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Labarthe A, Zizzari P, Fiquet O, Lebrun N, Veldhuis JD, Roelfsema F, Chauveau C, Bohlooly-Y M, Epelbaum J, Tolle V. Effect of Growth Hormone Secretagogue Receptor Deletion on Growth, Pulsatile Growth Hormone Secretion, and Meal Pattern in Male and Female Mice. Neuroendocrinology 2022; 112:215-234. [PMID: 33774644 DOI: 10.1159/000516147] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 03/25/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION While the vast majority of research investigating the role of ghrelin or its receptor, GHS-R1a, in growth, feeding, and metabolism has been conducted in male rodents, very little is known about sex differences in this system. Furthermore, the role of GHS-R1a signaling in the control of pulsatile GH secretion and its link with growth or metabolic parameters has never been characterized. METHODS We assessed the sex-specific contribution of GHS-R1a signaling in the activity of the GH/IGF-1 axis, metabolic parameters, and feeding behavior in adolescent (5-6 weeks old) or adult (10-19 weeks old) GHS-R KO (Ghsr-/-) and WT (Ghsr+/+) male and female mice. RESULTS Adult Ghsr-/- male and female mice displayed deficits in weight and linear growth that were correlated with reduced GH pituitary contents in males only. GHS-R1a deletion was associated with reduced meal frequency and increased meal intervals, as well as reduced hypothalamic GHRH and NPY mRNA in males, not females. In adult, GH release from Ghsr-/- mice pituitary explants ex vivo was reduced independently of the sex. However, in vivo pulsatile GH secretion decreased in adult but not adolescent Ghsr-/- females, while in males, GHS-R1a deletion was associated with reduction in pulsatile GH secretion during adolescence exclusively. In males, linear growth did not correlate with pulsatile GH secretion, but rather with ApEn, a measure that reflects irregularity of the rhythmic secretion. Fat mass, plasma leptin concentrations, or ambulatory activity did not predict differences in GH secretion. DISCUSSION/CONCLUSION These results point to a sex-dependent dimorphic effect of GHS-R1a signaling to modulate pulsatile GH secretion and meal pattern in mice with different compensatory mechanisms occurring in the hypothalamus of adult males and females after GHS-R1a deletion. Altogether, we show that GHS-R1a signaling plays a more critical role in the regulation of pulsatile GH secretion during adolescence in males and adulthood in females.
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Affiliation(s)
- Alexandra Labarthe
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Philippe Zizzari
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Oriane Fiquet
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Nicolas Lebrun
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Johannes D Veldhuis
- Endocrine Research Unit, Department of Medicine, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, New York, USA
| | - Ferdinand Roelfsema
- Department of Internal Medicine, Section of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, The Netherlands
| | - Christophe Chauveau
- Marrow Adiposity and Bone Lab - MABLab ULR 4490, University Littoral Côte d'Opale, Boulogne-sur-Mer, France
- University Lille, CHU Lille, Lille, France
| | - Mohammad Bohlooly-Y
- Translational Genomics, Discovery Sciences, Biopharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jacques Epelbaum
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
- UMR CNRS/MNHN 7179, Mécanismes Adaptatifs et Evolution, Brunoy, France
| | - Virginie Tolle
- Université de Paris, UMRS_1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
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Peris-Sampedro F, Le May MV, Stoltenborg I, Schéle E, Dickson SL. A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? J Neuroendocrinol 2021; 33:e13025. [PMID: 34427011 DOI: 10.1111/jne.13025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/09/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
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Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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Hassouna R, Fernandez G, Lebrun N, Fiquet O, Roelfsema F, Labarthe A, Zizzari P, Tomasetto C, Epelbaum J, Viltart O, Chauveau C, Perello M, Tolle V. Ghrelin Gene Deletion Alters Pulsatile Growth Hormone Secretion in Adult Female Mice. Front Endocrinol (Lausanne) 2021; 12:754522. [PMID: 34721302 PMCID: PMC8549963 DOI: 10.3389/fendo.2021.754522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Using preproghrelin-deficient mice (Ghrl-/-), we previously observed that preproghrelin modulates pulsatile growth hormone (GH) secretion in post-pubertal male mice. However, the role of ghrelin and its derived peptides in the regulation of growth parameters or feeding in females is unknown. We measured pulsatile GH secretion, growth, metabolic parameters and feeding behavior in adult Ghrl-/- and Ghrl+/+ male and female mice. We also assessed GH release from pituitary explants and hypothalamic growth hormone-releasing hormone (GHRH) expression and immunoreactivity. Body weight and body fat mass, linear growth, spontaneous food intake and food intake following a 48-h fast, GH pituitary contents and GH release from pituitary explants ex vivo, fasting glucose and glucose tolerance were not different among adult Ghrl-/- and Ghrl+/+ male or female mice. In vivo, pulsatile GH secretion was decreased, while approximate entropy, that quantified orderliness of secretion, was increased in adult Ghrl-/- females only, defining more irregular GH pattern. The number of neurons immunoreactive for GHRH visualized in the hypothalamic arcuate nucleus was increased in adult Ghrl-/- females, as compared to Ghrl+/+ females, whereas the expression of GHRH was not different amongst groups. Thus, these results point to sex-specific effects of preproghrelin gene deletion on pulsatile GH secretion, but not feeding, growth or metabolic parameters, in adult mice.
