1
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Intra-pituitary follicle-stimulating hormone signaling regulates hepatic lipid metabolism in mice. Nat Commun 2023; 14:1098. [PMID: 36841874 PMCID: PMC9968338 DOI: 10.1038/s41467-023-36681-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/09/2023] [Indexed: 02/27/2023] Open
Abstract
Inter-organ communication is a major hallmark of health and is often orchestrated by hormones released by the anterior pituitary gland. Pituitary gonadotropes secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to regulate gonadal function and control fertility. Whether FSH and LH also act on organs other than the gonads is debated. Here, we find that gonadotrope depletion in adult female mice triggers profound hypogonadism, obesity, glucose intolerance, fatty liver, and bone loss. The absence of sex steroids precipitates these phenotypes, with the notable exception of fatty liver, which results from ovary-independent actions of FSH. We uncover paracrine FSH action on pituitary corticotropes as a mechanism to restrain the production of corticosterone and prevent hepatic steatosis. Our data demonstrate that functional communication of two distinct hormone-secreting cell populations in the pituitary regulates hepatic lipid metabolism.
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Guérineau NC, Campos P, Le Tissier PR, Hodson DJ, Mollard P. Cell Networks in Endocrine/Neuroendocrine Gland Function. Compr Physiol 2022; 12:3371-3415. [PMID: 35578964 DOI: 10.1002/cphy.c210031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Reproduction, growth, stress, and metabolism are determined by endocrine/neuroendocrine systems that regulate circulating hormone concentrations. All these systems generate rhythms and changes in hormone pulsatility observed in a variety of pathophysiological states. Thus, the output of endocrine/neuroendocrine systems must be regulated within a narrow window of effective hormone concentrations but must also maintain a capacity for plasticity to respond to changing physiological demands. Remarkably most endocrinologists still have a "textbook" view of endocrine gland organization which has emanated from 20th century histological studies on thin 2D tissue sections. However, 21st -century technological advances, including in-depth 3D imaging of specific cell types have vastly changed our knowledge. We now know that various levels of multicellular organization can be found across different glands, that organizational motifs can vary between species and can be modified to enhance or decrease hormonal release. This article focuses on how the organization of cells regulates hormone output using three endocrine/neuroendocrine glands that present different levels of organization and complexity: the adrenal medulla, with a single neuroendocrine cell type; the anterior pituitary, with multiple intermingled cell types; and the pancreas with multiple intermingled cell types organized into distinct functional units. We give an overview of recent methodologies that allow the study of the different components within endocrine systems, particularly their temporal and spatial relationships. We believe the emerging findings about network organization, and its impact on hormone secretion, are crucial to understanding how homeostatic regulation of endocrine axes is carried out within endocrine organs themselves. © 2022 American Physiological Society. Compr Physiol 12:3371-3415, 2022.
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Affiliation(s)
| | - Pauline Campos
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Paul R Le Tissier
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Edgbaston, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK.,COMPARE University of Birmingham and University of Nottingham Midlands, UK.,Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Patrice Mollard
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
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3
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Powell D, Ngo PT, Nguyen HN, Knibb W, Elizur A. Transcriptomic responses of saline-adapted Nile tilapia (Oreochromis niloticus) to rearing in both saline and freshwater. Mar Genomics 2021; 60:100879. [PMID: 34023275 DOI: 10.1016/j.margen.2021.100879] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 03/26/2021] [Accepted: 05/12/2021] [Indexed: 11/25/2022]
Abstract
The Nile tilapia, Oreochromis niloticus, is an important species for global aquaculture. Recently, a single genetic line of Nile tilapia was developed using estimated breeding values (EBVs) for body weight under moderately saline water that showed significant improvement in growth performance. To explore the molecular mechanisms underlying this enhanced growth capacity, RNA-Seq was used to profile differences in gene expression in the liver and pituitary gland of high- and low-growth performance families of male Nile tilapia progeny, reared in either saline or freshwater environments. Comparisons of tissues from high- and low-EBV families, and also between fish reared in either saline or freshwater, revealed 142 and 2208 differentially expressed genes (DEGs), respectively. DEGs identified between the EBV groups comprised a number of genes involved in the regulation of growth and reproduction. We found an overexpression of hormone genes involved in growth-inhibition in the pituitary of Low-EBV tilapia including 2 somatostatin genes (GHIH), corticoliberin (CRH) and tachykinin-3-like protein. Furthermore, several genes associated with the cAMP pathway were underexpressed in low-EBV tilapia pituitary together with several early response genes. This study provides insight into the transcriptomic factors associated with growth performance in saline-adapted Nile tilapia reared in environments with high and low salinity levels and provides valuable knowledge for the future development of selection strategies to improve growth performance in this species.
