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Begon E, Bernard V. [Prolactin and its receptor: From animal models to pituitary pathophysiology]. Biol Aujourdhui 2023; 216:105-110. [PMID: 36744975 DOI: 10.1051/jbio/2022019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Indexed: 02/07/2023]
Abstract
Prolactin (PRL) is a polypeptide hormone that is mainly synthesized and secreted by lactotroph cells of the anterior pituitary gland. The actions of prolactin are mediated by its transmembrane receptor, PRLR. The principal role attributed to PRL is to stimulate the proliferation and differentiation of the mammary cells required for lactation, but studies of animal models have assigned more than 300 separate actions to this hormone in various species. Hyperprolactinaemia is the prototypical pathological state associated with this hormone. Indeed, hyperprolactinaemia is the most common cause of amenorrhoea due to hypogonadotropic anovulation and is one of the most prevalent endocrine causes of infertility in women. In recent years, the study of conditional or complete Prlr -/- mouse models had improved the understanding concerning the regulation of gonadotroph and lactotroph axes. It is now demonstrated that prolactin exerts autocrine or paracrine actions on lactotroph cells in vivo. One of the major advances was to better understand, using mouse models, the impact of hyperprolactinemia on gonadotroph axis. It is now accepted that hypogonadotropic hypogonadism in patients with hyperprolactinemia is mediated by a decrease of hypothalamic kisspeptin secretion. Gonadotroph axis can be restored by intravenous administration of kisspeptin. However, the mechanisms of lactotroph tumorigenesis in Prlr -/- animals remain incompletely understood and transposable to the human species, since the only patient with biallelic PRLR loss-of-function mutation leading to complete prolactin resistance that has been described so far did not have pituitary adenoma visible on MRI.
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Affiliation(s)
- Emmanuelle Begon
- Service de chirurgie gynécologique, gynécologie médicale et de médecine de la reproduction, Centre Aliénor d'Aquitaine, CHU et Université de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux Cedex, France
| | - Valérie Bernard
- Service de chirurgie gynécologique, gynécologie médicale et de médecine de la reproduction, Centre Aliénor d'Aquitaine, CHU et Université de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux Cedex, France
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2
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Lay CS, Bridges A, Goulding J, Briddon SJ, Soloviev Z, Craggs PD, Hill SJ. Probing the binding of interleukin-23 to individual receptor components and the IL-23 heteromeric receptor complex in living cells using NanoBRET. Cell Chem Biol 2022; 29:19-29.e6. [PMID: 34038748 PMCID: PMC8790524 DOI: 10.1016/j.chembiol.2021.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/06/2021] [Accepted: 05/04/2021] [Indexed: 02/07/2023]
Abstract
Interleukin-23 (IL-23) is a pro-inflammatory cytokine involved in the host defense against pathogens but is also implicated in the development of several autoimmune disorders. The IL-23 receptor has become a key target for drug discovery, but the exact mechanism of the receptor ligand interaction remains poorly understood. In this study the affinities of IL-23 for its individual receptor components (IL23R and IL12Rβ1) and the heteromeric complex formed between them have been measured in living cells using NanoLuciferase-tagged full-length proteins. Here, we demonstrate that TAMRA-tagged IL-23 has a greater than 7-fold higher affinity for IL12Rβ1 than IL23R. However, in the presence of both receptor subunits, IL-23 affinity is increased more than three orders of magnitude to 27 pM. Furthermore, we show that IL-23 induces a potent change in the position of the N-terminal domains of the two receptor subunits, consistent with a conformational change in the heteromeric receptor structure.
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Affiliation(s)
- Charles S Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK; Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Angela Bridges
- Protein and Cellular Sciences, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Joelle Goulding
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK
| | - Zoja Soloviev
- Protein and Cellular Sciences, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Peter D Craggs
- Medicine Design, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK; GSK-Francis Crick Institute Linklabs, Medicinal Science and Technology, GlaxoSmithKline, Stevenage SG1 2NY, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, Universities of Birmingham and Nottingham, The Midlands, UK.
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3
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Chhabra Y, Lee CMM, Müller AF, Brooks AJ. GHR signalling: Receptor activation and degradation mechanisms. Mol Cell Endocrinol 2021; 520:111075. [PMID: 33181235 DOI: 10.1016/j.mce.2020.111075] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 12/21/2022]
Abstract
Growth hormone (GH) actions via initiating cell signalling through the GH receptor (GHR) are important for many physiological processes, in addition to its well-known role in regulating growth. The activation of JAK-STAT signalling by GH is well characterized, however knowledge on GH activation of SRC family kinases (SFKs) is still limited. In this review we summarise the collective knowledge on the activation, regulation, and downstream signalling of GHR. We highlight studies on GH activation of SFKs and the important outcome of this signalling pathway with a focus on the different degradation mechanisms that can regulate GHR availability since this is an area that warrants further study considering its role in tumour progression.
