessio D. Ghrelin Impairs Prandial Glucose Tolerance and Insulin Secretion in Healthy Humans Despite Increasing GLP-1. J Clin Endocrinol Metab 2016; 101:2405-14. [PMID: 27055279 PMCID: PMC4891805 DOI: 10.1210/jc.2015-4154] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Administration of ghrelin inhibits the acute insulin response to glucose and worsens IV glucose tolerance in healthy subjects. Evidence from preclinical studies suggests that ghrelin may have differential effects on glucose metabolism during fasting and feeding. Our objective was to test the effects of ghrelin on glucose and insulin responses during a meal tolerance test. DESIGN Acyl ghrelin (0.26 and 2.0 μg/kg/h) or saline was infused in 13 healthy subjects on three separate occasions in randomized order. Ghrelin was infused for 45 minutes to achieve steady-state levels and continued for 240 minutes after ingestion of a liquid test meal. Primary outcomes were area under the curve for glucose and insulin secretion. RESULTS We found that ghrelin infusions of 0.26 and 2.0 μg/kg/h raised steady-state plasma total ghrelin levels to 1.7- and 4.8-fold above fasting concentrations, but did not alter fasting plasma glucose or insulin levels. During the meal tolerance test, ghrelin decreased insulin sensitivity, impaired β-cell function, and induced glucose intolerance. The high-dose ghrelin infusion also raised postprandial glucagon like peptide 1 secretion without affecting glucose dependent insulinotropic polypeptide, glucagon, or peptide YY concentrations. CONCLUSIONS We conclude that both physiologic and pharmacologic doses of ghrelin worsen the glucose and β-cell responses to meal ingestion in healthy humans. The increase in postprandial glucagon like peptide 1 secretion by ghrelin suggests a novel enteroendocrine connection, but does not mitigate the glucose intolerance.
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Affiliation(s)
- Jenny Tong
- Division of Endocrinology, Diabetes and Metabolism (J.T., H.W.D., D.D.), Department of Medicine, University of Cincinnati, Cincinnati, Ohio; Institute of Clinical Physiology (A.G.), National Research Council, Pisa, Italy; Cincinnati VA Medical Center (D.D.), Cincinnati, Ohio
| | - Harold W Davis
- Division of Endocrinology, Diabetes and Metabolism (J.T., H.W.D., D.D.), Department of Medicine, University of Cincinnati, Cincinnati, Ohio; Institute of Clinical Physiology (A.G.), National Research Council, Pisa, Italy; Cincinnati VA Medical Center (D.D.), Cincinnati, Ohio
| | - Amalia Gastaldelli
- Division of Endocrinology, Diabetes and Metabolism (J.T., H.W.D., D.D.), Department of Medicine, University of Cincinnati, Cincinnati, Ohio; Institute of Clinical Physiology (A.G.), National Research Council, Pisa, Italy; Cincinnati VA Medical Center (D.D.), Cincinnati, Ohio
| | - David D'Alessio
- Division of Endocrinology, Diabetes and Metabolism (J.T., H.W.D., D.D.), Department of Medicine, University of Cincinnati, Cincinnati, Ohio; Institute of Clinical Physiology (A.G.), National Research Council, Pisa, Italy; Cincinnati VA Medical Center (D.D.), Cincinnati, Ohio
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668
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Grossini E, Raina G, Farruggio S, Camillo L, Molinari C, Mary D, Walker GE, Bona G, Vacca G, Moia S, Prodam F, Surico D. Intracoronary Des-Acyl Ghrelin Acutely Increases Cardiac Perfusion Through a Nitric Oxide-Related Mechanism in Female Anesthetized Pigs. Endocrinology 2016; 157:2403-15. [PMID: 27100620 DOI: 10.1210/en.2015-1922] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Des-acyl ghrelin (DAG), the most abundant form of ghrelin in humans, has been found to reduce arterial blood pressure and prevent cardiac and endothelial cell apoptosis. Despite this, data regarding its direct effect on cardiac function and coronary blood flow, as well as the related involvement of autonomic nervous system and nitric oxide (NO), are scarce. We therefore examined these issues using both in vivo and in vitro studies. In 20 anesthetized pigs, intracoronary 100 pmol/mL DAG infusion with a constant heart rate and aortic blood pressure, increased coronary blood flow and NO release, whereas reducing coronary vascular resistances (P < .05). Dose responses to DAG were evaluated in five pigs. No effects on cardiac contractility/relaxation or myocardial oxygen consumption were observed. Moreover, whereas the blockade of muscarinic cholinoceptors (n = 5) or α- and β-adrenoceptors (n = 5 each) did not abolish the observed responses, NO synthase inhibition (n = 5) prevented the effects of DAG on coronary blood flow and NO release. In coronary artery endothelial cells, DAG dose dependently increased NO release through cAMP signaling and ERK1/2, Akt, and p38 MAPK involvement as well as the phosphorylation of endothelial NO synthase. In conclusion, in anesthetized pigs, DAG primarily increased cardiac perfusion through the involvement of NO release. Moreover, the phosphorylation of ERK1/2 and Akt appears to play roles in eliciting the observed NO production in coronary artery endothelial cells.
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Affiliation(s)
- Elena Grossini
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Giulia Raina
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Serena Farruggio
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Lara Camillo
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Claudio Molinari
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - David Mary
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Gillian Elisabeth Walker
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Gianni Bona
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Giovanni Vacca
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Stefania Moia
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Flavia Prodam
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
| | - Daniela Surico
- Laboratory Physiology/Experimental Surgery (E.G., G.R., S.F., L.C., C.M., D.M., G.V., D.S.), Department of Translational Medicine, and Pediatric Unit (G.E.W., G.B., S.M., F.P.), Department of Health Sciences, University E Piedmont "A. Avogadro," Azienda Ospedaliera Universitaria Maggiore della Carità, I-12800 Novara, Italy
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Satou M, Kaiya H, Nishi Y, Shinohara A, Kawada SI, Miyazato M, Kangawa K, Sugimoto H. Mole ghrelin: cDNA cloning, gene expression, and diverse molecular forms in Mogera imaizumii. Gen Comp Endocrinol 2016; 232:199-210. [PMID: 27102942 DOI: 10.1016/j.ygcen.2016.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/14/2016] [Accepted: 04/16/2016] [Indexed: 11/28/2022]
Abstract
Here, we describe cDNA cloning and purification of the ghrelin gene sequences and ghrelin peptides from the Japanese true mole, Mogera imaizumii. The gene spans >2.9kbp, has four exons and three introns, and shares structural similarity with those of terrestrial animals. Mature mole ghrelin peptide was predicted to be 28 amino acids long (GSSFLSPEHQKVQQRKESKKPPSKPQPR) and processed from a prepropeptide of 116 amino acids. To further elucidate molecular characteristics, we purified ghrelin peptides from mole stomach. By mass spectrometry, we found that the mole ghrelin peptides had higher ratios of the odd-number fatty acids (C9 and C11 as much as C8) attached to the third serine residue than other vertebrate ghrelin. Truncated forms of ghrelins such as [1-27], [1-19], [1-16] and [1-15], and that lacked the 14th glutamine residue (des-Gln14 ghrelin) were produced in the stomach. Marked expression of ghrelin mRNA in lung was observed as in stomach and brain. Phylogenetic analysis indicated that the branch of M. imaizumii has slightly higher dN/dS ratios (the nucleotide substitution rates at non-synonymous and synonymous sites) than did other eulipotyphlans. Peptide length was positively correlated with human ghrelin receptor activation, whereas the length of fatty-acyl chains showed no obvious functional correlation. The basal higher luciferase activities of the 5'-proximal promoter region of mole ghrelin were detected in ghrelin-negative C2C12 cells and hypoxic culture conditions impaired transcriptional activity. These results indicated that moles have acquired diverse species of ghrelin probably through distinctive fatty acid metabolism because of their food preferences. The results provide a gateway to understanding ghrelin metabolism in fossorial animals.