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Affiliation(s)
- Rim Hassouna
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Gimena Fernandez
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], La Plata, Buenos Aires, Argentina
| | - Nicolas Lebrun
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Oriane Fiquet
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Ferdinand Roelfsema
- Department of Internal Medicine, Section of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, Netherlands
| | - Alexandra Labarthe
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Philippe Zizzari
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
| | - Catherine Tomasetto
- Institut de génétique et de biologie moléculaire et cellulaire (IGBMC), UMR7104 CNRS/U1258 INSERM, Université de Strasbourg, Illkirch, France
| | - Jacques Epelbaum
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
- UMR CNRS/MNHN 7179, Mécanismes Adaptatifs et Evolution, Brunoy, France
| | - Odile Viltart
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
- Université de Lille, Faculté des Sciences et Technologies, Villeneuve d’Ascq, France
| | - Christophe Chauveau
- Marrow Adiposity and Bone Lab - MABLab ULR 4490, Univ. Littoral Côte d’Opale, Boulogne-sur-Mer, Univ. Lille and CHU Lille, Lille, France
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA). National University of La Plata], La Plata, Buenos Aires, Argentina
| | - Virginie Tolle
- Université de Paris, UMR-S 1266 INSERM, Institute of Psychiatry and Neuroscience of Paris, Paris, France
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Le Magueresse-Battistoni B. Endocrine disrupting chemicals and metabolic disorders in the liver: What if we also looked at the female side? CHEMOSPHERE 2021; 268:129212. [PMID: 33359838 DOI: 10.1016/j.chemosphere.2020.129212] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 05/07/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are linked to the worldwide epidemic incidence of metabolic disorders and fatty liver diseases, which affects quality of life and represents a high economic cost to society. Energy homeostasis exhibits strong sexual dimorphic traits, and metabolic organs respond to EDCs depending on sex, such as the liver, which orchestrates both drug elimination and glucose and lipid metabolism. In addition, fatty liver diseases show a strong sexual bias, which in part could also originate from sex differences observed in gut microbiota. The aim of this review is to highlight significant differences in endocrine and metabolic aspects of the liver, between males and females throughout development and into adulthood. It is also to illustrate how the male and female liver differently cope with exposure to various EDCs such as bisphenols, phthalates and persistent organic chemicals in order to draw attention to the need to include both sexes in experimental studies. Interesting data come from analyses of the composition and diversity of the gut microbiota in males exposed to the mentioned EDCs showing significant correlations with hepatic lipid accumulation and metabolic disorders but information on females is lacking or incomplete. As industrialization increases, the list of anthropogenic chemicals to which humans will be exposed will also likely increase. In addition to strengthening existing regulations, encouraging populations to protect themselves and promoting the substitution of harmful chemicals with safe products, innovative strategies based on sex differences in the gut microbiota and in the gut-liver axis could be optimistic outlook.
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Ngo ST, Wang H, Henderson RD, Bowers C, Steyn FJ. Ghrelin as a treatment for amyotrophic lateral sclerosis. J Neuroendocrinol 2021; 33:e12938. [PMID: 33512025 DOI: 10.1111/jne.12938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/27/2022]
Abstract
Ghrelin is a gut hormone best known for its role in regulating appetite and stimulating the secretion of the anabolic hormone growth hormone (GH). However, there is considerable evidence to show wider-ranging biological actions of ghrelin that favour improvements in cellular and systemic metabolism, as well as neuroprotection. Activation of these ghrelin-mediated pathways may alleviate pathogenic processes that are assumed to contribute to accelerated progression of disease in patients with neurodegenerative disease. Here, we provide a brief overview on the history of discoveries that led to the identification of ghrelin. Focussing on the neurodegenerative disease amyotrophic lateral sclerosis (ALS), we also present an overview of emerging evidence that suggests that ghrelin and ghrelin mimetics may serve as potential therapies for the treatment of ALS. Given that ALS is a highly heterogeneous disease, where multiple disease mechanisms contribute to variability in disease onset and rate of disease progression, we speculate that the wide-ranging biological actions of ghrelin might offer therapeutic benefit through modulating multiple disease-relevant processes observed in ALS. Expanding on the well-known actions of ghrelin in regulating food intake and GH secretion, we consider the potential of ghrelin-mediated pathways in improving body weight regulation, metabolism and the anabolic and neuroprotective actions of GH and insulin-like growth factor-1 (IGF-1). This is of clinical significance because loss of body weight, impairments in systemic and cellular metabolism, and reductions in IGF-1 are associated with faster disease progression and worse disease outcome in patients with ALS.
