1
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Neuropeptidergic control of neurosteroids biosynthesis. Front Neuroendocrinol 2022; 65:100976. [PMID: 34999057 DOI: 10.1016/j.yfrne.2021.100976] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 12/12/2021] [Accepted: 12/22/2021] [Indexed: 01/14/2023]
Abstract
Neurosteroids are steroids synthesized within the central nervous system either from cholesterol or by metabolic reactions of circulating steroid hormone precursors. It has been suggested that neurosteroids exert pleiotropic activities within the central nervous system, such as organization and activation of the central nervous system and behavioral regulation. It is also increasingly becoming clear that neuropeptides exert pleiotropic activities within the central nervous system, such as modulation of neuronal functions and regulation of behavior, besides traditional neuroendocrinological functions. It was hypothesized that some of the physiological functions of neuropeptides acting within the central nervous system may be through the regulation of neurosteroids biosynthesis. Various neuropeptides reviewed in this study possibly regulate neurosteroids biosynthesis by controlling the activities of enzymes that catalyze the production of neurosteroids. It is now required to thoroughly investigate the neuropeptidergic control mechanisms of neurosteroids biosynthesis to characterize the physiological significance of this new neuroendocrinological phenomenon.
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2
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Diviccaro S, Cioffi L, Falvo E, Giatti S, Melcangi RC. Allopregnanolone: An overview on its synthesis and effects. J Neuroendocrinol 2022; 34:e12996. [PMID: 34189791 PMCID: PMC9285581 DOI: 10.1111/jne.12996] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 12/23/2022]
Abstract
Allopregnanolone, a 3α,5α-progesterone metabolite, acts as a potent allosteric modulator of the γ-aminobutyric acid type A receptor. In the present review, the synthesis of this neuroactive steroid occurring in the nervous system is discussed with respect to physiological and pathological conditions. In addition, its physiological and neuroprotective effects are also reported. Interestingly, the levels of this neuroactive steroid, as well as its effects, are sex-dimorphic, suggesting a possible gender medicine based on this neuroactive steroid for neurological disorders. However, allopregnanolone presents low bioavailability and extensive hepatic metabolism, limiting its use as a drug. Therefore, synthetic analogues or a different therapeutic strategy able to increase allopregnanolone levels have been proposed to overcome any pharmacokinetic issues.
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Affiliation(s)
- Silvia Diviccaro
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Lucia Cioffi
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Eva Falvo
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Silvia Giatti
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
| | - Roberto Cosimo Melcangi
- Dipartimento di Scienze Farmacologiche e BiomolecolariUniversità degli Studi di MilanoMilanoItaly
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3
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Lattanzi S, Riva A, Striano P. Ganaxolone treatment for epilepsy patients: from pharmacology to place in therapy. Expert Rev Neurother 2021; 21:1317-1332. [PMID: 33724128 DOI: 10.1080/14737175.2021.1904895] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Nonsulfated neurosteroids can provide phasic and tonic inhibition through activation of synaptic and extra-synaptic γ-aminobutyric acid (GABA)A receptors, exhibiting a greater potency for the latter. These actions occur by interacting with modulatory sites that are distinct from those bound by benzodiazepines and barbiturates. Ganaxolone (GNX) is a synthetic analog of the endogenous neurosteroid allopregnanolone and a member of a novel class of neuroactive steroids called epalons.Areas covered: The authors review the pharmacology of GNX, summarize the main clinical evidence about its antiseizure efficacy and tolerability, and suggest implications for clinical practice and future research.Expert opinion: The clinical development of GNX is mainly oriented to target unmet needs and focused on status epilepticus and rare genetic epilepsies that have few or no treatment options.The availability of oral and intravenous formulations allows reaching adult and pediatric patients in acute and chronic care settings. Further evidence will complement the understanding of the potentialities of GNX and possibly lead to indications for use in clinical practice.
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Affiliation(s)
- Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
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4
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Long KLP, Breton JM, Barraza MK, Perloff OS, Kaufer D. Hormonal Regulation of Oligodendrogenesis I: Effects across the Lifespan. Biomolecules 2021; 11:biom11020283. [PMID: 33672939 PMCID: PMC7918364 DOI: 10.3390/biom11020283] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 02/07/2023] Open
Abstract
The brain’s capacity to respond to changing environments via hormonal signaling is critical to fine-tuned function. An emerging body of literature highlights a role for myelin plasticity as a prominent type of experience-dependent plasticity in the adult brain. Myelin plasticity is driven by oligodendrocytes (OLs) and their precursor cells (OPCs). OPC differentiation regulates the trajectory of myelin production throughout development, and importantly, OPCs maintain the ability to proliferate and generate new OLs throughout adulthood. The process of oligodendrogenesis, the creation of new OLs, can be dramatically influenced during early development and in adulthood by internal and environmental conditions such as hormones. Here, we review the current literature describing hormonal regulation of oligodendrogenesis within physiological conditions, focusing on several classes of hormones: steroid, peptide, and thyroid hormones. We discuss hormonal regulation at each stage of oligodendrogenesis and describe mechanisms of action, where known. Overall, the majority of hormones enhance oligodendrogenesis, increasing OPC differentiation and inducing maturation and myelin production in OLs. The mechanisms underlying these processes vary for each hormone but may ultimately converge upon common signaling pathways, mediated by specific receptors expressed across the OL lineage. However, not all of the mechanisms have been fully elucidated, and here, we note the remaining gaps in the literature, including the complex interactions between hormonal systems and with the immune system. In the companion manuscript in this issue, we discuss the implications of hormonal regulation of oligodendrogenesis for neurological and psychiatric disorders characterized by white matter loss. Ultimately, a better understanding of the fundamental mechanisms of hormonal regulation of oligodendrogenesis across the entire lifespan, especially in vivo, will progress both basic and translational research.
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Affiliation(s)
- Kimberly L. P. Long
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA; (J.M.B.); (D.K.)
- Correspondence:
| | - Jocelyn M. Breton
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA; (J.M.B.); (D.K.)
| | - Matthew K. Barraza
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA 94720, USA;
| | - Olga S. Perloff
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94143, USA;
| | - Daniela Kaufer
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA; (J.M.B.); (D.K.)
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Canadian Institute for Advanced Research, Toronto, ON M5G 1M1, Canada
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5
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Biosynthesis and signalling functions of central and peripheral nervous system neurosteroids in health and disease. Essays Biochem 2021; 64:591-606. [PMID: 32756865 PMCID: PMC7517341 DOI: 10.1042/ebc20200043] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/09/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023]
Abstract
Neurosteroids are steroid hormones synthesised de novo in the brain and peripheral nervous tissues. In contrast to adrenal steroid hormones that act on intracellular nuclear receptors, neurosteroids directly modulate plasma membrane ion channels and regulate intracellular signalling. This review provides an overview of the work that led to the discovery of neurosteroids, our current understanding of their intracellular biosynthetic machinery, and their roles in regulating the development and function of nervous tissue. Neurosteroids mediate signalling in the brain via multiple mechanisms. Here, we describe in detail their effects on GABA (inhibitory) and NMDA (excitatory) receptors, two signalling pathways of opposing function. Furthermore, emerging evidence points to altered neurosteroid function and signalling in neurological disease. This review focuses on neurodegenerative diseases associated with altered neurosteroid metabolism, mainly Niemann-Pick type C, multiple sclerosis and Alzheimer disease. Finally, we summarise the use of natural and synthetic neurosteroids as current and emerging therapeutics alongside their potential use as disease biomarkers.
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6
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Zamora-Sánchez CJ, Hernández-Vega AM, Gaona-Domínguez S, Rodríguez-Dorantes M, Camacho-Arroyo I. 5alpha-dihydroprogesterone promotes proliferation and migration of human glioblastoma cells. Steroids 2020; 163:108708. [PMID: 32730775 DOI: 10.1016/j.steroids.2020.108708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/12/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Glioblastomas (GBMs) are the most common and deadliest intracranial tumors. Steroid hormones, such as progesterone (P4), at physiological concentrations, promote proliferation, and migration of human GBM cells in vivo and in vitro. Neuronal and glial cells, but also GBMs, metabolize P4 and synthesize different active metabolites such as 5α-dihydroprogesterone (5α-DHP). However, their contribution to GBM malignancy remains unknown. Here, we determined the 5α-DHP effects on the number of cells, proliferation, and migration of the U87 and U251 human GBM-derived cell lines. Of the tested concentrations (1 nM-1 µM), 5α-DHP 10 nM significantly increased the number of U87 and U251 cells from day 2 of treatment, and proliferation (at day 3) in a similar manner as P4 (10 nM). The treatment with the progesterone receptor (PR) antagonist RU486 (mifepristone), blocked the effects of 5α-DHP on the number of cells and proliferation. Besides, in U251 and LN229 GBM cells, 5α-DHP promoted cell migration (from 12 to 24 h). We also determined that GBM cells expressed the 3α-hydroxysteroid oxidoreductases (3α-HSOR), which reversibly reduce 5α-DHP to allopregnanolone (3α-THP). These data indicate that 5α-DHP induces proliferation and migration of human GBM through the activation of PR.
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Affiliation(s)
- Carmen J Zamora-Sánchez
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico
| | - Ana M Hernández-Vega
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico
| | - Saúl Gaona-Domínguez
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico
| | - Mauricio Rodríguez-Dorantes
- Instituto Nacional de Medicina Genómica (INMEGEN), Periférico Sur No. 4809, Col. Arenal Tepepan, Delegación Tlalpan, C.P. 14610 Ciudad de Mexico, Mexico.
| | - Ignacio Camacho-Arroyo
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico.