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Affiliation(s)
- Motoyasu Satou
- Department of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
| | - Hiroyuki Kaiya
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Yoshihiro Nishi
- Department of Physiology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Akio Shinohara
- Division of Bio-resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan
| | - Shin-Ichiro Kawada
- Department of Zoology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Mikiya Miyazato
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Kenji Kangawa
- Department of Biochemistry, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
| | - Hiroyuki Sugimoto
- Department of Biochemistry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan.
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670
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Fields DA, Schneider CR, Pavela G. A narrative review of the associations between six bioactive components in breast milk and infant adiposity. Obesity (Silver Spring) 2016; 24:1213-21. [PMID: 27151491 PMCID: PMC5325144 DOI: 10.1002/oby.21519] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/01/2016] [Accepted: 03/06/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE This narrative review examines six important non-nutritive substances in breast milk, many of which were thought to have little to no biological significance. The overall objective is to provide background on key bioactive factors in breast milk believed to have an effect on infant outcomes (growth and body composition). METHODS The evidence for the effects of the following six bioactive compounds in breast milk on infant growth outcomes are reviewed: insulin, leptin, adiponectin, ghrelin, interleukin-6, and tumor necrosis factor-α. RESULTS The existing literature on the effects of breast milk insulin, ghrelin, interleukin-6, and tumor necrosis factor-α and their associations with infant growth and adiposity is sparse. Of the bioactive compounds reviewed, leptin and adiponectin are the most researched. Data reveal that breast milk adiponectin has negative associations with growth in infancy. CONCLUSIONS There is a need for innovative, well-designed studies to improve causal inference and advance our understanding in the effects of breast milk and its components on offspring growth and body composition. The recommendations provided, along with careful consideration of both known and unknown factors that affect breast milk composition, will help improve, standardize, and ultimately advance this emergent field.
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Affiliation(s)
- David A Fields
- Department of Pediatrics, Section of Endocrinology and Diabetes, University
of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Camille R Schneider
- Department of Nutrition Sciences, University of Alabama at Birmingham,
Birmingham, AL
| | - Gregory Pavela
- Department of Health Behavior, University of Alabama at Birmingham,
Birmingham, AL
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671
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Beauloye V, Diene G, Kuppens R, Zech F, Winandy C, Molinas C, Faye S, Kieffer I, Beckers D, Nergårdh R, Hauffa B, Derycke C, Delhanty P, Hokken-Koelega A, Tauber M. High unacylated ghrelin levels support the concept of anorexia in infants with prader-willi syndrome. Orphanet J Rare Dis 2016; 11:56. [PMID: 27146407 PMCID: PMC4855494 DOI: 10.1186/s13023-016-0440-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/27/2016] [Indexed: 12/14/2022] Open
Abstract
Background Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with different nutritional phases from suckling deficit with failure to thrive to early onset of obesity. Hyperghrelinemia has been described in PWS long before the development of obesity. Ghrelin is found in both acylated (AG) and unacylated (UAG) forms in the circulation. In contrast to AG, UAG has been shown to inhibit food intake and to be elevated in anorexia nervosa. The present project is aiming to determine the underlying mechanisms driving the different nutritional phases in PWS. Methods Measurement of at least 4 h-fasting plasma acylated and unacylated ghrelin in 37 infants with a genetic diagnosis of PWS aged from 1 month to 4 years and in 100 age-matched controls without endocrine disorder recruited prior to minor surgery. One blood sampling was analysed for each patient/control and clinical data were recorded. Eleven PWS infants underwent repetitive blood samples at 3 or 6-month intervals during routine visits. Results In infants with PWS, AG is not elevated (p = 0.45), UAG is significantly higher (p = 0.0044; confidence interval 1.06;1.33) resulting in a low AG/UAG ratio (p = 0.0056; confidence interval 0.76;0.95) compared to controls. Conclusion Unlike children and adults with PWS that have high AG and AG/UAG ratio, infants with PWS have elevated UAG that supports the concept of anorexia in the early phases of the disease. The change in AG/UAG ratio possibly drives the switch from failure to thrive to obesity. Clinical trial registration NCT02529085. Electronic supplementary material The online version of this article (doi:10.1186/s13023-016-0440-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Veronique Beauloye
- Unité d'Endocrinologie pédiatrique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Avenue Hippocrate 10/1300, B-1200, Brussels, Belgium.
| | - Gwenaelle Diene
- Unité d'Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader-Willi, Hôpital des Enfants, Toulouse, France
| | - Renske Kuppens
- Dutch Growth Research Foundation, Rotterdam, The Netherlands.,Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Francis Zech
- IREC, Université Catholique de Louvain, Brussels, Belgium
| | - Coralie Winandy
- Unité d'Endocrinologie pédiatrique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Avenue Hippocrate 10/1300, B-1200, Brussels, Belgium
| | - Catherine Molinas
- Unité d'Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader-Willi, Hôpital des Enfants, Toulouse, France.,Axe Pédiatrique du CIC 9302/INSERM. Hôpital des Enfants, Toulouse, France.,INSERM U1043, Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Toulouse, France
| | - Sandy Faye
- Unité d'Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader-Willi, Hôpital des Enfants, Toulouse, France.,Axe Pédiatrique du CIC 9302/INSERM. Hôpital des Enfants, Toulouse, France
| | - Isabelle Kieffer
- Unité d'Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader-Willi, Hôpital des Enfants, Toulouse, France.,Axe Pédiatrique du CIC 9302/INSERM. Hôpital des Enfants, Toulouse, France
| | - Dominique Beckers
- Unité d'Endocrinologie Pédiatrique, CHU Dinant Godinne, Yvoir, Belgium
| | - Ricard Nergårdh
- Karolinska University Hospital, Karolinska Institutet, Solna, Sweden
| | - Berthold Hauffa
- Department of Endocrinology, University Children's Hospital, Essen, Germany
| | - Christine Derycke
- BESPEED (Belgian Society for Pediatric Endocrinology and Diabetology), Brussels, Belgium
| | - Patrick Delhanty
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Anita Hokken-Koelega
- Dutch Growth Research Foundation, Rotterdam, The Netherlands.,Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Maithé Tauber
- Unité d'Endocrinologie, Obésité, Maladies Osseuses, Génétique et Gynécologie Médicale. Centre de Référence du Syndrome de Prader-Willi, Hôpital des Enfants, Toulouse, France.,Axe Pédiatrique du CIC 9302/INSERM. Hôpital des Enfants, Toulouse, France.,INSERM U1043, Centre de Physiopathologie de Toulouse Purpan, Université Paul Sabatier, Toulouse, France.,Unité d'Endocrinologie, Hôpital des Enfants, 330, Avenue de Grande Bretagne, TSA 70034, 31059, Toulouse Cedex 9, France
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672
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Comprehensive alpha, beta and delta cell transcriptomes reveal that ghrelin selectively activates delta cells and promotes somatostatin release from pancreatic islets. Mol Metab 2016; 5:449-458. [PMID: 27408771 PMCID: PMC4921781 DOI: 10.1016/j.molmet.2016.04.007] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/14/2016] [Accepted: 04/21/2016] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Complex local crosstalk amongst endocrine cells within the islet ensures tight coordination of their endocrine output. This is illustrated by the recent demonstration that the negative feedback control by delta cells within pancreatic islets determines the homeostatic set-point for plasma glucose during mouse postnatal development. However, the close association of islet endocrine cells that facilitates paracrine crosstalk also complicates the distinction between effects mediated directly on beta cells from indirect effects mediated via local intermediates, such as somatostatin from delta cells. METHODS To resolve this problem, we generated reporter mice that allow collection of pure pancreatic delta cells along with alpha and beta cells from the same islets and generated comprehensive transcriptomes for each islet endocrine cell type. These transcriptomes afford an unparalleled view of the receptors expressed by delta, alpha and beta cells, and allow the prediction of which signal targets which endocrine cell type with great accuracy. RESULTS From these transcriptomes, we discovered that the ghrelin receptor is expressed exclusively by delta cells within the islet, which was confirmed by fluorescent in situ hybridization and qPCR. Indeed, ghrelin increases intracellular calcium in delta cells in intact mouse islets, measured by GCaMP6 and robustly potentiates glucose-stimulated somatostatin secretion on mouse and human islets in both static and perfusion assays. In contrast, des-acyl-ghrelin at the same dose had no effect on somatostatin secretion and did not block the actions of ghrelin. CONCLUSIONS These results offer a straightforward explanation for the well-known insulinostatic actions of ghrelin. Rather than engaging beta cells directly, ghrelin engages delta cells to promote local inhibitory feedback that attenuates insulin release. These findings illustrate the power of our approach to resolve some of the long-standing conundrums with regard to the rich feedback that occurs within the islet that is integral to islet physiology and therefore highly relevant to diabetes.