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Affiliation(s)
- Daniel Powell
- Department of Biology, Lund University, 223 62 Lund, Sweden; Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Sippy Downs, Queensland 4558, Australia.
| | - Phu Thoa Ngo
- Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Sippy Downs, Queensland 4558, Australia; Mavin Aquaculture, Mavin Group, Hudland Tower Building, No. 6 Nguyen Huu Tho, Hoang Liet Ward, Hoang Mai District, Hanoi, Viet Nam; Research Institute for Aquaculture No.1, Dinh Bang, Tu Son, Bac Ninh, Viet Nam.
| | - Hong Nguyen Nguyen
- Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Sippy Downs, Queensland 4558, Australia.
| | - Wayne Knibb
- Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Sippy Downs, Queensland 4558, Australia.
| | - Abigail Elizur
- Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Sippy Downs, Queensland 4558, Australia.
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4
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McNamara AV, Awais R, Momiji H, Dunham L, Featherstone K, Harper CV, Adamson AA, Semprini S, Jones NA, Spiller DG, Mullins JJ, Finkenstädt BF, Rand D, White MRH, Davis JRE. Transcription Factor Pit-1 Affects Transcriptional Timing in the Dual-Promoter Human Prolactin Gene. Endocrinology 2021; 162:6060060. [PMID: 33388754 PMCID: PMC7871365 DOI: 10.1210/endocr/bqaa249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Indexed: 12/31/2022]
Abstract
Gene transcription occurs in short bursts interspersed with silent periods, and these kinetics can be altered by promoter structure. The effect of alternate promoter architecture on transcription bursting is not known. We studied the human prolactin (hPRL) gene that contains 2 promoters, a pituitary-specific promoter that requires the transcription factor Pit-1 and displays dramatic transcriptional bursting activity and an alternate upstream promoter that is active in nonpituitary tissues. We studied large hPRL genomic fragments with luciferase reporters, and used bacterial artificial chromosome recombineering to manipulate critical promoter regions. Stochastic switch mathematical modelling of single-cell time-lapse luminescence image data revealed that the Pit-1-dependent promoter showed longer, higher-amplitude transcriptional bursts. Knockdown studies confirmed that the presence of Pit-1 stabilized and prolonged periods of active transcription. Pit-1 therefore plays an active role in establishing the timing of transcription cycles, in addition to its cell-specific functions.
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Affiliation(s)
- Anne V McNamara
- Systems Microscopy Centre, Division of Molecular and Cellular Function, School of Biological Sciences, Faculty Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Raheela Awais
- School of Life Sciences, University of Liverpool, Liverpool, UK
| | - Hiroshi Momiji
- Mathematics Institute & Zeeman Institute for Systems Biology, and Infectious Epidemiology Research, University of Warwick, Senate House Coventry, UK
| | - Lee Dunham
- Division of Diabetes, Endocrinology & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Karen Featherstone
- Division of Diabetes, Endocrinology & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Claire V Harper
- Department of Biology, Edge Hill University, Ormskirk, Lancashire, UK
| | - Antony A Adamson
- Genome Editing Unit, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Sabrina Semprini
- University/BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Nicholas A Jones
- Systems Microscopy Centre, Division of Molecular and Cellular Function, School of Biological Sciences, Faculty Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - David G Spiller
- Systems Microscopy Centre, Division of Molecular and Cellular Function, School of Biological Sciences, Faculty Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - John J Mullins
- University/BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Bärbel F Finkenstädt
- Mathematics Institute & Zeeman Institute for Systems Biology, and Infectious Epidemiology Research, University of Warwick, Senate House Coventry, UK
| | - David Rand
- Mathematics Institute & Zeeman Institute for Systems Biology, and Infectious Epidemiology Research, University of Warwick, Senate House Coventry, UK
| | - Michael R H White
- Systems Microscopy Centre, Division of Molecular and Cellular Function, School of Biological Sciences, Faculty Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
- Correspondence: Professor Michael R. H. White, Systems Microscopy Centre, Division of Molecular and Cellular Function, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, M13 9PT, UK. E-mail: ; or Professor Julian R. E. Davis, Division of Diabetes, Endocrinology & Gastroenterology, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, M13 9PT, UK. E-mail:
| | - Julian R E Davis
- Division of Diabetes, Endocrinology & Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
- Correspondence: Professor Michael R. H. White, Systems Microscopy Centre, Division of Molecular and Cellular Function, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, M13 9PT, UK. E-mail: ; or Professor Julian R. E. Davis, Division of Diabetes, Endocrinology & Gastroenterology, Faculty of Biology, Medicine & Health, Manchester Academic Health Sciences Centre, University of Manchester, M13 9PT, UK. E-mail:
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5
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Harper CV, McNamara AV, Spiller DG, Charnock JC, White MRH, Davis JRE. Calcium dynamics and chromatin remodelling underlie heterogeneity in prolactin transcription. J Mol Endocrinol 2021; 66:59-69. [PMID: 33112804 PMCID: PMC7774774 DOI: 10.1530/jme-20-0223] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 12/01/2022]
Abstract
Pituitary cells have been reported to show spontaneous calcium oscillations and dynamic transcription cycles. To study both processes in the same living cell in real time, we used rat pituitary GH3 cells stably expressing human prolactin-luciferase or prolactin-EGFP reporter gene constructs loaded with a fluorescent calcium indicator and measured activity using single-cell time-lapse microscopy. We observed heterogeneity between clonal cells in the calcium activity and prolactin transcription in unstimulated conditions. There was a significant correlation between cells displaying spontaneous calcium spikes and cells showing spontaneous bursts in prolactin expression. Notably, cells showing no basal calcium activity showed low prolactin expression but elicited a significantly greater transcriptional response to BayK8644 compared to cells showing basal calcium activity. This suggested the presence of two subsets of cells within the population at any one time. Fluorescence-activated cell sorting was used to sort cells into two populations based on the expression level of prolactin-EGFP however, the bimodal pattern of expression was restored within 26 h. Chromatin immunoprecipitation showed that these sorted populations were distinct due to the extent of histone acetylation. We suggest that maintenance of a heterogeneous bimodal population is a fundamental characteristic of this cell type and that calcium activation and histone acetylation, at least in part, drive prolactin transcriptional competence.