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7
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Guennoun R. Progesterone in the Brain: Hormone, Neurosteroid and Neuroprotectant. Int J Mol Sci 2020; 21:ijms21155271. [PMID: 32722286 PMCID: PMC7432434 DOI: 10.3390/ijms21155271] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/29/2020] [Accepted: 07/22/2020] [Indexed: 12/19/2022] Open
Abstract
Progesterone has a broad spectrum of actions in the brain. Among these, the neuroprotective effects are well documented. Progesterone neural effects are mediated by multiple signaling pathways involving binding to specific receptors (intracellular progesterone receptors (PR); membrane-associated progesterone receptor membrane component 1 (PGRMC1); and membrane progesterone receptors (mPRs)) and local bioconversion to 3α,5α-tetrahydroprogesterone (3α,5α-THPROG), which modulates GABAA receptors. This brief review aims to give an overview of the synthesis, metabolism, neuroprotective effects, and mechanism of action of progesterone in the rodent and human brain. First, we succinctly describe the biosynthetic pathways and the expression of enzymes and receptors of progesterone; as well as the changes observed after brain injuries and in neurological diseases. Then, we summarize current data on the differential fluctuations in brain levels of progesterone and its neuroactive metabolites according to sex, age, and neuropathological conditions. The third part is devoted to the neuroprotective effects of progesterone and 3α,5α-THPROG in different experimental models, with a focus on traumatic brain injury and stroke. Finally, we highlight the key role of the classical progesterone receptors (PR) in mediating the neuroprotective effects of progesterone after stroke.
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Affiliation(s)
- Rachida Guennoun
- U 1195 Inserm and University Paris Saclay, University Paris Sud, 94276 Le kremlin Bicêtre, France
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8
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Giatti S, Diviccaro S, Falvo E, Garcia-Segura LM, Melcangi RC. Physiopathological role of the enzymatic complex 5α-reductase and 3α/β-hydroxysteroid oxidoreductase in the generation of progesterone and testosterone neuroactive metabolites. Front Neuroendocrinol 2020; 57:100836. [PMID: 32217094 DOI: 10.1016/j.yfrne.2020.100836] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/04/2020] [Accepted: 03/18/2020] [Indexed: 12/22/2022]
Abstract
The enzymatic complex 5α-reductase (5α-R) and 3α/3β-hydroxysteroid oxidoreductase (HSOR) is expressed in the nervous system, where it transforms progesterone (PROG) and testosterone (T) into neuroactive metabolites. These metabolites regulate myelination, brain maturation, neurotransmission, reproductive behavior and the stress response. The expression of 5α-R and 3α-HSOR and the levels of PROG and T reduced metabolites show regional and sex differences in the nervous system and are affected by changing physiological conditions as well as by neurodegenerative and psychiatric disorders. A decrease in their nervous tissue levels may negatively impact the course and outcome of some pathological events. However, in other pathological conditions their increased levels may have a negative impact. Thus, the use of synthetic analogues of these steroids or 5α-R modulation have been proposed as therapeutic approaches for several nervous system pathologies. However, further research is needed to fully understand the consequences of these manipulations, in particular with 5α-R inhibitors.
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Affiliation(s)
- Silvia Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Silvia Diviccaro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Eva Falvo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Luis Miguel Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Roberto Cosimo Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
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Antkowiak B, Rammes G. GABA(A) receptor-targeted drug development -New perspectives in perioperative anesthesia. Expert Opin Drug Discov 2019; 14:683-699. [DOI: 10.1080/17460441.2019.1599356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bernd Antkowiak
- Department of Anesthesiology and Intensive Care, Experimental Anesthesiology Section, Eberhard-Karls-University,
Tübingen, Germany
- Department of Anaesthesiology and Intensive Care, Experimental Anaesthesiology Section, Werner Reichardt Center for Integrative Neuroscience, Tübingen,
Germany
| | - Gerhard Rammes
- University Hospital rechts der Isar, Department of Anesthesiology, München,
Germany
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10
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Leicaj ML, Pasquini LA, Lima A, Gonzalez Deniselle MC, Pasquini JM, De Nicola AF, Garay LI. Changes in neurosteroidogenesis during demyelination and remyelination in cuprizone-treated mice. J Neuroendocrinol 2018; 30:e12649. [PMID: 30303567 DOI: 10.1111/jne.12649] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/20/2018] [Accepted: 10/01/2018] [Indexed: 12/28/2022]
Abstract
Changes of neurosteroids may be involved in the pathophysiology of multiple sclerosis (MS). The present study investigated whether changes of neurosteroidogenesis also occurred in the grey and white matter regions of the brain in mice subjected to cuprizone-induced demyelination. Accordingly, we compared the expression of neurosteroidogenic proteins, including steroidogenic acute regulatory protein (StAR), voltage-dependent anion channel (VDAC) and 18 kDa translocator protein (TSPO), as well as neurosteroidogenic enzymes, including the side chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase/isomerase and 5α-reductase (5α-R), during the demyelination and remyelination periods. Using immunohistochemistry and a quantitative polymerase chain reaction, we demonstrated a decreased expression of StAR, P450scc and 5α-R with respect to an increase astrocytic and microglial reaction and elevated levels of tumor necrosis factor (TNF)α during the cuprizone demyelination period in the hippocampus, cortex and corpus callosum. These parameters, as well as the glial reaction, were normalised after 2 weeks of spontaneous remyelination in regions containing grey matter. Conversely, persistent elevated levels of TNFα and low levels of StAR and P450scc were observed during remyelination in corpus callosum white matter. We conclude that neurosteroidogenesis/myelination status and glial reactivity are inversely related in the hippocampus and neocortex. Establishing a cause and effect relationship for the measured variables remains a future challenge for understanding the pathophysiology of MS.
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Affiliation(s)
- María L Leicaj
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
| | - Laura A Pasquini
- Department of Biological Chemistry, School of Pharmacy and Biochemistry, Institute of Chemistry and Biological Physicochemistry (IQUIFIB), University of Buenos Aires and National Research Council (CONICET), Buenos Aires, Argentina
| | - Analia Lima
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
| | - Maria C Gonzalez Deniselle
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Physiological Sciences, University of Buenos Aires, Buenos Aires, Argentina
| | - Juana M Pasquini
- Department of Biological Chemistry, School of Pharmacy and Biochemistry, Institute of Chemistry and Biological Physicochemistry (IQUIFIB), University of Buenos Aires and National Research Council (CONICET), Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Human Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Laura I Garay
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Human Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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11
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De Nicola AF, Garay LI, Meyer M, Guennoun R, Sitruk-Ware R, Schumacher M, Gonzalez Deniselle MC. Neurosteroidogenesis and progesterone anti-inflammatory/neuroprotective effects. J Neuroendocrinol 2018; 30. [PMID: 28675779 DOI: 10.1111/jne.12502] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 12/19/2022]
Abstract
Progesterone shows anti-inflammatory and promyelinating effects in mice with experimental autoimmune encephalomyelitis (EAE), a commonly used model for multiple sclerosis (MS). Because neurosteroids have been implicated as protective factors for MS and EAE, we analysed the expression of neurosteroidogenic enzymes in the compromised spinal cord of EAE mice. EAE was induced in female C57Bl6 mice, which were then killed on day 16 after induction. Progesterone was given by pellet implantation 1 week before EAE induction. Untreated EAE mice showed decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), cholesterol side-chain cleavage (P450scc), 5α-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSOR) and aromatase, whereas changes of 3β-hydroxysteroid dehydrogenase (3β-HSD) were not significant. mRNA translocator protein (18 kDa) (TSPO) was elevated, concomitantly with a reactive microgliosis. EAE mice also showed abnormal mitochondrial ultrastructure in axons and neuronal bodies, as well as reduced expression of fission and fusion protein mRNAs. Progesterone pretreatment before EAE induction increased Star, VDAC, P450scc, 5α-reductase type I, 3α-HSOR and aromatase mRNAs and did not modify 3β-HSD. TSPO mRNA was decreased, possibly as a result of reversal of microgliosis. Progesterone pretreatment also improved mitochondrial ultrastructure and increased fission/fusion protein mRNAs. These mitochondrial effects may be part of the progesterone recovery of neurosteroidogenesis. The enzymes 3β-HSD, 3α-HSOR and 5α-reductase are also responsible for the formation of androgens. Because MS patients and EAE rodents show changes of central androgen levels, it is likely that, together with progestins and oestrogens, neuroandrogens afford neuroprotection for EAE and MS. The data reviewed suggest that enhanced synthesis of neurosteroids contributes in an auto/paracrine manner to reinforce the neuroprotective and anti-inflammatory effects of exogenous progesterone given to EAE mice.
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Affiliation(s)
- A F De Nicola
- Department of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - L I Garay
- Department of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - M Meyer
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - R Guennoun
- U1195 Inserm and Université Paris-Sud, Le Kremlin-Bicêtre, France
| | | | - M Schumacher
- U1195 Inserm and Université Paris-Sud, Le Kremlin-Bicêtre, France
| | - M C Gonzalez Deniselle
- The Population Council, New York, NY, USA
- Department of Physiology and Biophysics, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
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12
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Barichello T, Simões LR, Collodel A, Giridharan VV, Dal-Pizzol F, Macedo D, Quevedo J. The translocator protein (18 kDa) and its role in neuropsychiatric disorders. Neurosci Biobehav Rev 2017; 83:183-199. [DOI: 10.1016/j.neubiorev.2017.10.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/20/2017] [Accepted: 10/10/2017] [Indexed: 02/08/2023]
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13
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Litim N, Morissette M, Caruso D, Melcangi RC, Di Paolo T. Effect of the 5α-reductase enzyme inhibitor dutasteride in the brain of intact and parkinsonian mice. J Steroid Biochem Mol Biol 2017; 174:242-256. [PMID: 28982631 DOI: 10.1016/j.jsbmb.2017.09.021] [Citation(s) in RCA: 9] [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: 04/10/2017] [Revised: 09/08/2017] [Accepted: 09/30/2017] [Indexed: 12/15/2022]
Abstract
Dutasteride is a 5alpha-reductase inhibitor in clinical use to treat endocrine conditions. The present study investigated the neuroprotective mechanisms of action of dutasteride in intact and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mice using a low dose of MPTP not affecting motor activity modeling early stages of Parkinson's disease (PD). We hypothesized that dutasteride neuroprotection is due to altered steroids levels. Dutasteride pre-treatment prevented loss of striatal dopamine (DA) and its metabolite DOPAC. Dutasteride decreased effects of MPTP on striatal dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2) and D2 DA receptor specific binding while D1 receptor specific binding remained unchanged. Dutasteride enhanced DAT specific binding and the glycosylated form of DAT in intact mice. MPTP-lesioned mice had plasma and brain testosterone and dihydrotestosterone levels lower than control mice whereas progesterone and its metabolites (dihydroprogesterone, isopregnanolone and tetrahydroprogesterone) pathway showed increases. Dutasteride treatment by inhibiting transformation of progesterone and testosterone to its metabolites elevated plasma and brain concentrations of testosterone compared to MPTP mice and decreased DHT levels in intact mice. Plasma and brain estradiol levels were low and remained unchanged by MPTP and/or dutasteride treatment. Dutasteride treatment did not affect striatal phosphorylation of Akt and its downstream substrate GSK3β as well as phosphorylation of ERK1/2 in intact and MPTP lesioned MPTP mice. Striatal glial fibrillary acidic protein (GFAP) levels were markedly elevated in MPTP compared to control mice and dutasteride reduced GFAP levels in MPTP mice. Treatment with dutasteride post-lesion left unchanged striatal DA levels. These results suggest dutasteride as promising drug for PD neuroprotection.