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673
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Valero J, Paris I, Sierra A. Lifestyle Shapes the Dialogue between Environment, Microglia, and Adult Neurogenesis. ACS Chem Neurosci 2016; 7:442-53. [PMID: 26971802 DOI: 10.1021/acschemneuro.6b00009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lifestyle modulates brain function. Diet, stress levels, and physical exercise among other factors influence the "brain cognitive reserve", that is, the capacity of the brain to maintain a normal function when confronting neurodegenerative diseases, injury, and/or aging. This cognitive reserve relays on several cellular and molecular elements that contribute to brain plasticity allowing adaptive responses to cognitive demands, and one of its key components is the hippocampal neurogenic reserve. Hippocampal neural stem cells give rise to new neurons that integrate into the local circuitry and contribute to hippocampal functions such as memory and learning. Importantly, adult hippocampal neurogenesis is well-known to be modulated by the demands of the environment and lifestyle factors. Diet, stress, and physical exercise directly act on neural stem cells and/or their progeny, but, in addition, they may also indirectly affect neurogenesis by acting on microglia. Microglia, the guardians of the brain, rapidly sense changes in the brain milieu, and it has been recently shown that their function is affected by lifestyle factors. However, few studies have analyzed the modulatory effect of microglia on adult neurogenesis in these conditions. Here, we review the current knowledge about the dialogue maintained between microglia and the hippocampal neurogenic cascade. Understanding how the communication between microglia and hippocampal neurogenesis is affected by lifestyle choices is crucial to maintain the brain cognitive reserve and prevent the maladaptive responses that emerge during disease or injury through adulthood and aging.
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Affiliation(s)
- Jorge Valero
- Achucarro Basque Center for Neuroscience, E-48170 Zamudio, Bizkaia Spain
- Ikerbasque Foundation, E-48013 Bilbao, Bizkaia Spain
| | - Iñaki Paris
- Achucarro Basque Center for Neuroscience, E-48170 Zamudio, Bizkaia Spain
| | - Amanda Sierra
- Achucarro Basque Center for Neuroscience, E-48170 Zamudio, Bizkaia Spain
- Ikerbasque Foundation, E-48013 Bilbao, Bizkaia Spain
- University of the Basque Country EHU/UPV, E-48940 Leioa, Bizkaia Spain
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674
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Chebani Y, Marion C, Zizzari P, Chettab K, Pastor M, Korostelev M, Geny D, Epelbaum J, Tolle V, Morisset-Lopez S, Pantel J. Enhanced responsiveness of Ghsr Q343X rats to ghrelin results in enhanced adiposity without increased appetite. Sci Signal 2016; 9:ra39. [PMID: 27095593 DOI: 10.1126/scisignal.aae0374] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ability of the gut hormone ghrelin to promote positive energy balance is mediated by the growth hormone secretagogue receptor (GHSR). GHSR is a G protein-coupled receptor (GPCR) that is found centrally and peripherally and that can signal in a ligand-independent manner basally or when heterodimerized with other GPCRs. However, current Ghsr knockout models cannot dissect ghrelin-dependent and ghrelin-independent signaling, precluding assessment of the physiological importance of these signaling pathways. An animal model carrying a Ghsr mutation that preserves GHSR cell surface abundance, but selectively alters GHSR signaling, would be a useful tool to decipher GHSR signaling in vivo. We used rats with the Ghsr(Q343X) mutation (Ghsr(M/M)), which is predicted to delete the distal part of the GHSR carboxyl-terminal tail, a domain critical for the signal termination processes of receptor internalization and β-arrestin recruitment. In cells, the GHSR-Q343X mutant showed enhanced ligand-induced G protein-dependent signaling and blunted activity of processes involved in GPCR signal termination. Ghsr(M/M)rats displayed enhanced responses to submaximal doses of ghrelin or GHSR agonist. Moreover, Ghsr(M/M)rats had a more stable body weight under caloric restriction, a condition that increases endogenous ghrelin tone, whereas under standard housing conditions,Ghsr(M/M)rats showed increased body weight and adiposity and reduced glucose tolerance. Overall, our data stress the physiological role of the distal domain of GHSR carboxyl terminus as a suppressor of ghrelin sensitivity, and we propose using the Ghsr(M/M)rat as a physiological model of gain of function in Ghsr to identify treatments for obesity-related conditions.
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Affiliation(s)
- Yacine Chebani
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Candice Marion
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Philippe Zizzari
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Khadidja Chettab
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Marie Pastor
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Marie Korostelev
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - David Geny
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Jacques Epelbaum
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France. CNRS, Muséum national d'Histoire naturelle, UMR 7179, Mécanismes adaptatifs et évolution, 91800 Brunoy, France
| | - Virginie Tolle
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France
| | - Séverine Morisset-Lopez
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, Université d'Orléans, 45071 Orléans, France
| | - Jacques Pantel
- INSERM, Université Paris Descartes, Sorbonne Paris Cité, UMR-S 894, Centre de Psychiatrie & Neurosciences, 75014 Paris, France. Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Nashville, TN 37232, USA
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675
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Periprandial changes and effects of short- and long-term fasting on ghrelin, GOAT, and ghrelin receptors in goldfish (Carassius auratus). J Comp Physiol B 2016; 186:727-38. [DOI: 10.1007/s00360-016-0986-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/26/2016] [Accepted: 03/29/2016] [Indexed: 02/06/2023]
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676
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Ngernsoungnern A, Ngernsoungnern P. Localization of ghrelin-like peptide in the gastrointestinal tract of the golden apple snail (Pomacea canaliculata) and changing of its concentration during fasting. Acta Histochem 2016; 118:244-51. [PMID: 26850996 DOI: 10.1016/j.acthis.2016.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/22/2016] [Accepted: 01/22/2016] [Indexed: 12/13/2022]
Abstract
Ghrelin is an endogenous hormone detected in the gastrointestinal tracts (GI) of various species. In the present study, ghrelin-like peptide (ghrelin-LP) was identified in the GI tract of the golden apple snail, Pomacea canaliculata. Using immunohistochemistry, the result revealed an immunoreactivity (-ir) of ghrelin-LP in regions of the GI tract. The ghrelin-LP-ir was observed in both opened-type and closed-type cells of the esophagus, stomach, and small and large intestines. The highest density of ghrelin-LP immunoreactive cells was found in the esophagus and the least density was detected in the stomach. The highest percentages of the opened-type and closed-type cells were present in the esophagus and small intestine, respectively. In immunoblotting, the molecular weight of ghrelin-LP was related to the human ghrelin peptide (∼13kDa). Moreover, the concentration of ghrelin-LP was significantly higher in snails that were fasted for 24h compared with fed snails. The concentration decreased after refeeding. The present study could be useful for understanding the physiological role of ghrelin-LP in mollusk species.