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Affiliation(s)
- Claire V Harper
- Department of Biology, Edge Hill University, Ormskirk, Lancashire, UK
- Correspondence should be addressed to C V Harper:
| | - Anne V McNamara
- Systems Microscopy Centre, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - David G Spiller
- Systems Microscopy Centre, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Jayne C Charnock
- Department of Biology, Edge Hill University, Ormskirk, Lancashire, UK
| | - Michael R H White
- Systems Microscopy Centre, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Julian R E Davis
- Endocrine Sciences Research Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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6
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Capp JP, Laforge B. A Darwinian and Physical Look at Stem Cell Biology Helps Understanding the Role of Stochasticity in Development. Front Cell Dev Biol 2020; 8:659. [PMID: 32793600 PMCID: PMC7391792 DOI: 10.3389/fcell.2020.00659] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/01/2020] [Indexed: 11/27/2022] Open
Abstract
Single-cell analysis allows biologists to gain huge insight into cell differentiation and tissue structuration. Randomness of differentiation, both in vitro and in vivo, of pluripotent (multipotent) stem cells is now demonstrated to be mainly based on stochastic gene expression. Nevertheless, it remains necessary to incorporate this inherent stochasticity of developmental processes within a coherent scheme. We argue here that the theory called ontophylogenesis is more relevant and better fits with experimental data than alternative theories which have been suggested based on the notions of self-organization and attractor states. The ontophylogenesis theory considers the generation of a differentiated state as a constrained random process: randomness is provided by the stochastic dynamics of biochemical reactions while the environmental constraints, including cell inner structures and cell-cell interactions, drive the system toward a stabilized state of equilibrium. In this conception, biological organization during development can be seen as the result of multiscale constraints produced by the dynamical organization of the biological system which retroacts on the stochastic dynamics at lower scales. This scheme makes it possible to really understand how the generation of reproducible structures at higher organization levels can be fully compatible with probabilistic behavior at the lower levels. It is compatible with the second law of thermodynamics but allows the overtaking of the limitations exhibited by models only based on entropy exchanges which cannot cope with the description nor the dynamics of the mesoscopic and macroscopic organization of biological systems.
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Affiliation(s)
- Jean-Pascal Capp
- Toulouse Biotechnology Institute, University of Toulouse, INSA, CNRS, INRAE, Toulouse, France
| | - Bertrand Laforge
- LPNHE, UMR 7585, Sorbonne Université, CNRS/IN2P3, Université de Paris, Paris, France
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7
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Ogoh K, Akiyoshi R, Suzuki H. Cloning and mutagenetic modification of the firefly luciferase gene and its use for bioluminescence microscopy of engrailed expression during Drosophila metamorphosis. Biochem Biophys Rep 2020; 23:100771. [PMID: 32490216 PMCID: PMC7262549 DOI: 10.1016/j.bbrep.2020.100771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/11/2020] [Accepted: 05/18/2020] [Indexed: 11/27/2022] Open
Abstract
Bioluminescence microscopy is an area attracting considerable interest in the field of cell biology because it offers several advantages over fluorescence microscopy, including no requirement for excitation light and being phototoxicity free. This method requires brighter luciferase for imaging; however, suitable genetic resource material for this purpose is not available at present. To achieve brighter bioluminescence microscopy, we developed a new firefly luciferase. Using the brighter luciferase, a reporter strain of Drosophila Gal4-UAS (Upstream Activating Sequence) system was constructed. This system demonstrated the expression pattern of engrailed, which is a segment polarity gene, during Drosophila metamorphosis by bioluminescence microscopy, and revealed drastic spatiotemporal change in the engrailed expression pattern during head eversion in the early stage of pupation. Bioluminescence microscopy is an ideal tool for the observation of gene expression pattern in Drosophila development. In the present study, we developed a new brighter firefly luciferase for use in bioluminescence microscopy. The spatiotemporal expression pattern of the engrailed was elucidated during Drosophila metamorphosis.
