1
|
Wójcik M, Krawczyńska A, Zieba DA, Antushevich H, Herman AP. Influence of Leptin on the Secretion of Growth Hormone in Ewes under Different Photoperiodic Conditions. Int J Mol Sci 2023; 24:ijms24098036. [PMID: 37175738 PMCID: PMC10178528 DOI: 10.3390/ijms24098036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
Leptin is an adipokine with a pleiotropic impact on many physiological processes, including hypothalamic-pituitary-somatotropic (HPS) axis activity, which plays a key role in regulating mammalian metabolism. Leptin insensitivity/resistance is a pathological condition in humans, but in seasonal animals, it is a physiological adaptation. Therefore, these animals represent a promising model for studying this phenomenon. This study aimed to determine the influence of leptin on the activity of the HPS axis. Two in vivo experiments performed during short- and long-day photoperiods were conducted on 12 ewes per experiment, and the ewes were divided randomly into 2 groups. The arcuate nucleus, paraventricular nucleus, anterior pituitary (AP) tissues, and blood were collected. The concentration of growth hormone (GH) was measured in the blood, and the relative expression of GHRH, SST, GHRHR, SSTR1, SSTR2, SSTR3, SSTR5, LEPR, and GH was measured in the collected brain structures. The study showed that the photoperiod, and therefore leptin sensitivity, plays an important role in regulating HPS axis activity in the seasonal ewe. However, leptin influences the release of GH in a season-dependent manner, and its effect seems to be targeted at the posttranscriptional stages of GH secretion.
Collapse
Affiliation(s)
- Maciej Wójcik
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland
| | - Agata Krawczyńska
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland
| | - Dorota Anna Zieba
- Department of Nutrition and Animal Biotechnology, and Fisheries, Faculty of Animal Sciences, University of Agriculture in Krakow, 31-120 Krakow, Poland
| | - Hanna Antushevich
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland
| | - Andrzej Przemysław Herman
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland
| |
Collapse
|
2
|
Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases. Biol Sex Differ 2023; 14:4. [PMID: 36750874 PMCID: PMC9903633 DOI: 10.1186/s13293-023-00490-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
Metabolic diseases, such as obesity, metabolic syndrome (MetS) and type 2 diabetes (T2D), are now a widespread pandemic in the developed world. These pathologies show sex differences in their development and prevalence, and sex steroids, mainly estrogen and testosterone, are thought to play a prominent role in this sexual dimorphism. The influence of sex hormones on these pathologies is not only reflected in differences between men and women, but also between women themselves, depending on the hormonal changes associated with the menopause. The observed sex differences in gut microbiota composition have led to multiple studies highlighting the interaction between steroid hormones and the gut microbiota and its influence on metabolic diseases, ultimately pointing to a new therapy for these diseases based on the manipulation of the gut microbiota. This review aims to shed light on the role of sexual hormones in sex differences in the development and prevalence of metabolic diseases, focusing on obesity, MetS and T2D. We focus also the interaction between sex hormones and the gut microbiota, and in particular the role of microbiota in aspects such as gut barrier integrity, inflammatory status, and the gut-brain axis, given the relevance of these factors in the development of metabolic diseases.
Collapse
|
3
|
Jouffe C, Weger BD, Martin E, Atger F, Weger M, Gobet C, Ramnath D, Charpagne A, Morin-Rivron D, Powell EE, Sweet MJ, Masoodi M, Uhlenhaut NH, Gachon F. Disruption of the circadian clock component BMAL1 elicits an endocrine adaption impacting on insulin sensitivity and liver disease. Proc Natl Acad Sci U S A 2022; 119:e2200083119. [PMID: 35238641 PMCID: PMC8916004 DOI: 10.1073/pnas.2200083119] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023] Open
Abstract
SignificanceWhile increasing evidence associates the disruption of circadian rhythms with pathologic conditions, including obesity, type 2 diabetes, and nonalcoholic fatty liver diseases (NAFLD), the involved mechanisms are still poorly described. Here, we show that, in both humans and mice, the pathogenesis of NAFLD is associated with the disruption of the circadian clock combined with perturbations of the growth hormone and sex hormone pathways. However, while this condition protects mice from the development of fibrosis and insulin resistance, it correlates with increased fibrosis in humans. This suggests that the perturbation of the circadian clock and its associated disruption of the growth hormone and sex hormone pathways are critical for the pathogenesis of metabolic and liver diseases.
Collapse
Affiliation(s)
- Céline Jouffe
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- Department of Pharmacology and Toxicology, University of Lausanne, CH-1011 Lausanne, Switzerland
- Helmholtz Diabetes Center, Helmholtz Zentrum München, DE-85764 Neuherberg, Germany
| | - Benjamin D. Weger
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Eva Martin
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
| | - Florian Atger
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- Department of Pharmacology and Toxicology, University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Meltem Weger
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Cédric Gobet
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Divya Ramnath
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Aline Charpagne
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
| | | | - Elizabeth E. Powell
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane QLD 4102, Australia
- Faculty of Medicine, Center for Liver Disease Research, Translational Research Institute, The University of Queensland, Brisbane QLD 4102, Australia
| | - Matthew J. Sweet
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia QLD 4072, Australia
| | - Mojgan Masoodi
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- Institute of Clinical Chemistry, Bern University Hospital, Bern 3010, Switzerland
| | - N. Henriette Uhlenhaut
- Helmholtz Diabetes Center, Helmholtz Zentrum München, DE-85764 Neuherberg, Germany
- Metabolic Programming, Technical University of Munich School of Life Sciences, DE-85354 Freising, Germany
| | - Frédéric Gachon
- Nestlé Research, Société des Produits Nestlé, CH-1015 Lausanne, Switzerland
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia QLD 4072, Australia
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
4
|
Sato B, Kanai S, Sakaguchi D, Yajima K, Matsumoto Y, Morohoshi K, Kagaya S, Izumo N, Ichinose M, Kang W, Miyado M, Miyado K, Kawano N. Suppressive Role of Lactoferrin in Overweight-Related Female Fertility Problems. Nutrients 2022; 14:nu14050938. [PMID: 35267914 PMCID: PMC8912823 DOI: 10.3390/nu14050938] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 11/16/2022] Open
Abstract
The secretory glycoprotein lactoferrin (LF) is suggested to ameliorate overweight regardless of non-genetic or genetic mechanisms. Although maternal overweight represents a key predictor of offspring growth, the efficacy of LF on fertility problems in overweight and obese mothers remains unknown. To address this issue, we examined the effect of LF ingestion by analyzing overweight mice (Institute of Cancer Research (ICR) mice with high-fat diets; HF mice) and obese mice (leptin-deficient mice with type II diabetes; ob/ob mice). Plasma insulin, leptin, glucose, and cholesterol levels were measured, and thermal imaging and histological analysis were employed. The litter size of HF females was reduced due to miscarriage, which was reversed by LF ingestion. In addition, LF ingestion suppressed overweight prevalence in their offspring. The component analysis of the maternal blood demonstrated that glucose concentration in both HF females and their offspring was normalized by LF ingestion, which further standardized the concentration of insulin, but not leptin. LF ingestion was unable to reverse female infertility in ob/ob mice, although their obesity and uterine function were partially improved. Our results indicate that LF upregulates female fertility by reinforcing ovarian and uterine functions in females that are overweight due to caloric surplus.
Collapse
Affiliation(s)
- Ban Sato
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Seiya Kanai
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Daiki Sakaguchi
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Kodai Yajima
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Yu Matsumoto
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Kazunori Morohoshi
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
| | - Shinji Kagaya
- NRL Pharma, Inc., East Block 203, Kanagawa Science Park, 3-2-1 Sakado, Takatsu-Ku, Kawasaki 213-0012, Japan;
| | - Nobuo Izumo
- Laboratory of Pharmacotherapy, Yokohama University of Pharmacy, 601 Matano, Totsuka, Yokohama 245-0066, Japan;
| | - Minoru Ichinose
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan; (M.I.); (W.K.)
| | - Woojin Kang
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan; (M.I.); (W.K.)
| | - Mami Miyado
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan;
| | - Kenji Miyado
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan; (M.I.); (W.K.)
- Correspondence: (K.M.); (N.K.); Tel.: +81-3-5494-7047 (K.M.); +81-44-934-7038 (N.K.)
| | - Natsuko Kawano
- Laboratory of Regulatory Biology, Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan; (B.S.); (S.K.); (D.S.); (K.Y.); (Y.M.); (K.M.)
- Correspondence: (K.M.); (N.K.); Tel.: +81-3-5494-7047 (K.M.); +81-44-934-7038 (N.K.)
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Cano G, Hernan SL, Sved AF. Centrally Projecting Edinger-Westphal Nucleus in the Control of Sympathetic Outflow and Energy Homeostasis. Brain Sci 2021; 11:1005. [PMID: 34439626 PMCID: PMC8392615 DOI: 10.3390/brainsci11081005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/13/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022] Open
Abstract
The centrally projecting Edinger-Westphal nucleus (EWcp) is a midbrain neuronal group, adjacent but segregated from the preganglionic Edinger-Westphal nucleus that projects to the ciliary ganglion. The EWcp plays a crucial role in stress responses and in maintaining energy homeostasis under conditions that require an adjustment of energy expenditure, by virtue of modulating heart rate and blood pressure, thermogenesis, food intake, and fat and glucose metabolism. This modulation is ultimately mediated by changes in the sympathetic outflow to several effector organs, including the adrenal gland, heart, kidneys, brown and white adipose tissues and pancreas, in response to environmental conditions and the animal's energy state, providing for appropriate energy utilization. Classic neuroanatomical studies have shown that the EWcp receives inputs from forebrain regions involved in these functions and projects to presympathetic neuronal populations in the brainstem. Transneuronal tracing with pseudorabies virus has demonstrated that the EWcp is connected polysynaptically with central circuits that provide sympathetic innervation to all these effector organs that are critical for stress responses and energy homeostasis. We propose that EWcp integrates multimodal signals (stress, thermal, metabolic, endocrine, etc.) and modulates the sympathetic output simultaneously to multiple effector organs to maintain energy homeostasis under different conditions that require adjustments of energy demands.
Collapse
Affiliation(s)
- Georgina Cano
- Department of Neuroscience, A210 Langley Hall, University of Pittsburgh, Pittsburgh, PA 15260, USA; (S.L.H.); (A.F.S.)
| | | | | |
Collapse
|
7
|
Peng J, Yin L, Wang X. Central and peripheral leptin resistance in obesity and improvements of exercise. Horm Behav 2021; 133:105006. [PMID: 34087669 DOI: 10.1016/j.yhbeh.2021.105006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/25/2021] [Accepted: 05/22/2021] [Indexed: 01/16/2023]
Abstract
Obesity is strongly related to leptin resistance that refers to the state in which leptin fails to inhibit appetite, enhance energy expenditure and regulate glycolipid metabolism, whereas decreasing leptin resistance is important for obesity treatment. Leptin resistance that develops in brain and also directly in peripheral tissues is considered as central and peripheral leptin resistance, respectively. The mechanism of central leptin resistance is the focus of intensive studies but still not totally clarified. A challenged notion about the effect of impaired leptin BBB transport emerges and a concept of "selective leptin resistance" is discussed. Peripheral leptin resistance, especially leptin resistance in muscle, has drawn more attention recently, while its mechanism remains unclear. Exercise is an effective way to reduce obesity, which is at least in part due to the alleviation of leptin resistance. Here, we summarized newly discovered data about the associated factors of central leptin resistance and peripheral leptin resistance, and the actions of exercise on leptin resistance, which is important to understand the mechanisms of leptin resistance and exercise-induced alleviation of leptin resistance, and to facilitate clinical application of leptin in obesity treatment.