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Affiliation(s)
- Apichart Ngernsoungnern
- School of Anatomy, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Piyada Ngernsoungnern
- School of Anatomy, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
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677
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Li S, Liu J, Lv Q, Zhang C, Xu S, Yang D, Huang B, Zeng Y, Gao Y, Wang W. AG and UAG induce β-casein expression via activation of ERK1/2 and AKT pathways. J Mol Endocrinol 2016; 56:213-25. [PMID: 26873999 PMCID: PMC5064986 DOI: 10.1530/jme-15-0287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 02/12/2016] [Indexed: 01/14/2023]
Abstract
The ghrelin peptides were found to circulate in two major forms: acylated ghrelin (AG) and unacylated ghrelin (UAG). Previous studies showed that AG regulates β-casein (CSN2) expression in mammary epithelial cells. However, little is known about the mechanisms by which AG regulates CSN2 gene and protein expression. Evidence suggests that UAG has biological activity through GHSR1a-independent mechanisms. Here, we investigated the possible GHSR1a-mediated effect of UAG on the expression of CSN2 in primary bovine mammary epithelial cells (pbMECs) isolated from lactating cow. We found that both AG and UAG increase the expression of CSN2 in a dose-dependent manner in pbMECs in comparison with the control group. Increased expression of CSN2 was blocked by [D-Lys3]-GHRP-6 (an antagonist of the GHSR1a) and NF449 (a Gs-α subunit inhibitor) in pbMECs. In addition, both AG and UAG activated AKT/protein kinase B (AKT) and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways, whereas [D-Lys3]-GHRP-6 and NF449 inhibited the phosphorylation of AKT and ERK1/2 in pbMECs respectively. Blockade of ERK1/2 and AKT signaling pathways prevented the expression of CSN2 induced by AG or UAG. Finally, we found that both AG and UAG cause cell proliferation through identical signaling pathways. Taken together, these results demonstrate that both AG and UAG act on ERK1/2 and AKT signaling pathways to facilitate the expression of CSN2 in a GHSR1a-dependent manner.
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Affiliation(s)
- Sunan Li
- College of Veterinary MedicineJilin University
| | - Juxiong Liu
- College of Veterinary MedicineJilin University
| | - Qingkang Lv
- College of Veterinary MedicineJilin University
| | - Chuan Zhang
- Department of Endocrinology and MetabolismThe Second Hospital of Jilin University, Changchun, China
| | - Shiyao Xu
- College of Veterinary MedicineJilin University
| | | | | | - Yalong Zeng
- College of Veterinary MedicineJilin University
| | - Yingjie Gao
- College of Veterinary MedicineJilin University
| | - Wei Wang
- College of Veterinary MedicineJilin University
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678
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Ghrelin Regulates Glucose and Glutamate Transporters in Hypothalamic Astrocytes. Sci Rep 2016; 6:23673. [PMID: 27026049 PMCID: PMC4812252 DOI: 10.1038/srep23673] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/07/2016] [Indexed: 01/02/2023] Open
Abstract
Hypothalamic astrocytes can respond to metabolic signals, such as leptin and insulin, to modulate adjacent neuronal circuits and systemic metabolism. Ghrelin regulates appetite, adiposity and glucose metabolism, but little is known regarding the response of astrocytes to this orexigenic hormone. We have used both in vivo and in vitro approaches to demonstrate that acylated ghrelin (acyl-ghrelin) rapidly stimulates glutamate transporter expression and glutamate uptake by astrocytes. Moreover, acyl-ghrelin rapidly reduces glucose transporter (GLUT) 2 levels and glucose uptake by these glial cells. Glutamine synthetase and lactate dehydrogenase decrease, while glycogen phosphorylase and lactate transporters increase in response to acyl-ghrelin, suggesting a change in glutamate and glucose metabolism, as well as glycogen storage by astrocytes. These effects are partially mediated through ghrelin receptor 1A (GHSR-1A) as astrocytes do not respond equally to desacyl-ghrelin, an isoform that does not activate GHSR-1A. Moreover, primary astrocyte cultures from GHSR-1A knock-out mice do not change glutamate transporter or GLUT2 levels in response to acyl-ghrelin. Our results indicate that acyl-ghrelin may mediate part of its metabolic actions through modulation of hypothalamic astrocytes and that this effect could involve astrocyte mediated changes in local glucose and glutamate metabolism that alter the signals/nutrients reaching neighboring neurons.
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679
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Chowen JA, Argente-Arizón P, Freire-Regatillo A, Frago LM, Horvath TL, Argente J. The role of astrocytes in the hypothalamic response and adaptation to metabolic signals. Prog Neurobiol 2016; 144:68-87. [PMID: 27000556 DOI: 10.1016/j.pneurobio.2016.03.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/09/2016] [Accepted: 03/04/2016] [Indexed: 12/19/2022]
Abstract
The hypothalamus is crucial in the regulation of homeostatic functions in mammals, with the disruption of hypothalamic circuits contributing to chronic conditions such as obesity, diabetes mellitus, hypertension, and infertility. Metabolic signals and hormonal inputs drive functional and morphological changes in the hypothalamus in attempt to maintain metabolic homeostasis. However, the dramatic increase in the incidence of obesity and its secondary complications, such as type 2 diabetes, have evidenced the need to better understand how this system functions and how it can go awry. Growing evidence points to a critical role of astrocytes in orchestrating the hypothalamic response to metabolic cues by participating in processes of synaptic transmission, synaptic plasticity and nutrient sensing. These glial cells express receptors for important metabolic signals, such as the anorexigenic hormone leptin, and determine the type and quantity of nutrients reaching their neighboring neurons. Understanding the mechanisms by which astrocytes participate in hypothalamic adaptations to changes in dietary and metabolic signals is fundamental for understanding the neuroendocrine control of metabolism and key in the search for adequate treatments of metabolic diseases.
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Affiliation(s)
- Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain.
| | - Pilar Argente-Arizón
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alejandra Freire-Regatillo
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Tamas L Horvath
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN). Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
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680
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Tine M, Kuhl H, Teske PR, Tschöp MH, Jastroch M. Diversification and coevolution of the ghrelin/growth hormone secretagogue receptor system in vertebrates. Ecol Evol 2016; 6:2516-35. [PMID: 27066235 PMCID: PMC4797157 DOI: 10.1002/ece3.2057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/08/2016] [Accepted: 02/09/2016] [Indexed: 12/13/2022] Open
Abstract
The gut hormone ghrelin is involved in numerous metabolic functions, such as the stimulation of growth hormone secretion, gastric motility, and food intake. Ghrelin is modified by ghrelin O-acyltransferase (GOAT) or membrane-bound O-acyltransferase domain-containing 4 (MBOAT4) enabling action through the growth hormone secretagogue receptors (GHS-R). During the course of evolution, initially strong ligand/receptor specificities can be disrupted by genomic changes, potentially modifying physiological roles of the ligand/receptor system. Here, we investigated the coevolution of ghrelin, GOAT, and GHS-R in vertebrates. We combined similarity search, conserved synteny analyses, phylogenetic reconstructions, and protein structure comparisons to reconstruct the evolutionary history of the ghrelin system. Ghrelin remained a single-gene locus in all vertebrate species, and accordingly, a single GHS-R isoform was identified in all tetrapods. Similar patterns of the nonsynonymous (dN) and synonymous (dS) ratio (dN/dS) in the vertebrate lineage strongly suggest coevolution of the ghrelin and GHS-R genes, supporting specific functional interactions and common physiological pathways. The selection profiles do not allow confirmation as to whether ghrelin binds specifically to GOAT, but the ghrelin dN/dS patterns are more similar to those of GOAT compared to MBOAT1 and MBOAT2 isoforms. Four GHS-R isoforms were identified in teleost genomes. This diversification of GHS-R resulted from successive rounds of duplications, some of which remained specific to the teleost lineage. Coevolution signals are lost in teleosts, presumably due to the diversification of GHS-R but not the ghrelin gene. The identification of the GHS-R diversity in teleosts provides a molecular basis for comparative studies on ghrelin's physiological roles and regulation, while the comparative sequence and structure analyses will assist translational medicine to determine structure-function relationships of the ghrelin/GHS-R system.