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Affiliation(s)
- Katsunori Ogoh
- Olympus Corporation, Kuboyama 2-3, Hachioji, Tokyo, 192-8512, Japan
| | - Ryutaro Akiyoshi
- Olympus Corporation, Kuboyama 2-3, Hachioji, Tokyo, 192-8512, Japan
| | - Hirobumi Suzuki
- Olympus Corporation, Kuboyama 2-3, Hachioji, Tokyo, 192-8512, Japan
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8
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Abstract
Life in seasonally changing environments is challenging. Biological systems have to not only respond directly to the environment, but also schedule life history events in anticipation of seasonal changes. The cellular and molecular basis of how these events are scheduled is unknown. Cellular decision-making processes in response to signals above certain thresholds regularly occur i.e. cellular fate determination, apoptosis and firing of action potentials. Binary switches, the result of cellular decision-making processes, are defined as a change in phenotype between two stable states. A recent study presents evidence of a binary switch operating in the pars tuberalis (PT) of the pituitary, seemingly timing seasonal reproduction in sheep. Though, how a binary switch would allow for anticipation of seasonal environmental changes, not just direct responsiveness, is unclear. The purpose of this review is to assess the evidence for a binary switching mechanism timing seasonal reproduction and to hypothesize how a binary switch would allow biological processes to be timed over weeks to years. I draw parallels with mechanisms used in development, cell fate determination and seasonal timing in plants. I propose that the adult PT is a plastic tissue, showing a seasonal cycle of cellular differentiation, and that the underlying processes are likely to be epigenetic. Therefore, considering the mechanisms behind adult cellular plasticity offers a framework to hypothesize how a long-term timer functions within the PT.
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Affiliation(s)
- Shona H Wood
- Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø, Norway
- Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, UK
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9
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Nasteska D, Hodson DJ. The role of beta cell heterogeneity in islet function and insulin release. J Mol Endocrinol 2018; 61:R43-R60. [PMID: 29661799 PMCID: PMC5976077 DOI: 10.1530/jme-18-0011] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/16/2018] [Indexed: 12/15/2022]
Abstract
It is becoming increasingly apparent that not all insulin-secreting beta cells are equal. Subtle differences exist at the transcriptomic and protein expression levels, with repercussions for beta cell survival/proliferation, calcium signalling and insulin release. Notably, beta cell heterogeneity displays plasticity during development, metabolic stress and type 2 diabetes mellitus (T2DM). Thus, heterogeneity or lack thereof may be an important contributor to beta cell failure during T2DM in both rodents and humans. The present review will discuss the molecular and cellular features of beta cell heterogeneity at both the single-cell and islet level, explore how this influences islet function and insulin release and look into the alterations that may occur during obesity and T2DM.
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Affiliation(s)
- Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR)University of Birmingham, Edgbaston, UK
- Centre for EndocrinologyDiabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
- COMPARE University of Birmingham and University of Nottingham MidlandsBirmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR)University of Birmingham, Edgbaston, UK
- Centre for EndocrinologyDiabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
- COMPARE University of Birmingham and University of Nottingham MidlandsBirmingham, UK
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10
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Cocks Eschler D, Javanmard P, Cox K, Geer EB. Prolactinoma through the female life cycle. Endocrine 2018; 59:16-29. [PMID: 29177641 DOI: 10.1007/s12020-017-1438-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 09/22/2017] [Indexed: 12/27/2022]
Abstract
Prolactinomas are the most common secretory pituitary adenoma. They typically occur in women in the 3rd-6th decade of life and rarely in the pediatric population or after menopause. Most women present with irregular menses and/or infertility. Dopamine (DA) agonists, used in their treatment, are safe during pregnancy, but in most cases are discontinued at conception with close monitoring for signs or symptoms of tumor growth. Breastfeeding is safe postpartum, provided there was no significant growth during pregnancy. Some women will experience normalization of prolactin levels postpartum. Menopause may also decrease prolactin levels and even those with macroprolactinomas may consider discontinuing their DA agonist with close follow-up. Prolactinomas may be associated with decreased quality of life scores in women, and play a role in bone health and cardiovascular risk factors. This review discusses the current literature and clinical understanding of prolactinomas throughout the entirety of the female life cycle.
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Affiliation(s)
- Deirdre Cocks Eschler
- Department of Medicine, Division of Endocrinology and Metabolism, SUNY Stony Brook School of Medicine, 26 Research Way, East Setauket, New York, NY, 11733, USA
| | - Pedram Javanmard
- Department of Medicine, Division of Endocrine, Diabetes, and Bone Disease, Icahn School of Medicine at The Mount Sinai Hospital, 1 Gustave L Levy Place box 1055, New York, NY, 10029, USA
| | - Katherine Cox
- Department of Medicine, Division of Endocrine, Diabetes, and Bone Disease, Icahn School of Medicine at The Mount Sinai Hospital, 1 Gustave L Levy Place box 1055, New York, NY, 10029, USA
| | - Eliza B Geer
- Multidisciplinary Pituitary and Skull Base Tumor Center, Memorial Sloan Kettering Cancer Center, 1275 York Ave, Box 419, New York, NY, 10065, USA.