Collapse
Affiliation(s)
- Jin Peng
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Lijun Yin
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China
| | - Xiaohui Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China.
| |
Collapse
|
8
|
Allensworth-James ML, Odle AK, Lim J, LaGasse AN, Miles TK, Hardy LL, Haney AC, MacNicol MC, MacNicol AM, Childs GV. Metabolic signalling to somatotrophs: Transcriptional and post-transcriptional mediators. J Neuroendocrinol 2020; 32:e12883. [PMID: 32657474 PMCID: PMC8086172 DOI: 10.1111/jne.12883] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/17/2020] [Accepted: 06/10/2020] [Indexed: 12/19/2022]
Abstract
In normal individuals, pituitary somatotrophs optimise body composition by responding to metabolic signals from leptin. To identify mechanisms behind the regulation of somatotrophs by leptin, we used Cre-LoxP technology to delete leptin receptors (LEPR) selectively in somatotrophs and developed populations purified by fluorescence-activated cell sorting (FACS) that contained 99% somatotrophs. FACS-purified, Lepr-null somatotrophs showed reduced levels of growth hormone (GH), growth hormone-releasing hormone receptor (GHRHR), and Pou1f1 proteins and Gh (females) and Ghrhr (both sexes) mRNAs. Pure somatotrophs also expressed thyroid-stimulating hormone (TSH) and prolactin (PRL), both of which were reduced in pure somatotrophs lacking LEPR. This introduced five gene products that were targets of leptin. In the present study, we tested the hypothesis that leptin is both a transcriptional and a post-transcriptional regulator of these gene products. Our tests showed that Pou1f1 and/or the Janus kinase/signal transducer and activator of transcription 3 transcriptional regulatory pathways are implicated in the leptin regulation of Gh or Ghrhr mRNAs. We then focused on potential actions by candidate microRNAs (miRNAs) with consensus binding sites on the 3' UTR of Gh or Ghrhr mRNAs. Somatotroph Lepr-null deletion mutants expressed elevated levels of miRNAs including miR1197-3p (in females), miR103-3p and miR590-3p (both sexes), which bind Gh mRNA, or miRNA-325-3p (elevated in both sexes), which binds Ghrhr mRNA. This elevation indicates repression of translation in the absence of LEPR. In addition, after detecting binding sites for Musashi on Tshb and Prl 3' UTR, we determined that Musashi1 repressed translation of both mRNAs in in vitro fluc assays and that Prl mRNA was enriched in Musashi immunoprecipitation assays. Finally, we tested ghrelin actions to determine whether its nitric oxide-mediated signalling pathways would restore somatotroph functions in deletion mutants. Ghrelin did not restore either GHRH binding or GH secretion in vitro. These studies show an unexpectedly broad role for leptin with respect to maintaining somatotroph functions, including the regulation of PRL and TSH in subsets of somatotrophs that may be progenitor cells.
Collapse
Affiliation(s)
- Melody L Allensworth-James
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Angela K Odle
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Juchan Lim
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Alex N LaGasse
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Tiffany K Miles
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Linda L Hardy
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Anessa C Haney
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Melanie C MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Angus M MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Gwen V Childs
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| |
Collapse
|
9
|
Vélez EJ, Unniappan S. A Comparative Update on the Neuroendocrine Regulation of Growth Hormone in Vertebrates. Front Endocrinol (Lausanne) 2020; 11:614981. [PMID: 33708174 PMCID: PMC7940767 DOI: 10.3389/fendo.2020.614981] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/31/2020] [Indexed: 12/22/2022] Open
Abstract
Growth hormone (GH), mainly produced from the pituitary somatotrophs is a key endocrine regulator of somatic growth. GH, a pleiotropic hormone, is also involved in regulating vital processes, including nutrition, reproduction, physical activity, neuroprotection, immunity, and osmotic pressure in vertebrates. The dysregulation of the pituitary GH and hepatic insulin-like growth factors (IGFs) affects many cellular processes associated with growth promotion, including protein synthesis, cell proliferation and metabolism, leading to growth disorders. The metabolic and growth effects of GH have interesting applications in different fields, including the livestock industry and aquaculture. The latest discoveries on new regulators of pituitary GH synthesis and secretion deserve our attention. These novel regulators include the stimulators adropin, klotho, and the fibroblast growth factors, as well as the inhibitors, nucleobindin-encoded peptides (nesfatin-1 and nesfatin-1-like peptide) and irisin. This review aims for a comparative analysis of our current understanding of the endocrine regulation of GH from the pituitary of vertebrates. In addition, we will consider useful pharmacological molecules (i.e. stimulators and inhibitors of the GH signaling pathways) that are important in studying GH and somatotroph biology. The main goal of this review is to provide an overview and update on GH regulators in 2020. While an extensive review of each of the GH regulators and an in-depth analysis of specifics are beyond its scope, we have compiled information on the main endogenous and pharmacological regulators to facilitate an easy access. Overall, this review aims to serve as a resource on GH endocrinology for a beginner to intermediate level knowledge seeker on this topic.
Collapse
|
10
|
Sarmento-Cabral A, L-López F, Luque RM. Adipokines and Their Receptors Are Widely Expressed and Distinctly Regulated by the Metabolic Environment in the Prostate of Male Mice: Direct Role Under Normal and Tumoral Conditions. Endocrinology 2017; 158:3540-3552. [PMID: 28938461 DOI: 10.1210/en.2017-00370] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/03/2017] [Indexed: 12/15/2022]
Abstract
Adipose tissue-derived adipokines (i.e., leptin/adiponectin/resistin) play important roles in the regulation of several pathophysiologic processes through the activation of specific receptors. However, although adipokines and their receptors are widely distributed in many tissues and exhibit a clear modulation according to particular metabolic conditions (e.g., obesity and/or fasting), their expression, regulation, and putative action on normal prostate glands (PGs; a hormone-dependent organ tightly regulated by the endocrine-metabolic milieu) are still to be defined. Different in vivo/in vitro models were used to comprehensively characterize the expression pattern and actions of different adipokine systems (i.e., leptin/adiponectin/resistin/receptors) in mouse PGs. Adiponectin, resistin, and adiponectin receptors (1 and 2) and leptin receptor are coexpressed at different levels in PG cells, wherein they are finely regulated under fasting and/or obesity conditions. Furthermore, treatment with different adipokines exerted both homologous and heterologous regulation of specific adipokines/receptor-synthesis and altered the expression of key proliferation and oncogenesis markers (i.e., Ki67/c-Myc/p53) in mouse PG cell cultures, wherein some of these actions might be elicited through extracellular signal-regulated kinase (ERK) activation. Moreover, treatment with leptin, adiponectin, and resistin differentially regulated key functional parameters [i.e., proliferation and migration capacity and/or prostate-specific antigen (PSA) secretion] in human normal and/or tumoral prostate cell lines. Altogether, our data show that various adipokine and receptor systems are differentially expressed in normal PG cells; that their expression is under a complex ligand- and receptor-selective regulation under extreme metabolic conditions; and that they mediate distinctive and common direct actions in normal and tumoral PG cells (i.e., homologous and heterologous regulation of ligand and receptor synthesis, ERK signaling activation, modulation of proliferation markers, proliferation and migration capacity, and PSA secretion), suggesting a relevant role of these systems in the regulation of PG pathophysiology.
Collapse
Affiliation(s)
- André Sarmento-Cabral
- Maimonides Institute of Biomedical Research of Cordoba, 14004 Cordoba, Spain
- Reina Sofía University Hospital, 14004 Cordoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain
- CIBER Physiopathology of Obesity and Nutrition, 14004 Cordoba, Spain
- Internacional Campus of Excellence on Agrifood, 14004 Cordoba, Spain
| | - Fernando L-López
- Maimonides Institute of Biomedical Research of Cordoba, 14004 Cordoba, Spain
- Reina Sofía University Hospital, 14004 Cordoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain
- CIBER Physiopathology of Obesity and Nutrition, 14004 Cordoba, Spain
- Internacional Campus of Excellence on Agrifood, 14004 Cordoba, Spain
| | - Raúl M Luque
- Maimonides Institute of Biomedical Research of Cordoba, 14004 Cordoba, Spain
- Reina Sofía University Hospital, 14004 Cordoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain
- CIBER Physiopathology of Obesity and Nutrition, 14004 Cordoba, Spain
- Internacional Campus of Excellence on Agrifood, 14004 Cordoba, Spain
| |
Collapse
|
11
|
Bello AR, Puertas‐Avendaño RA, González‐Gómez MJ, González‐Gómez M, Laborda J, Damas C, Ruiz‐Hidalgo M, Diaz C. Delta-like protein 1 in the pituitary-adipose axis in the adult male mouse. J Neuroendocrinol 2017; 29:e12507. [PMID: 28718206 PMCID: PMC6084355 DOI: 10.1111/jne.12507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 06/21/2017] [Accepted: 07/12/2017] [Indexed: 12/18/2022]
Abstract
With the aim of studying delta-like protein 1 (DLK1) with respect to the relationship between adipocyte leptin and adenohypophyseal hormones, we carried out an immunohistochemical study analysing the presence of receptors for these hormones in the pituitary and adipose cells of male wild-type (WT) mice (Dlk1+/+ ) compared to knockout (KO) mice (Dlk1-/- ). The mRNA expression of these molecules was also determined using the reverse transcriptase-polymerase chain reaction. The results obtained showed that, in WT adipose cells, all of the adenohypophyseal hormone receptors were present, with a higher mRNA expression for growth hormone (GH) receptor and thyroid-stimulating hormone (TSH) receptor. Of the total cells in the anterior pituitary lobe, 17.09±0.9% were leptin receptor (LEPR) immunoreactive (-IR), mainly in GH-IR and prolactin (PRL)-IR cells (41.5±3.8%; 13.5±1.7%, respectively). In Dlk1-/- mice, adipocyte cells showed a significant increase in the TSH receptor mRNA expression level. Moreover, the percentage of LEPR-IR GH cells showed a statistically significant increase compared to controls, from 41.5±3.8% to 53.1±4.0%. By contrast, only 3.0±0.6% of LEP-IR anterior pituitary cells were detected in Dlk1 KO mice, as opposed to 6.8±1.1% observed in WT mice. The results suggest that relationships exist between adipocytes and pituitary GH, PRL and TSH cells, in addition to an influence with respect to the synthesis and release of pituitary leptin, particularly in PRL cells.
