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Garcia-Rendueles AR, Chenlo M, Oroz-Gonjar F, Solomou A, Mistry A, Barry S, Gaston-Massuet C, Garcia-Lavandeira M, Perez-Romero S, Suarez-Fariña M, Pradilla-Dieste A, Dieguez C, Mehlen P, Korbonits M, Alvarez CV. RET signalling provides tumorigenic mechanism and tissue specificity for AIP-related somatotrophinomas. Oncogene 2021; 40:6354-6368. [PMID: 34588620 PMCID: PMC8585666 DOI: 10.1038/s41388-021-02009-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 08/21/2021] [Accepted: 09/06/2021] [Indexed: 02/07/2023]
Abstract
It is unclear how loss-of-function germline mutations in the widely-expressed co-chaperone AIP, result in young-onset growth hormone secreting pituitary tumours. The RET receptor, uniquely co-expressed in somatotrophs with PIT1, induces apoptosis when unliganded, while RET supports cell survival when it is bound to its ligand. We demonstrate that at the plasma membrane, AIP is required to form a complex with monomeric-intracellular-RET, caspase-3 and PKCδ resulting in PIT1/CDKN2A-ARF/p53-apoptosis pathway activation. AIP-deficiency blocks RET/caspase-3/PKCδ activation preventing PIT1 accumulation and apoptosis. The presence or lack of the inhibitory effect on RET-induced apoptosis separated pathogenic AIP variants from non-pathogenic ones. We used virogenomics in neonatal rats to demonstrate the effect of mutant AIP protein on the RET apoptotic pathway in vivo. In adult male rats altered AIP induces elevated IGF-1 and gigantism, with pituitary hyperplasia through blocking the RET-apoptotic pathway. In females, pituitary hyperplasia is induced but IGF-1 rise and gigantism are blunted by puberty. Somatotroph adenomas from pituitary-specific Aip-knockout mice overexpress the RET-ligand GDNF, therefore, upregulating the survival pathway. Somatotroph adenomas from patients with or without AIP mutation abundantly express GDNF, but AIP-mutated tissues have less CDKN2A-ARF expression. Our findings explain the tissue-specific mechanism of AIP-induced somatotrophinomas and provide a previously unknown tumorigenic mechanism, opening treatment avenues for AIP-related tumours.
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Affiliation(s)
- Angela R Garcia-Rendueles
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Miguel Chenlo
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Fernando Oroz-Gonjar
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Antonia Solomou
- Department of Endocrinology, William Harvey Research Institute, Barts and London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Anisha Mistry
- Department of Endocrinology, William Harvey Research Institute, Barts and London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Sayka Barry
- Department of Endocrinology, William Harvey Research Institute, Barts and London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Carles Gaston-Massuet
- Department of Endocrinology, William Harvey Research Institute, Barts and London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Montserrat Garcia-Lavandeira
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Sihara Perez-Romero
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Maria Suarez-Fariña
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Alberto Pradilla-Dieste
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Carlos Dieguez
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Patrick Mehlen
- Patrick Mehlen, Apoptosis, Cancer and Development Laboratory- Equipe labellisée 'La Ligue', LabEx DEVweCAN, Institut PLAsCAN, Centre de Recherche en Cancérologie de Lyon, INSERM U1052-CNRS UMR5286, Université de Lyon, Centre Léon Bérard, 69008, Lyon, France
| | - Márta Korbonits
- Department of Endocrinology, William Harvey Research Institute, Barts and London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
| | - Clara V Alvarez
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain.
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Pradilla Dieste A, Chenlo M, Perez-Romero S, Garcia-Rendueles ÁR, Suarez-Fariña M, Garcia-Lavandeira M, Bernabeu I, Cameselle-Teijeiro JM, Alvarez CV. GFRα 1-2-3-4 co-receptors for RET Are co-expressed in Pituitary Stem Cells but Individually Retained in Some Adenopituitary Cells. Front Endocrinol (Lausanne) 2020; 11:631. [PMID: 33071961 PMCID: PMC7543094 DOI: 10.3389/fendo.2020.00631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/04/2020] [Indexed: 11/26/2022] Open
Abstract
The RET tyrosine kinase receptor is expressed by the endocrine somatotroph cells of the pituitary where it has important functions regulating survival/apoptosis. However, RET is also expressed by the GPS pituitary stem cells localized in a niche between the adenopituitary and the intermediate lobe. To bind any of its four ligands, RET needs one of four co-receptors called GFRα1-4. It has been previously shown that GFRα1 is expressed by somatotroph cells and acromegaly tumors. GFRα2 was shown to be expressed by pituitary stem cells. GFRα4 was proposed as not expressed in the pituitary. Here we study the RNA and protein expression of the four GFRα co-receptors for RET in rat and human pituitary. The four co-receptors were abundantly expressed at the RNA level both in rat and human pituitary, although GFRα4 was the less abundant. Multiple immunofluorescence for each co-receptor and β-catenin, a marker of stem cell niche was performed. The four GFRα co-receptors were co-expressed by the GPS cells at the niche colocalizing with β-catenin. Isolated individual scattered cells positive for one or other receptor could be found through the adenopituitary with low β-catenin expression. Some of them co-express GFRα1 and PIT1. Immunohistochemistry in normal human pituitary confirmed the data. Our data suggest that the redundancy of GFRα co-expression is a self-supportive mechanism which ensures niche maintenance and proper differentiation.