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11
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Dunham LSS, Momiji H, Harper CV, Downton PJ, Hey K, McNamara A, Featherstone K, Spiller DG, Rand DA, Finkenstädt B, White MRH, Davis JRE. Asymmetry between Activation and Deactivation during a Transcriptional Pulse. Cell Syst 2017; 5:646-653.e5. [PMID: 29153839 PMCID: PMC5747351 DOI: 10.1016/j.cels.2017.10.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 08/04/2017] [Accepted: 10/18/2017] [Indexed: 11/23/2022]
Abstract
Transcription in eukaryotic cells occurs in gene-specific bursts or pulses of activity. Recent studies identified a spectrum of transcriptionally active “on-states,” interspersed with periods of inactivity, but these “off-states” and the process of transcriptional deactivation are poorly understood. To examine what occurs during deactivation, we investigate the dynamics of switching between variable rates. We measured live single-cell expression of luciferase reporters from human growth hormone or human prolactin promoters in a pituitary cell line. Subsequently, we applied a statistical variable-rate model of transcription, validated by single-molecule FISH, to estimate switching between transcriptional rates. Under the assumption that transcription can switch to any rate at any time, we found that transcriptional activation occurs predominantly as a single switch, whereas deactivation occurs with graded, stepwise decreases in transcription rate. Experimentally altering cAMP signalling with forskolin or chromatin remodelling with histone deacetylase inhibitor modifies the duration of defined transcriptional states. Our findings reveal transcriptional activation and deactivation as mechanistically independent, asymmetrical processes. Gene transcription switches between variable rates Single-cell microscopy and mathematical modeling quantifies switch dynamics We observe an asymmetry in the activation/deactivation of transcriptional bursts
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Affiliation(s)
- Lee S S Dunham
- Division of Endocrinology, Diabetes and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, AV Hill Building, Manchester M13 9PT, UK
| | - Hiroshi Momiji
- Warwick Systems Biology Centre, University of Warwick, Coventry CV4, 7AL, UK
| | - Claire V Harper
- Division of Cellular and Molecular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PT, UK
| | - Polly J Downton
- Division of Cellular and Molecular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PT, UK
| | - Kirsty Hey
- Department of Statistics, University of Warwick, Coventry CV4 7AL, UK
| | - Anne McNamara
- Division of Cellular and Molecular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PT, UK
| | - Karen Featherstone
- Division of Endocrinology, Diabetes and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, AV Hill Building, Manchester M13 9PT, UK
| | - David G Spiller
- Division of Cellular and Molecular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PT, UK
| | - David A Rand
- Warwick Systems Biology Centre, University of Warwick, Coventry CV4, 7AL, UK
| | | | - Michael R H White
- Division of Cellular and Molecular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester M13 9PT, UK.
| | - Julian R E Davis
- Division of Endocrinology, Diabetes and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, AV Hill Building, Manchester M13 9PT, UK.
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12
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Capp JP. Tissue disruption increases stochastic gene expression thus producing tumors: Cancer initiation without driver mutation. Int J Cancer 2017; 140:2408-2413. [DOI: 10.1002/ijc.30596] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/16/2016] [Accepted: 01/02/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Jean-Pascal Capp
- INSA/Université Fédérale de Toulouse, Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés, UMR CNRS 5504, UMR INRA 792; Toulouse 31077 France
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13
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Featherstone K, Hey K, Momiji H, McNamara AV, Patist AL, Woodburn J, Spiller DG, Christian HC, McNeilly AS, Mullins JJ, Finkenstädt BF, Rand DA, White MRH, Davis JRE. Spatially coordinated dynamic gene transcription in living pituitary tissue. eLife 2016; 5:e08494. [PMID: 26828110 PMCID: PMC4749562 DOI: 10.7554/elife.08494] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 12/13/2015] [Indexed: 12/22/2022] Open
Abstract
Transcription at individual genes in single cells is often pulsatile and stochastic. A key question emerges regarding how this behaviour contributes to tissue phenotype, but it has been a challenge to quantitatively analyse this in living cells over time, as opposed to studying snap-shots of gene expression state. We have used imaging of reporter gene expression to track transcription in living pituitary tissue. We integrated live-cell imaging data with statistical modelling for quantitative real-time estimation of the timing of switching between transcriptional states across a whole tissue. Multiple levels of transcription rate were identified, indicating that gene expression is not a simple binary 'on-off' process. Immature tissue displayed shorter durations of high-expressing states than the adult. In adult pituitary tissue, direct cell contacts involving gap junctions allowed local spatial coordination of prolactin gene expression. Our findings identify how heterogeneous transcriptional dynamics of single cells may contribute to overall tissue behaviour.
