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Šterk M, Zhang Y, Pohorec V, Leitgeb EP, Dolenšek J, Benninger RKP, Stožer A, Kravets V, Gosak M. Network representation of multicellular activity in pancreatic islets: Technical considerations for functional connectivity analysis. PLoS Comput Biol 2024; 20:e1012130. [PMID: 38739680 PMCID: PMC11115366 DOI: 10.1371/journal.pcbi.1012130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 05/23/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024] Open
Abstract
Within the islets of Langerhans, beta cells orchestrate synchronized insulin secretion, a pivotal aspect of metabolic homeostasis. Despite the inherent heterogeneity and multimodal activity of individual cells, intercellular coupling acts as a homogenizing force, enabling coordinated responses through the propagation of intercellular waves. Disruptions in this coordination are implicated in irregular insulin secretion, a hallmark of diabetes. Recently, innovative approaches, such as integrating multicellular calcium imaging with network analysis, have emerged for a quantitative assessment of the cellular activity in islets. However, different groups use distinct experimental preparations, microscopic techniques, apply different methods to process the measured signals and use various methods to derive functional connectivity patterns. This makes comparisons between findings and their integration into a bigger picture difficult and has led to disputes in functional connectivity interpretations. To address these issues, we present here a systematic analysis of how different approaches influence the network representation of islet activity. Our findings show that the choice of methods used to construct networks is not crucial, although care is needed when combining data from different islets. Conversely, the conclusions drawn from network analysis can be heavily affected by the pre-processing of the time series, the type of the oscillatory component in the signals, and by the experimental preparation. Our tutorial-like investigation aims to resolve interpretational issues, reconcile conflicting views, advance functional implications, and encourage researchers to adopt connectivity analysis. As we conclude, we outline challenges for future research, emphasizing the broader applicability of our conclusions to other tissues exhibiting complex multicellular dynamics.
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Affiliation(s)
- Marko Šterk
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Yaowen Zhang
- Department of Pediatrics, Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
| | - Viljem Pohorec
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | | | - Jurij Dolenšek
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Richard K. P. Benninger
- Department of Bioengineering, Barbara Davis Center for Diabetes, Aurora, Colorado, United States of America
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Andraž Stožer
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Vira Kravets
- Department of Pediatrics, Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
- Department of Bioengineering, Jacobs School of Engineering, University of California, San Diego, La Jolla, California, United States of America
| | - Marko Gosak
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea, Maribor
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2
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Royan MR, Hodne K, Nourizadeh-Lillabadi R, Weltzien FA, Henkel C, Fontaine R. Day length regulates gonadotrope proliferation and reproduction via an intra-pituitary pathway in the model vertebrate Oryzias latipes. Commun Biol 2024; 7:388. [PMID: 38553567 PMCID: PMC10980775 DOI: 10.1038/s42003-024-06059-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 03/16/2024] [Indexed: 04/01/2024] Open
Abstract
In seasonally breeding mammals and birds, the production of the hormones that regulate reproduction (gonadotropins) is controlled by a complex pituitary-brain-pituitary pathway. Indeed, the pituitary thyroid-stimulating hormone (TSH) regulates gonadotropin expression in pituitary gonadotropes, via dio2-expressing tanycytes, hypothalamic Kisspeptin, RFamide-related peptide, and gonadotropin-releasing hormone neurons. However, in fish, how seasonal environmental signals influence gonadotropins remains unclear. In addition, the seasonal regulation of gonadotrope (gonadotropin-producing cell) proliferation in the pituitary is, to the best of our knowledge, not elucidated in any vertebrate group. Here, we show that in the vertebrate model Japanese medaka (Oryzias latipes), a long day seasonally breeding fish, photoperiod (daylength) not only regulates hormone production by the gonadotropes but also their proliferation. We also reveal an intra-pituitary pathway that regulates gonadotrope cell number and hormone production. In this pathway, Tsh regulates gonadotropes via folliculostellate cells within the pituitary. This study suggests the existence of an alternative regulatory mechanism of seasonal gonadotropin production in fish.
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Affiliation(s)
- Muhammad Rahmad Royan
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Kjetil Hodne
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Rasoul Nourizadeh-Lillabadi
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Finn-Arne Weltzien
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Christiaan Henkel
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway
| | - Romain Fontaine
- Department of Preclinical Science and Pathology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Ås, Norway.
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3
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Pérez Millán MI, Cheung LYM, Mercogliano F, Camilletti MA, Chirino Felker GT, Moro LN, Miriuka S, Brinkmeier ML, Camper SA. Pituitary stem cells: past, present and future perspectives. Nat Rev Endocrinol 2024; 20:77-92. [PMID: 38102391 PMCID: PMC10964491 DOI: 10.1038/s41574-023-00922-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/31/2023] [Indexed: 12/17/2023]
Abstract
Pituitary cells that express the transcription factor SOX2 are stem cells because they can self-renew and differentiate into multiple pituitary hormone-producing cell types as organoids. Wounding and physiological challenges can activate pituitary stem cells, but cell numbers are not fully restored, and the ability to mobilize stem cells decreases with increasing age. The basis of these limitations is still unknown. The regulation of stem cell quiescence and activation involves many different signalling pathways, including those mediated by WNT, Hippo and several cytokines; more research is needed to understand the interactions between these pathways. Pituitary organoids can be formed from human or mouse embryonic stem cells, or from human induced pluripotent stem cells. Human pituitary organoid transplantation is sufficient to induce corticosterone release in hypophysectomized mice, raising the possibility of therapeutic applications. Today, pituitary organoids have the potential to assess the role of individual genes and genetic variants on hormone production ex vivo, providing an important tool for the advancement of exciting frontiers in pituitary stem cell biology and pituitary organogenesis. In this article, we provide an overview of notable discoveries in pituitary stem cell function and highlight important areas for future research.
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Affiliation(s)
- María Inés Pérez Millán
- Institute of Bioscience, Biotechnology and Translational Biology (IB3-UBA), University of Buenos Aires, Buenos Aires, Argentina
| | - Leonard Y M Cheung
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA
- Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, NY, USA
| | - Florencia Mercogliano
- Institute of Bioscience, Biotechnology and Translational Biology (IB3-UBA), University of Buenos Aires, Buenos Aires, Argentina
| | - Maria Andrea Camilletti
- Institute of Bioscience, Biotechnology and Translational Biology (IB3-UBA), University of Buenos Aires, Buenos Aires, Argentina
| | - Gonzalo T Chirino Felker
- Laboratory of Applied Research of Neurosciences (LIAN-CONICET), FLENI Sede Escobar, Buenos Aires, Argentina
| | - Lucia N Moro
- Laboratory of Applied Research of Neurosciences (LIAN-CONICET), FLENI Sede Escobar, Buenos Aires, Argentina
| | - Santiago Miriuka
- Laboratory of Applied Research of Neurosciences (LIAN-CONICET), FLENI Sede Escobar, Buenos Aires, Argentina
| | - Michelle L Brinkmeier
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Sally A Camper
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA.
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4
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Fazli M, Bertram R. Conversion of spikers to bursters in pituitary cell networks: Is it better to disperse for maximum exposure or circle the wagons? PLoS Comput Biol 2024; 20:e1011811. [PMID: 38289902 PMCID: PMC10826967 DOI: 10.1371/journal.pcbi.1011811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024] Open
Abstract
The endocrine cells of the pituitary gland are electrically active, and in vivo they form small networks where the bidirectional cell-cell coupling is through gap junctions. Numerous studies of dispersed pituitary cells have shown that typical behaviors are tonic spiking and bursting, the latter being more effective at evoking secretion. In this article, we use mathematical modeling to examine the dynamics of small networks of spiking and bursting pituitary cells. We demonstrate that intrinsic bursting cells are capable of converting intrinsic spikers into bursters, and perform a fast/slow analysis to show why this occurs. We then demonstrate the sensitivity of network dynamics to the placement of bursting cells within the network, and demonstrate strategies that are most effective at maximizing secretion from the population of cells. This study provides insights into the in vivo behavior of cells such as the stress-hormone-secreting pituitary corticotrophs that are switched from spiking to bursting by hypothalamic neurohormones. While much is known about the electrical properties of these cells when isolated from the pituitary, how they behave when part of an electrically coupled network has been largely unstudied.
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Affiliation(s)
- Mehran Fazli
- Department of Mathematics, Florida State University, Tallahassee, Florida, United States of America
| | - Richard Bertram
- Department of Mathematics, Florida State University, Tallahassee, Florida, United States of America
- Programs in Neuroscience and Molecular Biophysics, Florida State University, Tallahassee, Florida, United States of America
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5
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Shutova AS, Dzeranova LK, Vorotnikova SY, Kutin MA, Pigarova EA. [Modern concepts of genetic and immunohistochemical features of prolactin-secreting pituitary adenomas]. PROBLEMY ENDOKRINOLOGII 2023; 69:44-50. [PMID: 37448246 DOI: 10.14341/probl13222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 07/15/2023]
Abstract
Prolactinomas are the most common secreting adenomas of the pituitary. In 20% of cases resistance to dopamine-agonists treatment is observed. Medical therapy resistance causes progression of pathological symptoms of hyperprolactinemia and negative topographic and anatomical changes of prolactinoma. The causes of ineffectiveness of dopamine agonists therapy are not fully understood as well as approaches to managing patients require clarification. Current concepts of resistance are based on the data obtained as a result of surgery or after a period of long-term ineffective therapy. Thus, it is very important to find methods of assessing the sensitivity of prolactin-secreting adenomas to drug therapy before surgical treatment. Genetic and immunohistochemical studies find special place among these methods, making it possible to predict adenoma's response to drug therapy at early diagnostic stage. Obtained results will allow us to form personalized algorithm for managing patients.
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Affiliation(s)
| | | | | | - M A Kutin
- N.N. Burdenko National Medical Research Center of Neurosurgery
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6
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Wang X, Dai X, Chen Y. Sonopiezoelectric Nanomedicine and Materdicine. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2301693. [PMID: 37093550 DOI: 10.1002/smll.202301693] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/02/2023] [Indexed: 05/03/2023]
Abstract
Endogenous electric field is ubiquitous in a multitude of important living activities such as bone repair, cell signal transduction, and nerve regeneration, signifying that regulating the electric field in organisms is highly beneficial to maintain organism health. As an emerging and promising research direction, piezoelectric nanomedicine and materdicine precisely activated by ultrasound with synergetic advantages of deep tissue penetration, remote spatiotemporal selectivity, and mechanical-electrical energy interconversion, have been progressively utilized for disease treatment and tissue repair by participating in the modulation of endogenous electric field. This specific nanomedicine utilizing piezoelectric effect activated by ultrasound is typically regarded as "sonopiezoelectric nanomedicine". This comprehensive review summarizes and discusses the substantially employed sonopiezoelectric nanomaterials and nanotherapies to provide an insight into the internal mechanism of the corresponding biological behavior/effect of sonopiezoelectric biomaterials in versatile disease treatments. This review primarily focuses on the sonopiezoelectric biomaterials for biosensing, drug delivery, tumor therapy, tissue regeneration, antimicrobia, and further illuminates the underlying sonopiezoelectric mechanism. In addition, the challenges and developments/prospects of sonopiezoelectric nanomedicine are analyzed for promoting the further clinical translation. It is earnestly expected that this kind of nanomedicine/biomaterials-enabled sonopiezoelectric technology will provoke the comprehensive investigation and promote the clinical development of the next-generation multifunctional materdicine.
