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Ruggiero-Ruff RE, Le BH, Villa PA, Lainez NM, Athul SW, Das P, Ellsworth BS, Coss D. Single-Cell Transcriptomics Identifies Pituitary Gland Changes in Diet-Induced Obesity in Male Mice. Endocrinology 2024; 165:bqad196. [PMID: 38146776 PMCID: PMC10791142 DOI: 10.1210/endocr/bqad196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 12/27/2023]
Abstract
Obesity is a chronic disease with increasing prevalence worldwide. Obesity leads to an increased risk of heart disease, stroke, and diabetes, as well as endocrine alterations, reproductive disorders, changes in basal metabolism, and stress hormone production, all of which are regulated by the pituitary. In this study, we performed single-cell RNA sequencing of pituitary glands from male mice fed control and high-fat diet (HFD) to determine obesity-mediated changes in pituitary cell populations and gene expression. We determined that HFD exposure is associated with dramatic changes in somatotrope and lactotrope populations, by increasing the proportion of somatotropes and decreasing the proportion of lactotropes. Fractions of other hormone-producing cell populations remained unaffected. Gene expression changes demonstrated that in HFD, somatotropes became more metabolically active, with increased expression of genes associated with cellular respiration, and downregulation of genes and pathways associated with cholesterol biosynthesis. Despite a lack of changes in gonadotrope fraction, genes important in the regulation of gonadotropin hormone production were significantly downregulated. Corticotropes and thyrotropes were the least affected in HFD, while melanotropes exhibited reduced proportion. Lastly, we determined that changes in plasticity and gene expression were associated with changes in hormone levels. Serum prolactin was decreased corresponding to reduced lactotrope fraction, while lower luteinizing hormone and follicle-stimulating hormone in the serum corresponded to a decrease in transcription and translation. Taken together, our study highlights diet-mediated changes in pituitary gland populations and gene expression that play a role in altered hormone levels in obesity.
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Affiliation(s)
- Rebecca E Ruggiero-Ruff
- Division of Biomedical Sciences; School of Medicine, University of California, Riverside, CA 92521, USA
| | - Brandon H Le
- Institute for Integrative Genome Biology Bioinformatics Core Facility, University of California, Riverside, CA 92521, USA
| | - Pedro A Villa
- Division of Biomedical Sciences; School of Medicine, University of California, Riverside, CA 92521, USA
| | - Nancy M Lainez
- Division of Biomedical Sciences; School of Medicine, University of California, Riverside, CA 92521, USA
| | - Sandria W Athul
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL 62901, USA
| | - Pratyusa Das
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL 62901, USA
| | - Buffy S Ellsworth
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL 62901, USA
| | - Djurdjica Coss
- Division of Biomedical Sciences; School of Medicine, University of California, Riverside, CA 92521, USA
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Gonigam RL, Weis KE, Ge X, Yao B, Zhang Q, Raetzman LT. Characterization of Somatotrope Cell Expansion in Response to GHRH in the Neonatal Mouse Pituitary. Endocrinology 2023; 164:bqad131. [PMID: 37616545 PMCID: PMC11009787 DOI: 10.1210/endocr/bqad131] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/25/2023] [Accepted: 08/22/2023] [Indexed: 08/26/2023]
Abstract
In humans and mice, loss-of-function mutations in growth hormone-releasing hormone receptor (GHRHR) cause isolated GH deficiency. The mutant GHRHR mouse model, GhrhrLit/Lit (LIT), exhibits loss of serum GH, but also fewer somatotropes. However, how loss of GHRH signaling affects expansion of stem and progenitor cells giving rise to GH-producing cells is unknown. LIT mice and wild-type littermates were examined for differences in proliferation and gene expression of pituitary lineage markers by quantitative reverse transcription polymerase chain reaction and immunohistochemistry at postnatal day 5 (p5) and 5 weeks. At p5, the LIT mouse shows a global decrease in pituitary proliferation measured by proliferation marker Ki67 and phospho-histone H3. This proliferative defect is seen in a pituitary cell expressing POU1F1 with or without GH. SOX9-positive progenitors show no changes in proliferation in p5 LIT mice. Additionally, the other POU1F1 lineage cells are not decreased in number; rather, we observe an increase in lactotrope cell population as well as messenger RNA for Tshb and Prl. In the 5-week LIT pituitary, the proliferative deficit in POU1F1-expressing cells observed neonatally persists, while the number and proliferative proportion of SOX9 cells do not appear changed. Treatment of cultured pituitary explants with GHRH promotes proliferation of POU1F1-expressing cells, but not GH-positive cells, in a mitogen-activated protein kinase-dependent manner. These findings indicate that hypothalamic GHRH targets proliferation of a POU1F1-positive cell, targeted to the somatotrope lineage, to fine tune their numbers.