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Affiliation(s)
- Karen Featherstone
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester, United Kingdom
| | - Kirsty Hey
- Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Hiroshi Momiji
- Warwick Systems Biology, University of Warwick, Coventry, United Kingdom
| | - Anne V McNamara
- Systems Biology Centre, University of Manchester, Manchester, United Kingdom
| | - Amanda L Patist
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester, United Kingdom
| | - Joanna Woodburn
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester, United Kingdom
| | - David G Spiller
- Systems Biology Centre, University of Manchester, Manchester, United Kingdom
| | - Helen C Christian
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Alan S McNeilly
- MRC Centre for Reproductive Health, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - John J Mullins
- The Molecular Physiology Group, Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | | | - David A Rand
- Warwick Systems Biology, University of Warwick, Coventry, United Kingdom
| | - Michael RH White
- Systems Biology Centre, University of Manchester, Manchester, United Kingdom
| | - Julian RE Davis
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester, United Kingdom
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14
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McNamara AV, Adamson AD, Dunham LSS, Semprini S, Spiller DG, McNeilly AS, Mullins JJ, Davis JRE, White MRH. Role of Estrogen Response Element in the Human Prolactin Gene: Transcriptional Response and Timing. Mol Endocrinol 2015; 30:189-200. [PMID: 26691151 PMCID: PMC4792233 DOI: 10.1210/me.2015-1186] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The use of bacterial artificial chromosome (BAC) reporter constructs in molecular physiology enables the inclusion of large sections of flanking DNA, likely to contain regulatory elements and enhancers regions that contribute to the transcriptional output of a gene. Using BAC recombineering, we have manipulated a 160-kb human prolactin luciferase (hPRL-Luc) BAC construct and mutated the previously defined proximal estrogen response element (ERE) located -1189 bp relative to the transcription start site, to assess its involvement in the estrogen responsiveness of the entire hPRL locus. We found that GH3 cell lines stably expressing Luc under control of the ERE-mutated hPRL promoter (ERE-Mut) displayed a dramatically reduced transcriptional response to 17β-estradiol (E2) treatment compared with cells expressing Luc from the wild-type (WT) ERE hPRL-Luc promoter (ERE-WT). The -1189 ERE controls not only the response to E2 treatment but also the acute transcriptional response to TNFα, which was abolished in ERE-Mut cells. ERE-WT cells displayed a biphasic transcriptional response after TNFα treatment, the acute phase of which was blocked after treatment with the estrogen receptor antagonist 4-hydroxy-tamoxifen. Unexpectedly, we show the oscillatory characteristics of hPRL promoter activity in individual living cells were unaffected by disruption of this crucial response element, real-time bioluminescence imaging showed that transcription cycles were maintained, with similar cycle lengths, in ERE-WT and ERE-Mut cells. These data suggest the -1189 ERE is the dominant response element involved in the hPRL transcriptional response to both E2 and TNFα and, crucially, that cycles of hPRL promoter activity are independent of estrogen receptor binding.
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Affiliation(s)
- Anne V McNamara
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Antony D Adamson
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Lee S S Dunham
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Sabrina Semprini
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - David G Spiller
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Alan S McNeilly
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - John J Mullins
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Julian R E Davis
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
| | - Michael R H White
- Systems Microscopy Centre (A.V.M., A.D.A., D.G.S., M.R.H.W.), Faculty of Life Sciences, and Faculty of Medical and Human Sciences (L.S.S.D., J.R.E.D.), Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester M13 9PT, United Kingdom; and The Molecular Physiology Group (S.S., J.J.M.), Centre for Cardiovascular Science, and Medical Research Council Human Reproductive Sciences Unit (A.S.M.), Centre for Reproductive Biology, Queen's Medical Research Institute, Edinburgh EH16 4TJ, United Kingdom
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15
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Kosztolányi G. It is time to take timing seriously in clinical genetics. Eur J Hum Genet 2015; 23:1435-7. [PMID: 25537357 PMCID: PMC4613471 DOI: 10.1038/ejhg.2014.271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/14/2014] [Accepted: 11/10/2014] [Indexed: 11/08/2022] Open
Abstract
Observations made by molecular techniques on the genome along the individuals' lifetime indicate that the genome in somatic cells displays changes at molecular, cellular, and organismal levels. Timing of genetic events leading to somatic mosaicism and gene expression dynamism results in a highly important variable for comprehending the role of genetics in health and disease. Consideration of time in clinical genetics should be enthusiastically invested into research strategy, interpretation of the results, diagnostic routine, and particularly in ethical discussions.
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16
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Hodson DJ, Legros C, Desarménien MG, Guérineau NC. Roles of connexins and pannexins in (neuro)endocrine physiology. Cell Mol Life Sci 2015; 72:2911-28. [PMID: 26084873 DOI: 10.1007/s00018-015-1967-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/11/2015] [Indexed: 12/12/2022]
Abstract
To ensure appropriate secretion in response to demand, (neuro)endocrine tissues liberate massive quantities of hormones, which act to coordinate and synchronize biological signals in distant secretory and nonsecretory cell populations. Intercellular communication plays a central role in this control. With regard to molecular identity, junctional cell-cell communication is supported by connexin-based gap junctions. In addition, connexin hemichannels, the structural precursors of gap junctions, as well as pannexin channels have recently emerged as possible modulators of the secretory process. This review focuses on the expression of connexins and pannexins in various (neuro)endocrine tissues, including the adrenal cortex and medulla, the anterior pituitary, the endocrine hypothalamus and the pineal, thyroid and parathyroid glands. Upon a physiological or pathological stimulus, junctional intercellular coupling can be acutely modulated or persistently remodeled, thus offering multiple regulatory possibilities. The functional roles of gap junction-mediated intercellular communication in endocrine physiology as well as the involvement of connexin/pannexin-related hemichannels are also discussed.