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Affiliation(s)
- Shyuan T Ngo
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Hao Wang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Robert D Henderson
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Cyril Bowers
- Department of Internal Medicine, Tulane University Health Sciences Centre, New Orleans, LA, USA
| | - Frederik J Steyn
- Department of Neurology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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Tyrosine Hydroxylase Neurons Regulate Growth Hormone Secretion via Short-Loop Negative Feedback. J Neurosci 2020; 40:4309-4322. [PMID: 32317389 DOI: 10.1523/jneurosci.2531-19.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
Classical studies suggest that growth hormone (GH) secretion is controlled by negative-feedback loops mediated by GH-releasing hormone (GHRH)- or somatostatin-expressing neurons. Catecholamines are known to alter GH secretion and neurons expressing TH are located in several brain areas containing GH-responsive cells. However, whether TH-expressing neurons are required to regulate GH secretion via negative-feedback mechanisms is unknown. In the present study, we showed that between 50% and 90% of TH-expressing neurons in the periventricular, paraventricular, and arcuate hypothalamic nuclei and locus ceruleus of mice exhibited STAT5 phosphorylation (pSTAT5) after an acute GH injection. Ablation of GH receptor (GHR) from TH cells or in the entire brain markedly increased GH pulse secretion and body growth in both male and female mice. In contrast, GHR ablation in cells that express the dopamine transporter (DAT) or dopamine β-hydroxylase (DBH; marker of noradrenergic/adrenergic cells) did not affect body growth. Nevertheless, less than 50% of TH-expressing neurons in the hypothalamus were found to express DAT. Ablation of GHR in TH cells increased the hypothalamic expression of Ghrh mRNA, although very few GHRH neurons were found to coexpress TH- and GH-induced pSTAT5. In summary, TH neurons that do not express DAT or DBH are required for the autoregulation of GH secretion via a negative-feedback loop. Our findings revealed a critical and previously unidentified group of catecholaminergic interneurons that are apt to sense changes in GH levels and regulate the somatotropic axis in mice.SIGNIFICANCE STATEMENT Textbooks indicate until now that the pulsatile pattern of growth hormone (GH) secretion is primarily controlled by GH-releasing hormone and somatostatin neurons. The regulation of GH secretion relies on the ability of these cells to sense changes in circulating GH levels to adjust pituitary GH secretion within a narrow physiological range. However, our study identifies a specific population of tyrosine hydroxylase-expressing neurons that is critical to autoregulate GH secretion via a negative-feedback loop. The lack of this mechanism in transgenic mice results in aberrant GH secretion and body growth. Since GH plays a key role in cell proliferation, body growth, and metabolism, our findings provide a major advance to understand how the brain regulates the somatotropic axis.
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Huang L, Huang Z, Chen C. Rhythmic growth hormone secretion in physiological and pathological conditions: Lessons from rodent studies. Mol Cell Endocrinol 2019; 498:110575. [PMID: 31499134 DOI: 10.1016/j.mce.2019.110575] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 02/01/2023]
Abstract
Evolutionally conserved in all mammalians, the release of GH occurs in a rhythmic pattern, characterized by several dominant surges (pulsatile GH) with tonic low inter-pulse levels (tonic GH). Such pulsatile secretion pattern is essential for many physiological actions of GH on different tissues with defined gender dimorphism. Rhythmic release of pulsatile GH is tightly controlled by hypothalamic neurons as well as peripheral metabolic factors. Changes of GH pattern occur within a range of sophisticated physiological and pathological settings and significantly contribute to growth, ageing, survival and disease predispositions. Precise analysis of GH secretion pattern is vitally important for a comprehensive understanding of the function of GH and the components that regulate GH secretion pattern.
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Affiliation(s)
- Lili Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia
| | - Zhengxiang Huang
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Australia.