Collapse
Affiliation(s)
- A. R. Bello
- Cell Biology SectionSchool of Sciences/Institute for Tropical Diseases and Public HealthUniversity of La LagunaTenerifeSpain
| | - R. A. Puertas‐Avendaño
- Cell Biology SectionSchool of Sciences/Institute for Tropical Diseases and Public HealthUniversity of La LagunaTenerifeSpain
| | - M. J. González‐Gómez
- Department of Inorganic and Organic Chemistry and BiochemistrySchool of Medicine/Regional Centre for Biomedical ResearchBiomedicine Unit Spanish National Research Council/University of Castilla‐La ManchaAlbaceteSpain
| | - M. González‐Gómez
- Department of Basic Medical SciencesSchool of MedicineUniversity of La LagunaTenerifeSpain
| | - J. Laborda
- Department of Inorganic and Organic Chemistry and BiochemistrySchool of Medicine/Regional Centre for Biomedical ResearchBiomedicine Unit Spanish National Research Council/University of Castilla‐La ManchaAlbaceteSpain
| | - C. Damas
- Department of PsychobiologySchool of PsychologyUniversity of La LagunaTenerifeSpain
| | - M. Ruiz‐Hidalgo
- Department of Inorganic and Organic Chemistry and BiochemistrySchool of Medicine/Regional Centre for Biomedical ResearchBiomedicine Unit Spanish National Research Council/University of Castilla‐La ManchaAlbaceteSpain
| | - C. Diaz
- Department of Medical SciencesSchool of Medicine/Institute for Research in Neurological DisabilitiesUniversity of Castilla‐La ManchaAlbaceteSpain
| |
Collapse
|
12
|
Sarmento-Cabral A, Peinado JR, Halliday LC, Malagon MM, Castaño JP, Kineman RD, Luque RM. Adipokines (Leptin, Adiponectin, Resistin) Differentially Regulate All Hormonal Cell Types in Primary Anterior Pituitary Cell Cultures from Two Primate Species. Sci Rep 2017; 7:43537. [PMID: 28349931 PMCID: PMC5640086 DOI: 10.1038/srep43537] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/25/2017] [Indexed: 12/27/2022] Open
Abstract
Adipose-tissue (AT) is an endocrine organ that dynamically secretes multiple hormones, the adipokines, which regulate key physiological processes. However, adipokines and their receptors are also expressed and regulated in other tissues, including the pituitary, suggesting that locally- and AT-produced adipokines might comprise a regulatory circuit that relevantly modulate pituitary cell-function. Here, we used primary pituitary cell-cultures from two normal nonhuman-primate species [Papio-anubis/Macaca-fascicularis] to determine the impact of different adipokines on the functioning of all anterior-pituitary cell-types. Leptin and resistin stimulated GH-release, a response that was blocked by somatostatin. Conversely, adiponectin decreased GH-release, and inhibited GHRH-, but not ghrelin-stimulated GH-secretion. Furthermore: 1) Leptin stimulated PRL/ACTH/FSH- but not LH/TSH-release; 2) adiponectin stimulated PRL-, inhibited ACTH- and did not alter LH/FSH/TSH-release; and 3) resistin increased ACTH-release and did not alter PRL/LH/FSH/TSH-secretion. These effects were mediated through the activation of common (AC/PKA) and distinct (PLC/PKC, intra-/extra-cellular calcium, PI3K/MAPK/mTOR) signaling-pathways, and by the gene-expression regulation of key receptors/transcriptional-factors involved in the functioning of these pituitary cell-types (e.g. GHRH/ghrelin/somatostatin/insulin/IGF-I-receptors/Pit-1). Finally, we found that primate pituitaries expressed leptin/adiponectin/resistin. Altogether, these and previous data suggest that local-production of adipokines/receptors, in conjunction with circulating adipokine-levels, might comprise a relevant regulatory circuit that contribute to the fine-regulation of pituitary functions.
Collapse
Affiliation(s)
- André Sarmento-Cabral
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Juan R Peinado
- Department of Medical Sciences, Faculty of Medicine of Ciudad Real, University of Castilla-La Mancha, Spain
| | - Lisa C Halliday
- Biologic Resources Laboratory, University of Illinois at Chicago, Chicago, Illinois, USA
| | - María M Malagon
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
| | - Justo P Castaño
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| | - Rhonda D Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Medicine, Section of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Raúl M Luque
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), Córdoba, Spain.,Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain.,Hospital Universitario Reina Sofía (HURS), Córdoba, Spain.,CIBER de la Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain.,Campus de Excelencia Internacional Agroalimentario (ceiA3), Córdoba, Spain
| |
Collapse
|
13
|
Iwaniec UT, Turner RT. Influence of body weight on bone mass, architecture and turnover. J Endocrinol 2016; 230:R115-30. [PMID: 27352896 PMCID: PMC4980254 DOI: 10.1530/joe-16-0089] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 12/11/2022]
Abstract
Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating the development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. Although the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size.
Collapse
Affiliation(s)
- Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| | - Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USA Center for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USA
| |
Collapse
|
14
|
François M, Barde S, Legrand R, Lucas N, Azhar S, el Dhaybi M, Guerin C, Hökfelt T, Déchelotte P, Coëffier M, Fetissov SO. High-fat diet increases ghrelin-expressing cells in stomach, contributing to obesity. Nutrition 2016; 32:709-15. [DOI: 10.1016/j.nut.2015.12.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 12/11/2015] [Accepted: 12/14/2015] [Indexed: 12/31/2022]
|
15
|
Steyn FJ, Tolle V, Chen C, Epelbaum J. Neuroendocrine Regulation of Growth Hormone Secretion. Compr Physiol 2016; 6:687-735. [PMID: 27065166 DOI: 10.1002/cphy.c150002] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This article reviews the main findings that emerged in the intervening years since the previous volume on hormonal control of growth in the section on the endocrine system of the Handbook of Physiology concerning the intra- and extrahypothalamic neuronal networks connecting growth hormone releasing hormone (GHRH) and somatostatin hypophysiotropic neurons and the integration between regulators of food intake/metabolism and GH release. Among these findings, the discovery of ghrelin still raises many unanswered questions. One important event was the application of deconvolution analysis to the pulsatile patterns of GH secretion in different mammalian species, including Man, according to gender, hormonal environment and ageing. Concerning this last phenomenon, a great body of evidence now supports the role of an attenuation of the GHRH/GH/Insulin-like growth factor-1 (IGF-1) axis in the control of mammalian aging.
Collapse
Affiliation(s)
- Frederik J Steyn
- University of Queensland Centre for Clinical Research and the School of Biomedical Sciences, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Virginie Tolle
- Unité Mixte de Recherche en Santé 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| | - Jacques Epelbaum
- University of Queensland Centre for Clinical Research and the School of Biomedical Sciences, University of Queensland, St. Lucia, Brisbane, Queensland, Australia
| |
Collapse
|
16
|
Turner RT, Dube M, Branscum AJ, Wong CP, Olson DA, Zhong X, Kweh MF, Larkin IV, Wronski TJ, Rosen CJ, Kalra SP, Iwaniec UT. Hypothalamic leptin gene therapy reduces body weight without accelerating age-related bone loss. J Endocrinol 2015; 227:129-41. [PMID: 26487675 PMCID: PMC4917201 DOI: 10.1530/joe-15-0280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2015] [Indexed: 02/04/2023]
Abstract
Excessive weight gain in adults is associated with a variety of negative health outcomes. Unfortunately, dieting, exercise, and pharmacological interventions have had limited long-term success in weight control and can result in detrimental side effects, including accelerating age-related cancellous bone loss. We investigated the efficacy of using hypothalamic leptin gene therapy as an alternative method for reducing weight in skeletally-mature (9 months old) female rats and determined the impact of leptin-induced weight loss on bone mass, density, and microarchitecture, and serum biomarkers of bone turnover (CTx and osteocalcin). Rats were implanted with cannulae in the 3rd ventricle of the hypothalamus and injected with either recombinant adeno-associated virus encoding the gene for rat leptin (rAAV-Leptin, n=7) or a control vector encoding green fluorescent protein (rAAV-GFP, n=10) and sacrificed 18 weeks later. A baseline control group (n=7) was sacrificed at vector administration. rAAV-Leptin-treated rats lost weight (-4±2%) while rAAV-GFP-treated rats gained weight (14±2%) during the study. At study termination, rAAV-Leptin-treated rats weighed 17% less than rAAV-GFP-treated rats and had lower abdominal white adipose tissue weight (-80%), serum leptin (-77%), and serum IGF1 (-34%). Cancellous bone volume fraction in distal femur metaphysis and epiphysis, and in lumbar vertebra tended to be lower (P<0.1) in rAAV-GFP-treated rats (13.5 months old) compared to baseline control rats (9 months old). Significant differences in cancellous bone or biomarkers of bone turnover were not detected between rAAV-Leptin and rAAV-GFP rats. In summary, rAAV-Leptin-treated rats maintained a lower body weight compared to baseline and rAAV-GFP-treated rats with minimal effects on bone mass, density, microarchitecture, or biochemical markers of bone turnover.
Collapse
Affiliation(s)
- Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Michael Dube
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Adam J Branscum
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Carmen P Wong
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Dawn A Olson
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Xiaoying Zhong
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Mercedes F Kweh
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Iske V Larkin
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Thomas J Wronski
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Clifford J Rosen
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Satya P Kalra
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA Skeletal Biology LaboratorySchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USACenter for Healthy Aging ResearchOregon State University, Corvallis, Oregon, USADepartment of NeuroscienceMcKnight Brain Institute, University of Florida, Gainesville, Florida, USABiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon, USADepartment of Physiological SciencesUniversity of Florida, Gainesville, Florida, USADepartment of Large Animal Clinical SciencesUniversity of Florida, Gainesville, Florida, USAMaine Medical Center Research InstituteScarborough, Maine, USA
| |
Collapse
|
17
|
Murase D, Namekawa S, Ohkubo T. Leptin activates chicken growth hormone promoter without chicken STAT3 in vitro. Comp Biochem Physiol B Biochem Mol Biol 2015; 191:46-52. [PMID: 26403688 DOI: 10.1016/j.cbpb.2015.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/08/2015] [Accepted: 09/10/2015] [Indexed: 12/31/2022]
Abstract
Leptin is an adipocyte-derived hormone that not only regulates food intake and energy homeostasis but also induces growth hormone (GH) mRNA expression and release, thereby controlling growth and metabolism in mammals. The molecular mechanism of leptin-induced regulation of GH gene transcription is unclear. The current study investigated the effects of leptin on the chicken GH (cGH) promoter and the molecular mechanism underlying leptin-induced cGH gene expression in vitro. Leptin activated the cGH promoter in the presence of chPit-1α in CHO cells stably expressing the chicken leptin receptor. Promoter activation did not require STAT-binding elements in the cGH promoter or STAT3 activity. However, JAK2 activation was required for leptin-dependent activity. JAK2-dependent pathways include p42/44 MAPK and PI3K, and inhibition of these pathways partially blocked leptin-induced cGH gene transcription. Although CK2 directly activates JAK2, a CK2 inhibitor blocked leptin-dependent activation of the cGH gene without affecting JAK2 phosphorylation. The CK2 inhibitor suppressed Erk1/2 and Akt phosphorylation. Additional data implicate Src family kinases in leptin-dependent cGH gene activation. These results suggest that leptin activates the cGH gene in the presence of chPit-1α via several leptin-activated kinases. Although further study is required, we suggest that the leptin-induced JAK2/p42/44 MAPK and JAK2/PI3K cascades are activated by Src-meditated CK2, leading to CBP phosphorylation and interaction with chPit-1α, resulting in transactivation of the cGH promoter.
Collapse
Affiliation(s)
- Daisuke Murase
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-81-1 Harumi, Fuchu, Tokyo 790-8566, Japan
| | - Shoko Namekawa
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan
| | - Takeshi Ohkubo
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-81-1 Harumi, Fuchu, Tokyo 790-8566, Japan.
| |
Collapse
|
18
|
Allensworth-James ML, Odle A, Haney A, Childs G. Sex Differences in Somatotrope Dependency on Leptin Receptors in Young Mice: Ablation of LEPR Causes Severe Growth Hormone Deficiency and Abdominal Obesity in Males. Endocrinology 2015; 156:3253-64. [PMID: 26168341 PMCID: PMC4541611 DOI: 10.1210/en.2015-1198] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Leptin receptor (LEPR) signaling controls appetite and energy expenditure. Somatotrope-specific deletion of the LEPRb signaling isoform causes GH deficiency and obesity. The present study selectively ablated Lepr exon 1 in somatotropes, which removes the signal peptide, causing the loss of all isoforms of LEPR. Excision of Lepr exon 1 was restricted to the pituitary, and mutant somatotropes failed to respond to leptin. Young (2-3 mo) males showed a severe 84% reduction in serum GH levels and more than 60% reduction in immunolabeled GH cells compared with 41%-42% reductions in GH and GH cells in mutant females. Mutant males (35 d) and females (45 d) weighed less than controls and males had lower lean body mass. Image analysis of adipose tissue by magnetic resonance imaging showed that young males had a 2-fold increase in abdominal fat mass and increased adipose tissue density. Young females had only an overall increase in adipose tissue. Both males and females showed lower energy expenditure and higher respiratory quotient, indicating preferential carbohydrate burning. Young mutant males slept less and were more restless during the dark phase, whereas the opposite was true of females. The effects of a Cre-bearing sire on his non-Cre-recombinase bearing progeny are seen by increased respiratory quotient and reduced litter sizes. These studies elucidate clear sex differences in the extent to which somatotropes are dependent on all isoforms of LEPR. These results, which were not seen with the ablation of Lepr exon 17, highlight the severe consequences of ablation of LEPR in male somatotropes.