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Affiliation(s)
- David J Hodson
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, W12 0NN, UK
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17
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Hey KL, Momiji H, Featherstone K, Davis JRE, White MRH, Rand DA, Finkenstädt B. A stochastic transcriptional switch model for single cell imaging data. Biostatistics 2015; 16:655-69. [PMID: 25819987 PMCID: PMC4570576 DOI: 10.1093/biostatistics/kxv010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 02/21/2015] [Indexed: 12/03/2022] Open
Abstract
Gene expression is made up of inherently stochastic processes within single cells and can be modeled through stochastic reaction networks (SRNs). In particular, SRNs capture the features of intrinsic variability arising from intracellular biochemical processes. We extend current models for gene expression to allow the transcriptional process within an SRN to follow a random step or switch function which may be estimated using reversible jump Markov chain Monte Carlo (MCMC). This stochastic switch model provides a generic framework to capture many different dynamic features observed in single cell gene expression. Inference for such SRNs is challenging due to the intractability of the transition densities. We derive a model-specific birth–death approximation and study its use for inference in comparison with the linear noise approximation where both approximations are considered within the unifying framework of state-space models. The methodology is applied to synthetic as well as experimental single cell imaging data measuring expression of the human prolactin gene in pituitary cells.
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Affiliation(s)
- Kirsty L Hey
- Department of Statistics, University of Warwick, Coventry CV4 7AL, UK
| | - Hiroshi Momiji
- Warwick Systems Biology, University of Warwick, Coventry CV4 7AL, UK
| | - Karen Featherstone
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester M13 9PT, UK
| | - Julian R E Davis
- Centre for Endocrinology and Diabetes, University of Manchester, Manchester M13 9PT, UK
| | - Michael R H White
- Systems Biology Centre, University of Manchester, Manchester M13 9PL, UK
| | - David A Rand
- Warwick Systems Biology, University of Warwick, Coventry CV4 7AL, UK
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18
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Wood S, Loudon A. Clocks for all seasons: unwinding the roles and mechanisms of circadian and interval timers in the hypothalamus and pituitary. J Endocrinol 2014; 222:R39-59. [PMID: 24891434 PMCID: PMC4104039 DOI: 10.1530/joe-14-0141] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Adaptation to the environment is essential for survival, in all wild animal species seasonal variation in temperature and food availability needs to be anticipated. This has led to the evolution of deep-rooted physiological cycles, driven by internal clocks, which can track seasonal time with remarkable precision. Evidence has now accumulated that a seasonal change in thyroid hormone (TH) availability within the brain is a crucial element. This is mediated by local control of TH-metabolising enzymes within specialised ependymal cells lining the third ventricle of the hypothalamus. Within these cells, deiodinase type 2 enzyme is activated in response to summer day lengths, converting metabolically inactive thyroxine (T4) to tri-iodothyronine (T3). The availability of TH in the hypothalamus appears to be an important factor in driving the physiological changes that occur with season. Remarkably, in both birds and mammals, the pars tuberalis (PT) of the pituitary gland plays an essential role. A specialised endocrine thyrotroph cell (TSH-expressing) is regulated by the changing day-length signal, leading to activation of TSH by long days. This acts on adjacent TSH-receptors expressed in the hypothalamic ependymal cells, causing local regulation of deiodinase enzymes and conversion of TH to the metabolically active T3. In mammals, the PT is regulated by the nocturnal melatonin signal. Summer-like melatonin signals activate a PT-expressed clock-regulated transcription regulator (EYA3), which in turn drives the expression of the TSHβ sub-unit, leading to a sustained increase in TSH expression. In this manner, a local pituitary timer, driven by melatonin, initiates a cascade of molecular events, led by EYA3, which translates to seasonal changes of neuroendocrine activity in the hypothalamus. There are remarkable parallels between this PT circuit and the photoperiodic timing system used in plants, and while plants use different molecular signals (constans vs EYA3) it appears that widely divergent organisms probably obey a common set of design principles.
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Affiliation(s)
- Shona Wood
- Faculty of Life SciencesUniversity of Manchester, Manchester M13 9PT, UK
| | - Andrew Loudon
- Faculty of Life SciencesUniversity of Manchester, Manchester M13 9PT, UK
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19
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Abstract
In the reductionist perspective, genetic modifications are considered to initiate cancer. Their appearance is a stochastic phenomenon, but there are some biases linked to DNA sequence or exposure to mutagenic agents for instance. Cancer genome sequencing has shown a high inter- and intra-tumoral heterogeneity, sometimes questioning the genetic origin of cancer. Other stochastic processes are also studied in cancer, especially epigenetic modifications. They have a major role in diversifying phenotypes among cancer cells in the progression steps, but might also provide an alternative to genetic theories of cancer initiation. Nevertheless, the reductionist framework remains dominant here. Finally, stochastic cell-to-cell variations in gene expression constitute a third class of stochastic phenomena that can be considered as causal factors in cancer. Highlighting the role of high gene expression variability due to disruption of cellular interactions and communications allows avoiding reductionism by considering the interplay between genetic and tissue levels at every step of the disease. No organization level is privileged in this alternative theory.
