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Grattan DR. Does the brain make prolactin? J Neuroendocrinol 2024; 36:e13432. [PMID: 39041379 DOI: 10.1111/jne.13432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 07/24/2024]
Abstract
The prolactin receptor (Prlr) is widely expressed in the brain, particularly in the hypothalamus. Prolactin also has an increasing range of well-characterised effects on central nervous system function. Because of this, over many years, there has been interest in whether the hormone itself is also expressed within the brain, perhaps acting as a neuropeptide to regulate brain function via its receptor in neurons. The aim of this invited review is to critically evaluate the evidence for brain production of prolactin. Unlike the evidence for the Prlr, evidence for brain prolactin is inconsistent and variable. A range of different antibodies have been used, each characterising a different distribution of prolactin-like immunoreactivity. Prolactin mRNA has been detected in the brain, but only at levels markedly lower than seen in the pituitary gland. Importantly, it has largely only been detected by highly sensitive amplification-based techniques, and the extreme sensitivity means there is a risk of false-positive data. Modern in situ hybridisation methods and single-cell RNA sequencing have not provided supporting evidence, but it is hard to prove a negative! Finally, I acknowledge and discuss the possibility that prolactin might be produced in the brain under specific circumstances, such as to promote a neuroprotective response to cell damage. Collectively, however, based on this analysis, I have formed the opinion that brain production of prolactin is unlikely, and even if occurs, it is of little physiological consequence. Most, if not all of the brain actions of prolactin can be explained by pituitary prolactin gaining access to the brain.
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Affiliation(s)
- David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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Deffner F, Gleiser C, Mattheus U, Wagner A, Neckel PH, Fallier-Becker P, Hirt B, Mack AF. Aquaporin-4 expression in the human choroid plexus. Cell Mol Life Sci 2022; 79:90. [PMID: 35072772 PMCID: PMC8785037 DOI: 10.1007/s00018-022-04136-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/02/2022] [Accepted: 01/05/2022] [Indexed: 01/15/2023]
Abstract
The choroid plexus (CP) consists of specialized ependymal cells and underlying blood vessels and stroma producing the bulk of the cerebrospinal fluid (CSF). CP epithelial cells are considered the site of the internal blood-cerebrospinal fluid barrier, show epithelial characteristics (basal lamina, tight junctions), and express aquaporin-1 (AQP1) apically. In this study, we analyzed the expression of aquaporins in the human CP using immunofluorescence and qPCR. As previously reported, AQP1 was expressed apically in CP epithelial cells. Surprisingly, and previously unknown, many cells in the CP epithelium were also positive for aquaporin-4 (AQP4), normally restricted to ventricle-lining ependymal cells and astrocytes in the brain. Expression of AQP1 and AQP4 was found in the CP of all eight body donors investigated (3 males, 5 females; age 74–91). These results were confirmed by qPCR, and by electron microscopy detecting orthogonal arrays of particles. To find out whether AQP4 expression correlated with the expression pattern of relevant transport-related proteins we also investigated expression of NKCC1, and Na/K-ATPase. Immunostaining with NKCC1 was similar to AQP1 and revealed no particular pattern related to AQP4. Co-staining of AQP4 and Na/K-ATPase indicated a trend for an inverse correlation of their expression. We hypothesized that AQP4 expression in the CP was caused by age-related changes. To address this, we investigated mouse brains from young (2 months), adult (12 months) and old (30 months) mice. We found a significant increase of AQP4 on the mRNA level in old mice compared to young and adult animals. Taken together, we provide evidence for AQP4 expression in the CP of the aging brain which likely contributes to the water flow through the CP epithelium and CSF production. In two alternative hypotheses, we discuss this as a beneficial compensatory, or a detrimental mechanism influencing the previously observed CSF changes during aging.
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Affiliation(s)
- Felix Deffner
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Corinna Gleiser
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Ulrich Mattheus
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Andreas Wagner
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Peter H Neckel
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, University of Tübingen, Tübingen, Germany
| | - Bernhard Hirt
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany
| | - Andreas F Mack
- Institute of Clinical Anatomy and Cell Analysis, University of Tübingen, Österbergstr. 3, 72074, Tübingen, Germany.
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Costa-Brito AR, Gonçalves I, Santos CRA. The brain as a source and a target of prolactin in mammals. Neural Regen Res 2022; 17:1695-1702. [PMID: 35017416 PMCID: PMC8820687 DOI: 10.4103/1673-5374.332124] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Prolactin is a polypeptide hormone associated with an extensive variety of biological functions. Among the roles of prolactin in vertebrates, some were preserved throughout evolution. This is the case of its function in the brain, where prolactin receptors, are expressed in different structures of the central nervous system. In the brain, prolactin actions are principally associated with reproduction and parental behavior, and involves the modulation of adult neurogenesis, neuroprotection, and neuroplasticity, especially during pregnancy, thereby preparing the brain to parenthood. Prolactin is mainly produced by specialized cells in the anterior pituitary gland. However, during vertebrate evolution many other extrapituitary tissues do also produce prolactin, like the immune system, endothelial cells, reproductive structures and in several regions of the brain. This review summarizes the relevance of prolactin for brain function, the sources of prolactin in the central nervous system, as well as its local production and secretion. A highlight on the impact of prolactin in human neurological diseases is also provided.