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Affiliation(s)
- Nadhir Litim
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada
| | - Donatella Caruso
- Department of Pharmacological and Biomolecular Sciences, Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy
| | - Roberto C Melcangi
- Department of Pharmacological and Biomolecular Sciences, Center of Excellence on Neurodegenerative Diseases, Università degli Studi di Milano, Milan, Italy
| | - Thérèse Di Paolo
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada.
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14
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Garay L, Gonzalez Giqueaux P, Guennoun R, Schumacher M, Gonzalez Deniselle MC, De Nicola AF. Progesterone treatment modulates mRNA OF neurosteroidogenic enzymes in a murine model of multiple sclerosis. J Steroid Biochem Mol Biol 2017; 165:421-429. [PMID: 27597394 DOI: 10.1016/j.jsbmb.2016.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/29/2016] [Accepted: 09/01/2016] [Indexed: 11/20/2022]
Abstract
Previous studies of experimental autoimmune encephalomyelitis (EAE) have shown that progesterone decreases inflammatory cell infiltration and proinflammatory factors, increases myelination and attenuates clinical grade of EAE mice. To elucidate potential mediators of these effects, we analyzed the mRNA expression of neurosteroidogenic enzymes in the spinal cord, in view of the protective role of steroids in EAE. We also analyzed mitochondrial morphology and dynamics (fusion and fission proteins), considering the role of mitochondria in neurosteroidogenesis. EAE was induced in C57Bl6 mice using MOG40-54 and killed on day 16 after induction. Using qPCR, we found in steroid-untreated EAE mice decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), P450scc (cholesterol side-chain cleavage), 5α-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSD) and aromatase, whereas levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) showed a large intra-group variance. We also found increased mRNA expression of 18Kd translocator protein (TSPO), which likely resulted from the reactive microgliosis in this model. EAE mice also showed pathological mitochondrial morphology and reduced expression of fission and fusion protein mRNAs. Most importantly, pretreatment with progesterone a week before EAE induction increased Star,VDAC, P450scc, 5α-reductase type I, 3α-HSD and aromatase mRNAs and did not modify 3β-HSD. TSPO mRNA was decreased, consequent with the inhibition of microgliosis. Mitochondrial morphology was improved and fission/fusion protein mRNAs were enhanced by progesterone treatment. Furthermore, progesterone protective effects on mitochondrial and endoplasmic reticulum may allow the recovery of neurosteroidogenesis. In this way, endogenously synthesized neurosteroids may reinforce the beneficial effects of exogenous progesterone previously shown in MS mice.
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Affiliation(s)
- Laura Garay
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Biochemistry(,) Faculty of Medicine, University of Buenos Aires, Argentina
| | - Paula Gonzalez Giqueaux
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina
| | - Rachida Guennoun
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Kremlin-Bicêtre, France
| | - Michael Schumacher
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Kremlin-Bicêtre, France
| | - Maria Claudia Gonzalez Deniselle
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Physiology, Faculty of Medicine, University of Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Biochemistry(,) Faculty of Medicine, University of Buenos Aires, Argentina.
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Brunton PJ. Neuroactive steroids and stress axis regulation: Pregnancy and beyond. J Steroid Biochem Mol Biol 2016; 160:160-8. [PMID: 26259885 DOI: 10.1016/j.jsbmb.2015.08.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/31/2015] [Accepted: 08/03/2015] [Indexed: 01/09/2023]
Abstract
The hypothalamo-pituitary-adrenal (HPA) axis plays a critical role in regulating responses to stress and long term dysregulation of the HPA axis is associated with higher rates of mood disorders. There are circumstances where the HPA axis is more or less responsive to stress. For example, during late pregnancy ACTH and corticosterone responses to stress are markedly suppressed, whereas in offspring born to mothers that experienced repeated stress during pregnancy, the HPA axis is hyper-responsive to stress. Neuroactive steroids such as allopregnanolone, tetrahydrodeoxycorticosterone (THDOC) and androstanediol can modulate HPA axis activity and concentrations of some neuroactive steroids in the brain are altered during pregnancy and following stress. Thus, here altered neurosteroidogenesis is proposed as a mechanism that could underpin the dynamic changes in HPA axis regulation typically observed in late pregnant and in prenatally stressed individuals. In support of this hypothesis, evidence in rats demonstrates that elevated levels of allopregnanolone in pregnancy induce a central inhibitory opioid mechanism that serves to minimize stress-induced HPA axis activity. Conversely, in prenatally stressed rodents, where HPA axis stress responses are enhanced, evidence indicates the capacity of the brain for neurosteroidogenesis is reduced. Understanding the mechanisms involved in adaptations in HPA axis regulation may provide insights for manipulating stress sensitivity and for developing therapies for stress-related disorders in humans.
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Affiliation(s)
- Paula J Brunton
- Division of Neurobiology, The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, Scotland, UK.
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Kiyokage E, Toida K, Suzuki-Yamamoto T, Ishimura K. Cellular localization of 5α-reductase in the rat cerebellum. J Chem Neuroanat 2014; 59-60:8-16. [DOI: 10.1016/j.jchemneu.2014.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 04/11/2014] [Accepted: 04/25/2014] [Indexed: 01/14/2023]
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17
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Nothdurfter C, Baghai TC, Schüle C, Rupprecht R. Translocator protein (18 kDa) (TSPO) as a therapeutic target for anxiety and neurologic disorders. Eur Arch Psychiatry Clin Neurosci 2012; 262 Suppl 2:S107-12. [PMID: 22923187 DOI: 10.1007/s00406-012-0352-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/10/2012] [Indexed: 12/21/2022]
Abstract
The translocator protein (18 kD) (TSPO) plays a crucial role for the synthesis of neurosteroids by promoting the transport of cholesterol to the inner mitochondrial membrane, which is the rate-limiting step in neurosteroidogenesis. Neurosteroids are allosteric modulators of GABA(A) receptor function, which plays an important role in the pathophysiology of anxiety disorders. The TSPO ligand XBD173 enhances GABAergic neurotransmission by promoting neurosteroidogenesis without direct effects at the GABA(A) receptor. In humans, XBD173 shows potent antipanic efficacy without sedation and withdrawal after 7 days of treatment. XBD173 therefore appears to be a promising compound for rapid anxiolytic efficacy with a favorable side-effect profile. Furthermore, TSPO ligands show neuroprotective and antiinflammatory effects in experimental models of peripheral neuropathies and traumatic brain injury. These compounds might therefore also be valuable for the treatment of neurologic diseases with inflammation-related pathophysiology.
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Affiliation(s)
- Caroline Nothdurfter
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany.
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18
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Schumacher M, Hussain R, Gago N, Oudinet JP, Mattern C, Ghoumari AM. Progesterone synthesis in the nervous system: implications for myelination and myelin repair. Front Neurosci 2012; 6:10. [PMID: 22347156 PMCID: PMC3274763 DOI: 10.3389/fnins.2012.00010] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 01/16/2012] [Indexed: 11/15/2022] Open
Abstract
Progesterone is well known as a female reproductive hormone and in particular for its role in uterine receptivity, implantation, and the maintenance of pregnancy. However, neuroendocrine research over the past decades has established that progesterone has multiple functions beyond reproduction. Within the nervous system, its neuromodulatory and neuroprotective effects are much studied. Although progesterone has been shown to also promote myelin repair, its influence and that of other steroids on myelination and remyelination is relatively neglected. Reasons for this are that hormonal influences are still not considered as a central problem by most myelin biologists, and that neuroendocrinologists are not sufficiently concerned with the importance of myelin in neuron functions and viability. The effects of progesterone in the nervous system involve a variety of signaling mechanisms. The identification of the classical intracellular progesterone receptors as therapeutic targets for myelin repair suggests new health benefits for synthetic progestins, specifically designed for contraceptive use and hormone replacement therapies. There are also major advantages to use natural progesterone in neuroprotective and myelin repair strategies, because progesterone is converted to biologically active metabolites in nervous tissues and interacts with multiple target proteins. The delivery of progesterone however represents a challenge because of its first-pass metabolism in digestive tract and liver. Recently, the intranasal route of progesterone administration has received attention for easy and efficient targeting of the brain. Progesterone in the brain is derived from the steroidogenic endocrine glands or from local synthesis by neural cells. Stimulating the formation of endogenous progesterone is currently explored as an alternative strategy for neuroprotection, axonal regeneration, and myelin repair.
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Nothdurfter C, Rammes G, Baghai TC, Schüle C, Schumacher M, Papadopoulos V, Rupprecht R. Translocator protein (18 kDa) as a target for novel anxiolytics with a favourable side-effect profile. J Neuroendocrinol 2012; 24:82-92. [PMID: 21609361 DOI: 10.1111/j.1365-2826.2011.02166.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anxiety disorders are frequent and highly disabling diseases with considerable socio-economic impact. In the treatment of anxiety disorders, benzodiazepines (BZDs) as direct modulators of the GABA(A) receptor are used as emergency medication because of their rapid onset of action. However, BZDs act also as sedatives and rather quickly induce tolerance and abuse liability associated with withdrawal symptoms. Antidepressants with anxiolytic properties are also applied as first line long-term treatment of anxiety disorders. However, the onset of action of antidepressants takes several weeks. Obviously, novel pharmacological approaches are needed that combine a rapid anxiolytic efficacy with the lack of tolerance induction, abuse liability and withdrawal symptoms. Neurosteroids are potent allosteric modulators of GABA(A) receptor function. The translocator protein (18 kDa) (TSPO) plays an important role for the synthesis of neurosteroids by promoting the transport of cholesterol from the outer to the inner mitochondrial membrane, which is the rate-limiting step in neurosteroidogenesis. Etifoxine not only exerts anxiolytic effects as a TSPO ligand by enhancing neurosteroidogenesis, but also acts as a weak direct GABA(A) receptor enhancer. The TSPO ligand XBD173 enhances GABAergic neurotransmission via the promotion of neurosteroidogenesis without direct effects at the GABA(A) receptor. XBD173 counteracts pharmacologically-induced panic in rodents in the absence of sedation and tolerance development. Also in humans, XBD173 displays antipanic activity and does not cause sedation and withdrawal symptoms after 7 days of treatment. XBD173 therefore appears to be a promising candidate for fast-acting anxiolytic drugs with less severe side-effects than BZDs. In this review, we focus on the pathophysiology of anxiety disorders and TSPO ligands as a novel pharmacological approach in the treatment of these disorders.