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Affiliation(s)
- Jean-Pascal Capp
- INSA/Université de Toulouse, LISBP, UMR CNRS 5504, UMR INRA 792, 135, avenue de Rangueil, 31077 Toulouse Cedex 4, France
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20
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Le Tissier PR, Hodson DJ, Lafont C, Fontanaud P, Schaeffer M, Mollard P. Anterior pituitary cell networks. Front Neuroendocrinol 2012; 33:252-66. [PMID: 22981652 DOI: 10.1016/j.yfrne.2012.08.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/17/2012] [Accepted: 08/18/2012] [Indexed: 12/17/2022]
Abstract
Both endocrine and non-endocrine cells of the pituitary gland are organized into structural and functional networks which are formed during embryonic development but which may be modified throughout life. Structural mapping of the various endocrine cell types has highlighted the existence of distinct network motifs and relationships with the vasculature which may relate to temporal differences in their output. Functional characterization of the network activity of growth hormone and prolactin cells has revealed a role for cell organization in gene regulation, the plasticity of pituitary hormone output and remarkably the ability to memorize altered demand. As such, the description of these endocrine cell networks alters the concept of the pituitary from a gland which simply responds to external regulation to that of an oscillator which may memorize information and constantly adapt its coordinated networks' responses to the flow of hypothalamic inputs.
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Affiliation(s)
- P R Le Tissier
- Division of Molecular Neuroendocrinology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom;
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21
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Featherstone K, White MRH, Davis JRE. The prolactin gene: a paradigm of tissue-specific gene regulation with complex temporal transcription dynamics. J Neuroendocrinol 2012; 24:977-90. [PMID: 22420298 PMCID: PMC3505372 DOI: 10.1111/j.1365-2826.2012.02310.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Transcription of numerous mammalian genes is highly pulsatile, with bursts of expression occurring with variable duration and frequency. The presence of this stochastic or 'noisy' expression pattern has been relatively unexplored in tissue systems. The prolactin gene provides a model of tissue-specific gene regulation resulting in pulsatile transcription dynamics in both cell lines and endocrine tissues. In most cell culture models, prolactin transcription appears to be highly variable between cells, with differences in transcription pulse duration and frequency. This apparently stochastic transcription is constrained by a transcriptional refractory period, which may be related to cycles of chromatin remodelling. We propose that prolactin transcription dynamics result from the summation of oscillatory cellular inputs and by regulation through chromatin remodelling cycles. Observations of transcription dynamics in cells within pituitary tissue show reduced transcriptional heterogeneity and can be grouped into a small number of distinct patterns. Thus, it appears that the tissue environment is able to reduce transcriptional noise to enable coordinated tissue responses to environmental change. We review the current knowledge on the complex tissue-specific regulation of the prolactin gene in pituitary and extra-pituitary sites, highlighting differences between humans and rodent experimental animal models. Within this context, we describe the transcription dynamics of prolactin gene expression and how this may relate to specific processes occurring within the cell.
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Affiliation(s)
- K Featherstone
- Developmental Biomedicine Research Group, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK.
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22
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Mollard P, Hodson DJ, Lafont C, Rizzoti K, Drouin J. A tridimensional view of pituitary development and function. Trends Endocrinol Metab 2012; 23:261-9. [PMID: 22436593 DOI: 10.1016/j.tem.2012.02.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 01/05/2023]
Abstract
Recent advances in tridimensional (3D) tissue imaging have considerably enriched our view of the pituitary gland and its development. Whereas traditional histology of the pituitary anterior lobe portrayed this tissue as a patchwork of cells, 3D imaging revealed that cells of each lineage form extensive and structured homotypic networks. In the adult gland these networks contribute to the robustness and coordination of the cell response to secretagogs. In addition, the network organization adapts to changes in endocrine environment, as revealed by the sexually dimorphic growth hormone (GH) cell network. Further work is required to establish better the molecular basis for homotypic and heterotypic interactions in the pituitary as well as the implications of these interactions for pituitary function and dysfunction in humans.
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Affiliation(s)
- Patrice Mollard
- Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 5203, Institut de Génomique Fonctionnelle, 34000 Montpellier, France.
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23
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Davis JRE. Imaging of endocrine gene expression in a humanized transgenic rat. Ann N Y Acad Sci 2012; 1245:38-9. [PMID: 22211975 DOI: 10.1111/j.1749-6632.2011.06341.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reporter gene imaging has revealed cyclical patterns of gene expression in living cells. Transgenic animal studies show that these patterns are modified by tissue architecture.
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24
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Featherstone K, Harper CV, McNamara A, Semprini S, Spiller DG, McNeilly J, McNeilly AS, Mullins JJ, White MRH, Davis JRE. Pulsatile patterns of pituitary hormone gene expression change during development. Development 2011. [DOI: 10.1242/dev.076216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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