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Weger BD, Gobet C, Yeung J, Martin E, Jimenez S, Betrisey B, Foata F, Berger B, Balvay A, Foussier A, Charpagne A, Boizet-Bonhoure B, Chou CJ, Naef F, Gachon F. The Mouse Microbiome Is Required for Sex-Specific Diurnal Rhythms of Gene Expression and Metabolism. Cell Metab 2019; 29:362-382.e8. [PMID: 30344015 PMCID: PMC6370974 DOI: 10.1016/j.cmet.2018.09.023] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 06/27/2018] [Accepted: 09/25/2018] [Indexed: 02/08/2023]
Abstract
The circadian clock and associated feeding rhythms have a profound impact on metabolism and the gut microbiome. To what extent microbiota reciprocally affect daily rhythms of physiology in the host remains elusive. Here, we analyzed transcriptome and metabolome profiles of male and female germ-free mice. While mRNA expression of circadian clock genes revealed subtle changes in liver, intestine, and white adipose tissue, germ-free mice showed considerably altered expression of genes associated with rhythmic physiology. Strikingly, the absence of the microbiome attenuated liver sexual dimorphism and sex-specific rhythmicity. The resulting feminization of male and masculinization of female germ-free animals is likely caused by altered sexual development and growth hormone secretion, associated with differential activation of xenobiotic receptors. This defines a novel mechanism by which the microbiome regulates host metabolism.
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Affiliation(s)
- Benjamin D Weger
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland
| | - Cédric Gobet
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland; Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jake Yeung
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Eva Martin
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland
| | - Sonia Jimenez
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland
| | - Bertrand Betrisey
- Cellular Metabolism, Department of Cell Biology, Nestlé Institute of Health Sciences, Nestlé Research, 1015 Lausanne, Switzerland
| | - Francis Foata
- Host-Microbe Interaction, Department of Gastro-Intestinal Health, Nestlé Institute of Health Sciences, Nestlé Research, 1000 Lausanne, Switzerland
| | - Bernard Berger
- Host-Microbe Interaction, Department of Gastro-Intestinal Health, Nestlé Institute of Health Sciences, Nestlé Research, 1000 Lausanne, Switzerland
| | - Aurélie Balvay
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Anne Foussier
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Aline Charpagne
- Genomics, Department of Multi-Omics, Nestlé Institute of Health Sciences, Nestlé Research, 1015 Lausanne, Switzerland
| | - Brigitte Boizet-Bonhoure
- Institut de Génétique Humaine, CNRS-Université de Montpellier UMR9002, 34396 Montpellier, France
| | - Chieh Jason Chou
- Host-Microbe Interaction, Department of Gastro-Intestinal Health, Nestlé Institute of Health Sciences, Nestlé Research, 1000 Lausanne, Switzerland
| | - Felix Naef
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Frédéric Gachon
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, 1015 Lausanne, Switzerland; School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
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Roelfsema F, Yang RJ, Takahashi PY, Erickson D, Bowers CY, Veldhuis JD. Aromatized Estrogens Amplify Nocturnal Growth Hormone Secretion in Testosterone-Replaced Older Hypogonadal Men. J Clin Endocrinol Metab 2018; 103:4419-4427. [PMID: 30032193 PMCID: PMC6212797 DOI: 10.1210/jc.2018-00755] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 06/20/2018] [Indexed: 11/19/2022]
Abstract
CONTEXT Testosterone (T) increases GH secretion in older men with a relative lack of T, in hypogonadal men of all ages, and in patients undergoing sex reassignment. The role of estradiol (E2) in men is less well defined. OBJECTIVE To assess the contribution of aromatization of T to spontaneous nocturnal and stimulated GH secretion. PARTICIPANTS Four groups of healthy older men (N = 74, age range 57 to 77 years) were studied. The gonadotropic axis was clamped with the gonadotropin-releasing hormone antagonist degarelix. Three groups received T and one group placebo addback. Two T-replaced groups were treated with anastrozole (an aromatase inhibitor) and either placebo or E2 addback. MAIN OUTCOME MEASURES Ten-minute GH concentration profiles were quantified by deconvolution analysis, after overnight (2200 to 0800 hours) sampling, and after combined IV injection of GHRH (0.3 µg/kg) and GHRH-2 (0.3 µg/kg) and withdrawal of a 2-hour somatostatin infusion (1 µg/kg/h). RESULTS E2 addback during aromatase inhibition increased basal (P = 0.046), pulsatile (P = 0.020), and total (P = 0.018) GH secretion by 60% to 70%. E2 did not potentiate GH secretory stimuli. Logarithmically transformed pulsatile GH secretion correlated strongly and positively with concurrent E2 concentrations overall (P = 0.028) and under anastrozole treatment (P = 0.005). CONCLUSION E2 administration in older men transdermally stimulates overnight pulsatile GH secretion. The exact site of E2 action cannot be ascertained from these experiments but may include hypothalamic loci involved in GH regulation, especially because GH secretagogue effects on somatotrope pituitary cells were not affected.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Internal Medicine, Section of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, Netherlands