Collapse
Affiliation(s)
- Melody L Allensworth-James
- Department of Neurobiology and Developmental Sciences, College of Medicine University of Arkansas for Medical Sciences, Little Rock, Arkansas 72212
| | - Angela Odle
- Department of Neurobiology and Developmental Sciences, College of Medicine University of Arkansas for Medical Sciences, Little Rock, Arkansas 72212
| | - Anessa Haney
- Department of Neurobiology and Developmental Sciences, College of Medicine University of Arkansas for Medical Sciences, Little Rock, Arkansas 72212
| | - Gwen Childs
- Department of Neurobiology and Developmental Sciences, College of Medicine University of Arkansas for Medical Sciences, Little Rock, Arkansas 72212
| |
Collapse
|
19
|
Abstract
Muscle- and liver-derived IGF-1 play important roles in muscle anabolism throughout growth and aging. Yet, prolonged food restriction is thought to increase longevity in part by lowering levels of IGF-1, which in turn reduces the risk for developing various cancers. The dietary factors that modulate IGF-1 levels are, however, poorly understood. We tested the hypothesis that the adipokine leptin, which is elevated with food intake and suppressed during fasting, is a key mediator of IGF-1 levels with aging and food restriction. First, leptin levels in peripheral tissues were measured in young mice fed ad libitum, aged mice fed ad libitum, and aged calorie-restricted (CR) mice. A group of aged CR mice were also treated with recombinant leptin for 10 days. Later, aged mice fed ad libitum were treated with saline (VEH) or with a novel leptin receptor antagonist peptide (Allo-aca) and tissue-specific levels of IGF-1 were determined. On one hand, recombinant leptin induced a three-fold increase in liver-derived IGF-1 and a two-fold increase in muscle-derived IGF-1 in aged, CR mice. Leptin also significantly increased serum growth hormone levels in the aged, CR mice. On the other, the leptin receptor antagonist Allo-aca did not alter body weight or muscle mass in treated mice compared to VEH mice. Allo-aca did, however, produce a significant (20%) decline in liver-derived IGF-1 as well as an even more pronounced (>50%) decrease in muscle-derived IGF-1 compared to VEH-treated mice. The reduced IGF-1 levels in Allo-aca treated mice were not accompanied by any significant change in growth hormone levels compared to VEH mice. These findings suggest that leptin receptor antagonists may represent novel therapeutic agents for attenuating IGF-1 signaling associated with aging, and could potentially mimic some of the positive effects of calorie restriction on longevity.
Collapse
|
20
|
Qiu X, Dao H, Wang M, Heston A, Garcia KM, Sangal A, Dowling AR, Faulkner LD, Molitor SC, Elias CF, Hill JW. Insulin and Leptin Signaling Interact in the Mouse Kiss1 Neuron during the Peripubertal Period. PLoS One 2015; 10:e0121974. [PMID: 25946091 PMCID: PMC4422586 DOI: 10.1371/journal.pone.0121974] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 02/05/2015] [Indexed: 11/18/2022] Open
Abstract
Reproduction requires adequate energy stores for parents and offspring to survive. Kiss1 neurons, which are essential for fertility, have the potential to serve as the central sensors of metabolic factors that signal to the reproductive axis the presence of stored calories. Paradoxically, obesity is often accompanied by infertility. Despite excess circulating levels of insulin and leptin, obese individuals exhibit resistance to both metabolic factors in many neuron types. Thus, resistance to insulin or leptin in Kiss1 neurons could lead to infertility. Single deletion of the receptors for either insulin or the adipokine leptin from Kiss1 neurons does not impair adult reproductive dysfunction. However, insulin and leptin signaling pathways may interact in such a way as to obscure their individual functions. We hypothesized that in the presence of genetic or obesity-induced concurrent insulin and leptin resistance, Kiss1 neurons would be unable to maintain reproductive function. We therefore induced a chronic hyperinsulinemic and hyperleptinemic state in mice lacking insulin receptors in Kiss1 neurons through high fat feeding and examined the impact on fertility. In an additional, genetic model, we ablated both leptin and insulin signaling in Kiss1 neurons (IR/LepRKiss mice). Counter to our hypothesis, we found that the addition of leptin insensitivity did not alter the reproductive phenotype of IRKiss mice. We also found that weight gain, body composition, glucose and insulin tolerance were normal in mice of both genders. Nonetheless, leptin and insulin receptor deletion altered pubertal timing as well as LH and FSH levels in mid-puberty in a reciprocal manner. Our results confirm that Kiss1 neurons do not directly mediate the critical role that insulin and leptin play in reproduction. However, during puberty kisspeptin neurons may experience a critical window of susceptibility to the influence of metabolic factors that can modify the onset of fertility.
Collapse
Affiliation(s)
- Xiaoliang Qiu
- Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States of America
| | - Hoangha Dao
- Department of Bioengineering, University of Toledo, Toledo, Ohio, United States of America
| | - Mengjie Wang
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Amelia Heston
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Kaitlyn M. Garcia
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Alisha Sangal
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Abigail R. Dowling
- Center for Reproductive Genomics, Cornell University, Ithaca, NY, United States of America
| | - Latrice D. Faulkner
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
| | - Scott C. Molitor
- Department of Bioengineering, University of Toledo, Toledo, Ohio, United States of America
| | - Carol F. Elias
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States of America
| | - Jennifer W. Hill
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
- Department of Obstetrics-Gynecology, University of Toledo College of Medicine, Toledo, Ohio, United States of America
- * E-mail:
| |
Collapse
|
21
|
Odle AK, Drew PD, Childs GV. Giant mice reveal new roles for GH in regulating the adipose immune microenvironment. Endocrinology 2015; 156:1613-5. [PMID: 25886070 PMCID: PMC4398772 DOI: 10.1210/en.2015-1205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 03/06/2015] [Indexed: 11/19/2022]
Affiliation(s)
- Angela K Odle
- Department of Neurobiology and Developmental Sciences, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | | | | |
Collapse
|
22
|
Stieg MR, Sievers C, Farr O, Stalla GK, Mantzoros CS. Leptin: A hormone linking activation of neuroendocrine axes with neuropathology. Psychoneuroendocrinology 2015; 51:47-57. [PMID: 25290346 DOI: 10.1016/j.psyneuen.2014.09.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 09/03/2014] [Accepted: 09/06/2014] [Indexed: 11/24/2022]
Abstract
Leptin, a peptide hormone secreted by adipocytes, plays a central role in controlling appetite and weight in both rodents and humans. Basic science and clinical research suggest that this hormone not only affects the regulation of the neuroendocrine axes, but also exerts effects on the central nervous system with subsequent alterations in psychological functions. For instance, leptin suppresses cortisol secretion during stress-related activation of the adrenal axis. As psychiatric disorders like depression are associated with hypercortisolism, leptin is proposed to exert anti-depressant-like effects due to its inhibition of chronically overactive hypothalamo-pituitary-adrenal axis function. Moreover, leptin status of depressed patients could serve as a prognostic marker for therapy response. Besides its influence on neuroendocrine pathways leptin seems to have direct central effects on brain development and neuroplasticity. Low leptin levels have been shown to be associated with increased risk of developing dementia, supporting the idea of a pro-cognitive effect of leptin. These areas may have direct clinical implications and deserve to be studied further in the future.
Collapse
Affiliation(s)
- Mareike R Stieg
- Max-Planck-Institute of Psychiatry, Kreapelinstr. 2-10, 80804 Munich, Germany.
| | - Caroline Sievers
- Max-Planck-Institute of Psychiatry, Kreapelinstr. 2-10, 80804 Munich, Germany
| | - Olivia Farr
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA; Section of Endocrinology, Boston VA Healthcare System, Boston, USA
| | - Günter K Stalla
- Max-Planck-Institute of Psychiatry, Kreapelinstr. 2-10, 80804 Munich, Germany
| | - Christos S Mantzoros
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA; Section of Endocrinology, Boston VA Healthcare System, Boston, USA.
| |
Collapse
|
23
|
Odle AK, Haney A, Allensworth-James M, Akhter N, Childs GV. Adipocyte versus pituitary leptin in the regulation of pituitary hormones: somatotropes develop normally in the absence of circulating leptin. Endocrinology 2014; 155:4316-28. [PMID: 25116704 PMCID: PMC4197982 DOI: 10.1210/en.2014-1172] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Leptin is a cytokine produced by white fat cells, skeletal muscle, the placenta, and the pituitary gland among other tissues. Best known for its role in regulating appetite and energy expenditure, leptin is produced largely by and in proportion to white fat cells. Leptin is also important to the maintenance and function of the GH cells of the pituitary. This was shown when the deletion of leptin receptors on somatotropes caused decreased numbers of GH cells, decreased circulating GH, and adult-onset obesity. To determine the source of leptin most vital to GH cells and other pituitary cell types, we compared two different leptin knockout models with Cre-lox technology. The global Lep-null model is like the ob/ob mouse, whereby only the entire exon 3 is deleted. The selective adipocyte-Lep-null model lacks adipocyte leptin but retains pituitary leptin, allowing us to investigate the pituitary as a potential source of circulating leptin. Male and female mice lacking adipocyte leptin (Adipocyte-lep-null) did not produce any detectable circulating leptin and were infertile, suggesting that the pituitary does not contribute to serum levels. In the presence of only pituitary leptin, however, these same mutants were able to maintain somatotrope numbers and GH mRNA levels. Serum GH trended low, but values were not significant. However, hypothalamic GHRH mRNA was significantly reduced in these animals. Other serum hormone and pituitary mRNA differences were observed, some of which varied from previous results reported in ob/ob animals. Whereas pituitary leptin is capable of maintaining somatotrope numbers and GH mRNA production, the decreased hypothalamic GHRH mRNA and low (but not significant) serum GH levels indicate an important role for adipocyte leptin in the regulation of GH secretion in the mouse. Thus, normal GH secretion may require the coordinated actions of both adipocyte and pituitary leptin.
Collapse
Affiliation(s)
- Angela K Odle
- Department of Neurobiology and Developmental Sciences, College of Medicine, Center for Translational Neurosciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | | | | | | | | |
Collapse
|
24
|
Turner RT, Philbrick KA, Wong CP, Olson DA, Branscum AJ, Iwaniec UT. Morbid obesity attenuates the skeletal abnormalities associated with leptin deficiency in mice. J Endocrinol 2014; 223:M1-15. [PMID: 24990938 PMCID: PMC4161659 DOI: 10.1530/joe-14-0224] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Leptin-deficient ob/ob mice are morbidly obese and exhibit low total bone mass and mild osteopetrosis. In order to disassociate the skeletal effects of leptin deficiency from those associated with morbid obesity, we evaluated bone mass, architecture, gene expression, and indices of bone turnover in WT mice, ob/ob mice allowed to feed ad libitum (ob/ob), and ob/ob mice pair-fed equivalent to WT mice (pair-fed ob/ob). Mice were maintained at 32 °C (thermoneutral) from 6 to 18 weeks of age to minimize differences in resting energy expenditure. ob/ob mice were heavier, had more abdominal white adipose tissue (WAT), and were hyperglycemic compared with WT mice. Femur length, bone mineral content (BMC) and bone mineral density, and midshaft femur cortical thickness were lower in ob/ob mice than in WT mice. Cancellous bone volume (BV) fraction was higher but indices of bone formation and resorption were lower in ob/ob mice compared with WT mice; reduced bone resorption in ob/ob mice resulted in pathological retention of calcified cartilage. Pair-fed ob/ob mice were lighter and had lower WAT, uterine weight, and serum glucose than ob/ob mice. Similarly, femoral length, BMC, and cortical thickness were lower in pair-fed ob/ob mice compared with ob/ob mice, as were indices of cancellous bone formation and resorption. In contrast, bone marrow adiposity, calcified cartilage, and cancellous BV fraction were higher at one or more cancellous sites in pair-fed ob/ob mice compared with ob/ob mice. These findings indicate that the skeletal abnormalities caused by leptin deficiency are markedly attenuated in morbidly obese ob/ob mice.