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Affiliation(s)
- C Nothdurfter
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany.
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20
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Rupprecht R, Papadopoulos V, Rammes G, Baghai TC, Fan J, Akula N, Groyer G, Adams D, Schumacher M. Translocator protein (18 kDa) (TSPO) as a therapeutic target for neurological and psychiatric disorders. Nat Rev Drug Discov 2011; 9:971-88. [PMID: 21119734 DOI: 10.1038/nrd3295] [Citation(s) in RCA: 715] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The translocator protein (18 kDa) (TSPO) is localized primarily in the outer mitochondrial membrane of steroid-synthesizing cells, including those in the central and peripheral nervous system. One of its main functions is the transport of the substrate cholesterol into mitochondria, a prerequisite for steroid synthesis. TSPO expression may constitute a biomarker of brain inflammation and reactive gliosis that could be monitored by using TSPO ligands as neuroimaging agents. Moreover, initial clinical trials have indicated that TSPO ligands might be valuable in the treatment of neurological and psychiatric disorders. This Review focuses on the biology and pathophysiology of TSPO and the potential of currently available TSPO ligands for the diagnosis and treatment of neurological and psychiatric disorders.
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Affiliation(s)
- Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians University, Nussbaumstrasse 7, 80336 Munich, Germany.
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21
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Faroni A, Magnaghi V. The neurosteroid allopregnanolone modulates specific functions in central and peripheral glial cells. Front Endocrinol (Lausanne) 2011; 2:103. [PMID: 22654838 PMCID: PMC3356145 DOI: 10.3389/fendo.2011.00103] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Accepted: 12/05/2011] [Indexed: 12/15/2022] Open
Abstract
Since the first observations on the existence of "neurosteroids" in the 1980s, our understanding of the importance of these endogenous steroids in the control of the central and peripheral nervous system (PNS) has increased progressively. Although most of the observations were made in neuronal cells, equally important are the effects that neurosteroids exert on glial cells. Among the different classes of neurosteroids acting on glial cells, the progesterone 5α-3α metabolite, allopregnanolone, displays a particular mechanism of action involving primarily the modulation of classic GABA receptors. In this review, we focus our attention on allopregnanolone because its effects on the physiology of glial cells of the central and PNS are intriguing and could potentially lead to the development of new strategies for neuroprotection and/or regeneration of injured nervous tissues.
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Affiliation(s)
- Alessandro Faroni
- Blond McIndoe Laboratories, Regenerative Biomedicine, School of Medicine, The University of ManchesterManchester, UK
- Department of Endocrinology, Physiopathology, Applied Biology, University of MilanMilan, Italy
| | - Valerio Magnaghi
- Department of Endocrinology, Physiopathology, Applied Biology, University of MilanMilan, Italy
- *Correspondence: Valerio Magnaghi, Department of Endocrinology, Physiopathology, Applied Biology, University of Milan, Via G. Balzaretti 9, 20133 Milan, Italy. e-mail:
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22
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Immunohistochemical localization and biological activity of 3β-hydroxysteroid dehydrogenase and 5α-reductase in the brain of the frog, Rana esculenta, during development. J Chem Neuroanat 2010; 39:35-50. [DOI: 10.1016/j.jchemneu.2009.08.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 08/03/2009] [Accepted: 08/04/2009] [Indexed: 11/24/2022]
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23
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Do Rego JL, Seong JY, Burel D, Leprince J, Luu-The V, Tsutsui K, Tonon MC, Pelletier G, Vaudry H. Neurosteroid biosynthesis: enzymatic pathways and neuroendocrine regulation by neurotransmitters and neuropeptides. Front Neuroendocrinol 2009; 30:259-301. [PMID: 19505496 DOI: 10.1016/j.yfrne.2009.05.006] [Citation(s) in RCA: 277] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/12/2009] [Accepted: 05/21/2009] [Indexed: 01/09/2023]
Abstract
Neuroactive steroids synthesized in neuronal tissue, referred to as neurosteroids, are implicated in proliferation, differentiation, activity and survival of nerve cells. Neurosteroids are also involved in the control of a number of behavioral, neuroendocrine and metabolic processes such as regulation of food intake, locomotor activity, sexual activity, aggressiveness, anxiety, depression, body temperature and blood pressure. In this article, we summarize the current knowledge regarding the existence, neuroanatomical distribution and biological activity of the enzymes responsible for the biosynthesis of neurosteroids in the brain of vertebrates, and we review the neuronal mechanisms that control the activity of these enzymes. The observation that the activity of key steroidogenic enzymes is finely tuned by various neurotransmitters and neuropeptides strongly suggests that some of the central effects of these neuromodulators may be mediated via the regulation of neurosteroid production.
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Affiliation(s)
- Jean Luc Do Rego
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 413, 76821 Mont-Saint-Aignan, France
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24
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Foradori CD, Weiser MJ, Handa RJ. Non-genomic actions of androgens. Front Neuroendocrinol 2008; 29:169-81. [PMID: 18093638 PMCID: PMC2386261 DOI: 10.1016/j.yfrne.2007.10.005] [Citation(s) in RCA: 322] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 10/12/2007] [Accepted: 10/24/2007] [Indexed: 11/25/2022]
Abstract
Previous work in the endocrine and neuroendocrine fields has viewed the androgen receptor (AR) as a transcription factor activated by testosterone or one of its many metabolites. The bound AR acts as transcription regulatory element by binding to specific DNA response elements in target gene promoters, causing activation or repression of transcription and subsequently protein synthesis. Over the past two decades evidence at the cellular and organismal level has accumulated to implicate rapid responses to androgens, dependent or independent of the AR. Androgen's rapid time course of action; its effects in the absence or inhibition of the cellular machinery necessary for transcription/translation; and in the absence of translocation to the nucleus suggest a method of androgen action not initially dependent on genomic mechanisms (i.e. non-genomic in nature). In the present paper, the non-genomic effects of androgens are reviewed, along with a discussion of the possible role non-genomic androgen actions have on animal physiology and behavior.
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Affiliation(s)
- C D Foradori
- Department of Biomedical Sciences, Neurobiology Section, Colorado State University, Fort Collins, CO 80523, USA
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25
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Mellon SH. Neurosteroid regulation of central nervous system development. Pharmacol Ther 2007; 116:107-24. [PMID: 17651807 PMCID: PMC2386997 DOI: 10.1016/j.pharmthera.2007.04.011] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 04/25/2007] [Indexed: 12/28/2022]
Abstract
Neurosteroids are a relatively new class of neuroactive compounds brought to prominence in the past 2 decades. Despite knowing of their presence in the nervous system of various species for over 20 years and knowing of their functions as GABA(A) and N-methyl-d-aspartate (NMDA) ligands, new and unexpected functions of these compounds are continuously being identified. Absence or reduced concentrations of neurosteroids during development and in adults may be associated with neurodevelopmental, psychiatric, or behavioral disorders. Treatment with physiologic or pharmacologic concentrations of these compounds may also promote neurogenesis, neuronal survival, myelination, increased memory, and reduced neurotoxicity. This review highlights what is currently known about the neurodevelopmental functions and mechanisms of action of 4 distinct neurosteroids: pregnenolone, progesterone, allopregnanolone, and dehydroepiandrosterone (DHEA).
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Affiliation(s)
- Synthia H Mellon
- Department of Obstetrics, Gynecology and Reproductive Sciences, Center for Reproductive Sciences, University of California San Francisco, Box 0556, San Francisco, CA 94143-0556, USA.
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26
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Yawno T, Yan EB, Walker DW, Hirst JJ. Inhibition of neurosteroid synthesis increases asphyxia-induced brain injury in the late gestation fetal sheep. Neuroscience 2007; 146:1726-33. [PMID: 17449186 DOI: 10.1016/j.neuroscience.2007.03.023] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 03/06/2007] [Accepted: 03/19/2007] [Indexed: 11/19/2022]
Abstract
Allopregnanolone (AP) is a potent GABAergic agonist that suppresses CNS activity, seizure threshold, and excitotoxicity in the adult brain. AP is present in the fetal sheep brain and increases rapidly after asphyxial insult due to increased 5alpha-reductase type-2 (5alphaR-2) expression. The aim of this study was to use finasteride to suppress fetal neurosteroid synthesis, and then determine the effect on brain injury, particularly in the hippocampus, of asphyxia induced in utero by brief occlusion of the umbilical cord. Catheters and an inflatable umbilical cord cuff were implanted in fetal sheep at approximately 125 days gestation. Five days later the fetuses received either finasteride (20 mg/kg/h) or vehicle (40% hydroxypropyl-beta-cyclodextrin) for 2 h. The umbilical cord was occluded (UCO) for 5 min at 30 min after starting the infusion. The fetal brain was obtained 24 h later for examination of activated caspase-3 expression as an index of apoptosis, and to measure AP content. Finasteride treatment alone significantly reduced AP content and increased the number of caspase-3 positive cells in the hippocampus, cerebellum, and the subcallosal bundle, indicating that AP modulates the normal rate of apoptosis in the developing brain. UCO in vehicle and finasteride-treated fetuses produced a similar, marked decrease in O2 saturation (5.8+/-0.6%), but after finasteride treatment UCO caused a significantly greater increase in the number of caspase-3 positive cells in the hippocampal cornu ammonis 3 (CA3) (57.3+/-1.6%) compared with the vehicle-treated fetuses. Thus, 5alpha-reduced steroids such as AP may be protective in reducing cell death following acute fetal asphyxia. Perturbation of normal fetal neurosteroid levels in late gestation (e.g. due to preterm birth, or maternal synthetic steroid treatment to induce fetal lung maturation) could adversely affect brain development and increase its vulnerability to injury.