| | - Rebecca J Yang
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
| | - Paul Y Takahashi
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Dana Erickson
- Division of Endocrinology, Mayo Clinic, Rochester, Minnesota
| | - Cyril Y Bowers
- Department of Internal Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - Johannes D Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
- Correspondence and Reprint Requests: Johannes D. Veldhuis, MD, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905. E-mail:
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11
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McCosh RB, Kreisman MJ, Breen KM. Frequent Tail-tip Blood Sampling in Mice for the Assessment of Pulsatile Luteinizing Hormone Secretion. J Vis Exp 2018. [PMID: 30035764 DOI: 10.3791/57894] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
In many endocrine systems, circulating factors or hormones are not released continuously, but are secreted as a discrete pulse in response to a releasing factor. Single-point sampling measures are inadequate to fully understand the biological significance of the secretory pattern of pulsatile hormones either under normal physiologic conditions or during conditions of dysregulation. Luteinizing hormone (LH) is synthesized by the anterior pituitary gonadotrope cells and secreted in a pulsatile pattern which requires frequent collection of blood samples for pulse assessment. This has not been possible in mice until recently, due to the development of a high-sensitivity LH assay and advancement in a technique for frequent low-volume sample collection, initially described by Steyn and colleagues.1 Here we describe a protocol for the frequent peripheral blood sample collection from mice with sufficient handling acclimatization to detect pulsatile secretion of LH. The current protocol details an expanded acclimatization period that allows assessment of robust and continuous pulses of LH over multiple hours. In this protocol, the tip of the tail is clipped and blood is collected from the tail using a hand-held pipette. For assessment of pulsatile LH in gonadectomized mice, serial samples are collected every 5-6 min for 90-180 min. Importantly, the collection of blood and measurement of robust pulses of LH can be accomplished in awake, freely behaving mice, given adequate handling acclimatization and effort to minimize environmental stressors. Sufficient acclimatization can be achieved within 4-5 weeks prior to blood collection. This protocol highlights advances in the methodology to ensure collection of whole blood samples for assessment of pulsatile LH secretion patterns over multiple hours in the mouse, a powerful animal model for neuroendocrine research.
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Affiliation(s)
- Richard B McCosh
- Department of Reproductive Medicine, University of California, San Diego School of Medicine
| | - Michael J Kreisman
- Department of Reproductive Medicine, University of California, San Diego School of Medicine
| | - Kellie M Breen
- Department of Reproductive Medicine, University of California, San Diego School of Medicine;
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12
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Fisher DW, Luu P, Agarwal N, Kurz JE, Chetkovich DM. Loss of HCN2 leads to delayed gastrointestinal motility and reduced energy intake in mice. PLoS One 2018; 13:e0193012. [PMID: 29466436 PMCID: PMC5821371 DOI: 10.1371/journal.pone.0193012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/03/2018] [Indexed: 01/22/2023] Open
Abstract
Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels are important regulators of excitability in neural, cardiac, and other pacemaking cells, which are often altered in disease. In mice, loss of HCN2 leads to cardiac dysrhythmias, persistent spike-wave discharges similar to those seen in absence epilepsy, ataxia, tremor, reduced neuropathic and inflammatory pain, antidepressant-like behavior, infertility, and severely restricted growth. While many of these phenotypes have tissue-specific mechanisms, the cause of restricted growth in HCN2 knockout animals remains unknown. Here, we characterize a novel, 3kb insertion mutation of Hcn2 in the Tremor and Reduced Lifespan 2 (TRLS/2J) mouse that leads to complete loss of HCN2 protein, and we show that this mutation causes many phenotypes similar to other mice lacking HCN2 expression. We then demonstrate that while TRLS/2J mice have low blood glucose levels and impaired growth, dysfunction in hormonal secretion from the pancreas, pituitary, and thyroid are unlikely to lead to this phenotype. Instead, we find that homozygous TRLS/2J mice have abnormal gastrointestinal function that is characterized by less food consumption and delayed gastrointestinal transit as compared to wildtype mice. In summary, a novel mutation in HCN2 likely leads to impaired GI motility, causing the severe growth restriction seen in mice with mutations that eliminate HCN2 expression.