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Affiliation(s)
- Alberto Pradilla Dieste
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Miguel Chenlo
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Sihara Perez-Romero
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Ángela R. Garcia-Rendueles
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Maria Suarez-Fariña
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Montserrat Garcia-Lavandeira
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
| | - Ignacio Bernabeu
- Department of Endocrinology, Complejo Hospitalario Universitario de Santiago de Compostela (CHUS)-SERGAS, Instituto de Investigación Sanitaria de Santiago (IDIS), USC, Santiago de Compostela, Spain
| | - José Manuel Cameselle-Teijeiro
- Department of Pathology, Complejo Hospitalario Universitario de Santiago de Compostela (CHUS)-SERGAS, Instituto de Investigación Sanitaria de Santiago (IDIS), Santiago de Compostela, Spain
| | - Clara V. Alvarez
- Neoplasia & Endocrine Differentiation P0L5, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Instituto de Investigación Sanitaria (IDIS), University of Santiago de Compostela (USC), Santiago de Compostela, Spain
- *Correspondence: Clara V. Alvarez
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Haston S, Manshaei S, Martinez-Barbera JP. Stem/progenitor cells in pituitary organ homeostasis and tumourigenesis. J Endocrinol 2018; 236:R1-R13. [PMID: 28855316 PMCID: PMC5744558 DOI: 10.1530/joe-17-0258] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 08/30/2017] [Indexed: 01/06/2023]
Abstract
Evidence for the presence of pituitary gland stem cells has been provided over the last decade using a combination of approaches including in vitro clonogenicity assays, flow cytometric side population analysis, immunohistochemical analysis and genetic approaches. These cells have been demonstrated to be able to self-renew and undergo multipotent differentiation to give rise to all hormonal lineages of the anterior pituitary. Furthermore, evidence exists for their contribution to regeneration of the organ and plastic responses to changing physiological demand. Recently, stem-like cells have been isolated from pituitary neoplasms raising the possibility that a cytological hierarchy exists, in keeping with the cancer stem cell paradigm. In this manuscript, we review the evidence for the existence of pituitary stem cells, their role in maintaining organ homeostasis and the regulation of their differentiation. Furthermore, we explore the emerging concept of stem cells in pituitary tumours and their potential roles in these diseases.
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Affiliation(s)
- Scott Haston
- Developmental Biology and Cancer Research ProgrammeBirth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Saba Manshaei
- Developmental Biology and Cancer Research ProgrammeBirth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Juan Pedro Martinez-Barbera
- Developmental Biology and Cancer Research ProgrammeBirth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, London, UK
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Cheung LYM, Davis SW, Brinkmeier ML, Camper SA, Pérez-Millán MI. Regulation of pituitary stem cells by epithelial to mesenchymal transition events and signaling pathways. Mol Cell Endocrinol 2017; 445:14-26. [PMID: 27650955 PMCID: PMC5590650 DOI: 10.1016/j.mce.2016.09.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/15/2016] [Accepted: 09/16/2016] [Indexed: 12/11/2022]
Abstract
The anterior pituitary gland is comprised of specialized cell-types that produce and secrete polypeptide hormones in response to hypothalamic input and feedback from target organs. These specialized cells arise from stem cells that express SOX2 and the pituitary transcription factor PROP1, which is necessary to establish the stem cell pool and promote an epithelial to mesenchymal-like transition, releasing progenitors from the niche. The adult anterior pituitary responds to physiological challenge by mobilizing the SOX2-expressing progenitor pool and producing additional hormone-producing cells. Knowledge of the role of signaling pathways and extracellular matrix components in these processes may lead to improvements in the efficiency of differentiation of embryonic stem cells or induced pluripotent stem cells into hormone producing cells in vitro. Advances in our basic understanding of pituitary stem cell regulation and differentiation may lead to improved diagnosis and treatment for patients with hypopituitarism.