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Affiliation(s)
- T Yawno
- Department of Physiology, Monash University, Wellington Road, Clayton, Melbourne, VIC, Australia 3800.
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Agís-Balboa RC, Pinna G, Zhubi A, Maloku E, Veldic M, Costa E, Guidotti A. Characterization of brain neurons that express enzymes mediating neurosteroid biosynthesis. Proc Natl Acad Sci U S A 2006; 103:14602-7. [PMID: 16984997 PMCID: PMC1600006 DOI: 10.1073/pnas.0606544103] [Citation(s) in RCA: 288] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Allopregnanolone (ALLO) and tetrahydrodeoxycorticosterone (THDOC) are potent positive allosteric modulators of GABA action at GABA(A) receptors. ALLO and THDOC are synthesized in the brain from progesterone or deoxycorticosterone, respectively, by the sequential action of two enzymes: 5alpha-reductase (5alpha-R) type I and 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD). This study evaluates 5alpha-R type I and 3alpha-HSD mRNA expression level in mouse brain by using in situ hybridization combined with glutamic acid decarboxylase 67/65, vesicular glutamate transporter 2, glial fibrillary acidic protein, and S100beta immunohistochemistry. We demonstrate that 5alpha-R type I and 3alpha-HSD colocalize in cortical, hippocampal, and olfactory bulb glutamatergic principal neurons and in some output neurons of the amygdala and thalamus. Neither 5alpha-R type I nor 3alpha-HSD mRNAs are expressed in S100beta- or glial fibrillary acidic protein-positive glial cells. Using glutamic acid decarboxylase 67/65 antibodies to mark GABAergic neurons, we failed to detect 5alpha-R type I and 3alpha-HSD in cortical and hippocampal GABAergic interneurons. However, 5alpha-R type I and 3alpha-HSD are significantly expressed in principal GABAergic output neurons, such as striatal medium spiny, reticular thalamic nucleus, and cerebellar Purkinje neurons. A similar distribution and cellular location of neurosteroidogenic enzymes was observed in rat brain. Taken together, these data suggest that ALLO and THDOC, which can be synthesized in principal output neurons, modulate GABA action at GABA(A) receptors, either with an autocrine or a paracrine mechanism or by reaching GABA(A) receptor intracellular sites through lateral membrane diffusion.
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Affiliation(s)
- Roberto C. Agís-Balboa
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
| | - Graziano Pinna
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
| | - Adrian Zhubi
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
| | - Ekrem Maloku
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
| | - Marin Veldic
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
| | - Erminio Costa
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
- To whom correspondence should be addressed. E-mail:
| | - Alessandro Guidotti
- Department of Psychiatry, Psychiatric Institute, University of Illinois, 1601 Taylor Street, Chicago, IL 60612
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Havlíková H, Hill M, Kancheva L, Vrbíková J, Pouzar V, Cerny I, Kancheva R, Stárka L. Serum profiles of free and conjugated neuroactive pregnanolone isomers in nonpregnant women of fertile age. J Clin Endocrinol Metab 2006; 91:3092-9. [PMID: 16720657 DOI: 10.1210/jc.2005-2785] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pregnanolone isomers (PI) with a hydroxy group in the 3alpha-position are neuroinhibitors operating via positive modulation of GABA(A) receptors. The 3beta-PI and sulfates of PI and pregnenolone exert the opposite effect. In addition to the brain's in situ synthesis, some circulating steroids can penetrate the blood-brain barrier. METHODS To assess the physiological impact of peripheral endogenous neuroactive pregnanolone isomers and their polar conjugates in women, serum allopregnanolone (P3alpha5alpha), isopregnanolone (P3beta5alpha), pregnanolone (P3alpha5beta), epipregnanolone (P3beta5beta), pregnenolone, estradiol (including their polar conjugates), and additional steroids were measured in 16 women in the follicular and luteal phases of the menstrual cycle using gas chromatography/mass spectrometry and RIA for the analysis. Linear models and Spearman's correlations were used for data evaluation. RESULTS AND DISCUSSION The levels of conjugated PI were from one to almost three orders of magnitude higher in comparison with the free steroids. The results indicate that a substantial proportion of the progesterone is metabolized in the sequence progesterone-->5beta-dihydroprogesterone-->P3alpha5beta-->conjugated P3alpha5beta. The sulfation of PI and particularly of P3alpha5beta moderates the levels of free PI and restrains estradiol biosynthesis via progesterone degradation. PI including the conjugates reflected changing progesterone formation during the menstrual cycle. In the follicular phase, the positive correlation with conjugated pregnenolone, the independence of progesterone, and the negative age relationships of PI indicate their adrenal origin. The dependence on progesterone and the independence of conjugated pregnenolone suggest a gonadal source of PI in the luteal phase. The neuroactivating PI prevailed over neuroinhibiting PI.
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Affiliation(s)
- Helena Havlíková
- Institute of Endocrinology, Národní trida 8, CZ 116 94 Prague 1, Czech Republic
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Abstract
The present review describes concisely the topography and function of the three androgen-metabolizing enzymes, namely aromatase, 5alpha-reductase and 3alpha-hydroxysteroid dehydrogenase, in the central nervous system (CNS). Aromatase, estrogen synthetase, is the key enzyme for converting androgens to estrogens. Aromatase is indispensable for the sexual differentiation of the brain and the enzyme activity and expression of aromatase are high during the critical period of neural development, which extends from the late embryonal to the early neonatal period in rodents. Aromatase is expressed in neurons within specific hypothalamic and limbic regions. The locations of aromatase-immunoreactive neurons are divided into three groups according to the period of enzyme expression. Steroid 5alpha-reductase converts a number of steroids with a C3 ketone group and a C4-C5 double bond (delta4; androgens, progestins and glucocorticoids) to their 5alpha-reduced metabolites. Two isoforms of 5alpha-reductase are found and type 1 is predominant in neural tissues. The enzyme activity of 5alpha-reductase is found widely in the CNS and is high in white matter regions. The enzyme expression of 5alpha-reductase peaks during the late embryonic period. 3alpha-Hydroxysteroid dehydrogenase is the oxidoreductase that interconverts 3-ketosteroids to 3alpha-hydroxysteroids. Four isozymes have been found in humans and only one type has been found in rats. The enzyme converts 5alpha-reduced steroids (e.g. 5alpha-dihydroprogesterone) to tetrahydrosteroids (e.g. 3alpha,5alpha-tetrahydroprogesterone). The latter steroid is a potent stimulator of the GABA(A) receptor. The activity of 3alpha-hydroxysteroid dehydrogenase is high during the first 1-2 postnatal weeks, decreases with development and this enzyme is highly expressed in astrocytes.
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Affiliation(s)
- Yoshihiro Tsuruo
- Department of Anatomy and Cell Biology, Wakayama Medical University School of Medicine, Wakayama, Japan.
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Garcia-Ovejero D, Azcoitia I, Doncarlos LL, Melcangi RC, Garcia-Segura LM. Glia-neuron crosstalk in the neuroprotective mechanisms of sex steroid hormones. ACTA ACUST UNITED AC 2005; 48:273-86. [PMID: 15850667 DOI: 10.1016/j.brainresrev.2004.12.018] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2004] [Accepted: 12/09/2004] [Indexed: 11/22/2022]
Abstract
Proteins involved in the intramitochondrial trafficking of cholesterol, the first step in steroidogenesis, such as the steroidogenic acute regulatory protein (StAR) and the peripheral-type benzodiazepine receptor (PBR), are upregulated in the nervous system after injury. Accordingly, a local increase in the levels of steroids, such as pregnenolone and progesterone, is observed following traumatic injury in the brain and spinal cord. The expression and activity of aromatase, the enzyme that synthesizes estradiol, is also increased in injured brain areas and its inhibition results in an increased neurodegeneration. These findings suggest that an increase in steroidogenesis is part of an overall mechanism used by the nervous tissue to cope with neurodegenerative conditions. Neural steroidogenesis is the result of a coordinated interaction of neurons and glia. For example, after neural injury, there is an upregulation of StAR in neurons and of PBR in microglia and astroglia. Aromatase is expressed in neurons under basal conditions and is upregulated in reactive astrocytes after injury. Some of the steroids produced by glia are neuroprotective. Progesterone and progesterone derivatives produced by Schwann cells, promote myelin formation and the remyelination and regeneration of injured nerves. In the central nervous system, the steroids produced by glia regulate synaptic function, affect anxiety, cognition, sleep and behavior, and exert neuroprotective and reparative roles. In addition, glial cells are targets for steroids and mediate some of the effects of these molecules on neurons, including the regulation of survival and regeneration.
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Kiyokage E, Toida K, Suzuki-Yamamoto T, Ishimura K. Localization of 5α-reductase in the rat main olfactory bulb. J Comp Neurol 2005; 493:381-95. [PMID: 16261538 DOI: 10.1002/cne.20760] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The enzyme steroid 5alpha-reductase catalyzes the production of dihydroprogesterone and dihydrotestosterone, which were recently recognized as neurosteroids in the brain with variably potential neuroactivity. The present study reports for the first time detailed localization of 5alpha-reductase type 1 in the rat main olfactory bulb. The occurrence of 5alpha-reductase in the olfactory bulb was detected by reverse transcription-polymerase chain reaction and Western blotting analyses. In addition, the enzyme activity was also detected by thin layer chromatography. Immunocytochemistry showed that 5alpha-reductase immunoreactive cells of variable intensity were present in all layers of the olfactory bulb. Multiple immunolabeling revealed that 5alpha-reductase was mainly localized in glial cells, namely, in S-100beta- and glial fibrillary acidic protein-immunoreactive astrocytes, 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase)-immunoreactive oligodendrocytes, and in S-100beta- and neuropeptide-Y-immunoreactive olfactory ensheathing cells, whereas the bulbar neurons exhibited little immunoreactivity. Quantitative analysis revealed that the number of 5alpha-reductase-immunoreactive cells was greatest in the olfactory nerve layer. The most intense 5alpha-reductase-immunoreactivity was found in the olfactory ensheathing cells, and next in the CNPase-immunoreactive cells. The 5alpha-reductase in the olfactory bulb was expressed constantly throughout different ages and sexes and in neutered and hypophysectomized rats. Thus, 5alpha-reductase may contribute via 5alpha-reduced metabolites to the formation and maintenance of olfactory inputs and outputs, which were closely associated with the olfactory ensheathing cells and the oligodendrocytes, respectively.