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Affiliation(s)
- Xue Wang
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Xinyue Dai
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
| | - Yu Chen
- Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, P. R. China
- School of Medicine, Shanghai University, Shanghai, 200444, P. R. China
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7
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Galvis D, Hodson DJ, Wedgwood KC. Spatial distribution of heterogeneity as a modulator of collective dynamics in pancreatic beta-cell networks and beyond. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:fnetp.2023.1170930. [PMID: 36987428 PMCID: PMC7614376 DOI: 10.3389/fnetp.2023.1170930] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
We study the impact of spatial distribution of heterogeneity on collective dynamics in gap-junction coupled beta-cell networks comprised on cells from two populations that differ in their intrinsic excitability. Initially, these populations are uniformly and randomly distributed throughout the networks. We develop and apply an iterative algorithm for perturbing the arrangement of the network such that cells from the same population are increasingly likely to be adjacent to one another. We find that the global input strength, or network drive, necessary to transition the network from a state of quiescence to a state of synchronised and oscillatory activity decreases as network sortedness increases. Moreover, for weak coupling, we find that regimes of partial synchronisation and wave propagation arise, which depend both on network drive and network sortedness. We then demonstrate the utility of this algorithm for studying the distribution of heterogeneity in general networks, for which we use Watts-Strogatz networks as a case study. This work highlights the importance of heterogeneity in node dynamics in establishing collective rhythms in complex, excitable networks and has implications for a wide range of real-world systems that exhibit such heterogeneity.
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Affiliation(s)
- Daniel Galvis
- Centre for Systems Modelling and Quantitative Biomedicine, University of Birmingham, Birmingham, UK
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Correspondence: Daniel Galvis,
| | - David J. Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
- Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Kyle C.A. Wedgwood
- Living Systems Institute, University of Exeter, Exeter, UK
- EPSRC Hub for Quantitative Modelling in Healthcare, University of Exeter, Exeter, UK
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
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8
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Mollard P. [The pituitary gland unveiled: from the stimulation-secretion coupling to cellular networks wiring]. Biol Aujourdhui 2023; 216:83-87. [PMID: 36744973 DOI: 10.1051/jbio/2022021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Indexed: 02/07/2023]
Abstract
The year 2021 ended with an event of great sadness: the death of Andrée Tixier-Vidal. She was not only a pioneer in cell biology but also the charismatic promoter of stimulating and successful multidisciplinary collaborations. Her achievements led to subsequent major discoveries on both the stimulation-secretion coupling of pituitary endocrine cells and the hitherto unknown organization of these cells into multicellular 3D networks which build-up highly organized pulses of pituitary hormones controlling basic body functions such as growth and reproduction.
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Affiliation(s)
- Patrice Mollard
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 141 rue de la Cardonille, 34094 Montpellier Cedex 5, France
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9
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Begon E, Bernard V. [Prolactin and its receptor: From animal models to pituitary pathophysiology]. Biol Aujourdhui 2023; 216:105-110. [PMID: 36744975 DOI: 10.1051/jbio/2022019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Indexed: 02/07/2023]
Abstract
Prolactin (PRL) is a polypeptide hormone that is mainly synthesized and secreted by lactotroph cells of the anterior pituitary gland. The actions of prolactin are mediated by its transmembrane receptor, PRLR. The principal role attributed to PRL is to stimulate the proliferation and differentiation of the mammary cells required for lactation, but studies of animal models have assigned more than 300 separate actions to this hormone in various species. Hyperprolactinaemia is the prototypical pathological state associated with this hormone. Indeed, hyperprolactinaemia is the most common cause of amenorrhoea due to hypogonadotropic anovulation and is one of the most prevalent endocrine causes of infertility in women. In recent years, the study of conditional or complete Prlr -/- mouse models had improved the understanding concerning the regulation of gonadotroph and lactotroph axes. It is now demonstrated that prolactin exerts autocrine or paracrine actions on lactotroph cells in vivo. One of the major advances was to better understand, using mouse models, the impact of hyperprolactinemia on gonadotroph axis. It is now accepted that hypogonadotropic hypogonadism in patients with hyperprolactinemia is mediated by a decrease of hypothalamic kisspeptin secretion. Gonadotroph axis can be restored by intravenous administration of kisspeptin. However, the mechanisms of lactotroph tumorigenesis in Prlr -/- animals remain incompletely understood and transposable to the human species, since the only patient with biallelic PRLR loss-of-function mutation leading to complete prolactin resistance that has been described so far did not have pituitary adenoma visible on MRI.
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Affiliation(s)
- Emmanuelle Begon
- Service de chirurgie gynécologique, gynécologie médicale et de médecine de la reproduction, Centre Aliénor d'Aquitaine, CHU et Université de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux Cedex, France
| | - Valérie Bernard
- Service de chirurgie gynécologique, gynécologie médicale et de médecine de la reproduction, Centre Aliénor d'Aquitaine, CHU et Université de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux Cedex, France
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10
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Walker JJ, Romanò N. Fast dynamics in the HPA axis: Insight from mathematical and experimental studies. CURRENT OPINION IN ENDOCRINE AND METABOLIC RESEARCH 2022; 27:100403. [PMID: 36632146 PMCID: PMC9823091 DOI: 10.1016/j.coemr.2022.100403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The activity of the hypothalamic-pituitary-adrenal (HPA) axis is characterised by complex dynamics spanning several timescales. This ranges from slow circadian rhythms in blood hormone concentration to faster ultradian pulses of hormone secretion and even more rapid oscillations in electrical and calcium activity in neuroendocrine cells of the hypothalamus and pituitary gland. Here, we focus on the system's oscillations on the short timescale. We highlight some of the mathematical modelling and experimental work that has been carried out to characterise the mechanisms regulating this highly dynamic mode of neuroendocrine signalling and discuss some future directions that may be explored to enhance understanding of HPA function.
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Affiliation(s)
- Jamie J. Walker
- Department of Mathematics and Statistics, Faculty of Environment, Science and Economy, University of Exeter, UK,Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, UK,Corresponding author: Walker, Jamie J
| | - Nicola Romanò
- Centre for Discovery Brain Sciences, University of Edinburgh, UK,Corresponding author: Romanò, Nicola twitter icon
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11
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Drouin J. The corticotroph cells from early development to tumorigenesis. J Neuroendocrinol 2022; 34:e13147. [PMID: 35524583 DOI: 10.1111/jne.13147] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/06/2022] [Accepted: 04/15/2022] [Indexed: 11/27/2022]
Abstract
During development, highly specialized differentiated cells, such as pituitary secretory cells, acquire their identity and properties through a series of specification events exerted by transcription factors to implement a unique gene expression program and epigenomic state. The investigation of these developmental processes informs us on the unique features of a cell lineage, both to explain these features and also to outline where these processes may fail and cause disease. This review summarizes present knowledge on the developmental origin of pituitary corticotroph and melanotroph cells and on the underlying molecular mechanisms. At the onset, comparison of gene expression programs active in pituitary progenitors compared to those active in differentiated corticotrophs or melanotrophs indicated dramatic differences in the control of, for example, the cell cycle. Tpit is the transcription factor that determines terminal differentiation of pro-opiomelanocortin (POMC) lineages, both corticotrophs and melanotrophs, and its action involves this switch in cell cycle control in parallel with activation of cell-specific gene expression. There is thus far more to making a corticotroph cell than just activating transcription of the POMC gene. Indeed, Tpit also controls implementation of mechanisms for enhanced protein translation capacity and development of extensive secretory organelles. The corticotroph cell identity also includes mechanisms responsible for homotypic cell-cell interactions between corticotrophs and for privileged heterotypic cell interactions with pituitary cells of other lineages. The review also summarizes current knowledge on how a pioneer transcription factor, Pax7, remodels the epigenome such that the same determination transcription factor, Tpit, will implement the melanotroph program of gene expression. Finally, this canvas of regulatory mechanisms implementing POMC lineage identities constitutes the background to understand alterations that characterize corticotroph adenomas of Cushing's disease patients. The integration of all these data into a unified scheme will likely yield a scheme to globally understand pathogenic mechanisms in Cushing's disease.
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Affiliation(s)
- Jacques Drouin
- Institut de recherches cliniques de Montréal, Laboratoire de génétique moléculaire, Montréal, Québec, Canada
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12
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Le Tissier PR, Murray JF, Mollard P. A New Perspective on Regulation of Pituitary Plasticity: The Network of SOX2-Positive Cells May Coordinate Responses to Challenge. Endocrinology 2022; 163:6609891. [PMID: 35713880 PMCID: PMC9273012 DOI: 10.1210/endocr/bqac089] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Indexed: 11/19/2022]
Abstract
Plasticity of function is required for each of the anterior pituitary endocrine axes to support alterations in the demand for hormone with physiological status and in response to environmental challenge. This plasticity is mediated at the pituitary level by a change in functional cell mass resulting from a combination of alteration in the proportion of responding cells, the amount of hormone secreted from each cell, and the total number of cells within an endocrine cell population. The functional cell mass also depends on its organization into structural and functional networks. The mechanisms underlying alteration in gland output depend on the strength of the stimulus and are axis dependent but in all cases rely on sensing of output of the functional cell mass and its regulation. Here, we present evidence that the size of pituitary cell populations is constrained and suggest this is mediated by a form of quorum sensing. We propose that pituitary cell quorum sensing is mediated by interactions between the networks of endocrine cells and hormone-negative SOX2-positive (SOX2+ve) cells and speculate that the latter act as both a sentinel and actuator of cell number. Evidence for a role of the network of SOX2+ve cells in directly regulating secretion from multiple endocrine cell networks suggests that it also regulates other aspects of the endocrine cell functional mass. A decision-making role of SOX2+ve cells would allow precise coordination of pituitary axes, essential for their appropriate response to physiological status and challenge, as well as prioritization of axis modification.
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Affiliation(s)
- Paul R Le Tissier
- Correspondence: Paul R. Le Tissier, PhD, Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Bldg, 15 George Square, Edinburgh EH8 9XD, UK.
| | - Joanne F Murray
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Patrice Mollard
- Correspondence: Patrice Mollard, PhD, Institute of Functional Genomics, University of Montpellier, 141 rue de la Cardonille, F-34093, CNRS, INSERM, Montpellier, France.
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13
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Duncan PJ, McClafferty H, Nolan O, Ding Q, Homer NZM, Le Tissier P, Walker BR, Shipston MJ, Romanò N, Chambers TJG. Corticotroph isolation from Pomc-eGFP mice reveals sustained transcriptional dysregulation characterising a mouse model of glucocorticoid-induced suppression of the hypothalamus-pituitary-adrenal axis. J Neuroendocrinol 2022; 34:e13165. [PMID: 35833423 PMCID: PMC9539609 DOI: 10.1111/jne.13165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 11/27/2022]
Abstract
Glucocorticoids (GC) are prescribed for periods > 3 months to 1%-3% of the UK population; 10%-50% of these patients develop hypothalamus-pituitary-adrenal (HPA) axis suppression, which may last over 6 months and is associated with morbidity and mortality. Recovery of the pituitary and hypothalamus is necessary for recovery of adrenal function. We developed a mouse model of dexamethasone (DEX)-induced HPA axis dysfunction aiming to further explore recovery in the pituitary. Adult male wild-type C57BL6/J or Pomc-eGFP transgenic mice were randomly assigned to receive DEX (approximately 0.4 mg kg-1 bodyweight day-1 ) or vehicle via drinking water for 4 weeks following which treatment was withdrawn and tissues were harvested after another 0, 1, and 4 weeks. Corticotrophs were isolated from Pomc-eGFP pituitaries using fluorescence-activated cell sorting, and RNA extracted for RNA-sequencing. DEX treatment suppressed corticosterone production, which remained partially suppressed at least 1 week following DEX withdrawal. In the adrenal, Hsd3b2, Cyp11a1, and Mc2r mRNA levels were significantly reduced at time 0, with Mc2r and Cyp11a1 remaining reduced 1 week following DEX withdrawal. The corticotroph transcriptome was modified by DEX treatment, with some differences between groups persisting 4 weeks following withdrawal. No genes supressed by DEX exhibited ongoing attenuation 1 and 4 weeks following withdrawal, whereas only two genes were upregulated and remained so following withdrawal. A pattern of rebound at 1 and 4 weeks was observed in 14 genes that increased following suppression, and in six genes that were reduced by DEX and then increased. Chronic GC treatment may induce persistent changes in the pituitary that may influence future response to GC treatment or stress.