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Affiliation(s)
- Ana R Costa-Brito
- CICS-UBI - Health Sciences Research Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - Isabel Gonçalves
- CICS-UBI - Health Sciences Research Centre; C4-UBI -Cloud Computing Competence Centre, Universidade da Beira Interior, Covilhã, Portugal
| | - Cecília R A Santos
- CICS-UBI - Health Sciences Research Centre; C4-UBI -Cloud Computing Competence Centre, Universidade da Beira Interior, Covilhã, Portugal
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Costa-Brito AR, Quintela T, Gonçalves I, Duarte AC, Costa AR, Arosa FA, Cavaco JE, Lemos MC, Santos CRA. The Choroid Plexus Is an Alternative Source of Prolactin to the Rat Brain. Mol Neurobiol 2021; 58:1846-1858. [PMID: 33409838 DOI: 10.1007/s12035-020-02267-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 12/16/2020] [Indexed: 10/22/2022]
Abstract
Among the more than 300 functions attributed to prolactin (PRL), this hormone has been associated with the induction of neurogenesis and differentiation of olfactory neurons especially during pregnancy, which are essential for maternal behavior. Despite the original hypothesis that PRL enters the central nervous system through a process mediated by PRL receptors (PRLR) at the choroid plexus (CP), recent data suggested that PRL transport into the brain is independent of its receptors. Based on transcriptomic data suggesting that PRL could be expressed in the CP, this work aimed to confirm PRL synthesis and secretion by CP epithelial cells (CPEC). The secretion of PRL and the distribution of PRLR in CPEC were further characterized using an in vitro model of the rat blood-cerebrospinal fluid barrier. RT-PCR analysis of PRL transcripts showed its presence in pregnant rat CP, in CPEC, and in the rat immortalized CP cell line, Z310. These observations were reinforced by immunocytochemistry staining of PRL in CPEC and Z310 cell cytoplasm. A 63-kDa immunoreactive PRL protein was detected by Western blot in CP protein extracts as well as in culture medium incubated with rat pituitary and samples of rat cerebrospinal fluid and serum. Positive immunocytochemistry staining of PRLR was present throughout the CPEC cytoplasm and in the apical and basal membrane of these cells. Altogether, our evidences suggest that CP is an alternative source of PRL to the brain, which might impact neurogenesis of olfactory neurons at the subventricular zone, given its proximity to the CP.
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Affiliation(s)
- Ana R Costa-Brito
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Telma Quintela
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Isabel Gonçalves
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Ana C Duarte
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Ana R Costa
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Fernando A Arosa
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - José E Cavaco
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Manuel C Lemos
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
| | - Cecília R A Santos
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.
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Decoding signaling pathways involved in prolactin-induced neuroprotection: A review. Front Neuroendocrinol 2021; 61:100913. [PMID: 33766566 DOI: 10.1016/j.yfrne.2021.100913] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/11/2021] [Accepted: 03/13/2021] [Indexed: 11/23/2022]
Abstract
It has been well recognized that prolactin (PRL), a pleiotropic hormone, has many functions in the brain, such as maternal behavior, neurogenesis, and neuronal plasticity, among others. Recently, it has been reported to have a significant role in neuroprotection against excitotoxicity. Glutamate excitotoxicity is a common alteration in many neurological and neurodegenerative diseases, leading to neuronal death. In this sense, several efforts have been made to decrease the progression of these pathologies. Despite various reports of PRL's neuroprotective effect against excitotoxicity, the signaling pathways that underlie this mechanism remain unclear. This review aims to describe the most recent and relevant studies on the molecular signaling pathways, particularly, PI3K/AKT, NF-κB, and JAK2/STAT5, which are currently under investigation and might be implicated in the molecular mechanisms that explain the PRL effects against excitotoxicity and neuroprotection. Remarkable neuroprotective effects of PRL might be useful in the treatment of some neurological diseases.