Collapse
Affiliation(s)
- Russell T Turner
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Kenneth A Philbrick
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Carmen P Wong
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Dawn A Olson
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Adam J Branscum
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA Skeletal Biology LaboratorySchool of Biological and Population Health SciencesCenter for Healthy Aging ResearchBiostatisticsSchool of Biological and Population Health Sciences, Oregon State University, Corvallis, Oregon 97331, USA
| |
Collapse
|
25
|
Watson SL, Watson CJ, Baghdoyan HA, Lydic R. Adenosine A₁ receptors in mouse pontine reticular formation modulate nociception only in the presence of systemic leptin. Neuroscience 2014; 275:531-9. [PMID: 24976513 PMCID: PMC4143377 DOI: 10.1016/j.neuroscience.2014.06.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 06/09/2014] [Accepted: 06/12/2014] [Indexed: 01/07/2023]
Abstract
Human obesity is associated with increased leptin levels and pain, but the specific brain regions and neurochemical mechanisms underlying this association remain poorly understood. This study used adult male C57BL/6J (B6, n=14) mice and leptin-deficient, obese B6.Cg-Lep(ob)/J (obese, n=10) mice to evaluate the hypothesis that nociception is altered by systemic leptin levels and by adenosine A₁ receptors in the pontine reticular formation. Nociception was quantified as paw withdrawal latency (PWL) in s after onset of a thermal stimulus. PWL was converted to percent maximum possible effect (%MPE). After obtaining baseline PWL measures, the pontine reticular formation was microinjected with saline (control), three concentrations of the adenosine A₁ receptor agonist N(6)-p-sulfophenyladenosine (SPA), or super-active mouse leptin receptor antagonist (SMLA) followed by SPA 15 min later, and PWL was again quantified. In obese, leptin-deficient mice, nociception was quantified before and during leptin replacement via subcutaneous osmotic pumps. SPA was administered into the pontine reticular formation of leptin-replaced mice and PWL testing was repeated. During baseline (before vehicle or SPA administration), PWL was significantly (p=0.0013) lower in leptin-replaced obese mice than in B6 mice. Microinjecting SPA into the pontine reticular formation of B6 mice caused a significant (p=0.0003) concentration-dependent increase in %MPE. SPA also significantly (p<0.05) increased %MPE in B6 mice and in leptin-replaced obese mice, but not in leptin-deficient obese mice. Microinjection of SMLA into the pontine reticular formation before SPA did not alter PWL. The results show for the first time that pontine reticular formation administration of the adenosine A₁ receptor agonist SPA produced antinociception only in the presence of systemic leptin. The concentration-response data support the interpretation that adenosine A₁ receptors localized to the pontine reticular formation significantly alter nociception.
Collapse
Affiliation(s)
- S L Watson
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - C J Watson
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - H A Baghdoyan
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
| | - R Lydic
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
26
|
Briggs DI, Lockie SH, Benzler J, Wu Q, Stark R, Reichenbach A, Hoy AJ, Lemus MB, Coleman HA, Parkington HC, Tups A, Andrews ZB. Evidence that diet-induced hyperleptinemia, but not hypothalamic gliosis, causes ghrelin resistance in NPY/AgRP neurons of male mice. Endocrinology 2014; 155:2411-22. [PMID: 24742194 DOI: 10.1210/en.2013-1861] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
High-fat diet (HFD) feeding causes ghrelin resistance in arcuate neuropeptide Y (NPY)/Agouti-related peptide neurons. In the current study, we investigated the time course over which this occurs and the mechanisms responsible for ghrelin resistance. After 3 weeks of HFD feeding, neither peripheral nor central ghrelin increased food intake and or activated NPY neurons as demonstrated by a lack of Fos immunoreactivity or whole-cell patch-clamp electrophysiology. Pair-feeding studies that matched HFD calorie intake with chow calorie intake show that HFD exposure does not cause ghrelin resistance independent of body weight gain. We observed increased plasma leptin in mice fed a HFD for 3 weeks and show that leptin-deficient obese ob/ob mice are still ghrelin sensitive but become ghrelin resistant when central leptin is coadministered. Moreover, ob/ob mice fed a HFD for 3 weeks remain ghrelin sensitive, and the ability of ghrelin to induce action potential firing in NPY neurons was blocked by leptin. We also examined hypothalamic gliosis in mice fed a chow diet or HFD, as well as in ob/ob mice fed a chow diet or HFD and lean controls. HFD-fed mice exhibited increased glial fibrillary acidic protein-positive cells compared with chow-fed mice, suggesting that hypothalamic gliosis may underlie ghrelin resistance. However, we also observed an increase in hypothalamic gliosis in ob/ob mice fed a HFD compared with chow-fed ob/ob and lean control mice. Because ob/ob mice fed a HFD remain ghrelin sensitive, our results suggest that hypothalamic gliosis does not underlie ghrelin resistance. Further, pair-feeding a HFD to match the calorie intake of chow-fed controls did not increase body weight gain or cause central ghrelin resistance; thus, our evidence suggests that diet-induced hyperleptinemia, rather than diet-induced hypothalamic gliosis or HFD exposure, causes ghrelin resistance.
Collapse
Affiliation(s)
- Dana I Briggs
- Department of Physiology (D.I.B., S.H.L., Q.W., R.S., A.R., M.B.L., H.A.C., H.C.P., Z.B.A.), Monash University, Clayton, Victoria 3800, Australia; Traditional Chinese Medicine Department (Q.W.), Peking Union Medical College Hospital, Beijing, China 100730; Department of Physiology (J.B., A.J.H.), Bosch Institute, The University of Sydney, New South Wales 2006, Australia; and Department of Animal Physiology (A.T.), Faculty of Biology, Philipps University, Marburg, D-35043 Marburg, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Liu B, Kuang L, Liu J. Bariatric surgery relieves type 2 diabetes and modulates inflammatory factors and coronary endothelium eNOS/iNOS expression in db/db mice. Can J Physiol Pharmacol 2013; 92:70-7. [PMID: 24383875 DOI: 10.1139/cjpp-2013-0034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Overexpression of endothelial nitric oxide synthetase (eNOS)/inducible nitric oxide synthase (iNOS) and inhibition of inflammatory factors can improve vascular function. We hypothesized that bariatric (gastric bypass) surgery could inhibit inflammatory factors and improve the eNOS/iNOS expression of coronary arterioles in the db/db mice. The animals were randomly allocated to the following groups: sham-operated lean mice, lean mice that underwent surgery, sham-operated db/db mice, and db/db mice that underwent surgery (5, 10, 20, and 30 days post-operation). The plasma levels of adiponectin, ghrelin, and IL-6, as well as the protein expression of eNOS/iNOS in coronary arterioles were measured with Western blot. Bariatric surgery decreased body mass and blood glucose levels in db/db mice. Ghrelin receptor and GHS-R1a expression in the hypothalamus were increased in db/db mice, but surgery attenuated GHS-R1a expression. Bariatric surgery elevated plasma concentration and protein expression of adiponectin and ghrelin, and attenuated plasma concentration and protein expression of IL-6. Coronary protein expression of eNOS and SOD2 was lower in the sham-operated db/db mice, and bariatric surgery increased eNOS and SOD2 expression. Gastric bypass surgery upregulates ghrelin and adiponectin expression, and decreases IL-6 expression, which might induce up-regulation of eNOS and SOD2, and down-regulation of iNOS. These interactions could counteract the endothelium dysfunction in type 2 diabetes mellitus.
Collapse
Affiliation(s)
- Bingyang Liu
- a Department of Endocrinology, Shengjing Hospital of China Medical University, No. 36, Sanhao Street, Shenyang, Liaoning Province 110004, China
| | | | | |
Collapse
|
28
|
Kentish SJ, Wittert GA, Blackshaw LA, Page AJ. A chronic high fat diet alters the homologous and heterologous control of appetite regulating peptide receptor expression. Peptides 2013; 46:150-8. [PMID: 23792934 DOI: 10.1016/j.peptides.2013.06.004] [Citation(s) in RCA: 18] [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: 05/03/2013] [Revised: 06/04/2013] [Accepted: 06/04/2013] [Indexed: 10/26/2022]
Abstract
Leptin, ghrelin and neuropeptide W (NPW) modulate vagal afferent activity, which may underlie their appetite regulatory actions. High fat diet (HFD)-induced obesity induces changes in the plasma levels of these peptides and alters the expression of receptors on vagal afferents. We investigated homologous and heterologous receptor regulation by leptin, ghrelin and NPW. Mice were fed (12 weeks) a standard laboratory diet (SLD) or HFD. Nodose ganglia were cultured overnight in the presence or absence of each peptide. Leptin (LepR), ghrelin (GHS-R), NPW (GPR7) and cholecystokinin type-1 (CCK1R) receptor mRNA, and the plasma leptin, ghrelin and NPW levels were measured. SLD: leptin reduced LepR, GPR7, increased GHS-R and CCK1R mRNA; ghrelin increased LepR, GPR7, CCK1R, and decreased GHS-R. HFD: leptin decreased GHS-R and GPR7, ghrelin increased GHS-R and GPR7. NPW decreased all receptors except GPR7 which increased with HFD. Plasma leptin was higher and NPW lower in HFD. Thus, HFD-induced obesity disrupts inter-regulation of appetite regulatory receptors in vagal afferents.
Collapse
MESH Headings
- Animals
- Appetite/physiology
- Appetite Regulation/physiology
- Cells, Cultured
- Diet, High-Fat
- Female
- Ghrelin/blood
- Ghrelin/metabolism
- Leptin/blood
- Leptin/metabolism
- Mice
- Mice, Inbred C57BL
- Neuropeptides/blood
- Neuropeptides/metabolism
- Nodose Ganglion/cytology
- Nodose Ganglion/drug effects
- Obesity/blood
- RNA, Messenger
- Receptor, Cholecystokinin A/genetics
- Receptors, G-Protein-Coupled/biosynthesis
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Ghrelin/metabolism
- Receptors, Leptin/metabolism
- Receptors, Neuropeptide/biosynthesis
- Receptors, Neuropeptide/metabolism
- Vagus Nerve/metabolism
Collapse
Affiliation(s)
- Stephen J Kentish
- Nerve Gut Research Laboratory, Department of Medicine, University of Adelaide, Frome Road, Adelaide, SA 5005, Australia
| | | | | | | |
Collapse
|
29
|
Syed M, Cozart M, Haney AC, Akhter N, Odle AK, Allensworth-James M, Crane C, Syed FM, Childs GV. Ghrelin restoration of function in vitro in somatotropes from male mice lacking the Janus kinase (JAK)-binding site of the leptin receptor. Endocrinology 2013; 154:1565-76. [PMID: 23417423 PMCID: PMC3602631 DOI: 10.1210/en.2012-2254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Deletion of the signaling domain of leptin receptors selectively in somatotropes, with Cre-loxP technology, reduced the percentage of immunolabeled GH cells and serum GH. We hypothesized that the deficit occurred when leptin's postnatal surge failed to stimulate an expansion in the cell population. To learn more about the deficiency in GH cells, we tested their expression of GHRH receptors and GH mRNA and the restorative potential of secretagogue stimulation in vitro. In freshly plated dissociated pituitary cells from control male mice, GHRH alone (0.3 nM) increased the percentage of immunolabeled GH cells from 27 ± 0.05% (vehicle) to 42 ± 1.8% (P < .002) and the secretion of GH 1.8-3×. Deletion mutant pituitary cells showed a 40% reduction in percentages of immunolabeled GH cells (16.7 ± 0.4%), which correlated with a 47% reduction in basal GH levels (50 ng/mL control; 26.7 ng/mL mutants P = .01). A 50% reduction in the percentage of mutant cells expressing GHRH receptors (to 12%) correlated with no or reduced responses to GHRH. Ghrelin alone (10 nM) stimulated more GH cells in mutants (from 16.7-23%). When added with 1-3 nM GHRH, ghrelin restored GH cell percentages and GH secretion to levels similar to those of stimulated controls. Counts of somatotropes labeled for GH mRNA confirmed normal percentages of somatotropes in the population. These discoveries suggest that leptin may optimize somatotrope function by facilitating expression of membrane GHRH receptors and the production or maintenance of GH stores.