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Affiliation(s)
- Peter J. Duncan
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | | | - Oscar Nolan
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Qinghui Ding
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Natalie Z. M. Homer
- Centre for Cardiovascular ScienceUniversity of Edinburgh, Queen's Medical Research InstituteEdinburghUK
| | - Paul Le Tissier
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Brian R. Walker
- Centre for Cardiovascular ScienceUniversity of Edinburgh, Queen's Medical Research InstituteEdinburghUK
- Translational & Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUK
| | | | - Nicola Romanò
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Thomas J. G. Chambers
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
- Edinburgh Centre for Endocrinology and DiabetesNHS Lothian, Metabolic Unit, Western General HospitalEdinburghUK
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14
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Ghoreshi ZAS, Akbari H, Sharif-Zak M, Arefinia N, Abbasi-Jorjandi M, Asadikaram G. Recent findings on hyperprolactinemia and its pathological implications: a literature review. J Investig Med 2022; 70:1443-1451. [PMID: 35768141 DOI: 10.1136/jim-2022-002351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2022] [Indexed: 11/03/2022]
Abstract
The prolactin hormone (PRL) is often secreted by lactotrophic cells of the anterior pituitary and has been shown to play a role in various biological processes, including breast feeding and reproduction. The predominant form of this hormone is the 23 kDa form and acts through its receptor (PRLR) on the cell membrane. This receptor is a member of the superfamily of hematopoietic/cytokine receptors. PRL also has a 16 kDa subunit with anti-angiogenic, proapoptotic, and anti-inflammatory effects which is produced by the proteolytic breakdown of this hormone under oxidative stress. Although the common side effects of hyperprolactinemia are exerted on the reproductive system, new studies have shown that hyperprolactinemia has a wide variety of effects, including playing a role in the development of autoimmune diseases and increasing the risk of cardiovascular disease, peripartum cardiomyopathy, and diabetes among others. The range of PRL functions is increasing with the discovery of multiple sites of PRL secretion as well as PRLR expression in various tissues. This review summarizes current knowledge of the biology of PRL and its receptor, as well as the role of PRL in human pathophysiology.
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Affiliation(s)
- Zohreh Al-Sadat Ghoreshi
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Institute of Basic and Clinical Physiology Sciences, Kerman, The Islamic Republic of Iran
| | - Hamed Akbari
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Institute of Basic and Clinical Physiology Sciences, Kerman, The Islamic Republic of Iran.,Department of Clinical Biochemistry, Afzalipur Faculty of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran
| | - Mohsen Sharif-Zak
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Institute of Basic and Clinical Physiology Sciences, Kerman, The Islamic Republic of Iran.,Neuroscience Research Center, Institute of Neuropharmacology, School of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran
| | - Nasir Arefinia
- Neuroscience Research Center, Institute of Neuropharmacology, School of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran
| | - Mojtaba Abbasi-Jorjandi
- Department of Clinical Biochemistry, Afzalipur Faculty of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran
| | - Gholamreza Asadikaram
- Department of Clinical Biochemistry, Afzalipur Faculty of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran .,Neuroscience Research Center, Institute of Neuropharmacology, School of Medicine, Kerman University of Medical Sciences, Kerman, The Islamic Republic of Iran
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15
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Marolt U, Paradiž Leitgeb E, Pohorec V, Lipovšek S, Venglovecz V, Gál E, Ébert A, Menyhárt I, Potrč S, Gosak M, Dolenšek J, Stožer A. Calcium imaging in intact mouse acinar cells in acute pancreas tissue slices. PLoS One 2022; 17:e0268644. [PMID: 35657915 PMCID: PMC9165796 DOI: 10.1371/journal.pone.0268644] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/04/2022] [Indexed: 12/22/2022] Open
Abstract
The physiology and pathophysiology of the exocrine pancreas are in close connection to changes in intra-cellular Ca2+ concentration. Most of our knowledge is based on in vitro experiments on acinar cells or acini enzymatically isolated from their surroundings, which can alter their structure, physiology, and limit our understanding. Due to these limitations, the acute pancreas tissue slice technique was introduced almost two decades ago as a complementary approach to assess the morphology and physiology of both the endocrine and exocrine pancreas in a more conserved in situ setting. In this study, we extend previous work to functional multicellular calcium imaging on acinar cells in tissue slices. The viability and morphological characteristics of acinar cells within the tissue slice were assessed using the LIVE/DEAD assay, transmission electron microscopy, and immunofluorescence imaging. The main aim of our study was to characterize the responses of acinar cells to stimulation with acetylcholine and compare them with responses to cerulein in pancreatic tissue slices, with special emphasis on inter-cellular and inter-acinar heterogeneity and coupling. To this end, calcium imaging was performed employing confocal microscopy during stimulation with a wide range of acetylcholine concentrations and selected concentrations of cerulein. We show that various calcium oscillation parameters depend monotonically on the stimulus concentration and that the activity is rather well synchronized within acini, but not between acini. The acute pancreas tissue slice represents a viable and reliable experimental approach for the evaluation of both intra- and inter-cellular signaling characteristics of acinar cell calcium dynamics. It can be utilized to assess many cells simultaneously with a high spatiotemporal resolution, thus providing an efficient and high-yield platform for future studies of normal acinar cell biology, pathophysiology, and screening pharmacological substances.
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Affiliation(s)
- Urška Marolt
- Clinical department for abdominal and general surgery, University Medical Centre Maribor, Maribor, Slovenia
- * E-mail: (UM); (JD); (AS)
| | - Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Saška Lipovšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor, Slovenia
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Eleonóra Gál
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Attila Ébert
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - István Menyhárt
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Stojan Potrč
- Clinical department for abdominal and general surgery, University Medical Centre Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- * E-mail: (UM); (JD); (AS)
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- * E-mail: (UM); (JD); (AS)
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16
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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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17
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Stožer A, Šterk M, Paradiž Leitgeb E, Markovič R, Skelin Klemen M, Ellis CE, Križančić Bombek L, Dolenšek J, MacDonald PE, Gosak M. From Isles of Königsberg to Islets of Langerhans: Examining the Function of the Endocrine Pancreas Through Network Science. Front Endocrinol (Lausanne) 2022; 13:922640. [PMID: 35784543 PMCID: PMC9240343 DOI: 10.3389/fendo.2022.922640] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/16/2022] [Indexed: 12/12/2022] Open
Abstract
Islets of Langerhans are multicellular microorgans located in the pancreas that play a central role in whole-body energy homeostasis. Through secretion of insulin and other hormones they regulate postprandial storage and interprandial usage of energy-rich nutrients. In these clusters of hormone-secreting endocrine cells, intricate cell-cell communication is essential for proper function. Electrical coupling between the insulin-secreting beta cells through gap junctions composed of connexin36 is particularly important, as it provides the required, most important, basis for coordinated responses of the beta cell population. The increasing evidence that gap-junctional communication and its modulation are vital to well-regulated secretion of insulin has stimulated immense interest in how subpopulations of heterogeneous beta cells are functionally arranged throughout the islets and how they mediate intercellular signals. In the last decade, several novel techniques have been proposed to assess cooperation between cells in islets, including the prosperous combination of multicellular imaging and network science. In the present contribution, we review recent advances related to the application of complex network approaches to uncover the functional connectivity patterns among cells within the islets. We first provide an accessible introduction to the basic principles of network theory, enumerating the measures characterizing the intercellular interactions and quantifying the functional integration and segregation of a multicellular system. Then we describe methodological approaches to construct functional beta cell networks, point out possible pitfalls, and specify the functional implications of beta cell network examinations. We continue by highlighting the recent findings obtained through advanced multicellular imaging techniques supported by network-based analyses, giving special emphasis to the current developments in both mouse and human islets, as well as outlining challenges offered by the multilayer network formalism in exploring the collective activity of islet cell populations. Finally, we emphasize that the combination of these imaging techniques and network-based analyses does not only represent an innovative concept that can be used to describe and interpret the physiology of islets, but also provides fertile ground for delineating normal from pathological function and for quantifying the changes in islet communication networks associated with the development of diabetes mellitus.
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Affiliation(s)
- Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marko Šterk
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Rene Markovič
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- Institute of Mathematics and Physics, Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Cara E. Ellis
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | | | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Patrick E. MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
- *Correspondence: Marko Gosak,
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18
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Benninger RKP, Kravets V. The physiological role of β-cell heterogeneity in pancreatic islet function. Nat Rev Endocrinol 2022; 18:9-22. [PMID: 34667280 PMCID: PMC8915749 DOI: 10.1038/s41574-021-00568-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/07/2021] [Indexed: 01/03/2023]
Abstract
Endocrine cells within the pancreatic islets of Langerhans are heterogeneous in terms of transcriptional profile, protein expression and the regulation of hormone release. Even though this heterogeneity has long been appreciated, only within the past 5 years have detailed molecular analyses led to an improved understanding of its basis. Although we are beginning to recognize why some subpopulations of endocrine cells are phenotypically different to others, arguably the most important consideration is how this heterogeneity affects the regulation of hormone release to control the homeostasis of glucose and other energy-rich nutrients. The focus of this Review is the description of how endocrine cell heterogeneity (and principally that of insulin-secreting β-cells) affects the regulation of hormone secretion within the islets of Langerhans. This discussion includes an overview of the functional characteristics of the different islet cell subpopulations and describes how they can communicate to influence islet function under basal and glucose-stimulated conditions. We further discuss how changes to the specific islet cell subpopulations or their numbers might underlie islet dysfunction in type 2 diabetes mellitus. We conclude with a discussion of several key open questions regarding the physiological role of islet cell heterogeneity.
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Affiliation(s)
- Richard K P Benninger
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Vira Kravets
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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19
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Fazli M, Bertram R. Network Properties of Electrically Coupled Bursting Pituitary Cells. Front Endocrinol (Lausanne) 2022; 13:936160. [PMID: 35872987 PMCID: PMC9299381 DOI: 10.3389/fendo.2022.936160] [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: 05/04/2022] [Accepted: 06/01/2022] [Indexed: 12/03/2022] Open
Abstract
The endocrine cells of the anterior pituitary gland are electrically active when stimulated or, in some cases, when not inhibited. The activity pattern thought to be most effective in releasing hormones is bursting, which consists of depolarization with small spikes that are much longer than single spikes. Although a majority of the research on cellular activity patterns has been performed on dispersed cells, the environment in situ is characterized by networks of coupled cells of the same type, at least in the case of somatotrophs and lactotrophs. This produces some degree of synchronization of their activity, which can be greatly increased by hormones and changes in the physiological state. In this computational study, we examine how electrical coupling among model cells influences synchronization of bursting oscillations among the population. We focus primarily on weak electrical coupling, since strong coupling leads to complete synchronization that is not characteristic of pituitary cell networks. We first look at small networks to point out several unexpected behaviors of the coupled system, and then consider a larger random scale-free network to determine what features of the structural network formed through gap junctional coupling among cells produce a high degree of functional coupling, i.e., clusters of synchronized cells. We employ several network centrality measures, and find that cells that are closely related in terms of their closeness centrality are most likely to be synchronized. We also find that structural hubs (cells with extensive coupling to other cells) are typically not functional hubs (cells synchronized with many other cells). Overall, in the case of weak electrical coupling, it is hard to predict the functional network that arises from a structural network, or to use a functional network as a means for determining the structural network that gives rise to it.