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Affiliation(s)
- Yash Chhabra
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia; Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21231, USA
| | - Christine M M Lee
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Alexandra Franziska Müller
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia
| | - Andrew J Brooks
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD, 4102, Australia.
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4
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Wang Y, Langley RJ, Tamshen K, Jamieson SM, Lu M, Maynard HD, Perry JK. Long-Acting Human Growth Hormone Receptor Antagonists Produced in E. coli and Conjugated with Polyethylene Glycol. Bioconjug Chem 2020; 31:1651-1660. [PMID: 32423203 DOI: 10.1021/acs.bioconjchem.0c00208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Growth hormone (GH) is a peptide hormone that mediates actions through binding to a cell surface GH receptor (GHR). The GHR antagonist, B2036, combines an amino acid substitution at 120 that confers GHR antagonist activity, with eight additional amino acid substitutions. Conjugation to polyethylene glycol (PEG) increases the serum half-life of these proteins due to reduced renal clearance. Recombinant forms of GH and its antagonists are mainly produced in prokaryotic expression systems, such as E. coli. However, efficient production in E. coli is problematic, as these proteins form aggregates as inclusion bodies resulting in poor solubility. In the present study, we demonstrate that N-terminal fusion to a thioredoxin (Trx) fusion partner improves soluble expression of codon-optimized B2036 in E. coli when expressed at 18 °C. Expression, purification and PEGylation protocols were established for three GHR antagonists: B2036, B20, and G120Rv. Following purification, these antagonists inhibited the proliferation of Ba/F3-GHR cells in a concentration-dependent manner. PEGylation with amine-reactive 5 kDa methoxy PEG succinimidyl propionate yielded a heterogeneous mixture of conjugates containing four to seven PEG moieties. PEGylation significantly reduced in vitro bioactivity of the conjugates. However, substitution of lysine to arginine at amino acid residue 120 in B2036 improved the in vitro activity of the PEGylated protein when compared to unmodified PEGylated B2036. Pharmacokinetic analysis demonstrated that the circulating half-life of PEGylated B20 was 15.2 h in mice. Taken together, we describe an effective strategy to produce biologically active PEGylated human GHR antagonists.
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Affiliation(s)
- Yue Wang
- Liggins Institute, University of Auckland, Auckland 1023, New Zealand
| | - Ries J Langley
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1023, New Zealand
| | - Kyle Tamshen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States
| | - Stephen M Jamieson
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1023, New Zealand.,Auckland Cancer Society Research Centre, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand
| | - Man Lu
- Liggins Institute, University of Auckland, Auckland 1023, New Zealand
| | - Heather D Maynard
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, United States.,California NanoSystems Institute, University of California, Los Angeles, 570 Westwood Plaza Building, Los Angeles, California 90095, United States
| | - Jo K Perry
- Liggins Institute, University of Auckland, Auckland 1023, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1023, New Zealand
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5
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Sander M, Wu Z, Strasburger CJ. Short stature explained by dimerization of human growth hormone induced by a p.C53S point mutation. J Biol Chem 2020; 295:4893-4901. [PMID: 32132170 DOI: 10.1074/jbc.ra119.009101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 02/29/2020] [Indexed: 11/06/2022] Open
Abstract
A homozygous mutation in growth hormone 1 (GH1) was recently identified in an individual with growth failure. This mutation, c.705G>C, causes replacement of cysteine at position 53 of the 191-amino-acid sequence of 22 kDa human GH (hGH) with serine (p.C53S). This hGH molecule (hereafter referred to as GH-C53S) lacks the disulfide bond between p.Cys-53 and p.Cys-165, which is highly conserved among species. It has been reported previously that monomeric GH-C53S has reduced bioactivity compared with WT GH (GH-WT) because of its decreased ability to bind and activate the GH receptor in vitro In this study, we discovered that substitution of p.Cys-53 in hGH significantly increased formation of hGH dimers in pituitary cells. We expressed His-tagged hGH variants in the cytoplasm of genetically modified Rosetta-gami B DE3 Escherichia coli cells, facilitating high-yield production. We observed that the bioactivity of monomeric GH-C53S is 25.2% of that of GH-WT and that dimeric GH-C53S-His has no significant bioactivity in cell proliferation assays. We also found that the expression of GH-C53S in pituitary cells deviates from that of GH-WT. GH-C53S was exclusively stained in the Golgi apparatus, and no secretory granules formed for this variant, impairing its stimulated release. In summary, the unpaired Cys-165 in GH-C53S forms a disulfide bond linking two hGH molecules in pituitary cells. We conclude that the GH-C53S dimer is inactive and responsible for the growth failure in the affected individual.