Collapse
Affiliation(s)
- Mohsin Syed
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, College of Medicine, 4301 West Markham, Slot 510, Little Rock, Arkansas 72205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Akhter N, Odle AK, Allensworth-James ML, Haney AC, Syed MM, Cozart MA, Chua S, Kineman R, Childs GV. Ablation of leptin signaling to somatotropes: changes in metabolic factors that cause obesity. Endocrinology 2012; 153:4705-15. [PMID: 22865370 PMCID: PMC3512011 DOI: 10.1210/en.2012-1331] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 07/12/2012] [Indexed: 01/22/2023]
Abstract
Mice with somatotrope-specific deletion of the Janus kinase binding site in leptin receptors are GH deficient as young adults and become obese by 6 months of age. This study focused on the metabolic status of young (3-4.5 month old) preobese mutant mice. These mutants had normal body weights, lean body mass, serum leptin, glucose, and triglycerides. Mutant males and females showed significantly higher respiratory quotients (RQ) and lower energy output, resulting from a higher volume of CO(2) output and lower volume of O(2) consumption. Deletion mutant females were significantly less active than controls; they had higher levels of total serum ghrelin and ate more food. Mutant females also had lower serum insulin and higher glucagon. In contrast, deletion mutant males were not hyperphagic, but they were more active and spent less time sleeping. Adiponectin and resistin, both products of adipocytes, were increased in male and female mutant mice. In addition, mutant males showed an increase in circulating levels of the potent lipogenic hormone, glucose-dependent insulinotropic peptide. Taken together, these results indicate that mutant mice may become obese due to a reduction in lipid oxidation and energy expenditure. This may stem from GH deficiency. Reduced fat oxidation and enhanced insulin sensitivity (in females) are directly related to GH deficiency in mutant mice because GH has been shown by others to increase insulin sensitivity and fat oxidation and reduce carbohydrate oxidation. Gender-dependent alterations in metabolic signals may further exacerbate the future obese phenotype and affect the timing of its onset. Females show a delay in onset of obesity, perhaps because of their low serum insulin, which is lipogenic, whereas young males already have higher levels of the lipogenic hormone, glucose-dependent insulinotropic peptide. These findings signify that leptin signals to somatotropes are vital for the normal metabolic activity needed to optimize body composition.
Collapse
Affiliation(s)
- Noor Akhter
- Department of Neurobiology and Developmental Sciences, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Xu L, Scheenen WJJM, Roubos EW, Kozicz T. Peptidergic Edinger-Westphal neurons and the energy-dependent stress response. Gen Comp Endocrinol 2012; 177:296-304. [PMID: 22166814 DOI: 10.1016/j.ygcen.2011.11.039] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 11/22/2011] [Accepted: 11/23/2011] [Indexed: 11/18/2022]
Abstract
The continuously changing environment demands for adequate stress responses to maintain the internal dynamic equilibrium of body and mind. A successful stress response requires energy, in an amount matching the severity of the stressor and the type of response ('fight, flight or freeze'). The stress response is generated by the central nervous system, which needs to be informed about both the threatening stressor and the availability of energy. In this review, evidence is considered for a role of the midbrain Edinger-Westphal centrally projecting neuron population (EWcp; synonym: non-preganglionic Edinger-Westphal nucleus) in the energy-dependent stress adaptation response. It deals with studies on the neurochemical organization of the EWcp with particular reference to the neuropeptides urocortin-1 and cocaine- and amphetamine-regulated transcript peptide, on the EWcp responses to different types of stressor (e.g., acute and chronic) and a changed energy state (e.g., fasting and leptin change), and on the sex-specificity of these responses. Finally, a model is presented for the way the EWcp might contribute to the coordination of the energy-dependent stress adaptation response.
Collapse
Affiliation(s)
- Lu Xu
- Department of Cellular Animal Physiology, Faculty of Science, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands
| | | | | | | |
Collapse
|
32
|
Abstract
Leptin, a peptide hormone secreted by adipocytes in proportion of the amount of energy stored in fat, plays a central role in regulating human energy homeostasis. In addition, leptin plays a significant permissive role in the physiological regulation of several neuroendocrine axes, including the hypothalamic-pituitary-gonadal, -thyroid, -growth hormone, and -adrenal axes. Decreased levels of leptin, also known as hypoleptinemia, signal to the brain a state of energy deprivation. Hypoleptinemia can be a congenital or acquired condition, and is associated with alterations of the aforementioned axes aimed at promoting survival. More specifically, gonadotropin levels decrease and become less pulsatile under conditions of energy deprivation, and these changes can be at least partially reversed through leptin administration in physiological replacement doses. Similarly, leptin deficiency is associated with thyroid axis abnormalities including abnormal levels of thyrotropin-releasing hormone, and leptin administration may at least partially attenuate this effect. Leptin deficiency results in decreased insulin-like growth factor 1 levels which can be partially ameliorated through leptin administration, and leptin appears to have a much more pronounced effect on the growth of rodents than that of humans. Similarly, adrenal axis function is regulated more tightly by low leptin in rodents than in humans. In addition to congenital leptin deficiency, conditions that may be associated with decreased leptin levels include hypothalamic amenorrhea, anorexia nervosa, and congenital or acquired lipodystrophy syndromes. Accumulating evidence from proof of concept studies suggests that leptin administration, in replacement doses, may ameliorate neuroendocrine abnormalities in individuals who suffer from these conditions.
Collapse
Affiliation(s)
- Sami M. Khan
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Ole-Petter R. Hamnvik
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mary Brinkoetter
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
| | - Christos S. Mantzoros
- Division of Endocrinology, Diabetes & Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Section of Endocrinology, Boston VA Healthcare System, Boston, MA, USA
| |
Collapse
|
33
|
Gat-Yablonski G, Yackobovitch-Gavan M, Phillip M. Nutrition and bone growth in pediatrics. Pediatr Clin North Am 2011; 58:1117-40, ix. [PMID: 21981952 DOI: 10.1016/j.pcl.2011.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Children's growth is a hallmark of their normal development and the association between nutrition and linear growth in children is well accepted. Growth requires an adequate supply of many different nutritional factors, some form the "building materials," whereas others play regulatory roles. In this article we describe the growth of the growth plate and discuss the role of nutritional affected hormones on this process. In addition we describe the effect of local regulators and nutritional factors on the growth process and suggest the involvement of new regulatory factors in the translation of nutrition to growth.
Collapse
Affiliation(s)
- Galia Gat-Yablonski
- The Jesse Z. and Sara Lea Shafer Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, 14 Kaplan Street, Petah Tikva 49202, Israel
| | | | | |
Collapse
|
34
|
Puertas-Avendaño RA, González-Gómez MJ, Ruvira MD, Ruiz-Hidalgo MJ, Morales-Delgado N, Laborda J, Díaz C, Bello AR. Role of the non-canonical notch ligand delta-like protein 1 in hormone-producing cells of the adult male mouse pituitary. J Neuroendocrinol 2011; 23:849-59. [PMID: 21756269 DOI: 10.1111/j.1365-2826.2011.02189.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To better understand the role of the non-canonical Notch ligand delta-like protein 1 (DLK1), in hormone-producing cells, we studied the cell distribution and subcellular localisation of DLK1 in the pituitary of male adult 129/SvJ mice, and analysed the variations in the hormone-producing cells associated with the lack of this gene in Dlk1 knockout mice. The results obtained showed the presence of DLK1-immunoreactive (ir) cells in all hormone-producing cells of the anterior pituitary. Immunoelectron microscopy showed DLK1-ir in the rough endoplasmic reticulum and inside secretory vesicles, suggesting that DLK1 is released together with pituitary hormones. Moreover, we found that prolactin (PRL)-DLK1-ir cells are in intimate contact with follicle-stimulating hormone (FSH)-ir-DLK1-negative cells. In Dlk1 knockout mice, we detected a significantly lower number of gowth hormone (GH)-ir cells, a reduction in the FSH and PRL immunostaining intensity, and a significant decrease in FSH mRNA expression compared to wild-type mice. An increase in pituitary GH mRNA expression and serum leptin levels was also found. These findings provide evidence supporting several regulatory functions of DLK1 in the pituitary gland.
Collapse
Affiliation(s)
- R A Puertas-Avendaño
- Cell Biology Section, School of Biology, University of La Laguna, Tenerife, Spain
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Bartell SM, Rayalam S, Ambati S, Gaddam DR, Hartzell DL, Hamrick M, She JX, Della-Fera MA, Baile CA. Central (ICV) leptin injection increases bone formation, bone mineral density, muscle mass, serum IGF-1, and the expression of osteogenic genes in leptin-deficient ob/ob mice. J Bone Miner Res 2011; 26:1710-20. [PMID: 21520275 DOI: 10.1002/jbmr.406] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Both central and peripheral leptin administrations reduce body weight, food intake, and adiposity in ob/ob mice. In this study we compared effects of intracerebroventricular (ICV) and subcutaneous (SC) administration of leptin on bone metabolism in the appendicular and axial skeleton and adipose tissue gene expression and determined the effects of ICV leptin on bone marrow gene expression in ob/ob mice. In experiment 1, leptin (1.5 or 0.38 µg/d) or control was continuously injected ICV for 12 days. Gene expression analysis of femoral bone marrow stromal cells showed that expression of genes associated with osteogenesis was increased after ICV injection, whereas those associated with osteoclastogenesis, adipogenesis, and adipocyte lipid storage were decreased. In experiment 2, leptin was injected continuously ICV (0.0 or 1.5 µg/d) or SC (0.0 or 10 µg/d) for 12 days. In both experiments, regardless of mode of administration, leptin decreased body weight, food intake, and body fat and increased muscle mass, bone mineral density, bone mineral content, bone area, marrow adipocyte number, and mineral apposition rate. Serum insulin was decreased, whereas serum osteocalcin, insulin-like growth factor 1, osteoprotegerin, pyridinoline, and receptor activator of nuclear factor κB ligand concentrations were increased. In experiment 2, expression of genes in adipose tissue associated with apoptosis, lipid mobilization, insulin sensitivity, and thermogenesis was increased, whereas expression of genes associated with cell differentiation and maturation was decreased regardless of mode of administration. Thus ICV injection of leptin promotes expression of pro-osteogenic factors in bone marrow, leading to enhanced bone formation in ob/ob mice.