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Affiliation(s)
- Mehran Fazli
- Department of Mathematics, Florida State University, Tallahassee, FL, United States
| | - Richard Bertram
- Department of Mathematics, Florida State University, Tallahassee, FL, United States
- Programs in Neuroscience and Molecular Biophysics, Florida State University, Tallahassee, FL, United States
- *Correspondence: Richard Bertram,
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20
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Le Tissier PR, Mollard P. Renewing an old interest: Pituitary folliculostellate cells. J Neuroendocrinol 2021; 33:e13053. [PMID: 34734454 DOI: 10.1111/jne.13053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 12/13/2022]
Abstract
Anterior pituitary folliculostellate (FS) cells, first described almost 50 years ago, have a wide range of functions with respect to supporting and coordinating endocrine cell function, in particular through paracrine and gap junction-mediated signalling. Our previous studies identified the morphological organisation of FS cells, which mediates coordinated calcium activity throughout the homotypic FS network and allows signalling across the whole pituitary gland. It is also clear that FS cells can modify endocrine output and feedback on pituitary axes over a range of timescales. Recently, several studies have defined FS cells as a source of anterior pituitary endocrine cell renewal, which has resulted in a renaming of FS cells as "Sox2+ve stem cells". Here, we highlight the broader potential of the FS cell population in fine-tuning and coordinating pituitary axes function. In addition, we identify a need for: the definition of the possible subtypes of FS cell and their relationship with the stem cell population; the potential role of FS cells in pulsatile hormone secretion and coordination of heterotypic cell networks; and the roles that FS cells may play in both early-life programming of pituitary axes and in memory, or anticipation, of demand. Further studies of FS cells may demonstrate the fundamental importance of this cell type and its potential as a therapeutic target to correct pituitary gland dysfunction, one of which is stem cell therapy. Clearly, a thorough understanding of all of these interactions and relationships of FS and endocrine cells is required whatever therapeutic use is suggested by their various roles.
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Affiliation(s)
- Paul R Le Tissier
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Patrice Mollard
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, Montpellier, France
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21
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Korošak D, Jusup M, Podobnik B, Stožer A, Dolenšek J, Holme P, Rupnik MS. Autopoietic Influence Hierarchies in Pancreatic β Cells. PHYSICAL REVIEW LETTERS 2021; 127:168101. [PMID: 34723613 DOI: 10.1103/physrevlett.127.168101] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
β cells are biologically essential for humans and other vertebrates. Because their functionality arises from cell-cell interactions, they are also a model system for collective organization among cells. There are currently two contradictory pictures of this organization: the hub-cell idea pointing at leaders who coordinate the others, and the electrophysiological theory describing all cells as equal. We use new data and computational modeling to reconcile these pictures. We find via a network representation of interacting β cells that leaders emerge naturally (confirming the hub-cell idea), yet all cells can take the hub role following a perturbation (in line with electrophysiology).
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Affiliation(s)
- Dean Korošak
- Institute of Physiology, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
- Faculty of Civil Engineering, Transportation Engineering and Architecture, University of Maribor, 2000 Maribor, Slovenia
| | - Marko Jusup
- Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8552, Japan
| | - Boris Podobnik
- Faculty of Civil Engineering, University of Rijeka, 51000 Rijeka, Croatia
- Center for Polymer Studies, Boston University, Boston, Massachusetts 02215, USA
- Zagreb School of Economics and Management, 10000 Zagreb, Croatia
- Luxembourg School of Business, 2453 Luxembourg, Luxembourg
- Faculty of Information Studies in Novo mesto, 8000 Novo Mesto, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, 2000 Maribor, Slovenia
| | - Petter Holme
- Tokyo Tech World Research Hub Initiative (WRHI), Institute of Innovative Research, Tokyo Institute of Technology, Tokyo 152-8552, Japan
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
- Alma Mater Europaea-European Center Maribor, 2000 Maribor, Slovenia
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22
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Stožer A, Skelin Klemen M, Gosak M, Križančić Bombek L, Pohorec V, Slak Rupnik M, Dolenšek J. Glucose-dependent activation, activity, and deactivation of beta cell networks in acute mouse pancreas tissue slices. Am J Physiol Endocrinol Metab 2021; 321:E305-E323. [PMID: 34280052 DOI: 10.1152/ajpendo.00043.2021] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/09/2021] [Indexed: 12/14/2022]
Abstract
Many details of glucose-stimulated intracellular calcium changes in β cells during activation, activity, and deactivation, as well as their concentration-dependence, remain to be analyzed. Classical physiological experiments indicated that in islets, functional differences between individual cells are largely attenuated, but recent findings suggest considerable intercellular heterogeneity, with some cells possibly coordinating the collective responses. To address the above with an emphasis on heterogeneity and describing the relations between classical physiological and functional network properties, we performed functional multicellular calcium imaging in mouse pancreas tissue slices over a wide range of glucose concentrations. During activation, delays to activation of cells and any-cell-to-first-responder delays are shortened, and the sizes of simultaneously responding clusters increased with increasing glucose concentrations. Exactly the opposite characterized deactivation. The frequency of fast calcium oscillations during activity increased with increasing glucose up to 12 mM glucose concentration, beyond which oscillation duration became longer, resulting in a homogenous increase in active time. In terms of functional connectivity, islets progressed from a very segregated network to a single large functional unit with increasing glucose concentration. A comparison between classical physiological and network parameters revealed that the first-responders during activation had longer active times during plateau and the most active cells during the plateau tended to deactivate later. Cells with the most functional connections tended to activate sooner, have longer active times, and deactivate later. Our findings provide a common ground for recent differing views on β cell heterogeneity and an important baseline for future studies of stimulus-secretion and intercellular coupling.NEW & NOTEWORTHY We assessed concentration-dependence in coupled β cells, degree of functional heterogeneity, and uncovered possible specialized subpopulations during the different phases of the response to glucose at the level of many individual cells. To this aim, we combined acute mouse pancreas tissue slices with functional multicellular calcium imaging over a wide range from threshold (7 mM) and physiological (8 and 9 mM) to supraphysiological (12 and 16 mM) glucose concentrations, classical physiological, and advanced network analyses.
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Affiliation(s)
- Andraž Stožer
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
| | - Marko Gosak
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | | | - Viljem Pohorec
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Faculty of Medicine, Institute of Physiology, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
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23
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Arithmetic success and gender-based characterization of brain connectivity across EEG bands. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2020.102222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Laporte E, Vennekens A, Vankelecom H. Pituitary Remodeling Throughout Life: Are Resident Stem Cells Involved? Front Endocrinol (Lausanne) 2021; 11:604519. [PMID: 33584539 PMCID: PMC7879485 DOI: 10.3389/fendo.2020.604519] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first weeks after birth, an impressive growth and maturation phase is occurring in the gland during which the distinct hormonal cell populations expand. During pubertal growth and development, growth hormone (GH) levels need to peak which requires an adaptive enterprise in the GH-producing somatotrope population. At aging, pituitary function wanes which is associated with organismal decay including the somatopause in which GH levels drop. In addition to these key time points of life, the pituitary's endocrine cell landscape plastically adapts during specific (patho-)physiological conditions such as lactation (need for PRL) and stress (engagement of ACTH). Particular resilience is witnessed after physical injury in the (murine) gland, culminating in regeneration of destroyed cell populations. In many other tissues, adaptive and regenerative processes involve the local stem cells. Over the last 15 years, evidence has accumulated that the pituitary gland houses a resident stem cell compartment. Recent studies propose their involvement in at least some of the cell remodeling processes that occur in the postnatal pituitary but support is still fragmentary and not unequivocal. Many questions remain unsolved such as whether the stem cells are key players in the vivid neonatal growth phase and whether the decline in pituitary function at old age is associated with decreased stem cell fitness. Furthermore, the underlying molecular mechanisms of pituitary plasticity, in particular the stem cell-linked ones, are still largely unknown. Pituitary research heavily relies on transgenic in vivo mouse models. While having proven their value, answers to pituitary stem cell-focused questions may more diligently come from a novel powerful in vitro research model, termed organoids, which grow from pituitary stem cells and recapitulate stem cell phenotype and activation status. In this review, we describe pituitary plasticity conditions and summarize what is known on the involvement and phenotype of pituitary stem cells during these pituitary remodeling events.
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Affiliation(s)
| | | | - Hugo Vankelecom
- Laboratory of Tissue Plasticity in Health and Disease, Cluster of Stem Cell and Developmental Biology, Department of Development and Regeneration, KU Leuven (University of Leuven), Leuven, Belgium
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25
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Nasteska D, Fine NHF, Ashford FB, Cuozzo F, Viloria K, Smith G, Dahir A, Dawson PWJ, Lai YC, Bastidas-Ponce A, Bakhti M, Rutter GA, Fiancette R, Nano R, Piemonti L, Lickert H, Zhou Q, Akerman I, Hodson DJ. PDX1 LOW MAFA LOW β-cells contribute to islet function and insulin release. Nat Commun 2021; 12:674. [PMID: 33514698 PMCID: PMC7846747 DOI: 10.1038/s41467-020-20632-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/01/2020] [Indexed: 12/25/2022] Open
Abstract
Transcriptionally mature and immature β-cells co-exist within the adult islet. How such diversity contributes to insulin release remains poorly understood. Here we show that subtle differences in β-cell maturity, defined using PDX1 and MAFA expression, contribute to islet operation. Functional mapping of rodent and human islets containing proportionally more PDX1HIGH and MAFAHIGH β-cells reveals defects in metabolism, ionic fluxes and insulin secretion. At the transcriptomic level, the presence of increased numbers of PDX1HIGH and MAFAHIGH β-cells leads to dysregulation of gene pathways involved in metabolic processes. Using a chemogenetic disruption strategy, differences in PDX1 and MAFA expression are shown to depend on islet Ca2+ signaling patterns. During metabolic stress, islet function can be restored by redressing the balance between PDX1 and MAFA levels across the β-cell population. Thus, preserving heterogeneity in PDX1 and MAFA expression, and more widely in β-cell maturity, might be important for the maintenance of islet function.
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Affiliation(s)
- Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Nicholas H F Fine
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Fiona B Ashford
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Katrina Viloria
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Gabrielle Smith
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Aisha Dahir
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Peter W J Dawson
- School of Sport, Exercise and Rehabilitation Science, University of Birmingham, Edgbaston, UK.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston, UK
| | - Yu-Chiang Lai
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,School of Sport, Exercise and Rehabilitation Science, University of Birmingham, Edgbaston, UK.,MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston, UK
| | - Aimée Bastidas-Ponce
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.,Technical University of Munich, School of Medicine, Munich, Germany
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Department of Metabolism, Reproduction, and Digestion, Imperial College London, London, UK.,Lee Kong Chian School of Medicine, Nanyang Technological University, Nanyang, Singapore
| | - Remi Fiancette
- Institute of Immunology & Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Rita Nano
- San Raffaele Diabetes Research Institute, IRCCS Ospedale, San Raffaele, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Lorenzo Piemonti
- San Raffaele Diabetes Research Institute, IRCCS Ospedale, San Raffaele, Italy.,Vita-Salute San Raffaele University, Milan, Italy
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764, Neuherberg, Germany.,Institute of Stem Cell Research, Helmholtz Zentrum München, D-85764, Neuherberg, Germany.,Technical University of Munich, School of Medicine, Munich, Germany
| | - Qiao Zhou
- Division of Regenerative Medicine, Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Ildem Akerman
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK. .,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK. .,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK.