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Affiliation(s)
- Emi Kiyokage
- Department of Anatomy and Cell Biology, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto, Japan
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Conejo NM, González-Pardo H, Cimadevilla JM, Argüelles JA, Díaz F, Vallejo-Seco G, Arias JL. Influence of gonadal steroids on the glial fibrillary acidic protein-immunoreactive astrocyte population in young rat hippocampus. J Neurosci Res 2004; 79:488-94. [PMID: 15619230 DOI: 10.1002/jnr.20372] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is known that expression of glial fibrillary acidic protein (GFAP) as an astrocyte-specific marker can be regulated by levels of circulating gonadal steroids during postnatal development. In addition, astrocytes play an important role in the physiology of the hippocampus, a brain region considered sexually dimorphic at the neuronal level in rodents. To evaluate the contribution of glial cells to gender-related differences in the hippocampus, we estimated the number of GFAP-immunoreactive (GFAP-IR) astrocytes in the hippocampus (CA1 and CA3 areas, dorsal and ventral regions) of male and female rats aged 30 days. Groups of 30-day-old masculinized females (TP-females; injected with testosterone propionate at birth) and feminized males (FLU-males, castrated and treated with flutamide, an androgen receptor antagonist) were included to assess the effects of gonadal hormones on these hippocampal astrocytes. Using the optical fractionator method, the total number of GFAP-IR cells found in CA1 and CA3 areas was significantly higher in males compared to that in age-matched females. This numerical pattern was reversed in TP-females and FLU-males in both hippocampal areas. In addition, more GFAP-IR cells were found in dorsal hippocampus than in the ventral region in the CA1 area from all experimental groups, whereas this result was found in the CA3 area from males and TP-females. Our results suggest an essential contribution of gonadal hormones to gender differences found in the astrocyte population of the rat hippocampus during development.
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Affiliation(s)
- N M Conejo
- Laboratory of Psychobiology, Faculty of Psychology, University of Oviedo, Spain
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Maayan R, Fisch B, Galdor M, Kaplan B, Shinnar N, Kinor N, Zeldich E, Valevski A, Weizman A. Influence of 17beta-estradiol on the synthesis of reduced neurosteroids in the brain (in vivo) and in glioma cells (in vitro): possible relevance to mental disorders in women. Brain Res 2004; 1020:167-72. [PMID: 15312799 DOI: 10.1016/j.brainres.2004.06.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2004] [Indexed: 11/23/2022]
Abstract
Brain neurosteroids modulate gamma-aminobutyric acid type A (GABAA) receptor activity, thereby playing a role in mood disorders. Alterations in 17beta-estradiol (E2) and progesterone (P) are also known to play a significant role in psychopathology in women. The aim of the present study was to evaluate the synthesis of dihydroprogesterone (DHP), tetrahydroprogesterone (THP), and the activity of 5alpha-reductase (5alphaR) which regulates the reduction of P to DHP on exposure to supraphysiological levels of E2 in vitro (C6 glioma cells) and in vivo (mouse brain). The results showed that supraphysiological levels of E2 induced a decrease in the accumulation of both neurosteroids, probably by decreasing the activity of 5alphaR. We hypothesize that the high levels of E2 in pregnancy attenuate the increase in the conversion of P to THP in the brain and that the ratio of E2/P modulates the sedative effect of THP. This process may be relevant to psychopathological disorders that are ascribed to drastic alterations in estrogen levels, such as premenstrual syndrome, pregnancy-related mental disorders, and postpartum "blues".
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Affiliation(s)
- Rachel Maayan
- Laboratory of Biological Psychiatry, Felsenstein Medical Research Center, Tel Aviv University, Tel Aviv, Rabin Medical Center, Beilinson Campus, Petah Tikva 49100, Israel.
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Her S, Arimochi H, Morita K. Nerve growth factor induces elevation of steroid 5alpha-reductase mRNA levels in rat C6 glioma cells through expression of transcription factor Egr-1. ACTA ACUST UNITED AC 2004; 126:157-64. [PMID: 15249139 DOI: 10.1016/j.molbrainres.2004.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2004] [Indexed: 11/16/2022]
Abstract
Steroid 5alpha-reductase type 1 (5alpha-R), the enzyme converting progesterone and other steroid hormones to their 5alpha-reduced metabolites, has been shown to be localized in both neuronal and glial cells, and this enzyme in glial cells has previously been reported to be activated either by co-culturing with neuronal cells or by adding the conditioned medium of neuronal cells, thus suggesting that neuronal activity may be implicated in the regulation of neurosteroid metabolism in brain. In the present study, to investigate a potential role of neurotrophic factors in the mechanism regulating the production of neuroactive 5alpha-reduced steroid metabolites, the direct action of NGF on 5alpha-R gene expression was examined by measuring the steady-state levels of 5alpha-R mRNA levels in rat C6 glioma cells. Exposure of the glioma cells to NGF increased both 5alpha-R mRNA and its protein levels, and induced the transient elevation of Egr-1 mRNA levels prior to the expression of 5alpha-R mRNA in the cells. Furthermore, NGF failed to induce any significant elevation of 5alpha-R mRNA levels in the cells pretreated with Egr-1 antisense oligodeoxynucleotides. These findings indicate that NGF induces the elevation of 5alpha-R gene expression in the glioma cells through the expression of transcription factor Egr-1, proposing the possibility that NGF, and probably other neurotrophic factors as well, may play a potential role in the regulation of 5alpha-reduced steroid production as one of the factors mediating the intercellular communication between neuronal and glial cells in the brain.
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Affiliation(s)
- Song Her
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305-5485, USA
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Frye CA, Walf AA, Rhodes ME, Harney JP. Progesterone enhances motor, anxiolytic, analgesic, and antidepressive behavior of wild-type mice, but not those deficient in type 1 5 alpha-reductase. Brain Res 2004; 1004:116-24. [PMID: 15033426 DOI: 10.1016/j.brainres.2004.01.020] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2004] [Indexed: 11/21/2022]
Abstract
The importance of progesterone's (P(4)) metabolism by the 5 alpha-reductase type I enzyme was examined in homozygous and heterozygous 5 alpha-reductase type I knockout mice and their wild-type siblings. P(4) (1.0 mg) or vehicle was administered and effects on motor, anxiety, nociceptive, and depression behavior were observed. After testing, whole-brain progesterone and 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP) levels were determined by radioimmunoassay. Motor behavior in the horizontal crossing and open field tasks of 5 alpha-reductase-deficient mice administered P(4) was similar to vehicle control mice and significantly reduced compared to wild-type mice administered P(4). In the open field, 5 alpha-reductase-deficient mice administered P(4) had a similar number of central entries as did vehicle control mice, both were lower than central entries of P(4)-administered wild-type mice. However, in the plus maze, P(4) to 5 alpha-reductase-deficient or wild-type mice significantly increased open arm activity compared to vehicle-administered control mice. P(4) to wild-type, but not 5 alpha-reductase-deficient mice, significantly increased latencies to lick front and back paws in response to radiant heat stimuli compared to vehicle administration to control mice. In the forced swim test, 5 alpha-reductase-deficient mice administered P(4) were similar to vehicle control mice and the latency to immobility was significantly decreased, and the duration of immobility was significantly increased, compared to wild-type mice administered P(4). Thus, these data suggest metabolism by the 5 alpha-reductase type I enzyme may mitigate P(4)'s effects on some tasks of motor, anxiety, nociception, and depression behavior.
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Affiliation(s)
- Cheryl A Frye
- Department of Psychology and Center for Neurobiology, The University at Albany-SUNY, 1400 Washington Avenue, Albany, NY 12222, USA.
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Morita K, Arimochi H, Tsuruo Y. Adrenergic activation of steroid 5alpha-reductase gene expression in rat C6 glioma cells: involvement of cyclic amp/protein kinase A-mediated signaling pathway. J Mol Neurosci 2004; 22:205-12. [PMID: 14997014 DOI: 10.1385/jmn:22:3:205] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Accepted: 10/05/2003] [Indexed: 11/11/2022]
Abstract
Steroid 5alpha-reductase (5alpha-R) is well known as the enzyme converting progesterone and other steroid hormones to their 5alpha-reduced metabolites and has been reported to be localized in both neuronal and glial cells in the brain. Previously, the enzyme activity in glial cells has been shown to be enhanced either by coculturing with neuronal cells or by adding the conditioned medium of neuronal cells, suggesting a possible implication of neuro-glial interactions in the regulation of neurosteroid metabolism in the brain. In the present studies, the effects of adrenergic agonists on 5alpha-R mRNA and protein levels in rat C6 glioma cells were examined as one of the model experiments for investigating the influence of neuronal activity on the expression of 5alpha-R gene in the glial cell. The direct challenge of beta-adrenergic agonists to glioma cells resulted in the rapid and transient elevation of 5alpha-R mRNA levels through the activation of the cyclic AMP (cAMP)/protein kinase A-mediated signaling pathway. Further studies showed that cAMP-induced 5alpha-R mRNA expression was completely abolished by pretreatment of cells with actinomycin D and also indicated that the elevation of 5alpha-R mRNA levels was accompanied by an increase in enzyme protein in the cells. These findings provide strong evidence that the stimulation of beta-adrenergic receptors might induce the transcriptional activation of 5alpha-R gene expression in glial cells, proposing the possibility that neuronal activity might be involved in the production of neuroactive 5alpha-reduced steroids in the brain.
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Affiliation(s)
- Kyoji Morita
- Department of Pharmacology, Tokushima University Schoolof Medicine, Kuramoto, Tokushima 770-8503, Japan.