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Guardia-Escote L, Blanco J, Basaure P, Biosca-Brull J, Verkaik-Schakel RN, Cabré M, Peris-Sampedro F, Pérez-Fernández C, Sánchez-Santed F, Plösch T, Domingo JL, Colomina MT. Sex and Exposure to Postnatal Chlorpyrifos Influence the Epigenetics of Feeding-Related Genes in a Transgenic APOE Mouse Model: Long-Term Implications on Body Weight after a High-Fat Diet. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 18:ijerph18010184. [PMID: 33383760 PMCID: PMC7795072 DOI: 10.3390/ijerph18010184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/21/2020] [Accepted: 12/24/2020] [Indexed: 12/25/2022]
Abstract
Developmental exposure to toxicants and diet can interact with an individual's genetics and produce long-lasting metabolic adaptations. The different isoforms of the apolipoprotein E (APOE) are an important source of variability in metabolic disorders and influence the response to the pesticide chlorpyrifos (CPF). We aimed to study the epigenetic regulation on feeding control genes and the influence of postnatal CPF exposure, APOE genotype, and sex, and how these modifications impact on the metabolic response to a high-fat diet (HFD). Both male and female apoE3- and apoE4-TR mice were exposed to CPF on postnatal days 10-15. The DNA methylation pattern of proopiomelanocortin, neuropeptide Y, leptin receptor, and insulin-like growth factor 2 was studied in the hypothalamus. At adulthood, the mice were given a HFD for eight weeks. The results highlight the importance of sex in the epigenetic regulation and the implication of CPF treatment and APOE genotype. The body weight progression exhibited sex-dimorphic differences, apoE4-TR males being the most susceptible to the effects induced by CPF and HFD. Overall, these results underscore the pivotal role of sex, APOE genotype, and developmental exposure to CPF on subsequent metabolic disturbances later in life and show that sex is a key variable in epigenetic regulation.
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Affiliation(s)
- Laia Guardia-Escote
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Campus Sescelades, 43007 Tarragona, Spain
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, 43201 Reus, Spain;
| | - Jordi Blanco
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, 43201 Reus, Spain;
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, 43201 Reus, Spain
| | - Pia Basaure
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
| | - Judit Biosca-Brull
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Campus Sescelades, 43007 Tarragona, Spain
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, 43201 Reus, Spain;
| | - Rikst Nynke Verkaik-Schakel
- Department of Obstetrics and Gynecology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.N.V.-S.); (T.P.)
| | - Maria Cabré
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
- Department of Biochemistry and Biotechnology, Universitat Rovira i Virgili, 43007 Tarragona, Spain
| | - Fiona Peris-Sampedro
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Cristian Pérez-Fernández
- Department of Psychology and Health Research Center (CEINSA), Almeria University-ceiA3, 04120 Almeria, Spain; (C.P.-F.); (F.S.-S.)
| | - Fernando Sánchez-Santed
- Department of Psychology and Health Research Center (CEINSA), Almeria University-ceiA3, 04120 Almeria, Spain; (C.P.-F.); (F.S.-S.)
| | - Torsten Plösch
- Department of Obstetrics and Gynecology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands; (R.N.V.-S.); (T.P.)
| | - José L. Domingo
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, 43201 Reus, Spain;
- Department of Basic Medical Sciences, Universitat Rovira i Virgili, 43201 Reus, Spain
| | - Maria Teresa Colomina
- Research in Neurobehavior and Health (NEUROLAB), Universitat Rovira i Virgili, 43007 Tarragona, Spain; (L.G.-E.); (J.B.); (P.B.); (J.B.-B.); (M.C.)
- Department of Psychology and Research Center for Behavior Assessment (CRAMC), Universitat Rovira i Virgili, Campus Sescelades, 43007 Tarragona, Spain
- Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, 43201 Reus, Spain;
- Correspondence:
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Aoki M, Wartenberg P, Grünewald R, Phillipps HR, Wyatt A, Grattan DR, Boehm U. Widespread Cell-Specific Prolactin Receptor Expression in Multiple Murine Organs. Endocrinology 2019; 160:2587-2599. [PMID: 31373638 DOI: 10.1210/en.2019-00234] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/26/2019] [Indexed: 11/19/2022]
Abstract
The prolactin receptor (Prlr) mediates not only the multiple effects of prolactin, but also those of the placental lactogens and, in humans, some actions of growth hormone. Although Prlr expression has been reported to be widespread in the body, specific cellular expression patterns within tissues are undefined for many organs. One persisting problem in investigating Prlr function is that the protein is difficult to detect using conventional methods. To allow investigation of Prlr expression with a single cell resolution, we have recently developed a knock-in mouse strain in which Cre recombinase is expressed together with the long isoform of the Prlr using an internal ribosome entry site. When crossed to a Cre-dependent reporter mouse strain, Cre-mediated recombination will genetically label cells that acutely express the Prlr as well as cells that have transiently expressed the Prlr during development. We report here the anatomical distribution of cells which express the fluorescent reporter τ green fluorescent protein in a total of 38 organs prepared from young adult male and female Prlr reporter mice. Our results establish a resource for dissecting the functional role of Prlr in multiple murine tissues.
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Affiliation(s)
- Mari Aoki
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Philipp Wartenberg
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Ramona Grünewald
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Hollian R Phillipps
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Amanda Wyatt
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - David R Grattan
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
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