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26
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Santiago-Andres Y, Golan M, Fiordelisio T. Functional Pituitary Networks in Vertebrates. Front Endocrinol (Lausanne) 2021; 11:619352. [PMID: 33584547 PMCID: PMC7873642 DOI: 10.3389/fendo.2020.619352] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/07/2020] [Indexed: 11/13/2022] Open
Abstract
The pituitary is a master endocrine gland that developed early in vertebrate evolution and therefore exists in all modern vertebrate classes. The last decade has transformed our view of this key organ. Traditionally, the pituitary has been viewed as a randomly organized collection of cells that respond to hypothalamic stimuli by secreting their content. However, recent studies have established that pituitary cells are organized in tightly wired large-scale networks that communicate with each other in both homo and heterotypic manners, allowing the gland to quickly adapt to changing physiological demands. These networks functionally decode and integrate the hypothalamic and systemic stimuli and serve to optimize the pituitary output into the generation of physiologically meaningful hormone pulses. The development of 3D imaging methods and transgenic models have allowed us to expand the research of functional pituitary networks into several vertebrate classes. Here we review the establishment of pituitary cell networks throughout vertebrate evolution and highlight the main perspectives and future directions needed to decipher the way by which pituitary networks serve to generate hormone pulses in vertebrates.
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Affiliation(s)
- Yorgui Santiago-Andres
- Laboratorio de Neuroendocrinología Comparada, Departamento de Ecología y Recursos Naturales, Biología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
| | - Matan Golan
- Department of Poultry and Aquaculture, Institute of Animal Sciences, Agricultural Research Organization, Rishon Lezion, Israel
| | - Tatiana Fiordelisio
- Laboratorio de Neuroendocrinología Comparada, Departamento de Ecología y Recursos Naturales, Biología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
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27
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Chabosseau P, Rutter GA, Millership SJ. Importance of Both Imprinted Genes and Functional Heterogeneity in Pancreatic Beta Cells: Is There a Link? Int J Mol Sci 2021; 22:1000. [PMID: 33498234 PMCID: PMC7863946 DOI: 10.3390/ijms22031000] [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: 12/23/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/02/2023] Open
Abstract
Diabetes mellitus now affects more than 400 million individuals worldwide, with significant impacts on the lives of those affected and associated socio-economic costs. Although defects in insulin secretion underlie all forms of the disease, the molecular mechanisms which drive them are still poorly understood. Subsets of specialised beta cells have, in recent years, been suggested to play critical roles in "pacing" overall islet activity. The molecular nature of these cells, the means through which their identity is established and the changes which may contribute to their functional demise and "loss of influence" in both type 1 and type 2 diabetes are largely unknown. Genomic imprinting involves the selective silencing of one of the two parental alleles through DNA methylation and modified imprinted gene expression is involved in a number of diseases. Loss of expression, or loss of imprinting, can be shown in mouse models to lead to defects in beta cell function and abnormal insulin secretion. In the present review we survey the evidence that altered expression of imprinted genes contribute to loss of beta cell function, the importance of beta cell heterogeneity in normal and disease states, and hypothesise whether there is a direct link between the two.
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Affiliation(s)
| | | | - Steven J. Millership
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK; (P.C.); (G.A.R.)
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28
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Carrat GR, Haythorne E, Tomas A, Haataja L, Müller A, Arvan P, Piunti A, Cheng K, Huang M, Pullen TJ, Georgiadou E, Stylianides T, Amirruddin NS, Salem V, Distaso W, Cakebread A, Heesom KJ, Lewis PA, Hodson DJ, Briant LJ, Fung AC, Sessions RB, Alpy F, Kong AP, Benke PI, Torta F, Teo AKK, Leclerc I, Solimena M, Wigley DB, Rutter GA. The type 2 diabetes gene product STARD10 is a phosphoinositide-binding protein that controls insulin secretory granule biogenesis. Mol Metab 2020; 40:101015. [PMID: 32416313 PMCID: PMC7322359 DOI: 10.1016/j.molmet.2020.101015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/24/2020] [Accepted: 05/05/2020] [Indexed: 02/09/2023] Open
Abstract
OBJECTIVE Risk alleles for type 2 diabetes at the STARD10 locus are associated with lowered STARD10 expression in the β-cell, impaired glucose-induced insulin secretion, and decreased circulating proinsulin:insulin ratios. Although likely to serve as a mediator of intracellular lipid transfer, the identity of the transported lipids and thus the pathways through which STARD10 regulates β-cell function are not understood. The aim of this study was to identify the lipids transported and affected by STARD10 in the β-cell and the role of the protein in controlling proinsulin processing and insulin granule biogenesis and maturation. METHODS We used isolated islets from mice deleted selectively in the β-cell for Stard10 (βStard10KO) and performed electron microscopy, pulse-chase, RNA sequencing, and lipidomic analyses. Proteomic analysis of STARD10 binding partners was executed in the INS1 (832/13) cell line. X-ray crystallography followed by molecular docking and lipid overlay assay was performed on purified STARD10 protein. RESULTS βStard10KO islets had a sharply altered dense core granule appearance, with a dramatic increase in the number of "rod-like" dense cores. Correspondingly, basal secretion of proinsulin was increased versus wild-type islets. The solution of the crystal structure of STARD10 to 2.3 Å resolution revealed a binding pocket capable of accommodating polyphosphoinositides, and STARD10 was shown to bind to inositides phosphorylated at the 3' position. Lipidomic analysis of βStard10KO islets demonstrated changes in phosphatidylinositol levels, and the inositol lipid kinase PIP4K2C was identified as a STARD10 binding partner. Also consistent with roles for STARD10 in phosphoinositide signalling, the phosphoinositide-binding proteins Pirt and Synaptotagmin 1 were amongst the differentially expressed genes in βStard10KO islets. CONCLUSION Our data indicate that STARD10 binds to, and may transport, phosphatidylinositides, influencing membrane lipid composition, insulin granule biosynthesis, and insulin processing.
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Affiliation(s)
- Gaelle R. Carrat
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Elizabeth Haythorne
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Andreas Müller
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany,Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany,Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Alexandra Piunti
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK,Lille 1 University-Science and Technology, Cité Scientifique, 59655, Villeneuve d'Ascq Cedex, France
| | - Kaiying Cheng
- Section of Structural Biology, Department of Medicine, Imperial College London, London, UK
| | - Mutian Huang
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Timothy J. Pullen
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK,Department of Diabetes, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Theodoros Stylianides
- Loughborough University, Centre of Innovative and Collaborative Construction Engineering, Leicestershire, LE11 3TU, UK
| | - Nur Shabrina Amirruddin
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), A∗STAR, Proteos, Singapore, 138673, Singapore,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
| | - Victoria Salem
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK,Section of Investigative Medicine, Department of Medicine, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Walter Distaso
- Imperial College Business School, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Andrew Cakebread
- London Metallomics Facility, King's College London, Strand, London, WC2R 2LS, UK
| | | | | | - David J. Hodson
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK,Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, UK,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Midlands, UK
| | - Linford J. Briant
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Annie C.H. Fung
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Richard B. Sessions
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, BS8 1TD, UK
| | - Fabien Alpy
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U1258, Centre National de la Recherche Scientifique (CNRS), UMR 7104, Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch, France
| | - Alice P.S. Kong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Peter I. Benke
- Singapore Lipidomics Incubator, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Mdical Drive, Singapore, 117596, Singapore
| | - Federico Torta
- Singapore Lipidomics Incubator, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Mdical Drive, Singapore, 117596, Singapore
| | - Adrian Kee Keong Teo
- Stem Cells and Diabetes Laboratory, Institute of Molecular and Cell Biology (IMCB), A∗STAR, Proteos, Singapore, 138673, Singapore,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK
| | - Michele Solimena
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany,Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich, University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, Dresden, Germany,German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany,Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
| | - Dale B. Wigley
- Section of Structural Biology, Department of Medicine, Imperial College London, London, UK
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Imperial College London, du Cane Road, London, W12 0NN, UK,Corresponding author. +44 (0)20 7594 3340.
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29
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Adaptive Resetting of Tuberoinfundibular Dopamine (TIDA) Network Activity during Lactation in Mice. J Neurosci 2020; 40:3203-3216. [PMID: 32209609 DOI: 10.1523/jneurosci.1553-18.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/22/2023] Open
Abstract
Giving birth triggers a wide repertoire of physiological and behavioral changes in the mother to enable her to feed and care for her offspring. These changes require coordination and are often orchestrated from the CNS, through as of yet poorly understood mechanisms. A neuronal population with a central role in puerperal changes is the tuberoinfundibular dopamine (TIDA) neurons that control release of the pituitary hormone, prolactin, which triggers key maternal adaptations, including lactation and maternal care. Here, we used Ca2+ imaging on mice from both sexes and whole-cell recordings on female mouse TIDA neurons in vitro to examine whether they adapt their cellular and network activity according to reproductive state. In the high-prolactin state of lactation, TIDA neurons shift to faster membrane potential oscillations, a reconfiguration that reverses upon weaning. During the estrous cycle, however, which includes a brief, but pronounced, prolactin peak, oscillation frequency remains stable. An increase in the hyperpolarization-activated mixed cation current, Ih, possibly through unmasking as dopamine release drops during nursing, may partially explain the reconfiguration of TIDA rhythms. These findings identify a reversible plasticity in hypothalamic network activity that can serve to adapt the dam for motherhood.SIGNIFICANCE STATEMENT Motherhood requires profound behavioral and physiological adaptations to enable caring for offspring, but the underlying CNS changes are poorly understood. Here, we show that, during lactation, neuroendocrine dopamine neurons, the "TIDA" cells that control prolactin secretion, reorganize their trademark oscillations to discharge in faster frequencies. Unlike previous studies, which typically have focused on structural and transcriptional changes during pregnancy and lactation, we demonstrate a functional switch in activity and one that, distinct from previously described puerperal modifications, reverses fully on weaning. We further provide evidence that a specific conductance (Ih) contributes to the altered network rhythm. These findings identify a new facet of maternal brain plasticity at the level of membrane properties and consequent ensemble activity.
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30
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Abstract
The development of the anterior pituitary gland occurs in distinct sequential developmental steps, leading to the formation of a complex organ containing five different cell types secreting six different hormones. During this process, the temporal and spatial expression of a cascade of signaling molecules and transcription factors plays a crucial role in organ commitment, cell proliferation, patterning, and terminal differentiation. The morphogenesis of the gland and the emergence of distinct cell types from a common primordium are governed by complex regulatory networks involving transcription factors and signaling molecules that may be either intrinsic to the developing pituitary or extrinsic, originating from the ventral diencephalon, the oral ectoderm, and the surrounding mesenchyme. Endocrine cells of the pituitary gland are organized into structural and functional networks that contribute to the coordinated response of endocrine cells to stimuli; these cellular networks are formed during embryonic development and are maintained or may be modified in adulthood, contributing to the plasticity of the gland. Abnormalities in any of the steps of pituitary development may lead to congenital hypopituitarism that includes a spectrum of disorders from isolated to combined hormone deficiencies including syndromic disorders such as septo-optic dysplasia. Over the past decade, the acceleration of next-generation sequencing has allowed for rapid analysis of the patient genome to identify novel mutations and novel candidate genes associated with hypothalmo-pituitary development. Subsequent functional analysis using patient fibroblast cells, and the generation of stem cells derived from patient cells, is fast replacing the need for animal models while providing a more physiologically relevant characterization of novel mutations. Furthermore, CRISPR-Cas9 as the method for gene editing is replacing previous laborious and time-consuming gene editing methods that were commonly used, thus yielding knockout cell lines in a fraction of the time. © 2020 American Physiological Society. Compr Physiol 10:389-413, 2020.