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Affiliation(s)
- Max Sander
- Department of Endocrinology, Diabetes, and Nutritional Medicine, Campus Charité Mitte, Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Zida Wu
- Department of Endocrinology, Diabetes, and Nutritional Medicine, Campus Charité Mitte, Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Christian J Strasburger
- Department of Endocrinology, Diabetes, and Nutritional Medicine, Campus Charité Mitte, Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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6
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Gorby C, Martinez-Fabregas J, Wilmes S, Moraga I. Mapping Determinants of Cytokine Signaling via Protein Engineering. Front Immunol 2018; 9:2143. [PMID: 30319612 PMCID: PMC6170656 DOI: 10.3389/fimmu.2018.02143] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Cytokines comprise a large family of secreted ligands that are critical for the regulation of immune homeostasis. Cytokines initiate signaling via dimerization or oligomerization of the cognate receptor subunits, triggering the activation of the Janus Kinases (JAKs)/ signal transducer and activator of transcription (STATs) pathway and the induction of specific gene expression programs and bioactivities. Deregulation of cytokines or their downstream signaling pathways are at the root of many human disorders including autoimmunity and cancer. Identifying and understanding the mechanistic principles that govern cytokine signaling will, therefore, be highly important in order to harness the therapeutic potential of cytokines. In this review, we will analyze how biophysical (ligand-receptor binding geometry and affinity) and cellular (receptor trafficking and intracellular abundance of signaling molecules) parameters shape the cytokine signalosome and cytokine functional pleiotropy; from the initial cytokine binding to its receptor to the degradation of the cytokine receptor complex in the proteasome and/or lysosome. We will also discuss how combining advanced protein engineering with detailed signaling and functional studies has opened promising avenues to tackle complex questions in the cytokine signaling field.
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Affiliation(s)
- Claire Gorby
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Jonathan Martinez-Fabregas
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Stephan Wilmes
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ignacio Moraga
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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7
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EPO does not promote interaction between the erythropoietin and beta-common receptors. Sci Rep 2018; 8:12457. [PMID: 30127368 PMCID: PMC6102255 DOI: 10.1038/s41598-018-29865-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 07/19/2018] [Indexed: 12/13/2022] Open
Abstract
A direct interaction between the erythropoietin (EPOR) and the beta-common (βc) receptors to form an Innate Repair Receptor (IRR) is controversial. On one hand, studies have shown a functional link between EPOR and βc receptor in tissue protection while others have shown no involvement of the βc receptor in tissue repair. To date there is no biophysical evidence to confirm a direct association of the two receptors either in vitro or in vivo. We investigated the existence of an interaction between the extracellular regions of EPOR and the βc receptor in silico and in vitro (either in the presence or absence of EPO or EPO-derived peptide ARA290). Although a possible interaction between EPOR and βc was suggested by our computational and genomic studies, our in vitro biophysical analysis demonstrates that the extracellular regions of the two receptors do not specifically associate. We also explored the involvement of the βc receptor gene (Csf2rb) under anaemic stress conditions and found no requirement for the βc receptor in mice. In light of these studies, we conclude that the extracellular regions of the EPOR and the βc receptor do not directly interact and that the IRR is not involved in anaemic stress.
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8
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Dehkhoda F, Lee CMM, Medina J, Brooks AJ. The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects. Front Endocrinol (Lausanne) 2018; 9:35. [PMID: 29487568 PMCID: PMC5816795 DOI: 10.3389/fendo.2018.00035] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/29/2018] [Indexed: 01/02/2023] Open
Abstract
The growth hormone receptor (GHR), although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK-STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.