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Affiliation(s)
- Daniel W. Fisher
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - Phillip Luu
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - Neha Agarwal
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - Jonathan E. Kurz
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - Dane M. Chetkovich
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- * E-mail:
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13
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Sominsky L, Goularte JF, Andrews ZB, Spencer SJ. Acylated Ghrelin Supports the Ovarian Transcriptome and Follicles in the Mouse: Implications for Fertility. Front Endocrinol (Lausanne) 2018; 9:815. [PMID: 30697193 PMCID: PMC6340924 DOI: 10.3389/fendo.2018.00815] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/27/2018] [Indexed: 12/16/2022] Open
Abstract
Ghrelin, an orexigenic gut-derived peptide, is gaining increasing attention due to its multifaceted role in a number of physiological functions, including reproduction. Ghrelin exists in circulation primarily as des-acylated and acylated ghrelin. Des-acyl ghrelin, until recently considered to be an inactive form of ghrelin, is now known to have independent physiological functionality. However, the relative contribution of acyl and des-acyl ghrelin to reproductive development and function is currently unknown. Here we used ghrelin-O-acyltransferase (GOAT) knockout (KO) mice that have no measurable levels of endogenous acyl ghrelin and chronically high levels of des-acyl ghrelin, to characterize how the developmental and life-long absence of acyl ghrelin affects ovarian development and reproductive capacity. We combined the assessment of markers of reproductive maturity and the capacity to breed with measures of ovarian morphometry, as well as with ovarian RNA sequencing analysis. Our data show that while GOAT KO mice retain the capacity to breed in young adulthood, there is a diminished number of ovarian follicles (per mm3) in the juvenile and adult ovaries, due to a significant reduction in the number of small follicles, particularly the primordial follicles. We also show pronounced specific changes in the ovarian transcriptome in the juvenile GOAT KO ovary, indicative of a potential for premature ovarian development. Collectively, these findings indicate that an absence of acyl ghrelin does not prevent reproductive success but that appropriate levels of acyl and des-acyl ghrelin may be necessary for optimal ovarian maturation.
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Affiliation(s)
- Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
- *Correspondence: Luba Sominsky
| | - Jeferson F. Goularte
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Zane B. Andrews
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Sarah J. Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
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Abstract
Growth hormone (GH) secretory patterns emerge following birth, and changes in patterning occur throughout life. These secretory patterns are coupled to growth, reproduction and metabolism. Comparing human and animal studies, this review will highlight ultradian patterning of GH release and the mechanisms that contribute to this. Discussions will focus on the emergence in variations in the number and frequency of GH secretory events, and the amounts of GH released (peak and basal). Animal studies have contributed significantly to our understanding of the processes that regulate GH release. However, translation of knowledge from animal models to benefit our understanding of human physiology is sometimes limited. To overcome these limitations, it is critical that we reconcile the cause and consequences of differences in GH release between humans and model organisms. In doing so, we can embrace emerging technologies that will rapidly advance our knowledge of endogenous process that control GH release.
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Affiliation(s)
- Frederik J Steyn
- Centre for Clinical Research, The University of Queensland, Queensland, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Australia.
| | - Shyuan T Ngo
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Australia; Queensland Brain Institute, The University of Queensland, Australia.
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15
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Oelkrug R, Herrmann B, Geissler C, Harder L, Koch C, Lehnert H, Oster H, Kirchner H, Mittag J. Dwarfism and insulin resistance in male offspring caused by α1-adrenergic antagonism during pregnancy. Mol Metab 2017; 6:1126-1136. [PMID: 29031714 PMCID: PMC5641602 DOI: 10.1016/j.molmet.2017.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Maternal and environmental factors control the epigenetic fetal programming of the embryo, thereby defining the susceptibility for metabolic or endocrine disorders in the offspring. Pharmacological interventions required as a consequence of gestational problems, e.g. hypertension, can potentially interfere with correct fetal programming. As epigenetic alterations are usually only revealed later in life and not detected in studies focusing on early perinatal outcomes, little is known about the long-term epigenetic effects of gestational drug treatments. We sought to test the consequences of maternal α1-adrenergic antagonism during pregnancy, which can occur e.g. during hypertension treatment, for the endocrine and metabolic phenotype of the offspring. METHODS We treated C57BL/6NCrl female mice with the α1-adrenergic antagonist prazosin during pregnancy and analyzed the male and female offspring for endocrine and metabolic abnormalities. RESULTS Our data revealed that maternal α1-adrenergic blockade caused dwarfism, elevated body temperature, and insulin resistance in male offspring, accompanied by reduced IGF-1 serum concentrations as the result of reduced hepatic growth hormone receptor (Ghr) expression. We subsequently identified increased CpG DNA methylation at the transcriptional start site of the alternative Ghr promotor caused by the maternal treatment, which showed a strong inverse correlation to hepatic Ghr expression. CONCLUSIONS Our results demonstrate that maternal α1-adrenergic blockade can constitute an epigenetic cause for dwarfism and insulin resistance. The findings are of immediate clinical relevance as combined α/β-adrenergic blockers are first-line treatment of maternal hypertension.