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Affiliation(s)
- Kyriaki S Alatzoglou
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
| | - Louise C Gregory
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
| | - Mehul T Dattani
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London (UCL), London, UK
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31
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Phillipps HR, Yip SH, Grattan DR. Patterns of prolactin secretion. Mol Cell Endocrinol 2020; 502:110679. [PMID: 31843563 DOI: 10.1016/j.mce.2019.110679] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/11/2022]
Abstract
Prolactin is pleotropic in nature affecting multiple tissues throughout the body. As a consequence of the broad range of functions, regulation of anterior pituitary prolactin secretion is complex and atypical as compared to other pituitary hormones. Many studies have provided insight into the complex hypothalamic-pituitary networks controlling prolactin secretion patterns in different species using a range of techniques. Here, we review prolactin secretion in both males and females; and consider the different patterns of prolactin secretion across the reproductive cycle in representative female mammals with short versus long luteal phases and in seasonal breeders. Additionally, we highlight changes in the pattern of secretion during pregnancy and lactation, and discuss the wide range of adaptive functions that prolactin may have in these important physiological states.
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Affiliation(s)
- Hollian R Phillipps
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, 9016, New Zealand
| | - Siew H Yip
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, 9016, New Zealand
| | - David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, 9016, New Zealand.
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32
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Serdinšek T, Lipovšek S, Leitinger G, But I, Stožer A, Dolenšek J. A Novel in situ Approach to Studying Detrusor Smooth Muscle Cells in Mice. Sci Rep 2020; 10:2685. [PMID: 32060298 PMCID: PMC7021722 DOI: 10.1038/s41598-020-59337-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/28/2020] [Indexed: 11/09/2022] Open
Abstract
The aim of our study was to develop a novel approach to investigating mouse detrusor smooth muscle cell (SMC) physiological activity, utilizing an acute tissue dissection technique and confocal calcium imaging. The bladder of a sacrificed adult female NMRI mouse was dissected. We used light and transmission electron microscopy to assess morphology of SMCs within the tissue. Calcium imaging in individual SMCs was performed using confocal microscopy during stimulation with increasing concentrations of carbamylcholine (CCh). SMCs were identified according to their morphology and calcium activity. We determined several parameters describing the SMC responses: delays to response, recruitment, relative activity, and contraction of the tissue. CCh stimulation revealed three different SMC phenotypes: spontaneously active SMCs with and without CCh-enhanced activity and SMCs with CCh-induced activity only. SMCs were recruited into an active state in response to CCh-stimulation within a narrow range (1-25 µM); causing activation of virtually all SMCs. Maximum calcium activity of SMCs was at about 25 µM, which coincided with a visible tissue contraction. Finally, we observed shorter time lags before response onsets with higher CCh concentrations. In conclusion, our novel in situ approach proved to be a robust and reproducible method to study detrusor SMC morphology and physiology.
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Affiliation(s)
- Tamara Serdinšek
- Department of General Gynaecology and Urogynaecology, Clinic for Gynaecology and Perinatology, University Medical Centre Maribor, Ljubljanska 5, 2000, Maribor, Slovenia
| | - Saša Lipovšek
- Faculty of Medicine, University of Maribor, Taborska ulica 8, 2000, Maribor, Slovenia.,Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000, Maribor, Slovenia.,Faculty of Chemistry and Chemical Engineering, Smetanova ulica 17, University of Maribor, 2000, Maribor, Slovenia.,Gottfried Schatz Research Center, Division of Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010, Graz, Austria
| | - Gerd Leitinger
- Gottfried Schatz Research Center, Division of Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010, Graz, Austria
| | - Igor But
- Department of General Gynaecology and Urogynaecology, Clinic for Gynaecology and Perinatology, University Medical Centre Maribor, Ljubljanska 5, 2000, Maribor, Slovenia
| | - Andraž Stožer
- Faculty of Medicine, University of Maribor, Taborska ulica 8, 2000, Maribor, Slovenia.
| | - Jurij Dolenšek
- Faculty of Medicine, University of Maribor, Taborska ulica 8, 2000, Maribor, Slovenia. .,Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000, Maribor, Slovenia.
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33
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Fontaine R, Ciani E, Haug TM, Hodne K, Ager-Wick E, Baker DM, Weltzien FA. Gonadotrope plasticity at cellular, population and structural levels: A comparison between fishes and mammals. Gen Comp Endocrinol 2020; 287:113344. [PMID: 31794734 DOI: 10.1016/j.ygcen.2019.113344] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/27/2019] [Accepted: 11/26/2019] [Indexed: 12/22/2022]
Abstract
Often referred to as "the master gland", the pituitary is a key organ controlling growth, maturation, and homeostasis in vertebrates. The anterior pituitary, which contains several hormone-producing cell types, is highly plastic and thereby able to adjust the production of the hormones governing these key physiological processes according to the changing needs over the life of the animal. Hypothalamic neuroendocrine control and feedback from peripheral tissues modulate pituitary cell activity, adjusting levels of hormone production and release according to different functional or environmental requirements. However, in some physiological processes (e.g. growth, puberty, or metamorphosis), changes in cell activity may be not sufficient to meet the needs and a general reorganization of cell composition and pituitary structure may occur. Focusing on gonadotropes, this review examines plasticity at the cellular level, which allows precise and rapid control of hormone production and secretion, as well as plasticity at the population and structural levels, which allows more substantial changes in hormone production. Further, we compare current knowledge of the anterior pituitary plasticity in fishes and mammals in order to assess what has been conserved or not throughout evolution, and highlight important remaining questions.
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Affiliation(s)
- Romain Fontaine
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Elia Ciani
- Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Trude Marie Haug
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0372 Oslo, Norway
| | - Kjetil Hodne
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Eirill Ager-Wick
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway
| | - Dianne M Baker
- Department of Biological Sciences, University of Mary Washington, VA22401 Fredericksburg, VA, USA
| | - Finn-Arne Weltzien
- Department of Basic Sciences and Aquatic Medicine, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 0454 Oslo, Norway.
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Hoa O, Lafont C, Fontanaud P, Guillou A, Kemkem Y, Kineman RD, Luque RM, Fiordelisio Coll T, Le Tissier P, Mollard P. Imaging and Manipulating Pituitary Function in the Awake Mouse. Endocrinology 2019; 160:2271-2281. [PMID: 31329247 PMCID: PMC6760335 DOI: 10.1210/en.2019-00297] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022]
Abstract
Extensive efforts have been made to explore how the activities of multiple brain cells combine to alter physiology through imaging and cell-specific manipulation in different animal models. However, the temporal regulation of peripheral organs by the neuroendocrine factors released by the brain is poorly understood. We have established a suite of adaptable methodologies to interrogate in vivo the relationship of hypothalamic regulation with the secretory output of the pituitary gland, which has complex functional networks of multiple cell types intermingled with the vasculature. These allow imaging and optogenetic manipulation of cell activities in the pituitary gland in awake mouse models, in which both neuronal regulatory activity and hormonal output are preserved. These methodologies are now readily applicable for longitudinal studies of short-lived events (e.g., calcium signals controlling hormone exocytosis) and slowly evolving processes such as tissue remodeling in health and disease over a period of days to weeks.
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Affiliation(s)
- Ombeline Hoa
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Chrystel Lafont
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Pierre Fontanaud
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Anne Guillou
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Yasmine Kemkem
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Rhonda D Kineman
- Research and Development Division, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, Illinois
- Department of Medicine, Section of Endocrinology, Diabetes, and Metabolism, University of Illinois at Chicago, Chicago, Illinois
| | - Raul M Luque
- Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Reina Sofia University Hospital, Córdoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición, Córdoba, Spain
| | - Tatiana Fiordelisio Coll
- Laboratorio de Neuroendocrinología Comparada, Departamento de Ecología y Recursos Naturales, Biología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, DF, México
| | - Paul Le Tissier
- University of Edinburgh, Centre for Discovery Brain Sciences, Edinburgh, United Kingdom
| | - Patrice Mollard
- IGF, CNRS, INSERM, University of Montpellier, Montpellier, France
- Correspondence: Patrice Mollard, PhD, Institut de Génomique Fonctionnelle, 141 rue de la Cardonille, F-34000 Montpellier, France. E-mail:
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Momiji H, Hassall KL, Featherstone K, McNamara AV, Patist AL, Spiller DG, Christian HC, White MRH, Davis JRE, Finkenstädt BF, Rand DA. Disentangling juxtacrine from paracrine signalling in dynamic tissue. PLoS Comput Biol 2019; 15:e1007030. [PMID: 31194728 PMCID: PMC6592563 DOI: 10.1371/journal.pcbi.1007030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/25/2019] [Accepted: 04/15/2019] [Indexed: 11/18/2022] Open
Abstract
Prolactin is a major hormone product of the pituitary gland, the central endocrine regulator. Despite its physiological importance, the cell-level mechanisms of prolactin production are not well understood. Having significantly improved the resolution of real-time-single-cell-GFP-imaging, the authors recently revealed that prolactin gene transcription is highly dynamic and stochastic yet shows space-time coordination in an intact tissue slice. However, it still remains an open question as to what kind of cellular communication mediates the observed space-time organization. To determine the type of interaction between cells we developed a statistical model. The degree of similarity between two expression time series was studied in terms of two distance measures, Euclidean and geodesic, the latter being a network-theoretic distance defined to be the minimal number of edges between nodes, and this was used to discriminate between juxtacrine from paracrine signalling. The analysis presented here suggests that juxtacrine signalling dominates. To further determine whether the coupling is coordinating transcription or post-transcriptional activities we used stochastic switch modelling to infer the transcriptional profiles of cells and estimated their similarity measures to deduce that their spatial cellular coordination involves coupling of transcription via juxtacrine signalling. We developed a computational model that involves an inter-cell juxtacrine coupling, yielding simulation results that show space-time coordination in the transcription level that is in agreement with the above analysis. The developed model is expected to serve as the prototype for the further study of tissue-level organised gene expression for epigenetically regulated genes, such as prolactin.