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Affiliation(s)
- Mbaye Tine
- Genome Centre at Max Planck Institute for Plant Breeding Research Carl-von-Linné-Weg 10D-50829 Köln Germany; Molecular Zoology Laboratory Department of Zoology University of Johannesburg Kingsway Campus Auckland Park 2006 South Africa
| | - Heiner Kuhl
- Max Planck Institute for Molecular Genetics Ihnestrasse 63-73 14195 Berlin Germany
| | - Peter R Teske
- Molecular Zoology Laboratory Department of Zoology University of Johannesburg Kingsway Campus Auckland Park 2006 South Africa
| | - Matthias H Tschöp
- Helmholtz Diabetes Center & German Diabetes Center (DZD) Helmholtz Zentrum München, 85764 Neuherberg, Germany; Division of Metabolic Diseases Technische Universität München 80333 Munich Germany
| | - Martin Jastroch
- Helmholtz Diabetes Center & German Diabetes Center (DZD) Helmholtz Zentrum München, 85764 Neuherberg, Germany; Division of Metabolic Diseases Technische Universität München 80333 Munich Germany
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681
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Distinct phosphorylation sites on the ghrelin receptor, GHSR1a, establish a code that determines the functions of ß-arrestins. Sci Rep 2016; 6:22495. [PMID: 26935831 PMCID: PMC4776146 DOI: 10.1038/srep22495] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 02/15/2016] [Indexed: 01/14/2023] Open
Abstract
The growth hormone secretagogue receptor, GHSR1a, mediates the biological activities
of ghrelin, which includes the secretion of growth hormone, as well as the
stimulation of appetite, food intake and maintenance of energy homeostasis. Mapping
phosphorylation sites on GHSR1a and knowledge of how these sites control specific
functional consequences unlocks new strategies for the development of therapeutic
agents targeting individual functions. Herein, we have identified the
phosphorylation of different sets of sites within GHSR1a which engender distinct
functionality of ß-arrestins. More specifically, the
Ser362, Ser363 and Thr366 residues
at the carboxyl-terminal tail were primarily responsible for ß-arrestin
1 and 2 binding, internalization and ß-arrestin-mediated proliferation
and adipogenesis. The Thr350 and Ser349 are not
necessary for ß-arrestin recruitment, but are involved in the
stabilization of the GHSR1a-ß-arrestin complex in a manner that
determines the ultimate cellular consequences of ß-arrestin signaling.
We further demonstrated that the mitogenic and adipogenic effect of ghrelin were
mainly dependent on the ß-arrestin bound to the phosphorylated GHSR1a.
In contrast, the ghrelin function on GH secretion was entirely mediated by G protein
signaling. Our data is consistent with the hypothesis that the phosphorylation
pattern on the C terminus of GHSR1a determines the signaling and physiological
output.
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682
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Velasco C, Librán-Pérez M, Otero-Rodiño C, López-Patiño MA, Míguez JM, Soengas JL. Intracerebroventricular ghrelin treatment affects lipid metabolism in liver of rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol 2016; 228:33-39. [PMID: 26828819 DOI: 10.1016/j.ygcen.2016.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/22/2016] [Accepted: 01/28/2016] [Indexed: 12/21/2022]
Abstract
We aimed to elucidate in rainbow trout (Oncorhynchus mykiss) the effects of central ghrelin (GHRL) treatment on the regulation of liver lipid metabolism, and the possible modulatory effect of central GHRL treatment on the simultaneous effects of raised levels of oleate. Thus, we injected intracerebroventricularly (ICV) rainbow trout GHRL in the presence or absence of oleate and evaluated in liver variables related to lipid metabolism. Oleate treatment elicited in liver of rainbow trout decreased lipogenesis and increased oxidative capacity in agreement with previous studies. Moreover, as demonstrated for the first time in fish in the present study, GHRL also acts centrally modulating lipid metabolism in liver, resulting in increased potential for lipogenesis and decreased potential for fatty acid oxidation, i.e. the converse effects to those elicited by central oleate treatment. The simultaneous treatment of GHRL and oleate confirmed these counteractive effects. Thus, the nutrient sensing mechanisms present in hypothalamus, particularly those involved in sensing of fatty acid, are involved in the control of liver energy metabolism in fish, and this control is modulated by the central action of GHRL. These results give support to the notion of hypothalamus as an integrative place for the regulation of peripheral energy metabolism in fish.
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Affiliation(s)
- Cristina Velasco
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - Marta Librán-Pérez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - Cristina Otero-Rodiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - Marcos A López-Patiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - Jesús M Míguez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain.
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683
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Svendsen B, Holst JJ. Regulation of gut hormone secretion. Studies using isolated perfused intestines. Peptides 2016; 77:47-53. [PMID: 26275337 DOI: 10.1016/j.peptides.2015.08.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 07/03/2015] [Accepted: 08/04/2015] [Indexed: 12/28/2022]
Abstract
The incretin hormones glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are secreted from enteroendocrine cells in the intestine along with other gut hormones (PYY, CCK and neurotensin) shown to affect metabolism and/or appetite. The secretion of many gut hormones is highly increased after gastric bypass operations, which have turned out to be an effective therapy of not only obesity but also type 2 diabetes. These effects are likely to be due, at least in part, to increases in the secretion of these gut hormones (except GIP). Therefore, stimulation of the endogenous hormone represents an appealing therapeutic strategy, which has spurred an interest in understanding the regulation of gut hormone secretion and a search for particularly GLP-1 and PYY secretagogues. The secretion of the gut hormones is stimulated by oral intake of nutrients often including carbohydrate, protein and lipid. This review focuses on stimulators of gut hormone secretion, the mechanisms involved, and in particular models used to investigate secretion. A major break-through in this field was the development of methods to identify and isolate specific hormone producing cells, which allow detailed mapping of the expression profiles of these cells, whereas they are less suitable for physiological studies of secretion. Isolated perfused preparations of mouse and rat intestines have proven to be reliable models for dynamic hormone secretion and should be able to bridge the gap between the molecular details derived from the single cells to the integrated patterns observed in the intact animals.
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Affiliation(s)
- Berit Svendsen
- Department of Biomedical Sciences, Faculty of health Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
| | - Jens Juul Holst
- Department of Biomedical Sciences, Faculty of health Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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684
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Weber HC. Overview of gastrointestinal regulatory peptides. Curr Opin Endocrinol Diabetes Obes 2016; 23:1-2. [PMID: 26702844 DOI: 10.1097/med.0000000000000222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- H Christian Weber
- Section of Gastroenterology, Boston University School of Medicine, Boston, Massachusetts, USA
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685
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Wiedemann T, Bielohuby M, Müller TD, Bidlingmaier M, Pellegata NS. Obesity in MENX Rats Is Accompanied by High Circulating Levels of Ghrelin and Improved Insulin Sensitivity. Diabetes 2016; 65:406-20. [PMID: 26512025 DOI: 10.2337/db15-0374] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 10/23/2015] [Indexed: 11/13/2022]
Abstract
Ghrelin, the natural ligand of the growth hormone secretagogue receptor type 1a (GHS-R1a), is mainly secreted from the stomach and regulates food intake and energy homeostasis. p27 regulates cell cycle progression in many cell types. Here, we report that rats affected by the multiple endocrine neoplasia syndrome MENX, caused by a p27 mutation, develop pancreatic islet hyperplasia containing elevated numbers of ghrelin-producing ε-cells. The metabolic phenotype of MENX-affected rats featured high endogenous acylated and unacylated plasma ghrelin levels. Supporting increased ghrelin action, MENX rats show increased food intake, enhanced body fat mass, and elevated plasma levels of triglycerides and cholesterol. Ghrelin effect on food intake was confirmed by treating MENX rats with a GHS-R1a antagonist. At 7.5 months, MENX-affected rats show decreased mRNA levels of hypothalamic GHS-R1a, neuropeptide Y (NPY), and agouti-related protein (AgRP), suggesting that prolonged hyperghrelinemia may lead to decreased ghrelin efficacy. In line with ghrelin's proposed role in glucose metabolism, we find decreased glucose-stimulated insulin secretion in MENX rats, while insulin sensitivity is improved. In summary, we provide a novel nontransgenic rat model with high endogenous ghrelin plasma levels and, interestingly, improved glucose tolerance. This model might aid in identifying new therapeutic approaches for obesity and obesity-related diseases, including type 2 diabetes.