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Affiliation(s)
- Leonard Y M Cheung
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA.
| | - Shannon W Davis
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208-0001, USA.
| | - Michelle L Brinkmeier
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA.
| | - Sally A Camper
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA.
| | - María Inés Pérez-Millán
- Institute of Biomedical Investgations (UBA-CONICET), University of Buenos Aires, Buenos Aires, Argentina.
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Michau A, Hodson DJ, Fontanaud P, Guillou A, Espinosa-Carrasco G, Molino F, Peters CJ, Robinson IC, Le Tissier P, Mollard P, Schaeffer M. Metabolism Regulates Exposure of Pancreatic Islets to Circulating Molecules In Vivo. Diabetes 2016; 65:463-75. [PMID: 26581596 DOI: 10.2337/db15-1168] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/10/2015] [Indexed: 11/13/2022]
Abstract
Pancreatic β-cells modulate insulin secretion through rapid sensing of blood glucose and integration of gut-derived signals. Increased insulin demand during pregnancy and obesity alters islet function and mass and leads to gestational diabetes mellitus and type 2 diabetes in predisposed individuals. However, it is unclear how blood-borne factors dynamically access the islets of Langerhans. Thus, understanding the changes in circulating molecule distribution that accompany compensatory β-cell expansion may be key to developing novel antidiabetic therapies. Here, using two-photon microscopy in vivo in mice, we demonstrate that islets are almost instantly exposed to peaks of circulating molecules, which rapidly pervade the tissue before clearance. In addition, both gestation and short-term high-fat-diet feeding decrease molecule extravasation and uptake rates in vivo in islets, independently of β-cell expansion or islet blood flow velocity. Together, these data support a role for islet vascular permeability in shaping β-cell adaptive responses to metabolic demand by modulating the access and sensing of circulating molecules.
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Affiliation(s)
- Aurélien Michau
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France
| | - David J Hodson
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, Imperial Centre for Translational and Experimental Medicine, Hammersmith Hospital, London, U.K. Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, U.K
| | - Pierre Fontanaud
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France
| | - Anne Guillou
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France
| | - Gabriel Espinosa-Carrasco
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France Lymphocyte Differentiation, Tolerance, and Metabolism Laboratory, Institute for Regenerative Medicine and Biotherapy, U1183, Montpellier, France
| | - François Molino
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France Charles Coulomb Laboratory, University of Montpellier, CNRS, UMR-5221, Montpellier, France
| | - Catherine J Peters
- Division of Molecular Neuroendocrinology, National Institute for Medical Research, London, U.K
| | - Iain C Robinson
- Division of Molecular Neuroendocrinology, National Institute for Medical Research, London, U.K
| | - Paul Le Tissier
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, U.K
| | - Patrice Mollard
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France
| | - Marie Schaeffer
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, Montpellier, France INSERM, U1191, Montpellier, France University of Montpellier, Montpellier, France
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Dose-dependent dual role of PIT-1 (POU1F1) in somatolactotroph cell proliferation and apoptosis. PLoS One 2015; 10:e0120010. [PMID: 25822178 PMCID: PMC4379079 DOI: 10.1371/journal.pone.0120010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 02/02/2015] [Indexed: 12/11/2022] Open
Abstract
To test the role of wtPIT-1 (PITWT) or PIT-1 (R271W) (PIT271) in somatolactotroph cells, we established, using inducible lentiviral vectors, sublines of GH4C1 somatotroph cells that allow the blockade of the expression of endogenous PIT-1 and/or the expression of PITWT or PIT271, a dominant negative mutant of PIT-1 responsible for Combined Pituitary Hormone Deficiency in patients. Blocking expression of endogenous PIT-1 induced a marked decrease of cell proliferation. Overexpressing PITWT twofold led also to a dose-dependent decrease of cell proliferation that was accompanied by cell death. Expression of PIT271 induced a strong dose-dependent decrease of cell proliferation accompanied by a very pronounced cell death. These actions of PIT271 are independent of its interaction/competition with endogenous PIT-1, as they were unchanged when expression of endogenous PIT-1 was blocked. All these actions are specific for somatolactotroph cells, and could not be observed in heterologous cells. Cell death induced by PITWT or by PIT271 was accompanied by DNA fragmentation, but was not inhibited by inhibitors of caspases, autophagy or necrosis, suggesting that this cell death is a caspase-independent apoptosis. Altogether, our results indicate that under normal conditions PIT-1 is important for the maintenance of cell proliferation, while when expressed at supra-normal levels it induces cell death. Through this dual action, PIT-1 may play a role in the expansion/regression cycles of pituitary lactotroph population during and after lactation. Our results also demonstrate that the so-called “dominant-negative” action of PIT271 is independent of its competition with PIT-1 or a blockade of the actions of the latter, and are actions specific to this mutant variant of PIT-1.