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Affiliation(s)
- Hiroshi Momiji
- Zeeman Institute for Systems Biology & Infectious Disease Epidemiology Research, University of Warwick, Coventry, United Kingdom, Mathematics Institute, University of Warwick, Coventry, United Kingdom
- * E-mail: (HM); (MRHW); (JRED); (BFF); (DAR)
| | - Kirsty L. Hassall
- Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Karen Featherstone
- Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - Anne V. McNamara
- Systems Microscopy Centre, University of Manchester, Manchester, United Kingdom
| | - Amanda L. Patist
- Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
| | - David G. Spiller
- Systems Microscopy Centre, University of Manchester, Manchester, United Kingdom
| | - Helen C. Christian
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Michael R. H. White
- Systems Microscopy Centre, University of Manchester, Manchester, United Kingdom
- * E-mail: (HM); (MRHW); (JRED); (BFF); (DAR)
| | - Julian R. E. Davis
- Faculty of Biology, Medicine & Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (HM); (MRHW); (JRED); (BFF); (DAR)
| | - Bärbel F. Finkenstädt
- Department of Statistics, University of Warwick, Coventry, United Kingdom
- * E-mail: (HM); (MRHW); (JRED); (BFF); (DAR)
| | - David A. Rand
- Zeeman Institute for Systems Biology & Infectious Disease Epidemiology Research, University of Warwick, Coventry, United Kingdom, Mathematics Institute, University of Warwick, Coventry, United Kingdom
- * E-mail: (HM); (MRHW); (JRED); (BFF); (DAR)
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Abstract
The principal role of prolactin in mammals is the regulation of lactation. Prolactin is a hormone that is mainly synthesized and secreted by lactotroph cells in the anterior pituitary gland. Prolactin signalling occurs via a unique transmembrane prolactin receptor (PRL-R). The structure of the PRL-R has now been elucidated and is similar to that of many biologically fundamental receptors of the class 1 haematopoietic cytokine receptor family such as the growth hormone receptor. The PRL-R is expressed in a wide array of tissues, and a growing number of biological processes continue to be attributed to prolactin. In this Review, we focus on the newly discovered roles of prolactin in human health and disease, particularly its involvement in metabolic homeostasis including body weight control, adipose tissue, skin and hair follicles, pancreas, bone, the adrenal response to stress, the control of lactotroph cell homeostasis and maternal behaviour. New data concerning the pathological states of hypoprolactinaemia and hyperprolactinaemia will also be presented and discussed.
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Affiliation(s)
- Valérie Bernard
- Inserm U1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin Bicêtre, France
- Hôpital Saint Antoine, Service d'Endocrinologie et des Maladies de la Reproduction, Paris, France
| | - Jacques Young
- Inserm U1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin Bicêtre, France
- Hôpital Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Paris, France
| | - Nadine Binart
- Inserm U1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin Bicêtre, France.
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Salem V, Silva LD, Suba K, Georgiadou E, Neda Mousavy Gharavy S, Akhtar N, Martin-Alonso A, Gaboriau DCA, Rothery SM, Stylianides T, Carrat G, Pullen TJ, Singh SP, Hodson DJ, Leclerc I, Shapiro AMJ, Marchetti P, Briant LJB, Distaso W, Ninov N, Rutter GA. Leader β-cells coordinate Ca 2+ dynamics across pancreatic islets in vivo. Nat Metab 2019; 1:615-629. [PMID: 32694805 DOI: 10.1038/s42255-019-0075-2] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 05/08/2019] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells form highly connected networks within isolated islets. Whether this behaviour pertains to the situation in vivo, after innervation and during continuous perfusion with blood, is unclear. In the present study, we used the recombinant Ca2+ sensor GCaMP6 to assess glucose-regulated connectivity in living zebrafish Danio rerio, and in murine or human islets transplanted into the anterior eye chamber. In each setting, Ca2+ waves emanated from temporally defined leader β-cells, and three-dimensional connectivity across the islet increased with glucose stimulation. Photoablation of zebrafish leader cells disrupted pan-islet signalling, identifying these as likely pacemakers. Correspondingly, in engrafted mouse islets, connectivity was sustained during prolonged glucose exposure, and super-connected 'hub' cells were identified. Granger causality analysis revealed a controlling role for temporally defined leaders, and transcriptomic analyses revealed a discrete hub cell fingerprint. We thus define a population of regulatory β-cells within coordinated islet networks in vivo. This population may drive Ca2+ dynamics and pulsatile insulin secretion.
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Affiliation(s)
- Victoria Salem
- Department of Medicine, Imperial College London, London, UK.
| | - Luis Delgadillo Silva
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Kinga Suba
- Department of Medicine, Imperial College London, London, UK
| | | | | | - Nadeem Akhtar
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | | | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, Imperial College London, London, UK
| | - Stephen M Rothery
- Facility for Imaging by Light Microscopy, Imperial College London, London, UK
| | | | - Gaelle Carrat
- Department of Medicine, Imperial College London, London, UK
| | - Timothy J Pullen
- Department of Diabetes, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Sumeet Pal Singh
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - David J Hodson
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK
| | | | - A M James Shapiro
- Clinical Islet Laboratory and Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | - Nikolay Ninov
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany.
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus of TU Dresden, German Center for Diabetes Research, Dresden, Germany.
| | - Guy A Rutter
- Department of Medicine, Imperial College London, London, UK.
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Yip SH, Romanò N, Gustafson P, Hodson DJ, Williams EJ, Kokay IC, Martin AO, Mollard P, Grattan DR, Bunn SJ. Elevated Prolactin during Pregnancy Drives a Phenotypic Switch in Mouse Hypothalamic Dopaminergic Neurons. Cell Rep 2019; 26:1787-1799.e5. [DOI: 10.1016/j.celrep.2019.01.067] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 09/27/2018] [Accepted: 01/16/2019] [Indexed: 12/19/2022] Open
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Binart N, Young J, Chanson P. Prolactin Assays and Regulation of Secretion: Animal and Human Data. PROLACTIN DISORDERS 2019. [DOI: 10.1007/978-3-030-11836-5_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Le Tissier P, Fiordelisio Coll T, Mollard P. The Processes of Anterior Pituitary Hormone Pulse Generation. Endocrinology 2018; 159:3524-3535. [PMID: 30020429 DOI: 10.1210/en.2018-00508] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/11/2018] [Indexed: 12/16/2022]
Abstract
More than 60 years ago, Geoffrey Harris described his "neurohumoral theory," in which the regulation of pituitary hormone secretion was a "simple" hierarchal relationship, with the hypothalamus as the controller. In models based on this theory, the electrical activity of hypothalamic neurons determines the release of hypophysiotropic hormones into the portal circulation, and the pituitary simply responds with secretion of a pulse of hormone into the bloodstream. The development of methodologies allowing the monitoring of the activities of members of the hypothalamic-vascular-pituitary unit is increasingly allowing dissection of the mechanisms generating hypothalamic and pituitary pulses. These have revealed that whereas hypothalamic input is required, its role as a driver of pulsatile pituitary hormone secretion varies between pituitary axes. The organization of pituitary cells has a key role in the modification of their response to hypophysiotropic factors that can lead to a memory of previous demand and enhanced function. Feedback can lead to oscillatory hormone output that is independent of pulses of hypophysiotropic factors and instead, results from the temporal relationship between pituitary output and target organ response. Thus, the mechanisms underlying the generation of pulses cannot be generalized, and the circularity of feedforward and feedback interactions must be considered to understand both normal physiological function and pathology. We describe some examples of the clinical implications of recognizing the importance of the pituitary and target organs in pulse generation and suggest avenues for future research in both the short and long term.
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Affiliation(s)
- Paul Le Tissier
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Tatiana Fiordelisio Coll
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, University of Montpellier, Montpellier, France
- Laboratorio de Neuroendocrinología Comparada, Departamento de Ecología y Recursos Naturales, Biología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, México City, Distrito Federal, México
| | - Patrice Mollard
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, University of Montpellier, Montpellier, France
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41
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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: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 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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42
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Vitale ML, Pelletier RM. The anterior pituitary gap junctions: potential targets for toxicants. Reprod Toxicol 2018; 79:72-78. [PMID: 29906538 DOI: 10.1016/j.reprotox.2018.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/31/2018] [Accepted: 06/07/2018] [Indexed: 01/16/2023]
Abstract
The anterior pituitary regulates endocrine organs and physiological activities in the body. Environmental pollutants and drugs deleterious to the endocrine system may affect anterior pituitary activity through direct action on anterior pituitary cells. Within the gland, endocrine and folliculostellate cells are organized into and function as individual tridimensional networks, each network regulating its activity by coordinating the connected cells' responses to physiological or pathological cues. The gap junctions connecting endocrine cells and/or folliculostellate cells allow transmission of information among cells that is necessary for adequate network function. Toxicants may affect gap junctions as well as the physiology of the anterior pituitary. However, whether toxicants effects on anterior pituitary hormone secretion involve gap junctions is unknown. The folliculostellate cell gap junctions are sensitive to hormones, cytokines and growth factors. These cells may be an interesting experimental model for evaluating whether toxicants target anterior pituitary gap junctions.
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Affiliation(s)
- María Leiza Vitale
- Département de pathologie et biologie cellulaire, Faculté de Médecine, Université de Montréal, Montréal, QC Canada.
| | - R-Marc Pelletier
- Département de pathologie et biologie cellulaire, Faculté de Médecine, Université de Montréal, Montréal, QC Canada
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Abstract
Endocrine organs secrete a variety of hormones involved in the regulation of a multitude of body functions. Although pancreatic islets were discovered at the turn of the 19th century, other endocrine glands remained commonly described as diffuse endocrine systems. Over the last two decades, development of new imaging techniques and genetically-modified animals with cell-specific fluorescent tags or specific hormone deficiencies have enabled in vivo imaging of endocrine organs and revealed intricate endocrine cell network structures and plasticity. Overall, these new tools have revolutionized our understanding of endocrine function. The overarching aim of this Review is to describe the current mechanistic understanding that has emerged from imaging studies of endocrine cell network structure/function relationships in animal models, with a particular emphasis on the pituitary gland and the endocrine pancreas.
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Affiliation(s)
- Patrice Mollard
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, F-34094, Montpellier, France
| | - Marie Schaeffer
- Institute of Functional Genomics, CNRS, INSERM, University of Montpellier, F-34094, Montpellier, France.
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Bernard V, Lamothe S, Beau I, Guillou A, Martin A, Le Tissier P, Grattan D, Young J, Binart N. Autocrine actions of prolactin contribute to the regulation of lactotroph function in vivo. FASEB J 2018; 32:4791-4797. [PMID: 29596024 DOI: 10.1096/fj.201701111rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Prolactin (PRL), whose principal role is regulation of lactation, is mainly synthesized and secreted by lactotroph anterior pituitary cells. Its signaling is exerted via a transmembrane PRL receptor (PRLR) expressed in a wide variety of tissues, including the anterior pituitary. Dopamine, which is secreted by tuberoinfundibular hypothalamic neurons, is the major inhibitory regulator of prolactin secretion. Although PRL is well established to stimulate hypothalamic dopamine secretion, thereby exerting a negative feedback regulation on its own release, autocrine or paracrine actions of PRL on lactotroph cells have also been suggested. Within the pituitary, PRL may inhibit both lactotroph proliferation and secretion, but in vivo evaluation of these putative functions is limited. To determine whether the autocrine actions of prolactin have a significant role in the physiologic function of lactotrophs in vivo, we examined the consequences of conditional deletion of Prlr in lactotroph cells using a novel mouse line with loxP sites flanking the Prlr gene ( Prlrlox/lox) and Cre-recombinase (Cre) expressed under the control of the pituitary-specific Prl promoter. Prlrlox/lox/Prl-Cre mice have normal PRL levels and did not develop any pituitary lactotroph adenoma, even at 20 mo of age. Nevertheless, Prlrlox/lox/Prl-Cre mice displayed an increased dopaminergic inhibitory tone compared with control Prlrlox/lox mice. These results elegantly confirm an autocrine/paracrine feedback of PRL on lactotroph cells in vivo, which can be fully compensated by an intact hypothalamic feedback system.-Bernard, V., Lamothe, S., Beau, I., Guillou, A., Martin, A., Le Tissier, P., Grattan, D., Young, J., Binart, N. Autocrine actions of prolactin contribute to the regulation of lactotroph function in vivo.