Collapse
Affiliation(s)
- Shoshana M Bartell
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Finger BC, Schellekens H, Dinan TG, Cryan JF. Is there altered sensitivity to ghrelin-receptor ligands in leptin-deficient mice?: importance of satiety state and time of day. Psychopharmacology (Berl) 2011; 216:421-9. [PMID: 21373788 DOI: 10.1007/s00213-011-2234-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 02/15/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Several fine-tuned and interconnected hypothalamic peptidergic systems orchestrate the regulation of energy homeostasis in the body. The orexigenic peptide ghrelin and the anorexigenic peptide leptin are among the most important, and both have been implicated in the development of eating disorders from obesity to anorexia nervosa. OBJECTIVES The goal of these studies was to examine the response of leptin-deficient ob/ob mice in ghrelin-receptor ligands in a food intake task. METHODS Changes in cumulative food intake were measured after peripheral administration of ghrelin (1 and 2 nmol/10 g) and the ghrelin-receptor antagonist (D-Lys(3))-GHRP-6 (66.6 and 133.3 nmol/10 g) in obese and lean control mice during the light and dark cycle as well as in a state of food restriction. Hypothalamic ghrelin and ghrelin-receptor expression was measured in ob/ob and lean mice at two different timepoints. RESULTS Ghrelin increased food intake in lean and obese mice in the light and dark cycle, whereas the ghrelin-receptor antagonist caused significantly stronger reduction in food intake in obese mice only in the dark cycle. After fasting, ob/ob mice displayed decreased light cycle sensitivity to the anorexigenic effects of the ghrelin-receptor antagonist. Hypothalamic expression levels of ghrelin were unaltered during the light cycle but decreased during the dark cycle in ob/ob mice; whereas, although unchanged in the light cycle, ghrelin-receptor expression was increased in the dark cycle in obese mice. CONCLUSION The functionality and sensitivity of the ghrelinergic system is dependent on the time of day and the satiety state in leptin-deficient ob/ob mice.
Collapse
Affiliation(s)
- Beate C Finger
- School of Pharmacy, Cavanagh Pharmacy Building, University College Cork, Cork, Ireland
| | | | | | | |
Collapse
|
37
|
Luque RM, Gahete MD, Cordoba-Chacon J, Childs GV, Kineman RD. Does the pituitary somatotrope play a primary role in regulating GH output in metabolic extremes? Ann N Y Acad Sci 2011; 1220:82-92. [PMID: 21388406 DOI: 10.1111/j.1749-6632.2010.05913.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Circulating growth hormone (GH) levels rise in response to nutrient deprivation and fall in states of nutrient excess. Because GH regulates carbohydrate, lipid, and protein metabolism, defining the mechanisms by which changes in metabolism alter GH secretion will aid in our understanding of the cause, progression, and treatment of metabolic diseases. This review will summarize what is currently known regarding the impact of systemic metabolic signals on GH-axis function. In addition, ongoing studies using the Cre/loxP system to generate mouse models with selective somatotrope resistance to metabolic signals will be discussed, where these models will serve to enhance our understanding of the specific role the somatotrope plays in sensing the metabolic environment and adjusting GH output in metabolic extremes.
Collapse
Affiliation(s)
- Raul M Luque
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba, CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | | | | | | | | |
Collapse
|
38
|
Vijayakumar A, Yakar S, LeRoith D. The intricate role of growth hormone in metabolism. Front Endocrinol (Lausanne) 2011; 2:32. [PMID: 22654802 PMCID: PMC3356038 DOI: 10.3389/fendo.2011.00032] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 08/30/2011] [Indexed: 11/18/2022] Open
Abstract
Growth hormone (GH), a master regulator of somatic growth, also regulates carbohydrate and lipid metabolism via complex interactions with insulin and insulin-like growth factor-1 (IGF-1). Data from human and rodent studies reveal the importance of GH in insulin synthesis and secretion, lipid metabolism and body fat remodeling. In this review, we will summarize the tissue-specific metabolic effects of GH, with emphasis on recent targets identified to mediate these effects. Furthermore, we will discuss what role GH plays in obesity and present possible mechanisms by which this may occur.
Collapse
Affiliation(s)
- Archana Vijayakumar
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
| | - Shoshana Yakar
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Department of Medicine, Mount Sinai School of MedicineNew York, NY, USA
- *Correspondence: Derek LeRoith, Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, One Gustav Levy Place, Box 1055, New York, NY 10029-6574, USA. e-mail:
| |
Collapse
|
39
|
Childs GV, Akhter N, Haney A, Syed M, Odle A, Cozart M, Brodrick Z, Gaddy D, Suva LJ, Akel N, Crane C, Benes H, Charlesworth A, Luque R, Chua S, Kineman RD. The somatotrope as a metabolic sensor: deletion of leptin receptors causes obesity. Endocrinology 2011; 152:69-81. [PMID: 21084451 PMCID: PMC3033057 DOI: 10.1210/en.2010-0498] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 10/07/2010] [Indexed: 01/01/2023]
Abstract
Leptin, the product of the Lep gene, reports levels of adiposity to the hypothalamus and other regulatory cells, including pituitary somatotropes, which secrete GH. Leptin deficiency is associated with a decline in somatotrope numbers and function, suggesting that leptin may be important in their maintenance. This hypothesis was tested in a new animal model in which exon 17 of the leptin receptor (Lepr) protein was selectively deleted in somatotropes by Cre-loxP technology. Organ genotyping confirmed the recombination of the floxed LepR allele only in the pituitary. Deletion mutant mice showed a 72% reduction in pituitary cells bearing leptin receptor (LEPR)-b, a 43% reduction in LEPR proteins and a 60% reduction in percentages of immunopositive GH cells, which correlated with reduced serum GH. In mutants, LEPR expression by other pituitary cells was like that of normal animals. Leptin stimulated phosphorylated Signal transducer and activator of transcription 3 expression in somatotropes from normal animals but not from mutants. Pituitary weights, cell numbers, IGF-I, and the timing of puberty were not different from control values. Growth curves were normal during the first 3 months. Deletion mutant mice became approximately 30-46% heavier than controls with age, which was attributed to an increase in fat mass. Serum leptin levels were either normal in younger animals or reflected the level of obesity in older animals. The specific ablation of the Lepr exon 17 gene in somatotropes resulted in GH deficiency with a consequential reduction in lipolytic activity normally maintained by GH and increased adiposity.
Collapse
Affiliation(s)
- Gwen V Childs
- Professor and Chair, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Gahete MD, Córdoba-Chacón J, Salvatori R, Castaño JP, Kineman RD, Luque RM. Metabolic regulation of ghrelin O-acyl transferase (GOAT) expression in the mouse hypothalamus, pituitary, and stomach. Mol Cell Endocrinol 2010; 317:154-60. [PMID: 20035826 PMCID: PMC2819060 DOI: 10.1016/j.mce.2009.12.023] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 12/16/2009] [Indexed: 01/07/2023]
Abstract
Ghrelin acts as an endocrine link connecting physiological processes regulating food intake, body composition, growth, and energy balance. Ghrelin is the only peptide known to undergo octanoylation. The enzyme mediating this process, ghrelin O-acyltransferase (GOAT), is expressed in the gastrointestinal tract (GI; primary source of circulating ghrelin) as well as other tissues. The present study demonstrates that stomach GOAT mRNA levels correlate with circulating acylated-ghrelin levels in fasted and diet-induced obese mice. In addition, GOAT was found to be expressed in both the pituitary and hypothalamus (two target tissues of ghrelin's actions), and regulated in response to metabolic status. Using primary pituitary cell cultures as a model system to study the regulation of GOAT expression, we found that acylated-ghrelin, but not desacyl-ghrelin, increased GOAT expression. In addition, growth-hormone-releasing hormone (GHRH) and leptin increased, while somatostatin (SST) decreased GOAT expression. The physiologic relevance of these later results is supported by the observation that pituitary GOAT expression in mice lacking GHRH, SST and leptin showed opposite changes to those observed after in vitro treatment with the corresponding peptides. Therefore, it seems plausible that these hormones directly contribute to the regulation of pituitary GOAT. Interestingly, in all the models studied, pituitary GOAT expression paralleled changes in the expression of a dominant spliced-variant of ghrelin (In2-ghrelin) and therefore this transcript may be a primary substrate for pituitary GOAT. Collectively, these observations support the notion that the GI tract is not the only source of acylated-ghrelin, but in fact locally produced des-acylated-ghrelin could be converted to acylated-ghrelin within target tissues by locally active GOAT, to mediate its tissue-specific effects.
Collapse
Affiliation(s)
- Manuel D. Gahete
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, 14004 Córdoba, Spain
| | - Jose Córdoba-Chacón
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, 14004 Córdoba, Spain
| | | | - Justo P. Castaño
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, 14004 Córdoba, Spain
| | - Rhonda D. Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, IL, 60612
- Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Illinois at Chicago, Chicago, IL, 60612
| | - Raul M. Luque
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), and CIBER Fisiopatología de la Obesidad y Nutrición, 14004 Córdoba, Spain
| |
Collapse
|
41
|
Córdoba-Chacón J, Gahete MD, Duran-Prado M, Pozo-Salas AI, Malagón MM, Gracia-Navarro F, Kineman RD, Luque RM, Castaño JP. Identification and characterization of new functional truncated variants of somatostatin receptor subtype 5 in rodents. Cell Mol Life Sci 2010; 67:1147-63. [PMID: 20063038 PMCID: PMC11115927 DOI: 10.1007/s00018-009-0240-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 12/08/2009] [Accepted: 12/18/2009] [Indexed: 12/11/2022]
Abstract
Somatostatin and cortistatin exert multiple biological actions through five receptors (sst1-5); however, not all their effects can be explained by activation of sst1-5. Indeed, we recently identified novel truncated but functional human sst5-variants, present in normal and tumoral tissues. In this study, we identified and characterized three novel truncated sst5 variants in mice and one in rats displaying different numbers of transmembrane-domains [TMD; sst5TMD4, sst5TMD2, sst5TMD1 (mouse-variants) and sst5TMD1 (rat-variant)]. These sst5 variants: (1) are functional to mediate ligand-selective-induced variations in [Ca(2+)]i and cAMP despite being truncated; (2) display preferential intracellular distribution; (3) mostly share full-length sst5 tissue distribution, but exhibit unique differences; (4) are differentially regulated by changes in hormonal/metabolic environment in a tissue- (e.g., central vs. systemic) and ligand-dependent manner. Altogether, our results demonstrate the existence of new truncated sst5-variants with unique ligand-selective signaling properties, which could contribute to further understanding the complex, distinct pathophysiological roles of somatostatin and cortistatin.
Collapse
Affiliation(s)
- Jose Córdoba-Chacón
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - Manuel D. Gahete
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - Mario Duran-Prado
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - Ana I. Pozo-Salas
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - María M. Malagón
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - F. Gracia-Navarro
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - Rhonda D. Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, Chicago, IL USA
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL USA
| | - Raul M. Luque
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| | - Justo P. Castaño
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Edificio Severo Ochoa. Planta 3. Campus de Rabanales, 14014 Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn 06/03), Córdoba, Spain
| |
Collapse
|
42
|
Abstract
Cancellous bone decreases and bone marrow fat content increases with age. Osteoblasts and adipocytes are derived from a common precursor, and growth hormone (GH), a key hormone in integration of energy metabolism, regulates the differentiation and function of both cell lineages. Since an age-related decline in GH is associated with bone loss, we investigated the relationship between GH and bone marrow adiposity in hypophysectomized (HYPOX) rats and in mice with defects in GH signaling. HYPOX dramatically reduced body weight gain, bone growth and mineralizing perimeter, serum insulin-like growth factor 1 (IGF-1) levels, and mRNA levels for IGF-1 in liver and bone. Despite reduced body mass and adipocyte precursor pool size, HYPOX resulted in a dramatic increase in bone lipid levels, as reflected by increased bone marrow adiposity and bone triglyceride and cholesterol content. GH replacement normalized bone marrow adiposity and precursor pool size, as well as mineralizing perimeter in HYPOX rats. In contrast, 17beta -estradiol, IGF-1, thyroxine, and cortisone were ineffective. Parathyroid hormone (PTH) reversed the inhibitory effects of HYPOX on mineralizing perimeter but had no effect on adiposity. Finally, bone marrow adiposity was increased in mice deficient in GH and IGF-1 but not in mice deficient in serum IGF-1. Taken together, our findings indicate that the reciprocal changes in bone and fat mass in GH signaling-deficient rodents are not directly coupled with one another. Rather, GH enhances adipocyte as well as osteoblast precursor pool size. However, GH increases osteoblast differentiation while suppressing bone marrow lipid accumulation.