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Chung D, Gao F, Jegga AG, Das SK. Estrogen mediated epithelial proliferation in the uterus is directed by stromal Fgf10 and Bmp8a. Mol Cell Endocrinol 2015; 400:48-60. [PMID: 25451979 PMCID: PMC4751583 DOI: 10.1016/j.mce.2014.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/03/2014] [Accepted: 11/03/2014] [Indexed: 11/25/2022]
Abstract
To define endometrial stromal-derived paracrine mediators that participate in estradiol-17β (E2)-induced epithelial proliferation, microarray analysis of gene expression was carried out in mouse uterine epithelial-stromal co-culture systems under the condition of E2 or vehicle (control). Our results demonstrated gene alteration by E2: in epithelial cells, we found up-regulation of 119 genes and down-regulation of 28 genes, while in stroma cells we found up-regulation of 144 genes and down-regulation of 184 genes. A functional enrichment analysis of the upregulated epithelial genes implicated them for proliferation, while upregulated stromal genes were associated with extracellular functions. Quantitative RT-PCR and in situ hybridization results confirmed differential gene expression in both cell cultures and ovariectomized uteri after the above treatments. Based on our identification of stromal secretory factors, we found evidence that suppression by siRNA specifically for Bmp8a and/or Fgf10 in the stromal layer caused significant inhibition of proliferation by E2 in the co-culture system, suggesting Bmp8a and Fgf10 act as paracrine mediators during E2-dependent control of uterine proliferation. The localization of receptors and receptor activation signaling in epithelial cells in both the co-culture system and uteri was consistent with their involvement in ligand-receptor signaling. Interestingly, loss of Bmp8a or Fgf10 also caused abrogation of E2-regulated epithelial receptor signaling in co-culture systems, suggesting that stroma-derived Fgf10 and Bmp8a are responsible for epithelial communication. Overall, stromal Fgf10 and Bmp8a serve as potential paracrine factors for E2-dependent regulation of epithelial proliferation in the uterus.
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Affiliation(s)
- Daesuk Chung
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; The Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Fei Gao
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; The Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Anil G Jegga
- Biomedical Informatics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Sanjoy K Das
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; The Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
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Garcia-Lavandeira M, Diaz-Rodriguez E, Bahar D, Garcia-Rendueles AR, Rodrigues JS, Dieguez C, Alvarez CV. Pituitary Cell Turnover: From Adult Stem Cell Recruitment through Differentiation to Death. Neuroendocrinology 2015; 101:175-92. [PMID: 25662152 DOI: 10.1159/000375502] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/23/2015] [Indexed: 11/19/2022]
Abstract
The recent demonstration using genetic tracing that in the adult pituitary stem cells are normally recruited from the niche in the marginal zone and differentiate into secretory cells in the adenopituitary has elegantly confirmed the proposal made when the pituitary stem cell niche was first discovered 5 years ago. Some of the early controversies have also been resolved. However, many questions remain, such as which are the markers that make a pituitary stem cell truly unique and the exact mechanisms that trigger recruitment from the niche. Little is known about the processes of commitment and differentiation once a stem cell has left the niche. Moreover, the acceptance that pituitary cells are renewed by stem cells implies the existence of regulated mechanisms of cell death in differentiated cells which must themselves be explained. The demonstration of an apoptotic pathway mediated by RET/caspase 3/Pit-1/Arf/p53 in normal somatotrophs is therefore an important step towards understanding how pituitary cell number is regulated. Further work will elucidate how the rates of the three processes of cell renewal, differentiation and apoptosis are balanced in tissue homeostasis after birth, but altered in pituitary hyperplasia in response to physiological stimuli such as puberty and lactation. Thus, we can aim to understand the mechanisms underlying human disease due to insufficient (hypopituitarism) or excess (pituitary tumor) cell numbers.
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Affiliation(s)
- Montserrat Garcia-Lavandeira
- Neoplasia and Endocrine Differentiation, Centre for Investigations in Medicine (CIMUS), Instituto de Investigaciones Sanitarias, School of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain
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