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Ordyan NE, Pivina SG. Anxiety levels and neurosteroid synthesis in the brains of prenatally stressed male rats. ACTA ACUST UNITED AC 2004; 33:899-903. [PMID: 14969429 DOI: 10.1023/a:1025952906715] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This report presents studies of the effects of immobilization stress applied to pregnant female rats during the last third of pregnancy on anxiety levels and neurosteroid synthesis in brain structures of adult offspring. Neurosteroid synthesis was assessed in terms of changes in the activity of 5alpha-reductase, the enzyme which converts progesterone into active metabolites. Prenatal stress results in a significant decrease in the level of anxiety and an increase in movement activity among adult males. Stressed rats showed increases in progesterone-5alpha-reductase activity in the hypothalamus, hippocampus, and frontal cortex. These results provide evidence that changes in the behavior of adult male rats due to stress in the prenatal period of development may be due to the formation of active progesterone metabolites in the brain.
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Affiliation(s)
- N E Ordyan
- I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia
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Ibanez C, Shields SA, El-Etr M, Leonelli E, Magnaghi V, Li WW, Sim FJ, Baulieu EE, Melcangi RC, Schumacher M, Franklin RJM. Steroids and the reversal of age-associated changes in myelination and remyelination. Prog Neurobiol 2004; 71:49-56. [PMID: 14611867 DOI: 10.1016/j.pneurobio.2003.09.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The myelin sheaths that surround all but the smallest diameter axons within the mammalian central nervous system (CNS) must maintain their structural integrity for many years. Like many tissues, however, this function is prone to the effects of ageing, and various structural anomalies become apparent in the aged CNS. Similarly, the regenerative process by which myelin sheaths, lost as a consequence of exposure to a demyelinating insult, are restored (remyelination) is also affected by age. As animals grow older, the efficiency of remyelination progressively declines. In this article, we review both phenomena and describe how both can be partially reversed by steroid hormones and their derivatives.
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Affiliation(s)
- C Ibanez
- INSERM U488, 80 rue du Général Leclerc, 94276 Le Kremlin Bicêtre-Cedex, France
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Melcangi RC, Azcoitia I, Ballabio M, Cavarretta I, Gonzalez LC, Leonelli E, Magnaghi V, Veiga S, Garcia-Segura LM. Neuroactive steroids influence peripheral myelination: a promising opportunity for preventing or treating age-dependent dysfunctions of peripheral nerves. Prog Neurobiol 2003; 71:57-66. [PMID: 14611868 DOI: 10.1016/j.pneurobio.2003.09.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The process of aging deeply influences morphological and functional parameters of peripheral nerves. The observations summarized here indicate that the deterioration of myelin occurring in the peripheral nerves during aging may be explained by the fall of the levels of the major peripheral myelin proteins [e.g., glycoprotein Po (Po) and peripheral myelin protein 22 (PMP22)]. Neuroactive steroids, such as progesterone (PROG), dihydroprogesterone (5alpha-DH PROG), and tetrahydroprogesterone (3alpha,5alpha-TH PROG), are able to stimulate the low expression of these two myelin proteins present in the sciatic nerve of aged male rats. Since Po and PMP22 play an important physiological role in the maintenance of the multilamellar structure of PNS myelin, we have evaluated the effect of PROG and its neuroactive derivatives, 5alpha-DH PROG and 3alpha,5alpha-TH PROG, on the morphological alterations of myelinated fibers in the sciatic nerve of 22-24-month-old male rats. Data obtained clearly indicate that neuroactive steroids are able to reduce aging-associated morphological abnormalities of myelin and aging-associated myelin fiber loss in the sciatic nerve.
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Affiliation(s)
- R C Melcangi
- Department of Endocrinology, Center of Excellence on Neurodegenerative Diseases, University of Milan, Via G. Balzaretti 9, 20133 Milan, Italy.
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Ghoumari AM, Ibanez C, El-Etr M, Leclerc P, Eychenne B, O'Malley BW, Baulieu EE, Schumacher M. Progesterone and its metabolites increase myelin basic protein expression in organotypic slice cultures of rat cerebellum. J Neurochem 2003; 86:848-59. [PMID: 12887683 DOI: 10.1046/j.1471-4159.2003.01881.x] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have previously shown that progesterone (PROG) is synthesized by Schwann cells and promotes myelin formation in the peripheral nervous system (PNS). We now report that this neurosteroid also stimulates myelination in organotypic slice cultures of 7-day-old (P7) rat and mouse cerebellum. Myelination was evaluated by immunofluorescence analysis of the myelin basic protein (MBP). After 7 days in culture (7DIV), we found that adding PROG (2(-5) x 10(-5) M) to the culture medium caused a fourfold increase in MBP expression when compared to control slices. The effect of PROG on MBP expression involves the classical intracellular PROG receptor (PR): the selective PR agonist R5020 significantly increased MBP expression and the PR antagonist mifepristone (RU486) completely abolished the effect of PROG on this MBP expression. Moreover, treatment of P7-cerebellar slice cultures from PR knockout (PRKO) mice with PROG had no significant effect on MBP expression. PROG was metabolized in the cerebellar slices to 5alpha-dihydroprogesterone (5alpha-DHP) and to the GABAA receptor-active metabolite 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP, allopregnanolone). The 5alpha-reductase inhibitor L685-273 partially inhibited the effect of PROG, and 3alpha,5alpha-THP (2(-5) x 10(-5) M) significantly stimulated the MBP expression, although to a lesser extent than PROG. The increase in MBP expression by 3alpha,5alpha-THP involved GABAA receptors, as it could be inhibited by the selective GABAA receptor antagonist bicuculline. These findings suggest that progestins stimulate MBP expression and consequently suggest an increase in CNS myelination via two signalling systems, the intracellular PR and membrane GABAA receptors, and they confirm a new role of GABAA receptors in myelination.
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Nguyen PN, Billiards SS, Walker DW, Hirst JJ. Changes in 5alpha-pregnane steroids and neurosteroidogenic enzyme expression in the perinatal sheep. Pediatr Res 2003; 53:956-64. [PMID: 12646725 DOI: 10.1203/01.pdr.0000064905.64688.10] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pregnane steroids have sedative and neuroprotective effects on the brain as a result of interactions with the steroid-binding site of the GABAA receptor. To determine whether the fetal brain is able to synthesize pregnane steroids de novo from cholesterol, we measured the expression of cytochrome P450 side-chain cleavage (P450scc) and 5alpha-reductase type II (5alphaRII) enzymes in fetal sheep from 72 to 144 d gestation (term approximately 147 d) and in newborn lambs at 3 and 19-26 d of age. Both P450scc and 5alphaRII expression was detectable by 90 d gestation in the major regions of the brain and also in the adrenal glands. Expression increased with advancing gestation and was either maintained at fetal levels or increased further after birth. In contrast, the relatively high content (200-400 pmol/g) of allopregnanolone (5alpha-pregnan-3alpha-ol-20-one), a major sedative 5alpha-pregnane steroid, present throughout the brain from 90 d gestation to term, was reduced significantly (<50 pmol/g) immediately after birth. These results suggest that although the perinatal brain has the enzymes potentially to synthesize pregnane steroids de novo from cholesterol, either the placenta is a major source of these steroids to the brain or other factors associated with intrauterine life may be responsible for high levels of allopregnanolone production in the fetal brain until birth.
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Affiliation(s)
- Phuong N Nguyen
- Fetal and Neonatal Research Group, Department of Physiology, Monash University, Clayton Victoria 3800, Australia
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42
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Non-neuronal cells in the nervous system: sources and targets of neuroactive steroids. ADVANCES IN MOLECULAR AND CELL BIOLOGY 2003. [DOI: 10.1016/s1569-2558(03)31024-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Melcangi RC, Martini L, Galbiati M. Growth factors and steroid hormones: a complex interplay in the hypothalamic control of reproductive functions. Prog Neurobiol 2002; 67:421-49. [PMID: 12385863 DOI: 10.1016/s0301-0082(02)00060-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The mechanisms through which LHRH-secreting neurons are controlled still represent a crucial and debated field of research in the neuroendocrine control of reproduction. In the present review, we have specifically considered two potential signals reaching these hypothalamic neurons: steroid hormones and growth factors. Examples of the relevant physiological role of the interactions between these two families of biologically acting molecules have been provided. In many cases, these interactions occur at the level of hypothalamic astrocytes, which are presently accepted as functional partners of the LHRH-secreting neurons. On the basis of the observations here summarized, we have formulated the hypothesis that a functional co-operation of steroid hormones and growth factors occurring in the hypothalamic astrocytic compartment represents a key factor in the neuroendocrine control of reproductive functions.
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Affiliation(s)
- Roberto C Melcangi
- Department of Endocrinology, Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Balzaretti 9, 20133, Milan, Italy.
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Melcangi RC, Magnaghi V, Galbiati M, Martini L. Formation and effects of neuroactive steroids in the central and peripheral nervous system. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 46:145-76. [PMID: 11599299 DOI: 10.1016/s0074-7742(01)46062-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
This chapter summarizes several observations that emphasize the importance of neuroactive steroids in the physiology of the central and peripheral nervous systems. A new, and probably important, concept is emerging: Neuroactive steroids not only modify neuronal physiology but also intervene in the control of glial cell functions. The data presented here underscore that (1) the mechanism of action of the various steroidal molecules may involve both classical (progesterone and androgens) and nonclassical steroid receptors [gamma-aminobutyric acid type A (GABAA) receptor], (2) in many instances, the actions of hormonal steroids are not due to their native molecular forms but to their 5 alpha- and 3 alpha,5 alpha-reduced metabolites, (3) several neuroactive steroids exert dramatic actions on the proteins proper of the peripheral myelin (e.g., glycoprotein Po and peripheral myelin protein 22), and (4) the effects of steroids and of their metabolites might have clinical significance in cases in which the rebuilding of the peripheral myelin is needed (e.g., aging, peripheral injury).
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Affiliation(s)
- R C Melcangi
- Department of Endocrinology, University of Milan, 20133, Milan, Italy
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Mellon SH, Vaudry H. Biosynthesis of neurosteroids and regulation of their synthesis. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 46:33-78. [PMID: 11599305 DOI: 10.1016/s0074-7742(01)46058-2] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The brain, like the gonads, adrenal glands, and placenta, is a steroidogenic organ. The steroids synthesized by the brain and by the nervous system, given the name neurosteroids, have a wide variety of diverse functions. In general, they mediate their actions not through classic steroid hormone nuclear receptors but through ion-gated neurotransmitter receptors. This chapter summarizes the biochemistry of the enzymes involved in the biosynthesis of neurosteroids, their localization during development and in adulthood, and the regulation of their expression, highlighting both similarities and differences between expression in the brain and in classic steroidogenic tissues.