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Affiliation(s)
- Richard L Gonigam
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Karen E Weis
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Xiyu Ge
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Boyuan Yao
- Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
- National Center for Neurological Disorders, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
| | - Qilin Zhang
- Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
- National Center for Neurological Disorders, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China
| | - Lori T Raetzman
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
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Allensworth-James M, Banik J, Odle A, Hardy L, Lagasse A, Moreira ARS, Bird J, Thomas CL, Avaritt N, Kharas MG, Lengner CJ, Byrum SD, MacNicol MC, Childs GV, MacNicol AM. Control of the Anterior Pituitary Cell Lineage Regulator POU1F1 by the Stem Cell Determinant Musashi. Endocrinology 2021; 162:6054984. [PMID: 33373440 PMCID: PMC7814296 DOI: 10.1210/endocr/bqaa245] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Indexed: 12/14/2022]
Abstract
The adipokine leptin regulates energy homeostasis through ubiquitously expressed leptin receptors. Leptin has a number of major signaling targets in the brain, including cells of the anterior pituitary (AP). We have previously reported that mice lacking leptin receptors in AP somatotropes display growth hormone (GH) deficiency, metabolic dysfunction, and adult-onset obesity. Among other targets, leptin signaling promotes increased levels of the pituitary transcription factor POU1F1, which in turn regulates the specification of somatotrope, lactotrope, and thyrotrope cell lineages within the AP. Leptin's mechanism of action on somatotropes is sex dependent, with females demonstrating posttranscriptional control of Pou1f1 messenger RNA (mRNA) translation. Here, we report that the stem cell marker and mRNA translational control protein, Musashi1, exerts repression of the Pou1f1 mRNA. In female somatotropes, Msi1 mRNA and protein levels are increased in the mouse model that lacks leptin signaling (Gh-CRE Lepr-null), coincident with lack of POU1f1 protein, despite normal levels of Pou1f1 mRNA. Single-cell RNA sequencing of pituitary cells from control female animals indicates that both Msi1 and Pou1f1 mRNAs are expressed in Gh-expressing somatotropes, and immunocytochemistry confirms that Musashi1 protein is present in the somatotrope cell population. We demonstrate that Musashi interacts directly with the Pou1f1 mRNA 3' untranslated region and exerts translational repression of a Pou1f1 mRNA translation reporter in a leptin-sensitive manner. Musashi immunoprecipitation from whole pituitary reveals coassociated Pou1f1 mRNA. These findings suggest a mechanism in which leptin stimulation is required to reverse Musashi-mediated Pou1f1 mRNA translational control to coordinate AP somatotrope function with metabolic status.
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Affiliation(s)
- Melody Allensworth-James
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jewel Banik
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Angela Odle
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Linda Hardy
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Alex Lagasse
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ana Rita Silva Moreira
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jordan Bird
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | | | - Nathan Avaritt
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | | | | | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Arkansas Children’s Research Institute, Little Rock, Arkansas, USA
| | - Melanie C MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Gwen V Childs
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Angus M MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Correspondence: Angus M. MacNicol, PhD, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR 72205, USA.