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Affiliation(s)
- Tobias Wiedemann
- Institute of Pathology, Helmholtz Center Munich, German Research Center for Environmental Health, Technical University Munich, Munich, Germany
| | - Maximilian Bielohuby
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwigs-Maximilians University, Munich, Germany
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Center Munich, German Research Center for Environmental Health, Technical University Munich, Munich, Germany
| | - Martin Bidlingmaier
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwigs-Maximilians University, Munich, Germany
| | - Natalia S Pellegata
- Institute of Pathology, Helmholtz Center Munich, German Research Center for Environmental Health, Technical University Munich, Munich, Germany
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686
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Thevis M, Kuuranne T, Walpurgis K, Geyer H, Schänzer W. Annual banned-substance review: analytical approaches in human sports drug testing. Drug Test Anal 2016; 8:7-29. [PMID: 26767774 DOI: 10.1002/dta.1928] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 12/30/2022]
Abstract
The aim of improving anti-doping efforts is predicated on several different pillars, including, amongst others, optimized analytical methods. These commonly result from exploiting most recent developments in analytical instrumentation as well as research data on elite athletes' physiology in general, and pharmacology, metabolism, elimination, and downstream effects of prohibited substances and methods of doping, in particular. The need for frequent and adequate adaptations of sports drug testing procedures has been incessant, largely due to the uninterrupted emergence of new chemical entities but also due to the apparent use of established or even obsolete drugs for reasons other than therapeutic means, such as assumed beneficial effects on endurance, strength, and regeneration capacities. Continuing the series of annual banned-substance reviews, literature concerning human sports drug testing published between October 2014 and September 2015 is summarized and reviewed in reference to the content of the 2015 Prohibited List as issued by the World Anti-Doping Agency (WADA), with particular emphasis on analytical approaches and their contribution to enhanced doping controls.
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Affiliation(s)
- Mario Thevis
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.,European Monitoring Center for Emerging Doping Agents, Cologne/Bonn, Germany
| | - Tiia Kuuranne
- Doping Control Laboratory, United Medix Laboratories, Höyläämötie 14, 00380, Helsinki, Finland
| | - Katja Walpurgis
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany
| | - Hans Geyer
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany
| | - Wilhelm Schänzer
- Center for Preventive Doping Research, Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany
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687
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Abstract
When eating control is overridden by hedonic reward, a condition of obesity dyshomeostasis occurs. Appetitive hedonic reward is a natural response to an obesogenic environment containing endemic stress and easily accessible and palatable high-energy foods and beverages. Obesity dyshomeostasis is mediated by the prefrontal cortex, amygdala and hypothalamic-pituitary-adrenal axis. The ghrelin axis provides the perfect signalling system for feeding dyshomeostasis, affect control and hedonic reward. Dyshomeostasis plays a central role in obesity causation, the addictions and chronic conditions and in persons with diverse bodies. Prevention and treatment efforts that target sources of dyshomeostasis provide ways of reducing adiposity, ameliorating the health impacts of addiction and raising the quality of life in people suffering from chronic stress.
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688
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Ekström LMNK, Björck IME, Östman EM. An improved course of glycaemia after a bread based breakfast is associated with beneficial effects on acute and semi-acute markers of appetite. Food Funct 2016; 7:1040-7. [DOI: 10.1039/c5fo00969c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A breakfast giving low and sustained glycaemia results in beneficial effects on appetite, both acute and after a subsequentad libmeal.
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Affiliation(s)
| | | | - Elin M. Östman
- Food for Health Science Centre
- Lund University
- SE-221 00 Lund
- Sweden
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689
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690
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Zhang C, Li L, Zhao B, Jiao A, Li X, Sun N, Zhang J. Ghrelin Protects against Dexamethasone-Induced INS-1 Cell Apoptosis via ERK and p38MAPK Signaling. Int J Endocrinol 2016; 2016:4513051. [PMID: 27190513 PMCID: PMC4844876 DOI: 10.1155/2016/4513051] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 11/17/2022] Open
Abstract
Glucocorticoid excess induces apoptosis of islet cells, which may result in diabetes. In this study, we investigated the protective effect of ghrelin on dexamethasone-induced INS-1 cell apoptosis. Our data showed that ghrelin (0.1 μM) inhibited dexamethasone-induced (0.1 μM) apoptosis of INS-1 cells and facilitated cell proliferation. Moreover, ghrelin upregulated Bcl-2 expression, downregulated Bax expression, and decreased caspase-3 activity. The protective effect of ghrelin against dexamethasone-induced INS-1 cell apoptosis was mediated via growth hormone secretagogue receptor 1a. Further studies revealed that ghrelin increased ERK activation and decreased p38MAPK expression after dexamethasone treatment. Ghrelin-mediated protection of dexamethasone-induced apoptosis of INS-1 cells was attenuated using the ERK inhibitor U0126 (10 μM), and cell viability increased using the p38MAPK inhibitor SB203580 (10 μM). In conclusion, ghrelin could protect against dexamethasone-induced INS-1 cell apoptosis, at least partially via GHS-R1a and the signaling pathway of ERK and p38MAPK.
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Affiliation(s)
- Chengshuo Zhang
- Hepatobiliary Surgery Department and Unit of Organ Transplantation, First Hospital of China Medical University, Shenyang 110001, China
| | - Le Li
- Hepatobiliary Surgery Department, Chifeng Municipal Hospital, Chifeng 024000, China
| | - Bochao Zhao
- Hepatobiliary Surgery Department and Unit of Organ Transplantation, First Hospital of China Medical University, Shenyang 110001, China
| | - Ao Jiao
- Hepatobiliary Surgery Department and Unit of Organ Transplantation, First Hospital of China Medical University, Shenyang 110001, China
| | - Xin Li
- Department of General Surgery, Fourth Hospital of China Medical University, Shenyang 110032, China
| | - Ning Sun
- Hepatobiliary Surgery Department and Unit of Organ Transplantation, First Hospital of China Medical University, Shenyang 110001, China
| | - Jialin Zhang
- Hepatobiliary Surgery Department and Unit of Organ Transplantation, First Hospital of China Medical University, Shenyang 110001, China
- *Jialin Zhang:
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691
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Velasco C, Librán-Pérez M, Otero-Rodiño C, López-Patiño MA, Míguez JM, Cerdá-Reverter JM, Soengas JL. Ghrelin modulates hypothalamic fatty acid-sensing and control of food intake in rainbow trout. J Endocrinol 2016; 228:25-37. [PMID: 26459641 DOI: 10.1530/joe-15-0391] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/12/2015] [Indexed: 12/17/2022]
Abstract
There is no information available on fish as far as the possible effects of ghrelin on hypothalamic fatty acid metabolism and the response of fatty acid-sensing systems, which are involved in the control of food intake. Therefore, we assessed in rainbow trout the response of food intake, hypothalamic fatty acid-sensing mechanisms and expression of neuropeptides involved in the control of food intake to the central treatment of ghrelin in the presence or absence of a long-chain fatty acid such as oleate. We observed that the orexigenic actions of ghrelin in rainbow trout are associated with changes in fatty acid metabolism in the hypothalamus and an inhibition of fatty acid-sensing mechanisms, which ultimately lead to changes in the expression of anorexigenic and orexigenic peptides resulting in increased orexigenic potential and food intake. Moreover, the response to increased levels of oleate of hypothalamic fatty acid-sensing systems (activation), expression of neuropeptides (enhanced anorexigenic potential) and food intake (decrease) were counteracted by the simultaneous treatment with ghrelin. These changes provide evidence for the first time in fish of a possible modulatory role of ghrelin on the metabolic regulation by fatty acid of food intake occurring in the hypothalamus.