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Affiliation(s)
- Rebecca Oelkrug
- Department of Molecular Endocrinology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Beate Herrmann
- Department of Molecular Endocrinology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Cathleen Geissler
- Department of Epigenetics & Metabolism/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Lisbeth Harder
- Department of Molecular Endocrinology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Christiane Koch
- Department of Chronophysiology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Hendrik Lehnert
- Department of Experimental Neuroendocrinology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Henrik Oster
- Department of Chronophysiology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Henriette Kirchner
- Department of Epigenetics & Metabolism/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Jens Mittag
- Department of Molecular Endocrinology/CBBM, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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16
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Gatford KL, Muhlhausler BS, Huang L, Sim PSL, Roberts CT, Velhuis JD, Chen C. Rising maternal circulating GH during murine pregnancy suggests placental regulation. Endocr Connect 2017; 6:260-266. [PMID: 28404685 PMCID: PMC5457489 DOI: 10.1530/ec-17-0032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 04/12/2017] [Indexed: 11/15/2022]
Abstract
Placenta-derived hormones including growth hormone (GH) in humans contribute to maternal adaptation to pregnancy, and intermittent maternal GH administration increases foetal growth in several species. Both patterns and abundance of circulating GH are important for its activity, but their changes during pregnancy have only been reported in humans and rats. The aim of the present study was to characterise circulating profiles and secretory characteristics of GH in non-pregnant female mice and throughout murine pregnancy. Circulating GH concentrations were measured in whole blood (2 μL) collected every 10 min for 6 h in non-pregnant diestrus female C57Bl/6J mice (n = 9), and pregnant females at day 8.5-9.5 (early pregnancy, n = 8), day 12.5-13.5 (mid-pregnancy, n = 7) and day 17.5 after mating (late pregnancy, n = 7). Kinetics and secretory patterns of GH secretion were determined by deconvolution analysis, while orderliness and regularity of serial GH concentrations were calculated by approximate entropy analysis. Circulating GH was pulsatile in all groups. Mean circulating GH and total and basal GH secretion rates increased markedly from early to mid-pregnancy, and then remained elevated. Pulse frequency and pulsatile GH secretion rate were similar between groups. The irregularity of GH pulses was higher in all pregnant groups than that in non-pregnant mice. Increased circulating GH in murine pregnancy is consistent with an important role for this hormone in maternal adaptation to pregnancy and placental development. The timing of increased basal secretion from mid-pregnancy, concurrent with the formation of the chorioallantoic placenta and initiation of maternal blood flow through it, suggests regulation of pituitary secretion by placenta-derived factors.
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Affiliation(s)
- Kathryn L Gatford
- Robinson Research InstituteThe University of Adelaide, Adelaide, Australia
- Adelaide Medical SchoolThe University of Adelaide, Adelaide, Australia
| | - Beverly S Muhlhausler
- FOOD plus Research CentreSchool of Agriculture, Food and Wine, The University of Adelaide, Adelaide, Australia
| | - Lili Huang
- School of Biomedical SciencesUniversity of Queensland, St Lucia, Brisbane, Australia
| | - Pamela Su-Lin Sim
- FOOD plus Research CentreSchool of Agriculture, Food and Wine, The University of Adelaide, Adelaide, Australia
| | - Claire T Roberts
- Robinson Research InstituteThe University of Adelaide, Adelaide, Australia
- Adelaide Medical SchoolThe University of Adelaide, Adelaide, Australia
| | - Johannes D Velhuis
- Endocrine Research UnitMayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota, USA
| | - Chen Chen
- School of Biomedical SciencesUniversity of Queensland, St Lucia, Brisbane, Australia
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17
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Hopkins AL, Nelson TAS, Guschina IA, Parsons LC, Lewis CL, Brown RC, Christian HC, Davies JS, Wells T. Unacylated ghrelin promotes adipogenesis in rodent bone marrow via ghrelin O-acyl transferase and GHS-R 1a activity: evidence for target cell-induced acylation. Sci Rep 2017; 7:45541. [PMID: 28361877 PMCID: PMC5374529 DOI: 10.1038/srep45541] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/21/2017] [Indexed: 11/09/2022] Open
Abstract
Despite being unable to activate the cognate ghrelin receptor (GHS-R), unacylated ghrelin (UAG) possesses a unique activity spectrum that includes promoting bone marrow adipogenesis. Since a receptor mediating this action has not been identified, we re-appraised the potential interaction of UAG with GHS-R in the regulation of bone marrow adiposity. Surprisingly, the adipogenic effects of intra-bone marrow (ibm)-infused acylated ghrelin (AG) and UAG were abolished in male GHS-R-null mice. Gas chromatography showed that isolated tibial marrow adipocytes contain the medium-chain fatty acids utilised in the acylation of UAG, including octanoic acid. Additionally, immunohistochemistry and immunogold electron microscopy revealed that tibial marrow adipocytes show prominent expression of the UAG-activating enzyme ghrelin O-acyl transferase (GOAT), which is located in the membranes of lipid trafficking vesicles and in the plasma membrane. Finally, the adipogenic effect of ibm-infused UAG was completely abolished in GOAT-KO mice. Thus, the adipogenic action of exogenous UAG in tibial marrow is dependent upon acylation by GOAT and activation of GHS-R. This suggests that UAG is subject to target cell-mediated activation – a novel mechanism for manipulating hormone activity.