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4
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Mirczuk SM, Scudder CJ, Read JE, Crossley VJ, Regan JT, Richardson KM, Simbi B, McArdle CA, Church DB, Fenn J, Kenny PJ, Volk HA, Wheeler-Jones CP, Korbonits M, Niessen SJ, McGonnell IM, Fowkes RC. Natriuretic Peptide Expression and Function in GH3 Somatolactotropes and Feline Somatotrope Pituitary Tumours. Int J Mol Sci 2021; 22:ijms22031076. [PMID: 33499110 PMCID: PMC7865297 DOI: 10.3390/ijms22031076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Patients harbouring mutations in genes encoding C-type natriuretic peptide (CNP; NPPC) or its receptor guanylyl cyclase B (GC-B, NPR2) suffer from severe growth phenotypes; loss-of-function mutations cause achondroplasia, whereas gain-of-function mutations cause skeletal overgrowth. Although most of the effects of CNP/GC-B on growth are mediated directly on bone, evidence suggests the natriuretic peptides may also affect anterior pituitary control of growth. Our previous studies described the expression of NPPC and NPR2 in a range of human pituitary tumours, normal human pituitary, and normal fetal human pituitary. However, the natriuretic peptide system in somatotropes has not been extensively explored. Here, we examine the expression and function of the CNP/GC-B system in rat GH3 somatolactotrope cell line and pituitary tumours from a cohort of feline hypersomatotropism (HST; acromegaly) patients. Using multiplex RT-qPCR, all three natriuretic peptides and their receptors were detected in GH3 cells. The expression of Nppc was significantly enhanced following treatment with either 100 nM TRH or 10 µM forskolin, yet only Npr1 expression was sensitive to forskolin stimulation; the effects of forskolin and TRH on Nppc expression were PKA- and MAPK-dependent, respectively. CNP stimulation of GH3 somatolactotropes significantly inhibited Esr1, Insr and Lepr expression, but dramatically enhanced cFos expression at the same time point. Oestrogen treatment significantly enhanced expression of Nppa, Nppc, Npr1, and Npr2 in GH3 somatolactotropes, but inhibited CNP-stimulated cGMP accumulation. Finally, transcripts for all three natriuretic peptides and receptors were expressed in feline pituitary tumours from patients with HST. NPPC expression was negatively correlated with pituitary tumour volume and SSTR5 expression, but positively correlated with D2R and GHR expression. Collectively, these data provide mechanisms that control expression and function of CNP in somatolactotrope cells, and identify putative transcriptional targets for CNP action in somatotropes.
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Affiliation(s)
- Samantha M. Mirczuk
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Christopher J. Scudder
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
| | - Jordan E. Read
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Victoria J. Crossley
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Jacob T. Regan
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
| | - Karen M. Richardson
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
| | - Bigboy Simbi
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Craig A. McArdle
- Department of Translational Science, Bristol Medical School, University of Bristol, Whitson Street, Bristol BS1 3NY, UK;
| | - David B. Church
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
| | - Joseph Fenn
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
| | - Patrick J. Kenny
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
- Small Animal Specialist Hospital, 1 Richardson Place, North Ryde, 2113 NSW, Australia
| | - Holger A. Volk
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559 Hannover, Germany
| | - Caroline P. Wheeler-Jones
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Márta Korbonits
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK;
| | - Stijn J. Niessen
- Clinical Sciences & Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; (D.B.C.); (J.F.); (P.J.K.); (H.A.V.); (S.J.N.)
| | - Imelda M. McGonnell
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
| | - Robert C. Fowkes
- Endocrine Signalling Group, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (S.M.M.); (C.J.S.); (J.E.R.); (V.J.C.); (J.T.R.); (K.M.R.)
- Comparative Biomedical Sciences, Royal Veterinary College, University of London, Royal College Street, London NW1 0TU, UK; (B.S.); (C.P.W.-J.); (I.M.M.)
- Correspondence: ; Tel.: +11-44-207-468-1215
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Miles TK, Silva Moreira AR, Allensworth-James ML, Odle AK, Haney AC, MacNicol AM, MacNicol MC, Childs GV. Sex differences in somatotrope response to fasting: biphasic responses in male mice. J Endocrinol 2020; 247:213-224. [PMID: 33112825 PMCID: PMC7673470 DOI: 10.1530/joe-20-0275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 09/22/2020] [Indexed: 11/08/2022]
Abstract
Anterior pituitary somatotropes are important metabolic sensors responding to leptin by secreting growth hormone (GH). However, reduced leptin signals caused by fasting have not always correlated with reduced serum GH. Reports show that fasting may stimulate or reduce GH secretion, depending on the species. Mechanisms underlying these distinct somatotrope responses to fasting remain unknown. To define the somatotrope response to decreased leptin signaling we examined markers of somatotrope function over different time periods of fasting. Male mice were fasted for 24 and 48 h, with female mice fasted for 24 h compared to fed controls ad libitum. Body weight and serum glucose were reduced in both males and females, but, unexpectedly, serum leptin was reduced only in males. Furthermore, in males, serum GH levels showed a biphasic response with significant reductions at 24 h followed by a significant rise at 48 h, which coincided with the rise in serum ghrelin levels. In contrast, females showed an increase in serum GH at 24 h. We then explored mechanisms underlying the differential somatotrope responses seen in males and observed that pituitary levels of Gh mRNA increased, with no distinction between acute and prolonged fasting. By contrast, the Ghrhr mRNA (encoding GH releasing hormone receptor) and the Ghsr mRNA (encoding the ghrelin receptor) were both greatly increased at prolonged fasting times coincident with increased serum GH. These findings show sex differences in the somatotrope and adipocyte responses to fasting and support an adaptive role for somatotropes in males in response to multiple metabolic signals.