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Affiliation(s)
- Cristina Velasco
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - Marta Librán-Pérez
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - Cristina Otero-Rodiño
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - Marcos A López-Patiño
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - Jesús M Míguez
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - José Miguel Cerdá-Reverter
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
| | - José L Soengas
- Laboratorio de Fisioloxía AnimalDepartamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, SpainDepartamento de Fisiología de Peces y BiotecnologíaInstituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain
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692
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Zigman JM, Bouret SG, Andrews ZB. Obesity Impairs the Action of the Neuroendocrine Ghrelin System. Trends Endocrinol Metab 2016; 27:54-63. [PMID: 26542050 PMCID: PMC4814209 DOI: 10.1016/j.tem.2015.09.010] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 09/22/2015] [Accepted: 09/28/2015] [Indexed: 01/08/2023]
Abstract
Ghrelin is a metabolic hormone that promotes energy conservation by regulating appetite and energy expenditure. Although some studies suggest that antagonizing ghrelin function attenuates body weight gain and glucose intolerance on a high calorie diet, there is little information about the metabolic actions of ghrelin in the obese state. In this review, we discuss the novel concept of obesity-induced central ghrelin resistance in neural circuits regulating behavior, and impaired ghrelin secretion from the stomach. Interestingly, weight loss restores ghrelin secretion and function, and we hypothesize that ghrelin resistance is a mechanism designed to protect a higher body weight set-point established during times of food availability, to maximize energy reserves during a time of food scarcity.
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Affiliation(s)
- Jeffrey M Zigman
- Departments of Internal Medicine (Divisions of Hypothalamic Research and Endocrinology and Metabolism) and Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, 75390-9077, USA.
| | - Sebastien G Bouret
- The Saban Research Institute, Developmental Neuroscience Program, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA 90027, USA; Inserm, Jean-Pierre Aubert Research Center, U1172, University Lille 2, Lille, 59045, France
| | - Zane B Andrews
- Metabolic Disease and Obesity Theme, Biomedicine Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria 3183, Australia
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693
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Anker SD, Coats AJS, Morley JE. Evidence for partial pharmaceutical reversal of the cancer anorexia-cachexia syndrome: the case of anamorelin. J Cachexia Sarcopenia Muscle 2015; 6:275-7. [PMID: 26675382 PMCID: PMC4670734 DOI: 10.1002/jcsm.12063] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 07/14/2015] [Indexed: 01/04/2023] Open
Abstract
A major component of the cancer anorexia-cachexia syndrome is a decline in food intake. Up until now none of the drugs that improve appetite also improve skeletal muscle. Recent studies have suggested that the oral ghrelin-analog, anamorelin, increased food intake and muscle mass. Unfortunately, it does not increase muscle power. Its regulatory future is uncertain, although it has important clinical effects.
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Affiliation(s)
- Stefan D Anker
- Division of Innovative Clinical Trials, Department of Cardiology and Pneumology, University Medical Center Göttingen (UMG) Göttingen, Germany
| | - Andrew J S Coats
- Monash University Melbourne, Australia ; University of Warwick Coventry, UK
| | - John E Morley
- Divisions of Geriatric Medicine and Endocrinology, Saint Louis University School of Medicine St Louis, MO, USA
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694
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Hawkes CP, Grimberg A. Insulin-Like Growth Factor-I is a Marker for the Nutritional State. PEDIATRIC ENDOCRINOLOGY REVIEWS : PER 2015; 13:499-511. [PMID: 26841638 PMCID: PMC5576178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Measurement of the serum concentration of insulin-like growth factor-I (IGF-l) is generally used as a screening investigation for disorders of the growth hormone (GH)/IGF-I axis in children and adolescents with short stature. IGF-I concentration is sensitive to short-term and chronic alterations in the nutritional state, and the interpretation of IGF-I measurements requires knowledge of the child's nutritional status. In this review, we summarize the effects of nutrition on the GH/IGF-I axis, and review the clinical implications of these interactions throughout childhood, both in under-nutrition and over-nutrition.
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Affiliation(s)
- Colin P Hawkes
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
- The National Children’s Research Centre, Dublin, Ireland
| | - Adda Grimberg
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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695
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Sales de Gauzy J, Gennero I, Delrous O, Salles JP, Lepage B, Accadbled F. Fasting total ghrelin levels are increased in patients with adolescent idiopathic scoliosis. SCOLIOSIS 2015; 10:33. [PMID: 26628906 PMCID: PMC4666062 DOI: 10.1186/s13013-015-0054-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/02/2015] [Indexed: 12/31/2022]
Abstract
Background A control study was designed to investigate circulating Ghrelin levels in adolescent girls with adolescent idiopathic scoliosis (AIS) and controls. Eating behavioral disorders, endocrine disorders, abnormal growth pattern and osteopenia have been well documented in AIS. Ghrelin is an orexigenic hormone produced by the stomach which reflects body weight changes and stimulates growth hormone secretion. Recently, it has been shown to be associated with bone metabolism and eating behavior. However, the circulating levels of ghrelin have never been evaluated in AIS patients. Methods Forty nine AIS girls and 15 controls were included. Anthropometric parameters and fasting circulating total ghrelin were measured. Curve severity was evaluated in AIS girls. The relationships between ghrelin and age, body weight, height, body mass index (BMI), BMI Z-score and corrected anthropometric parameters were analyzed in AIS girls and controls. Results There was no significant difference in body weight, height, BMI or BMI Z-score between AIS and controls. Serum ghrelin level was 1.8 fold higher in AIS girls than in controls. Elevation of ghrelin levels remained significant when corrected BMI or corrected BMI Z-score were considered. Unlike in controls, positive correlations were found between ghrelin and age in AIS girls with a gradual increase of circulating ghrelin with age. Conclusions We have observed significantly higher circulating ghrelin levels in AIS than in controls with a positive correlation with age. This pilot-study suggests that ghrelin signaling might play a role in the initiation or development of AIS. Further studies are needed to validate theses results.
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Affiliation(s)
- Jérôme Sales de Gauzy
- Pediatric Orthopaedics Unit, Children Hospital, CHU de Toulouse, France ; Biomechanics Laboratory, Paul-Sabatier University, Toulouse, France
| | - Isabelle Gennero
- INSERM Unit 1043, Physiopathology Center of Toulouse Purpan (CTPT), Paul-Sabatier University, Toulouse, France ; Biochemistry Laboratory, Institut Fédératif de Biologie, University Hospital Center, CHU de Toulouse, France
| | - Olivier Delrous
- Biochemistry Laboratory, Institut Fédératif de Biologie, University Hospital Center, CHU de Toulouse, France
| | - Jean-Pierre Salles
- INSERM Unit 1043, Physiopathology Center of Toulouse Purpan (CTPT), Paul-Sabatier University, Toulouse, France ; Endocrine and Bone Diseases Unit, Children Hospital, University Hospital Center, CHU de Toulouse, France ; Pediatric Clinical Investigation Center, Children Hospital, University Hospital Center, CHU de Toulouse, France
| | - Benoit Lepage
- Department of Epidemiology, University Hospital Center, Paul-Sabatier University, CHU de Toulouse, France
| | - Franck Accadbled
- Pediatric Orthopaedics Unit, Children Hospital, CHU de Toulouse, France ; Biomechanics Laboratory, Paul-Sabatier University, Toulouse, France
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696
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Laermans J, Vancleef L, Tack J, Depoortere I. Role of the clock gene Bmal1 and the gastric ghrelin-secreting cell in the circadian regulation of the ghrelin-GOAT system. Sci Rep 2015; 5:16748. [PMID: 26576661 PMCID: PMC4649743 DOI: 10.1038/srep16748] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/19/2015] [Indexed: 11/09/2022] Open
Abstract
As adequate food intake is crucial to survival, organisms have evolved endogenous circadian clocks to generate optimal temporal patterns of food-related behavior and physiology. The gastric ghrelin-secreting cell is thought to be part of this network of peripheral food-entrainable oscillators (FEOs), regulating the circadian release of this orexigenic peptide. This study aimed to determine the role of the core clock gene Bmal1 and the gastric ghrelin-secreting cell as an FEO in the circadian rhythmicity of ghrelin expression and secretion in vivo and in vitro. Bmal1-deficient mice not only lacked circadian rhythmicity in plasma ghrelin levels and food intake, but also showed decreased gastric mRNA expression of ghrelin and ghrelin O-acyltransferase (GOAT), the ghrelin activating enzyme. Furthermore, in the absence of the hypothalamic master clock, food-related stimuli entrained the molecular clock of gastric ghrelinoma cells to regulate the rhythmic release of ghrelin. Divergent responses in octanoyl and total ghrelin release towards different food cues were observed, suggesting that the FEO also regulates the circadian rhythmicity of GOAT. Collectively, these findings indicate that circadian rhythmicity of ghrelin signaling requires Bmal1 and is driven by a food-responsive clock in the gastric ghrelin-secreting cell that not only regulates ghrelin, but also GOAT activity.