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Affiliation(s)
- Anna L Hopkins
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Timothy A S Nelson
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Irina A Guschina
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Lydia C Parsons
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Charlotte L Lewis
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Richard C Brown
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Helen C Christian
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3QX, UK
| | - Jeffrey S Davies
- Institute of Life Science, School of Medicine, Swansea University, Swansea, SA2 8PP, UK
| | - Timothy Wells
- Neuroscience &Mental Health Research Institute, and School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
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18
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Labarthe A, Tolle V. [Ghrelin: a gastric hormone at the crossroad between growth and appetite regulation]. Biol Aujourdhui 2017; 210:237-257. [PMID: 28327282 DOI: 10.1051/jbio/2016027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Indexed: 06/06/2023]
Abstract
Ghrelin is a 28 amino acid peptide hormone synthesized within the gastrointestinal tract. Initially identified as the endogenous ligand of the GHS-R1a (Growth Hormone Secretagogue Receptor 1a), ghrelin is a powerful stimulator of growth hormone (GH) secretion. At the crossroad between nutrition, growth and long-term energy metabolism, ghrelin also plays a unique role as the first identified gastric hormone increasing appetite and adiposity. However, the role of the ghrelin/GHS-R system in the physiology of growth, feeding behaviour and energy homeostasis needs to be better understood. Utilization of pharmacological tools and complementary animal models with deficiency in preproghrelin, ghrelin-O-acyl-transferase (GOAT - the enzyme that acylates ghrelin -) or GHS-R in situations of chronic undernutrition or high fat diet gives a more precise overview of the role of ghrelin in the pathophysiology of eating and metabolic disorders.
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Hassouna R, Labarthe A, Tolle V. Hypothalamic regulation of body growth and appetite by ghrelin-derived peptides during balanced nutrition or undernutrition. Mol Cell Endocrinol 2016; 438:42-51. [PMID: 27693419 DOI: 10.1016/j.mce.2016.09.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 12/16/2022]
Abstract
Among the gastrointestinal hormones that regulate food intake and energy homeostasis, ghrelin plays a unique role as the first one identified to increases appetite and stimulate GH secretion. This review highlights the latest mechanism by which ghrelin modulates body growth, appetite and energy metabolism by exploring pharmacological actions of the hormone and consequences of genetic or pharmacological blockade of the ghrelin/GHS-R (Growth Hormone Secretagogue Receptor) system on physiological responses in specific nutritional situations. Within the hypothalamus, novel mechanisms of action of this hormone involve its interaction with other ghrelin-derived peptides, such as desacyl ghrelin and obestatin, which are thought to act as functional ghrelin antagonists, and possible modulation of the GHS-R with other G-protein coupled receptors. During chronic undernutrition such as anorexia nervosa, variations of ghrelin-derived peptides may be an adaptative metabolic response to maintain normal glycemic control. Interestingly, some of ghrelin's metabolic actions are thought to be relayed through modulation of GH, an anabolic and hyperglycemic agent.
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Affiliation(s)
- Rim Hassouna
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France; Naomi Berrie Diabetes Center, Department of Pediatrics, Columbia University Medical Center, New York, NY, 10032, USA
| | - Alexandra Labarthe
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France
| | - Virginie Tolle
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France.
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