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Affiliation(s)
- Valérie Bernard
- Unité INSERM 1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Sophie Lamothe
- Unité INSERM 1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Isabelle Beau
- Unité INSERM 1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Anne Guillou
- Unité INSERM 1191, Centre National de la Recherche Scientifique (CNRS), Institut de Génomique Fonctionnelle, Montpellier, France
| | - Agnès Martin
- Unité INSERM 1191, Centre National de la Recherche Scientifique (CNRS), Institut de Génomique Fonctionnelle, Montpellier, France
| | - Paul Le Tissier
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - David Grattan
- Department of Anatomy, Centre for Neuroendocrinology, University of Otago, Dunedin, New Zealand
| | - Jacques Young
- Unité INSERM 1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital de Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction, Le Kremlin-Bicêtre, France
| | - Nadine Binart
- Unité INSERM 1185, Faculté de Médecine Paris Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
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Anterior Pituitary Transcriptome Suggests Differences in ACTH Release in Tame and Aggressive Foxes. G3-GENES GENOMES GENETICS 2018; 8:859-873. [PMID: 29378821 PMCID: PMC5844307 DOI: 10.1534/g3.117.300508] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Domesticated species exhibit a suite of behavioral, endocrinological, and morphological changes referred to as "domestication syndrome." These changes may include a reduction in reactivity of the hypothalamic-pituitary-adrenal (HPA) axis and specifically reduced adrenocorticotropic hormone release from the anterior pituitary. To investigate the biological mechanisms targeted during domestication, we investigated gene expression in the pituitaries of experimentally domesticated foxes (Vulpes vulpes). RNA was sequenced from the anterior pituitary of six foxes selectively bred for tameness ("tame foxes") and six foxes selectively bred for aggression ("aggressive foxes"). Expression, splicing, and network differences identified between the two lines indicated the importance of genes related to regulation of exocytosis, specifically mediated by cAMP, organization of pseudopodia, and cell motility. These findings provide new insights into biological mechanisms that may have been targeted when these lines of foxes were selected for behavior and suggest new directions for research into HPA axis regulation and the biological underpinnings of domestication.
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46
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Gosak M, Markovič R, Dolenšek J, Slak Rupnik M, Marhl M, Stožer A, Perc M. Network science of biological systems at different scales: A review. Phys Life Rev 2018; 24:118-135. [DOI: 10.1016/j.plrev.2017.11.003] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/13/2017] [Accepted: 10/15/2017] [Indexed: 12/20/2022]
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Westacott MJ, Ludin NWF, Benninger RKP. Spatially Organized β-Cell Subpopulations Control Electrical Dynamics across Islets of Langerhans. Biophys J 2017; 113:1093-1108. [PMID: 28877492 DOI: 10.1016/j.bpj.2017.07.021] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 07/21/2017] [Accepted: 07/31/2017] [Indexed: 10/18/2022] Open
Abstract
Understanding how heterogeneous cells within a multicellular system interact and affect overall function is difficult without a means of perturbing individual cells or subpopulations. Here we apply optogenetics to understand how subpopulations of β-cells control the overall [Ca2+]i response and insulin secretion dynamics of the islets of Langerhans. We spatiotemporally perturbed electrical activity in β-cells of channelrhodopsin2-expressing islets, mapped the [Ca2+]i response, and correlated this with the cellular metabolic activity and an in silico electrophysiology model. We discovered organized regions of metabolic activity across the islet, and these affect the way in which β-cells electrically interact. Specific regions acted as pacemakers by initiating calcium wave propagation. Our findings reveal the functional architecture of the islet, and show how distinct subpopulations of cells can disproportionality affect function. These results also suggest ways in which other neuroendocrine systems can be regulated, and demonstrate how optogenetic tools can discern their functional architecture.
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Affiliation(s)
| | - Nurin W F Ludin
- Department of Bioengineering, University of Colorado, Aurora, Colorado
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado, Aurora, Colorado; Barbara Davis Center for Diabetes, University of Colorado, Aurora, Colorado.
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48
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Le Tissier P, Campos P, Lafont C, Romanò N, Hodson DJ, Mollard P. An updated view of hypothalamic-vascular-pituitary unit function and plasticity. Nat Rev Endocrinol 2017; 13:257-267. [PMID: 27934864 DOI: 10.1038/nrendo.2016.193] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The discoveries of novel functional adaptations of the hypothalamus and anterior pituitary gland for physiological regulation have transformed our understanding of their interaction. The activity of a small proportion of hypothalamic neurons can control complex hormonal signalling, which is disconnected from a simple stimulus and the subsequent hormone secretion relationship and is dependent on physiological status. The interrelationship of the terminals of hypothalamic neurons and pituitary cells with the vasculature has an important role in determining the pattern of neurohormone exposure. Cells in the pituitary gland form networks with distinct organizational motifs that are related to the duration and pattern of output, and modifications of these networks occur in different physiological states, can persist after cessation of demand and result in enhanced function. Consequently, the hypothalamus and pituitary can no longer be considered as having a simple stratified relationship: with the vasculature they form a tripartite system, which must function in concert for appropriate hypothalamic regulation of physiological processes, such as reproduction. An improved understanding of the mechanisms underlying these regulatory features has implications for current and future therapies that correct defects in hypothalamic-pituitary axes. In addition, recapitulating proper network organization will be an important challenge for regenerative stem cell treatment.
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Affiliation(s)
- Paul Le Tissier
- Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh, EH8 9XD, UK
| | - Pauline Campos
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, rue de la Cardonille, F-34000 Montpellier, France
- INSERM, U661, rue de la Cardonille, F-34000 Montpellier, France
- Université de Montpellier, rue de la Cardonille, UMR-5203, F-34000 Montpellier, France
| | - Chrystel Lafont
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, rue de la Cardonille, F-34000 Montpellier, France
- INSERM, U661, rue de la Cardonille, F-34000 Montpellier, France
- Université de Montpellier, rue de la Cardonille, UMR-5203, F-34000 Montpellier, France
| | - Nicola Romanò
- Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh, EH8 9XD, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Edgbaston, B15 2TT, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TH, UK
| | - Patrice Mollard
- Centre National de la Recherche Scientifique (CNRS), UMR-5203, Institut de Génomique Fonctionnelle, rue de la Cardonille, F-34000 Montpellier, France
- INSERM, U661, rue de la Cardonille, F-34000 Montpellier, France
- Université de Montpellier, rue de la Cardonille, UMR-5203, F-34000 Montpellier, France
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49
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Mitchell RK, Nguyen-Tu MS, Chabosseau P, Callingham RM, Pullen TJ, Cheung R, Leclerc I, Hodson DJ, Rutter GA. The transcription factor Pax6 is required for pancreatic β cell identity, glucose-regulated ATP synthesis, and Ca 2+ dynamics in adult mice. J Biol Chem 2017; 292:8892-8906. [PMID: 28377501 PMCID: PMC5448123 DOI: 10.1074/jbc.m117.784629] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/03/2017] [Indexed: 12/20/2022] Open
Abstract
Heterozygous mutations in the human paired box gene PAX6 lead to impaired glucose tolerance. Although embryonic deletion of the Pax6 gene in mice leads to loss of most pancreatic islet cell types, the functional consequences of Pax6 loss in adults are poorly defined. Here we developed a mouse line in which Pax6 was selectively inactivated in β cells by crossing animals with floxed Pax6 alleles to mice expressing the inducible Pdx1CreERT transgene. Pax6 deficiency, achieved by tamoxifen injection, caused progressive hyperglycemia. Although β cell mass was preserved 8 days post-injection, total insulin content and insulin:chromogranin A immunoreactivity were reduced by ∼60%, and glucose-stimulated insulin secretion was eliminated. RNA sequencing and quantitative real-time PCR analyses revealed that, although the expression of key β cell genes, including Ins2, Slc30a8, MafA, Slc2a2, G6pc2, and Glp1r, was reduced after Pax6 deletion, that of several genes that are usually selectively repressed (“disallowed”) in β cells, including Slc16a1, was increased. Assessed in intact islets, glucose-induced ATP:ADP increases were significantly reduced (p < 0.05) in βPax6KO versus control β cells, and the former displayed attenuated increases in cytosolic Ca2+. Unexpectedly, glucose-induced increases in intercellular connectivity were enhanced after Pax6 deletion, consistent with increases in the expression of the glucose sensor glucokinase, but decreases in that of two transcription factors usually expressed in fully differentiated β-cells, Pdx1 and Nkx6.1, were observed in islet “hub” cells. These results indicate that Pax6 is required for the functional identity of adult β cells. Furthermore, deficiencies in β cell glucose sensing are likely to contribute to defective insulin secretion in human carriers of PAX6 mutations.
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Affiliation(s)
- Ryan K Mitchell
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Marie-Sophie Nguyen-Tu
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Pauline Chabosseau
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Rebecca M Callingham
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Timothy J Pullen
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Rebecca Cheung
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - Isabelle Leclerc
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom
| | - David J Hodson
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom, .,the Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors, University of Birmingham, Edgbaston B15 2TT, United Kingdom, and.,the Centre for Endocrinology, Diabetes, and Metabolism, Birmingham Health Partners, Birmingham B15 2TH, United Kingdom
| | - Guy A Rutter
- From the Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology, and Metabolism, Imperial College London, Du Cane Road, London W12 0NN, United Kingdom,
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50
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Beck A, Götz V, Qiao S, Weissgerber P, Flockerzi V, Freichel M, Boehm U. Functional Characterization of Transient Receptor Potential (TRP) Channel C5 in Female Murine Gonadotropes. Endocrinology 2017; 158:887-902. [PMID: 28324107 DOI: 10.1210/en.2016-1810] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/25/2017] [Indexed: 12/22/2022]
Abstract
Gonadotrope cells in the anterior pituitary gland secrete gonadotropins regulating gonadal function in mammals. Recent results have implicated transient receptor potential (TRP) cation channels in pituitary physiology; however, if and how TRP channels contribute to gonadotrope function is not known. Here, we report that 14 out of 28 TRP channels encoded in the mouse genome are expressed in murine gonadotropes with highest expression levels found for canonical TRP (TRPC) channel 5 in juvenile females. We show that TRP channel expression in these cells exhibits considerable plasticity and that it depends on the sex and the developmental and hormonal status of the animal. We then combine different genetic strategies including genetic confocal Ca2+ imaging in whole-mount pituitary gland preparations to characterize TRPC5 channel function in gonadotropes from juvenile females. We show that the TRPC5 agonist Englerin A activates a cytosolic Ca2+ signal and a whole-cell current in these cells, which is absent in TRPC5-deficient mice, and demonstrate that TRPC5 forms functional heteromultimers with TRPC1 in gonadotropes. We further show that the Englerin A-activated TRPC5-dependent Ca2+ signal is mediated by Ca2+ influx both via TRPC5 and via l-type voltage-gated Ca2+ channels, activated by the depolarization through TRPC5-mediated cation influx. Finally, we demonstrate that the gonadotropin-releasing hormone (GnRH)-mediated net depolarization is significantly reduced in gonadotropes isolated from TRPC5-deficient mice. In conclusion, our data suggest that TRPC5 contributes to depolarization of the plasma membrane in gonadotropes upon GnRH stimulation and increases the intracellular Ca2+ concentration via its own Ca2+ permeability and via the activation of voltage-gated Ca2+ channels.
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Affiliation(s)
- Andreas Beck
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
- Center of Human and Molecular Biology (ZHMB), Saarland University, Homburg, Germany
| | - Viktoria Götz
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Sen Qiao
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Petra Weissgerber
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Veit Flockerzi
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Ulrich Boehm
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
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