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Affiliation(s)
- J Laermans
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
| | - L Vancleef
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
| | - J Tack
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
| | - I Depoortere
- Gut Peptide Research Lab, Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Leuven, Belgium
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697
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Xu G, Hong X, Tang H, Jiang S, Liu F, Shen Z, Li Z, Zhang W. Ghrelin regulates GLP-1 production through mTOR signaling in L cells. Mol Cell Endocrinol 2015; 416:9-18. [PMID: 26279396 DOI: 10.1016/j.mce.2015.08.016] [Citation(s) in RCA: 18] [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: 06/22/2015] [Revised: 08/08/2015] [Accepted: 08/11/2015] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide (GLP-1), an intestinal incretin produced in L-cells and released in response to meal intake, functions to promote insulin secretion and to decrease plasma glucose. Ghrelin is an orexigenic hormone critical for glucose homeostasis. The molecular mechanism by which ghrelin alters GLP-1 production remains largely unknown. Here we showed that ghrelin attenuates GLP-1 production through mTOR signaling. In GHSR1a null mice, ileal mTOR signaling, proglucagon and circulating GLP-1 were significantly increased. Antagonism of the GHSR1a by D-Lys-3-GHRP-6 increased GLP-1 synthesis and release in STC-1 cells. Treatment of STC-1 cells with ghrelin decreased the production of GLP-1. This effect was associated with a significant inhibition of mTOR signaling. Overexpression of ghrelin inhibited proglucagon promoter activity and GLP-1 production. Inhibition of mTOR activity by mTOR siRNA blocked D-Lys-3-GHRP-6 induced GLP-1 production in STC-1 cells. Our results suggest that mTOR signaling mediates the inhibitory effect of ghrelin on GLP-1 production.
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Affiliation(s)
- Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China.
| | - Xiaosi Hong
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Hong Tang
- Shenzhen University Diabetes Center, Shenzhen University Health Science Center, 3688 Nanhai Avenue, Nanshan District, Shenzhen, Guangdong, 518060, China
| | - Sushi Jiang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Fenting Liu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Zhemin Shen
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Ziru Li
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA
| | - Weizhen Zhang
- Shenzhen University Diabetes Center, Shenzhen University Health Science Center, 3688 Nanhai Avenue, Nanshan District, Shenzhen, Guangdong, 518060, China; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI, 48109-0346, USA.
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698
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Luscher TF. Cholesterol production, accumulation, reverse transport, and excretion: opportunities for statins, PPAR- agonists, and PCSK9 inhibitors. Eur Heart J 2015; 36:2965-7. [DOI: 10.1093/eurheartj/ehv576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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699
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Ritze Y, Hengelhaupt C, Bárdos G, Ernst B, Thurnheer M, D'Haese JG, Bischoff SC, Schultes B. Altered intestinal neuroendocrine gene expression in humans with obesity. Obesity (Silver Spring) 2015; 23:2278-85. [PMID: 26381270 DOI: 10.1002/oby.21253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/01/2015] [Accepted: 07/12/2015] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Gastrointestinal hormones are critically involved in the regulation of food intake and body weight. Previous studies support an interplay between gastrointestinal hormones and the serotonergic system. This study explored intestinal neuroendocrine expression patterns in humans with obesity versus nonobese humans. METHODS Jejunum samples were collected from 164 humans with obesity (120 women; BMI (mean ± SD): 43.5 ± 6.6 kg/m(2) ) while they underwent Roux-en-Y gastric bypass surgery and from 18 nonobese humans (7 women; BMI: 23.5 ± 3.0 kg/m(2) ) undergoing distinct intestinal surgeries. mRNA expression of cholecystokinin (CCK), peptide YY3-36 (PYY), nesfatin1, ghrelin, ghrelin O-acyltransferase (GOAT), leptin, leptin receptor (leptinR), glucagon-like-peptide 1 receptor (GLP1R), serotonin transporter (SERT), tryptophan hydroxylase 1 (TPH1), and serotonin receptor 3A (5HT3A R) was determined with qRT-PCR. Ghrelin and GOAT protein expression was quantified using immunohistological stainings. Statistical analyses were performed with SPSS. RESULTS Jejunum samples from humans with obesity showed a higher expression of GOAT (mRNA and protein), TPH1, and SERT mRNA compared with the nonobese humans (all P < 0.05). Positive correlations were observed between TPH1, CCK, PYY, and nesfatin1 in nonobese and GOAT, ghrelin, TPH1, SERT, CCK, and PYY in humans with obesity (all P < 0.01). CONCLUSIONS Our top-down approach substantiates the dysregulation of jejunal neuroendocrine hormones in obesity.
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Affiliation(s)
- Yvonne Ritze
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | | | - Gyöngyi Bárdos
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - Barbara Ernst
- eSwiss Medical and Surgical Center, Interdisciplinary Obesity Center, St. Gallen, Switzerland
| | - Martin Thurnheer
- eSwiss Medical and Surgical Center, Interdisciplinary Obesity Center, St. Gallen, Switzerland
| | - Jan G D'Haese
- Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stephan C Bischoff
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - Bernd Schultes
- eSwiss Medical and Surgical Center, Interdisciplinary Obesity Center, St. Gallen, Switzerland
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700
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Chemosensory signalling pathways involved in sensing of amino acids by the ghrelin cell. Sci Rep 2015; 5:15725. [PMID: 26510380 PMCID: PMC4625164 DOI: 10.1038/srep15725] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/01/2015] [Indexed: 01/06/2023] Open
Abstract
Taste receptors on enteroendocrine cells sense nutrients and transmit signals that control gut hormone release. This study aimed to investigate the amino acid (AA) sensing mechanisms of the ghrelin cell in a gastric ghrelinoma cell line, tissue segments and mice. Peptone and specific classes of amino acids stimulate ghrelin secretion in the ghrelinoma cell line. Sensing of L-Phe occurs via the CaSR, monosodium glutamate via the TAS1R1-TAS1R3 while L-Ala and peptone act via 2 different amino acid taste receptors: CaSR &TAS1R1-TAS1R3 and CaSR &GPRC6A, respectively. The stimulatory effect of peptone on ghrelin release was mimicked ex vivo in gastric but not in jejunal tissue segments, where peptone inhibited ghrelin release. The latter effect could not be blocked by receptor antagonists for CCK, GLP-1 or somatostatin. In vivo, plasma ghrelin levels were reduced both upon intragastric (peptone or L-Phe) or intravenous (L-Phe) administration, indicating that AA- sensing is not polarized and is due to inhibition of ghrelin release from the stomach or duodenum respectively. In conclusion, functional AA taste receptors regulate AA-induced ghrelin release in vitro. The effects differ between stomach and jejunum but these local nutrient sensing mechanisms are overruled in vivo by indirect mechanisms inhibiting ghrelin release.
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