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Affiliation(s)
- Farhad Dehkhoda
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Christine M. M. Lee
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Johan Medina
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Andrew J. Brooks
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
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9
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Chen L, Pan H, Zhang YH, Feng K, Kong X, Huang T, Cai YD. Network-Based Method for Identifying Co- Regeneration Genes in Bone, Dentin, Nerve and Vessel Tissues. Genes (Basel) 2017; 8:genes8100252. [PMID: 28974058 PMCID: PMC5664102 DOI: 10.3390/genes8100252] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/28/2017] [Indexed: 12/26/2022] Open
Abstract
Bone and dental diseases are serious public health problems. Most current clinical treatments for these diseases can produce side effects. Regeneration is a promising therapy for bone and dental diseases, yielding natural tissue recovery with few side effects. Because soft tissues inside the bone and dentin are densely populated with nerves and vessels, the study of bone and dentin regeneration should also consider the co-regeneration of nerves and vessels. In this study, a network-based method to identify co-regeneration genes for bone, dentin, nerve and vessel was constructed based on an extensive network of protein–protein interactions. Three procedures were applied in the network-based method. The first procedure, searching, sought the shortest paths connecting regeneration genes of one tissue type with regeneration genes of other tissues, thereby extracting possible co-regeneration genes. The second procedure, testing, employed a permutation test to evaluate whether possible genes were false discoveries; these genes were excluded by the testing procedure. The last procedure, screening, employed two rules, the betweenness ratio rule and interaction score rule, to select the most essential genes. A total of seventeen genes were inferred by the method, which were deemed to contribute to co-regeneration of at least two tissues. All these seventeen genes were extensively discussed to validate the utility of the method.
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Affiliation(s)
- Lei Chen
- School of Life Sciences, Shanghai University, Shanghai 200444, China.
- College of Information Engineering, Shanghai Maritime University, Shanghai 201306, China.
| | - Hongying Pan
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Harvard University, Boston, MA 02115, USA.
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA 02115, USA.
| | - Yu-Hang Zhang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Kaiyan Feng
- Department of Computer Science, Guangdong AIB Polytechnic, Guangzhou 510507, Guangdong, China.
| | - XiangYin Kong
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Tao Huang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Yu-Dong Cai
- School of Life Sciences, Shanghai University, Shanghai 200444, China.
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10
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Cell non-autonomous regulation of hepatic IGF-1 and neonatal growth by Kinase Suppressor of Ras 2 (KSR2). Sci Rep 2016; 6:32093. [PMID: 27561547 PMCID: PMC4999994 DOI: 10.1038/srep32093] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/02/2016] [Indexed: 12/18/2022] Open
Abstract
Individuals with poor postnatal growth are at risk for cardiovascular and metabolic problems as adults. Here we show that disruption of the molecular scaffold Kinase Suppressor of Ras 2 (KSR2) causes selective inhibition of hepatic GH signaling in neonatal mice with impaired expression of IGF-1 and IGFBP3. ksr2(-/-) mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development. However, disrupting FGF21 in ksr2(-/-) mice does not normalize mass, length, or bone density and content in fgf21(-/-)ksr2(-/-) mice. Body length, BMC and BMD, but not body mass, are rescued by infection of two-day-old ksr2(-/-) mice with a recombinant adenovirus encoding human IGF-1. Relative to wild-type mice, GH injections reveal a significant reduction in JAK2 and STAT5 phosphorylation in liver, but not in skeletal muscle, of ksr2(-/-) mice. However, primary hepatocytes isolated from ksr2(-/-) mice show no reduction in GH-stimulated STAT5 phosphorylation. These data indicate that KSR2 functions in a cell non-autonomous fashion to regulate GH-stimulated IGF-1 expression in the liver of neonatal mice, which plays a key role in the development of body length.
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11
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Corbett MSP, Poger D, Mark AE. Revisiting the scissor-like mechanism of activation for the erythropoietin receptor. FEBS Lett 2016; 590:3083-8. [PMID: 27490140 DOI: 10.1002/1873-3468.12340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 07/27/2016] [Accepted: 07/28/2016] [Indexed: 01/28/2023]
Abstract
An interpretation of alternative crystal structures of the erythropoietin receptor, with and without ligand, led to the proposal of a scissor-like mechanism of activation. This model has been propagated in the literature and is still being used to interpret crystal structures of related type-I cytokine receptors. Here, we assess whether the model remains compatible with current knowledge on the family of type-I cytokine receptors, and consider whether the model, as initially presented, is truly supported by the crystal structures on which it was originally based.
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Affiliation(s)
- Michael S P Corbett
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - David Poger
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Alan E Mark
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia.