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Affiliation(s)
- S H Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Sciences, Metabolic Research Unit, University of California-San Francisco, San Francisco, California 94143-0556, USA
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Baulieu EE, Robel P, Schumacher M. Neurosteroids: beginning of the story. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 46:1-32. [PMID: 11599297 DOI: 10.1016/s0074-7742(01)46057-0] [Citation(s) in RCA: 239] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Neurosteroids are synthetisized in the central and the peripheral nervous system, in glial cells, and also in neurons, from cholesterol or steroidal precursors imported from peripheral sources. They include 3 beta-hydroxy-delta 5-compounds, such as pregnenolone (PREG) and dehydroepiandrosterone, their sulfate esters, and compounds known as reduced metabolites of steroid hormones, such as the tetrahydroderivative of progesterone 3 alpha-hydroxy-5 alpha-pregnan-20-one. These neurosteroids can act as modulators of neurotransmitter receptors, such as GABAA, NMDA, and sigma 1 receptors. Progesterone itself is also a neurosteroid, and a progesterone receptor has been detected in peripheral and central glial cells. At different sites in the brain, neurosteroid concentrations vary according to environmental and behavioral circumstances, such as stress, sex recognition, or aggressiveness. A physiological function of neurosteroids in the central nervous system is strongly suggested by the role of hippocampal PREGS with respect to memory performance, observed in aging rats. In the peripheral nervous system, a role for PROG synthesized in Schwann cells has been demonstrated in remyelination after cryolesion of the sciatic nerve in vivo and in cultures of dorsal root ganglia. A new mechanism of PREG action discovered in the brain involves specific steroid binding to microtubule associated protein and increased tubulin polymerization for assembling microtubules. It may be important to study the effects of abnormal neurosteroid concentration/metabolism in view of the possible treatment of functional and trophic disturbances of the nervous system.
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Gago N, Akwa Y, Sananès N, Guennoun R, Baulieu EE, El-Etr M, Schumacher M. Progesterone and the oligodendroglial lineage: stage-dependent biosynthesis and metabolism. Glia 2001; 36:295-308. [PMID: 11746767 DOI: 10.1002/glia.1117] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Evidence has been accumulated showing that neurosteroids, particularly progesterone (PROG) and its metabolites, may participate in myelination and remyelination in the peripheral nervous system, but very few studies have been undertaken in the central nervous system (CNS). The aim of this work was to investigate the capacities of synthesis and metabolism of PROG at three important stages of the oligodendroglial lineage: oligodendrocyte pre-progenitors (OPP), oligodendrocyte progenitors (OP), and fully differentiated oligodendrocytes (OL). Experiments have been conducted in vitro using highly purified primary cell cultures from rat brain. Cells were incubated with (3)H-pregnenolone ((3)H-PREG), the immediate precursor of PROG, or with (3)H-PROG, and steroids metabolites were then identified by thin layer chromatography and high-performance liquid chromatography (HPLC). mRNA expression of key steroidogenic enzymes was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that only OPP and OP, but not OL, expressed 3 beta-hydroxysteroid dehydrogenase/Delta 5-Delta 4 isomerase mRNA and were able to synthesize PROG from PREG. In the three cell types studied, PROG was metabolized by the type 1 isoform of 5 alpha-reductase into 5 alpha-dihydroprogesterone (5 alpha-DHPROG). This enzyme exhibited a 5-fold higher activity in OL than in OPP and OP. 5 alpha-DHPROG was further transformed either into 3 alpha,5 alpha-tetrahydroprogesterone (3 alpha,5 alpha-THPROG), known as a positive allosteric modulator of the GABA(A) receptor, or into the 3 beta-isomer. The 3 alpha,5 alpha-THPROG synthesis was 10 times higher in OPP than in the other cell studied, while the 3 beta,5 alpha-THPROG production did not change with cell differentiation. PROG synthesis and metabolism and the dramatic changes in neurosteroidogenesis observed during the oligodendroglial differentiation may contribute to oligodendrocyte development or the myelination process.
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Affiliation(s)
- N Gago
- INSERM U 488, Bicêtre, France.
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Frye CA, Vongher JM. Ventral tegmental area infusions of inhibitors of the biosynthesis and metabolism of 3alpha,5alpha-THP attenuate lordosis of hormone-primed and behavioural oestrous rats and hamsters. J Neuroendocrinol 2001; 13:1076-86. [PMID: 11722704 DOI: 10.1046/j.1365-2826.2001.00731.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The importance of progesterone biosynthesis and metabolism to 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), which exerts its effects via GABAA/benzodiazepine receptor complexes (GBRs) rather than intracellular progestin receptors (PRs), was investigated for its effects on sexual receptivity. Epostane, a 3beta-hydroxysteroid dehydrogenase inhibitor, blocks progesterone and 3alpha,5alpha-THP biosynthesis. Finasteride, a 5alpha-reductase inhibitor, blocks the metabolism of progesterone to dihydroprogesterone (DHP), which is subsequently metabolized to 3alpha,5alpha-THP. Indomethacin, a 3alpha-hydroxysteroid oxidoreductase inhibitor, blocks DHP's metabolism to 3alpha,5alpha-THP, and its oxidation to DHP. Epostane, finasteride, indomethacin or vehicle were infused intracranially in the ventral tegmental area (VTA) of hormone-primed or naturally receptive rats and hamsters and sexual behaviour was recorded. Epostane, finasteride and indomethacin to the VTA significantly reduced lordosis, compared to vehicle infusions, in hormone-primed and behavioural oestrous rats and hamsters. Radioimmunoassay revealed that concentrations of midbrain 3alpha,5alpha-THP were reduced following epostane, finasteride or indomethacin infusions that significantly decreased lordosis. Immunocytochemistry for 3alpha,5alpha-THP revealed the number of immunoreactive cells were significantly reduced in the VTA following epostane, finasteride or indomethacin infusion to the VTA, but not other midbrain sites. These data suggest that biosynthesis of progestins, and the metabolism of progesterone to 3alpha,5alpha-THP in the VTA, are important for progestin-facilitated sexual receptivity of rats and hamsters.
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Affiliation(s)
- C A Frye
- Department of Psychology, Biological Sciences and the Center for Neuroscience Research, The University at Albany-SUNY, Albany, New York 12222, USA.
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Mellon SH, Griffin LD, Compagnone NA. Biosynthesis and action of neurosteroids. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 37:3-12. [PMID: 11744070 DOI: 10.1016/s0165-0173(01)00109-6] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Over the past decade, it has become clear that the brain, like the gonad, adrenal and placenta, is a steroidogenic organ. However, unlike classic steroidogenic tissues, the synthesis of steroids in the nervous system requires the coordinate expression and regulation of the genes encoding the steroidogenic enzymes in several different cell types (neurons and glia) at different locations in the nervous system, and at distances from the cell bodies. The steroids synthesized by the brain and nervous system, given the name neurosteroids, have a wide variety of diverse functions. In general, they mediate their actions, not through classic steroid hormone nuclear receptors, but through other mechanisms such as through ion gated neurotransmitter receptors, or through direct or indirect modulation of other neurotransmitter receptors. We have briefly summarized the biochemistry of the enzymes involved in the biosynthesis of neurosteroids, their localization during development and in the adult, and the regulation of their expression, highlighting both similarities and differences between expression in the brain and in classic steroidogenic tissues.
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Affiliation(s)
- S H Mellon
- Department of Obstetrics, Gynecology and Reproductive Sciences, The Center for Reproductive Sciences, The Metabolic Research Unit, University of California, San Francisco, CA 94143, USA.
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Frye CA. The role of neurosteroids and non-genomic effects of progestins and androgens in mediating sexual receptivity of rodents. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 37:201-22. [PMID: 11744087 DOI: 10.1016/s0165-0173(01)00119-9] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Progestins and androgens modulate sexual receptivity in rodents, in part through mechanisms independent of traditional intracellular steroid receptors. Progesterone (PROG) in the ventromedial hypothalamus (VMH) and ventral tegmental (VTA) facilitates lordosis but has different actions in these brain areas. Primarily using lordosis in rodents as an in vivo experimental model, we have examined the effects that progestins exert in the midbrain and hypothalamus. Localization and blocker studies indicate that PROG's actions in the VMH require intracellular progestin receptors (PRs) but in the VTA they do not. Progestins that have rapid, membrane effects, and/or are devoid of affinity for PRs, facilitate lordosis when applied to the VTA. Manipulation of GABA and/or GABA(A)/benzodiazepine receptor complexes (GBRs) in the VTA alters lordosis, which suggests that progestins may interact with GBRs to facilitate receptivity by enhancing the function of GABAergic neurons. Interfering with PROG's metabolism to, or the biosynthesis of, 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-TH PROG or allopregnanolone), the most effective endogenous GBR agonist, in the VTA attenuates female sexual behavior in rodents. Stimulation of mitochondrial benzodiazepine receptors (MBRs), which enhances neurosteroid production, by infusions of an MBR agonist to the VTA enhances lordosis. 3alpha,5alpha-TH PROG is increased in the midbrain of mated>proestrous>diestrous rodents. These data suggest that in the VTA, PROG may facilitate lordosis following metabolism to and/or biosynthesis of 3alpha,5alpha-TH PROG, which may have subsequent actions at GBRs and/or MBRs to acutely modulate female sexual behavior in rodents. The 3alpha-hydroxysteroid oxidoreduced metabolite of dihydrotestosterone (DHT), 5alpha-androstane-3alpha,17beta-diol (3alpha-androstanediol), is important for termination of sexual receptivity in rodents and has these effects in the absence of functional intracellular androgens receptors. As well, altering GBR function in the hypothalamus can influence 3alpha-androstanediol's inhibition of sexual receptivity. Through actions in the hypothalamus that are independent of intracellular androgen receptors but involving GBRs, 3alpha-androstanediol inhibits lordosis. These findings suggest that the PROG metabolite and pregnane neurosteroid, 3alpha,5alpha-TH PROG, and the testosterone metabolite and androstane neurosteroid, 3alpha-androstanediol, can have proximate influences on lordosis that is via nonclassical actions at intracellular steroid receptors.
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Affiliation(s)
- C A Frye
- Department of Psychology, Biological Sciences and The Center for Neuroscience Research, The University at Albany, SUNY, Albany, NY 12222, USA.
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