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Affiliation(s)
- Tiffany K Miles
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ana Rita Silva Moreira
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Melody L Allensworth-James
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Angela K Odle
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Anessa C Haney
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Angus M MacNicol
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Melanie C MacNicol
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Gwen V Childs
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Peel MT, Ho Y, Liebhaber SA. The Transcription Factor NR4A2 Plays an Essential Role in Driving Prolactin Expression in Female Pituitary Lactotropes. Endocrinology 2020; 161:5809733. [PMID: 32188976 PMCID: PMC7195901 DOI: 10.1210/endocr/bqaa046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 03/13/2020] [Indexed: 12/11/2022]
Abstract
Differentiation of the hormone-producing cells of the pituitary represents an informative model of cell fate determination. The generation and maintenance of 2 pituitary lineages, the growth hormone (GH)- producing somatotropes and the prolactin (PRL)- producing lactotropes, are dependent on the pituitary-specific transcription factor, POU1F1. While POU1F1 is expressed in both cell types, and plays a role in activation of both the Gh and Prl genes, expression of Gh and Prl is restricted to somatotropes and lactotropes, respectively. These observations imply the existence of additional factors that contribute to the somatotrope and lactotrope identities and their hormone expressions. Prior transcriptome analysis of primary somatotropes and lactotropes isolated from the mouse pituitary identified enrichment of a transcription factor, Nr4a2, in the lactotropes. Nr4a2 was shown in a cell culture model to bind the Prl promoter at a position adjacent to Pou1f1 and to synergize with Pou1f1 in driving Prl transcription. Here we demonstrate in vivo the role of Nr4a2 as an enhancer of Prl expression by conditional gene inactivation of the Nr4a2 gene in mouse lactotropes. We demonstrate that nuclear orphan receptor transcription factor (NR4A2) binding at the Prl promoter is dependent on actions of POU1F1; while POU1F1 is essential to loading polymerase (Pol) II on the Prl promoter, Nr4a2 plays a role in enhancing Pol II release into the Prl gene body. These studies establish an in vivo role of Nr4a2 in enhancing Prl expression in mouse lactotropes, explore its mechanism of action, and establish a system for further study of the lactotrope lineage in the pituitary.
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MESH Headings
- Animals
- Cells, Cultured
- Female
- Gene Expression Regulation
- Lactotrophs/cytology
- Lactotrophs/metabolism
- Mice, Inbred Strains
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Fluorescence
- Nuclear Receptor Subfamily 4, Group A, Member 2/genetics
- Nuclear Receptor Subfamily 4, Group A, Member 2/metabolism
- Pituitary Gland/cytology
- Pituitary Gland/metabolism
- Prolactin/genetics
- Prolactin/metabolism
- Promoter Regions, Genetic/genetics
- Protein Binding
- Transcription Factor Pit-1/genetics
- Transcription Factor Pit-1/metabolism
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Affiliation(s)
- Michael T Peel
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
| | - Yugong Ho
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
- Correspondence: Yugong Ho, Department of Genetics, Clinical Research Building, 415 Curie Blvd, Philadelphia, PA, 19104. E-mail:
| | - Stephen A Liebhaber
- Department of Genetics, University of Pennsylvania, Philadelphia, PA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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Ellsworth BS, Stallings CE. Molecular Mechanisms Governing Embryonic Differentiation of Pituitary Somatotropes. Trends Endocrinol Metab 2018; 29:510-523. [PMID: 29759686 DOI: 10.1016/j.tem.2018.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 02/07/2023]
Abstract
Pituitary somatotropes secrete growth hormone (GH), which is essential for normal growth and metabolism. Somatotrope defects result in GH deficiency (GHD), leading to short stature in childhood and increased cardiovascular morbidity and mortality in adulthood. Current hormone replacement therapies fail to recapitulate normal pulsatile GH secretion. Stem cell therapies could overcome this problem but are dependent on a thorough understanding of somatotrope differentiation. Although several transcription factors, signaling pathways, and hormones that regulate this process have been identified, the mechanisms of action are not well understood. The purpose of this review is to highlight the known players in somatotrope differentiation while emphasizing the need to better understand these pathways to serve patients with GHD.