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12
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Abstract
The regulation of organ size is essential to human health and has fascinated biologists for centuries. Key to the growth process is the ability of most organs to integrate organ-extrinsic cues (eg, nutritional status, inflammatory processes) with organ-intrinsic information (eg, genetic programs, local signals) into a growth response that adapts to changing environmental conditions and ensures that the size of an organ is coordinated with the rest of the body. Paired organs such as the vertebrate limbs and the long bones within them are excellent models for studying this type of regulation because it is possible to manipulate one member of the pair and leave the other as an internal control. During development, growth plates at the end of each long bone produce a transient cartilage model that is progressively replaced by bone. Here, we review how proliferation and differentiation of cells within each growth plate are tightly controlled mainly by growth plate-intrinsic mechanisms that are additionally modulated by extrinsic signals. We also discuss the involvement of several signaling hubs in the integration and modulation of growth-related signals and how they could confer remarkable plasticity to the growth plate. Indeed, long bones have a significant ability for "catch-up growth" to attain normal size after a transient growth delay. We propose that the characterization of catch-up growth, in light of recent advances in physiology and cell biology, will provide long sought clues into the molecular mechanisms that underlie organ growth regulation. Importantly, catch-up growth early in life is commonly associated with metabolic disorders in adulthood, and this association is not completely understood. Further elucidation of the molecules and cellular interactions that influence organ size coordination should allow development of novel therapies for human growth disorders that are noninvasive and have minimal side effects.
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Affiliation(s)
- Alberto Roselló-Díez
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065
| | - Alexandra L Joyner
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065
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13
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Li Q, Wong YL, Yueqi Lee M, Li Y, Kang C. Solution structure of the transmembrane domain of the mouse erythropoietin receptor in detergent micelles. Sci Rep 2015; 5:13586. [PMID: 26316120 PMCID: PMC4551963 DOI: 10.1038/srep13586] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 07/31/2015] [Indexed: 12/19/2022] Open
Abstract
Erythropoiesis is regulated by the erythropoietin receptor (EpoR) binding to its ligand. The transmembrane domain (TMD) and the juxtamembrane (JM) regions of the EpoR are important for signal transduction across the cell membrane. We report a solution NMR study of the mouse erythropoietin receptor (mEpoR) comprising the TMD and the JM regions reconstituted in dodecylphosphocholine (DPC) micelles. The TMD and the C-terminal JM region of the mEpoR are mainly α-helical, adopting a similar structure to those of the human EpoR. Residues from S216 to T219 in mEpoR form a short helix. Relaxation study demonstrates that the TMD of the mEpoR is rigid whilst the N-terminal region preceding the TMD is flexible. Fluorescence spectroscopy and sequence analysis indicate that the C-terminal JM region is exposed to the solvent. Helix wheel result shows that there is hydrophilic patch in the TMD of the mEpoR formed by residues S231, S238 and T242, and these residues might be important for the receptor dimerization.
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Affiliation(s)
- Qingxin Li
- Institute of Chemical &Engineering Sciences, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Ying Lei Wong
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Michelle Yueqi Lee
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - Yan Li
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
| | - CongBao Kang
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore, 138669 Singapore
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14
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Abstract
Prolactin is a hormone that is mainly secreted by lactotroph cells of the anterior pituitary gland, and is involved in many biological processes including lactation and reproduction. Animal models have provided insights into the biology of prolactin proteins and offer compelling evidence that the different prolactin isoforms each have independent biological functions. The major isoform, 23 kDa prolactin, acts via its membrane receptor, the prolactin receptor (PRL-R), which is a member of the haematopoietic cytokine superfamily and for which the mechanism of activation has been deciphered. The 16 kDa prolactin isoform is a cleavage product derived from native prolactin, which has received particular attention as a result of its newly described inhibitory effects on angiogenesis and tumorigenesis. The discovery of multiple extrapituitary sites of prolactin secretion also increases the range of known functions of this hormone. This Review summarizes current knowledge of the biology of prolactin and its receptor, as well as its physiological and pathological roles. We focus on the role of prolactin in human pathophysiology, particularly the discovery of the mechanism underlying infertility associated with hyperprolactinaemia and the identification of the first mutation in human PRLR.