Collapse
|
43
|
Rodríguez-Pacheco F, Vázquez-Martínez R, Martínez-Fuentes AJ, Pulido MR, Gahete MD, Vaudry H, Gracia-Navarro F, Diéguez C, Castaño JP, Malagón MM. Resistin regulates pituitary somatotrope cell function through the activation of multiple signaling pathways. Endocrinology 2009; 150:4643-52. [PMID: 19589870 DOI: 10.1210/en.2009-0116] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adipokine resistin is an insulin-antagonizing factor that also plays a regulatory role in inflammation, immunity, food intake, and gonadal function. Although adipose tissue is the primary source of resistin, it is also expressed in other tissues and organs, including the pituitary. However, there is no information on whether resistin, as described previously for other adipokines such as leptin and adiponectin, could regulate this gland. Likewise, the molecular basis of resistin actions remains largely unexplored. Here we show that administration of resistin to dispersed rat anterior pituitary cells increased GH release in both the short (4 h) and long (24 h) term, decreased mRNA levels of the receptor of the somatotrope regulator ghrelin, and increased free cytosolic Ca(2+) concentration in single somatotropes. By means of a pharmacological approach, we found that the stimulatory action of resistin occurs through a Gs protein-dependent mechanism and that the adenylate cyclase/cAMP/protein kinase A pathway, the phosphatidylinositol 3-kinase/Akt pathway, protein kinase C, and extracellular Ca(2+) entry through L-type voltage-sensitive Ca(2+) channels are essential players in mediating the effects of resistin on somatotropes. Taken together, our results demonstrate for the first time a regulatory role for resistin on somatotrope function and provide novel insights on the intracellular mechanisms activated by this protein.
Collapse
|
44
|
Gat-Yablonski G, Yackobovitch-Gavan M, Phillip M. Nutrition and bone growth in pediatrics. Endocrinol Metab Clin North Am 2009; 38:565-86. [PMID: 19717005 DOI: 10.1016/j.ecl.2009.07.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Children's growth is a hallmark of their normal development and the association between nutrition and linear growth in children is well accepted. Growth requires an adequate supply of many different nutritional factors, some form the "building materials," whereas others play regulatory roles. In this article we describe the growth of the growth plate and discuss the role of nutritional affected hormones on this process. In addition we describe the effect of local regulators and nutritional factors on the growth process and suggest the involvement of new regulatory factors in the translation of nutrition to growth.
Collapse
Affiliation(s)
- Galia Gat-Yablonski
- The Jesse Z. and Sara Lea Shafer Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, 14 Kaplan Street, Petah Tikva 49202, Israel
| | | | | |
Collapse
|
45
|
Belin de Chantemèle EJ, Muta K, Mintz J, Tremblay ML, Marrero MB, Fulton DJ, Stepp DW. Protein tyrosine phosphatase 1B, a major regulator of leptin-mediated control of cardiovascular function. Circulation 2009; 120:753-63. [PMID: 19687357 DOI: 10.1161/circulationaha.109.853077] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Obesity causes hypertension and sympathoactivation, a process proposed to be mediated by leptin. Protein tyrosine phosphatase 1B (PTP1B), a major new pharmaceutical target in the treatment of obesity and type II diabetes mellitus, constrains the metabolic actions of leptin, but the extent to which PTP1B regulates its cardiovascular effects is unclear. This study examined the hypothesis that PTP1B is a negative regulator of the cardiovascular effects of leptin. METHODS AND RESULTS PTP1B knockout mice had lower body fat but higher mean arterial pressure (116+/-5 versus 105+/-5 mm Hg, P<0.05) than controls. Leptin infusion produced a greater anorexic effect in PTP1B knockout mice and a marked increase in mean arterial pressure (135+/-5 mm Hg) in PTP1B knockout mice only. The decrease in mean arterial pressure in response to ganglionic blockade was higher in PTP1B knockout mice (-38+/-3% versus -29+/-3%, P<0.05), which suggests increased sympathetic tone. PTP1B deletion blunted mean arterial pressure responses to phenylephrine injection (55+/-10% versus 93+/-7%, P<0.05). Phenylephrine-induced aortic contraction was reduced in PTP1B knockout mice (57.7+/-9% versus 96.3+/-12% of KCl, P<0.05), consistent with desensitization to chronically elevated sympathetic tone. Furthermore, PTP1B deletion significantly reduced gene expression of 3 alpha(1)-adrenergic receptor subtypes, consistent with blunted constriction to phenylephrine. CONCLUSIONS These data indicate that PTP1B is a key regulator of the cardiovascular effects of leptin and that reduced vascular adrenergic reactivity provides a compensatory limit to the effects of leptin on mean arterial pressure.
Collapse
|
46
|
Gahete MD, Durán-Prado M, Luque RM, Martínez-Fuentes AJ, Quintero A, Gutiérrez-Pascual E, Córdoba-Chacón J, Malagón MM, Gracia-Navarro F, Castaño JP. Understanding the multifactorial control of growth hormone release by somatotropes: lessons from comparative endocrinology. Ann N Y Acad Sci 2009; 1163:137-53. [PMID: 19456335 DOI: 10.1111/j.1749-6632.2008.03660.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Control of postnatal growth is the main, but not the only, role for growth hormone (GH) as this hormone also contributes to regulating metabolism, reproduction, immunity, development, and osmoregulation in different species. Likely owing to this variety of group-specific functions, GH production is differentially regulated across vertebrates, with an apparent evolutionary trend to simplification, especially in the number of stimulatory factors governing substantially GH release. Thus, teleosts exhibit a multifactorial regulation of GH secretion, with a number of factors, from the newly discovered fish GH-releasing hormone (GHRH) to pituitary adenylate cyclase-activating peptide (PACAP) but also gonadotropin-releasing hormone, dopamine, corticotropin-releasing hormone, and somatostatin(s) directly controlling somatotropes. In amphibians and reptiles, GH secretion is primarily stimulated by the major hypothalamic peptides GHRH and PACAP and inhibited by somatostatin(s), while other factors (ghrelin, thyrotropin-releasing hormone) also influence GH release. Finally, in birds and mammals, primary control of GH secretion is exerted by a dual interplay between GHRH and somatostatin. In addition, somatotrope function is modulated by additional hypothalamic and peripheral factors (e.g., ghrelin, leptin, insulin-like growth factor-I), which together enable a balanced integration of feedback signals related to processes in which GH plays a relevant regulatory role, such as metabolic and energy status, reproductive, and immune function. Interestingly, in contrast to the high number of stimulatory factors impinging upon somatotropes, somatostatin(s) stand(s) as the main primary inhibitory regulator(s) for this cell type.
Collapse
Affiliation(s)
- Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Cordoba, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
|
48
|
Kappeler L, De Magalhaes Filho C, Leneuve P, Xu J, Brunel N, Chatziantoniou C, Le Bouc Y, Holzenberger M. Early postnatal nutrition determines somatotropic function in mice. Endocrinology 2009; 150:314-23. [PMID: 18801897 DOI: 10.1210/en.2008-0981] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increasing evidence suggests a developmental origin for a number of human diseases, notably after intrauterine or postnatal nutrient deprivation. Nutritional changes readily translate into alterations of somatic growth. However, whereas intrauterine growth retardation often shows postnatal catch-up growth, recovery from food restriction immediately after birth is limited. Therefore, we investigated whether early postnatal nutrition (undernutrition and overfeeding) modifies plasticity of growth through developmental control of the somatotropic hormone axis. We used cross-fostering in mice to induce changes in early nutrition, and examined endocrine growth regulation and the development of specific disease phenotypes in adults. We showed that underfeeding during the early postnatal period delayed growth, whereas overfeeding accelerated it. In both cases, final body size was permanently altered. We found coordinated alterations in pituitary GH, plasma IGF-I and acid labile subunit, and gene expression of hypothalamic GHRH during postnatal development. These changes were consistent with the observed phenotypes. Alterations in the somatotropic axis persisted throughout adulthood. Although limited to the early postnatal period, both underfeeding and overfeeding led to reduced glucose tolerance later in life. These metabolic abnormalities were in line with defective insulin secretion in restricted mice and insulin resistance in overfed mice. Moreover, both restricted and overfed mice had increased arterial blood pressure, suggestive of vascular impairment. Our findings indicate a significant link between early postnatal diet, somatotropic development, and specific late onset diseases in mice. We suggest that, together with other hormones like leptin, IGF-I may play a role in modulating hypothalamic stimulation of the developing somatotropic function.
Collapse
Affiliation(s)
- Laurent Kappeler
- Institut National de la Santé et de la Recherche Médicale, Centre De Recherche Saint Antoine, Paris, France.
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Morgan DA, Thedens DR, Weiss R, Rahmouni K. Mechanisms mediating renal sympathetic activation to leptin in obesity. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1730-6. [PMID: 18815209 DOI: 10.1152/ajpregu.90324.2008] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Leptin plays a critical role in the control of energy homeostasis. The sympathetic cardiovascular actions of leptin have emerged as a potential link between obesity and hypertension. We previously demonstrated that in mice, modest obesity induced by 10 wk of a high-fat diet is associated with preservation of leptin ability to increase renal sympathetic nerve activity (SNA) despite the resistance to the metabolic effects of leptin. Here, we examined whether selective leptin resistance exists in mice with late-stage diet-induced obesity (DIO) produced by 20 wk of a high-fat diet. The decrease in food intake and body weight induced by intraperitoneal or intracerebroventricular injection of leptin was significantly attenuated in the DIO mice. Regional SNA responses to intravenous leptin were also attenuated in DIO mice. In contrast, intracerebroventricularly administered leptin caused contrasting effects on regional SNA in DIO mice. Renal SNA response to intracerebroventricular leptin was preserved, whereas lumbar and brown adipose tissue SNA responses were attenuated. Intact renal SNA response to leptin combined with the increased cerebrospinal fluid leptin levels in DIO mice represents a potential mechanism for the adverse cardiovascular consequences of obesity. Lastly, we examined the role of phosphoinositol-3 kinase (PI3K) and melanocortin receptors (MCR) in mediating the preserved renal SNA response to leptin in obesity. Presence of PI3K inhibitor (LY294002) or MC3/4R antagonist (SHU9119) significantly attenuated the renal SNA response to leptin in DIO and agouti obese mice. Our results demonstrate the importance of PI3K and melanocortin receptors in the transduction of leptin-induced renal sympathetic activation in obesity.
Collapse
Affiliation(s)
- Donald A Morgan
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | | | | | | |
Collapse
|
50
|
Abstract
PURPOSE OF REVIEW Leptin, first identified as the product of the ob gene in leptin-deficient obese (ob/ob) mice, was originally described as a circulating hormone involved in feeding behavior and energy homeostasis. It was later found to be a pleiotropic hormone involved in the regulation of a variety of physiological processes. This review summarizes our recent understanding of the role of leptin as a linear growth-stimulating factor. RECENT FINDINGS Leptin was found to have mitogenic effects on numerous cell types in vivo and in vitro, including several cancer cells, cells of the immune system, as well as chondrocytes of the epiphyseal growth plate. SUMMARY Leptin stimulates linear growth by regulating the energy balance of the organism and by stimulating the production and secretion of growth hormone from the hypothalamus; at the same time, it is involved with bone remodeling and has a direct effect on the chondrocytes of the growth plate.
Collapse
Affiliation(s)
- Galia Gat-Yablonski
- Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, Israel
| | | |
Collapse
|