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Affiliation(s)
- Buffy S Ellsworth
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL 62901-6523, USA.
| | - Caitlin E Stallings
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL 62901-6523, USA
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8
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Chen D, Yang W, Han S, Yang H, Cen X, Liu J, Zhang L, Zhang W. A Type IIb, but Not Type IIa, GnRH Receptor Mediates GnRH-Induced Release of Growth Hormone in the Ricefield Eel. Front Endocrinol (Lausanne) 2018; 9:721. [PMID: 30555419 PMCID: PMC6283897 DOI: 10.3389/fendo.2018.00721] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022] Open
Abstract
Multiple gonadotropin-releasing hormone receptors (GnRHRs) are present in vertebrates, but their differential physiological relevances remain to be clarified. In the present study, we identified three GnRH ligands GnRH1 (pjGnRH), GnRH2 (cGnRH-II), and GnRH3 (sGnRH) from the brain, and two GnRH receptors GnRHR1 (GnRHR IIa) and GnRHR2 (GnRHR IIb) from the pituitary of the ricefield eel Monopterus albus. GnRH1 and GnRH3 but not GnRH2 immunoreactive neurons were detected in the pre-optic area, hypothalamus, and pituitary, suggesting that GnRH1 and GnRH3 may exert hypophysiotropic roles in ricefield eels. gnrhr1 mRNA was mainly detected in the pituitary, whereas gnrhr2 mRNA broadly in tissues of both females and males. In the pituitary, GnRHR1 and GnRHR2 immunoreactive cells were differentially distributed, with GnRHR1 immunoreactive cells mainly in peripheral areas of the adenohypophysis whereas GnRHR2 immunoreactive cells in the multicellular layers of adenohypophysis adjacent to the neurohypophysis. Dual-label fluorescent immunostaining showed that GnRHR2 but not GnRHR1 was localized to somatotropes, and all somatotropes are GnRHR2-positive cells and vice versa at all stages examined. GnRH1 and GnRH3 were shown to stimulate growth hormone (Gh) release from primary culture of pituitary cells, and to decrease Gh contents in the pituitary of ricefield eels 12 h post injection. GnRH1 and GnRH3 stimulated Gh release probably via PLC/IP3/PKC and Ca2+ pathways. These results, as a whole, suggested that GnRHs may bind to GnRHR2 but not GnRHR1 to trigger Gh release in ricefield eels, and provided novel information on differential roles of multiple GnRH receptors in vertebrates.