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Affiliation(s)
- Valérie Bernard
- Inserm U1185, 63 rue Gabriel Péri, 94276 Le Kremlin-Bicêtre Cedex, France
| | - Jacques Young
- Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, 78 rue du Général Leclerc 94275 Le Kremlin-Bicêtre Cedex, France
| | - Philippe Chanson
- Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, 78 rue du Général Leclerc 94275 Le Kremlin-Bicêtre Cedex, France
| | - Nadine Binart
- Inserm U1185, 63 rue Gabriel Péri, 94276 Le Kremlin-Bicêtre Cedex, France
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15
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Waters M, Brooks A. JAK2 activation by growth hormone and other cytokines. Biochem J 2015; 466:1-11. [PMID: 25656053 PMCID: PMC4325515 DOI: 10.1042/bj20141293] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 11/17/2014] [Accepted: 11/24/2014] [Indexed: 12/30/2022]
Abstract
Growth hormone (GH) and structurally related cytokines regulate a great number of physiological and pathological processes. They do this by coupling their single transmembrane domain (TMD) receptors to cytoplasmic tyrosine kinases, either as homodimers or heterodimers. Recent studies have revealed that many of these receptors exist as constitutive dimers rather than being dimerized as a consequence of ligand binding, which has necessitated a new paradigm for describing their activation process. In the present study, we describe a model for activation of the tyrosine kinase Janus kinase 2 (JAK2) by the GH receptor homodimer based on biochemical data and molecular dynamics simulations. Binding of the bivalent ligand reorientates and rotates the receptor subunits, resulting in a transition from a form with parallel TMDs to one where the TMDs separate at the point of entry into the cytoplasm. This movement slides the pseudokinase inhibitory domain of one JAK kinase away from the kinase domain of the other JAK within the receptor dimer-JAK complex, allowing the two kinase domains to interact and trans-activate. This results in phosphorylation and activation of STATs and other signalling pathways linked to this receptor which then regulate postnatal growth, metabolism and stem cell activation. We believe that this model will apply to most if not all members of the class I cytokine receptor family, and will be useful in the design of small antagonists and agonists of therapeutic value.
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Key Words
- class i cytokine receptors
- cytokine receptor signalling
- growth hormone
- growth hormone receptor
- janus kinase 2 (jak2)
- srk family kinases
- cntf, ciliary neurotropic factor
- crh, cytokine receptor homology
- ct-1, cardiotropin-1
- ecd, extracellular domain
- epo, erythropoietin
- fniii, fibronectin iii-like
- gh, growth hormone
- gm-csf, granulocyte-macrophage colony-stimulating factor
- jak, janus kinase
- jm, juxtamembrane
- mab, monoclonal antibody
- osm, oncostatin-m
- pk, pseudokinase
- tmd, transmembrane domain
- tpo, thrombopoietin
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Affiliation(s)
- Michael J. Waters
- *Institute for Molecular Bioscience, The University of Queensland Institute, QLD 4072, Australia
| | - Andrew J. Brooks
- *Institute for Molecular Bioscience, The University of Queensland Institute, QLD 4072, Australia
- †The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, QLD 4072, Australia
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Zheng X, Li S, Zhang WH, Yang H. Metabolic abnormalities in pituitary adenoma patients: a novel therapeutic target and prognostic factor. Diabetes Metab Syndr Obes 2015; 8:357-61. [PMID: 26347444 PMCID: PMC4531036 DOI: 10.2147/dmso.s86319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Metabolic abnormalities are common in cancers, and targeting metabolism is emerging as a novel therapeutic approach to cancer management. Pituitary adenoma (PA) is a type of benign tumor. Impairment of tumor cells' metabolism in PA seems not to be as apparent as that of other malignant tumor cells; however, aberrant hormone secretion is conspicuous in most PAs. Hormones have direct impacts on systemic metabolism, which in turn, may affect the progression of PA. Nowadays, conventional therapeutic strategies for PA do not include modalities of adjusting whole-body metabolism, which is most likely due to the current consideration of the aberrant whole-body metabolism of PA patients as a passive associated symptom and not involved in PA progression. Because systemic metabolic abnormalities are presented by 22.3%-52.5% PA patients and are closely correlated with disease progression and prognosis, we propose that assessment of metabolic status should be emphasized during the treatment of PA and that control of metabolic abnormalities should be added into the current therapies for PA.
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Affiliation(s)
- Xin Zheng
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Shapingba District, Chongqing, People’s Republic of China
| | - Song Li
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Shapingba District, Chongqing, People’s Republic of China
| | - Wei-hua Zhang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Hui Yang
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Shapingba District, Chongqing, People’s Republic of China
- Correspondence: Hui Yang, Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, 183 Xinqiao Main Street, Shapingba District, Chongqing 400037, People’s Republic of China, Tel +86 023 6875 5610, Fax +86 023 6521 8204, Email
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