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Affiliation(s)
- Dong Chen
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wei Yang
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Shiying Han
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Huiyi Yang
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Xin Cen
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jiang Liu
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Lihong Zhang
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
- *Correspondence: Lihong Zhang
| | - Weimin Zhang
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, Sun Yat-Sen University, Guangzhou, China
- Weimin Zhang
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Kobayashi K, Yamamoto K, Kikuyama S, Machida T, Kobayashi T. Impaired Development of Somatotropes, Lactotropes and Thyrotropes in Growth-Retarded (grt) Mice. J Toxicol Pathol 2009; 22:187-94. [PMID: 22271993 PMCID: PMC3252040 DOI: 10.1293/tox.22.187] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 06/17/2009] [Indexed: 11/22/2022] Open
Abstract
Congenitally primary hypothyroid growth-retarded (grt) mice exhibit a characteristic growth pause followed by delayed onset of pubertal growth. We characterized the developmental pattern of somatotropes, lactotropes and thyrotropes in the anterior pituitary, as well as plasma levels of their secretory hormones, in grt mice. Compared with normal mice, the weight of grt pituitary gland was similar at 8 weeks of age but significantly heavier after 12 weeks of age. Compared with normal mice, there were significantly fewer somatotropes in the grt pituitary until 8 weeks of age, but the number gradually increased up to 48 weeks. The number of lactotropes in grt mice was consistently lower than that in normal mice from 2 through 48 weeks, whereas the number of thyrotropes in the grt pituitary was consistently higher than in the normal pituitary. Thyrotropes in the grt pituitary exhibited hypertrophy and hyperplasia with less intensive thyroid-stimulating hormone (TSH) immunoreactivity than normal thyrotropes. In normal mice, the sum of the relative proportions of these cells plateaued at 8 weeks, where it remained up to 48 weeks of age. In grt mice, these proportions almost reached normal levels at 12 weeks of age but gradually declined after 24 weeks. Plasma growth hormone concentrations did not differ between grt and normal mice until 24 weeks of age. Compared with normal mice, grt mice exhibited significantly lower plasma prolactin and thyroxine levels but higher TSH levels. These findings indicate that development of somatotropes, lactotropes and thyrotropes in grt mice is impaired, being followed by altered hormone secretion.
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Affiliation(s)
- Kenichi Kobayashi
- Department of Regulation Biology, Faculty of Science, Saitama University, 255 Shimookubo, Sakura, Saitama 338–8570, Japan
- National Institute of Occupational Safety and Health, 6–21–1 Nagao, Tama-ku, Kawasaki 214–8585, Japan
| | - Kazutoshi Yamamoto
- Department of Biology, School of Education, Waseda University, 1–104 Totsuka-machi, Shinjuku-ku, Tokyo 169–8050, Japan
| | - Sakae Kikuyama
- Department of Biology, School of Education, Waseda University, 1–104 Totsuka-machi, Shinjuku-ku, Tokyo 169–8050, Japan
| | - Takeo Machida
- Department of Regulation Biology, Faculty of Science, Saitama University, 255 Shimookubo, Sakura, Saitama 338–8570, Japan
| | - Tetsuya Kobayashi
- Department of Regulation Biology, Faculty of Science, Saitama University, 255 Shimookubo, Sakura, Saitama 338–8570, Japan
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Shimokawa I, Tomita M, Higami Y, Okimoto T, Kawahara T, Ikeda T. Dietary restriction maintains the basal rate of somatotrope renewal in later life in male rats. Age (Omaha) 1997; 20:169-174. [PMID: 23604309 PMCID: PMC3455894 DOI: 10.1007/s11357-997-0016-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We investigated the impact of dietary restriction on the basal rate of somatotrope renewal in the pituitary gland. Bromodeoxyuridine (BrdU), a thymidine analog, was administered continuously for 1 week in male F344 rats at 3, 8 and 20 months of age (mo), fed ad libitum (AL) or diet restricted from 1.5 mo (DR). Combined immunostainings for BrdU and GH visualized newly formed somatotropes as well as pituitary cells in tissue sections. The rate of incorporation of BrdU by anterior pituitary cells (BrdU-labeled nuclei/100 nuclei) was not influenced by the dietary regimen or age. The fraction of BrdU-labeled somatotropes relative to all labeled cells precipitously decreased to the same level in both dietary groups between 3 and 8 mo, although the fraction was greater in DR rats at 3 mo. In AL rats, the fraction decreased further between 8 and 20 mo, while it stabilized in DR rats. Our results suggested that dietary restriction maintains the basal rate of somatotrope renewal in later life in male rats. Although one must also estimate the effects of dietary restriction on apoptotic cell death in pituitary cells, the present study provides evidence that dietary restriction modulates somatotropes cell turnover and preserves the cell population for GH secretion during aging.
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Affiliation(s)
- Isao Shimokawa
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
| | - Masato Tomita
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
| | - Yoshikazu Higami
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
| | - Tomoaki Okimoto
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
| | - Toshio Kawahara
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
| | - Takayoshi Ikeda
- Department of Pathology, Nagasaki University School of Medicine, 1-12-4 Sakamoto, Nagasaki City, 852 Japan
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