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Tomaselli G, Vallée M. Stress and drug abuse-related disorders: The promising therapeutic value of neurosteroids focus on pregnenolone-progesterone-allopregnanolone pathway. Front Neuroendocrinol 2019; 55:100789. [PMID: 31525393 DOI: 10.1016/j.yfrne.2019.100789] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 08/14/2019] [Accepted: 09/09/2019] [Indexed: 02/06/2023]
Abstract
The pregnenolone-progesterone-allopregnanolone pathway is receiving increasing attention in research on the role of neurosteroids in pathophysiology, particularly in stress-related and drug use disorders. These disorders involve an allostatic change that may result from deficiencies in allostasis or adaptive responses, and may be downregulated by adjustments in neurotransmission by neurosteroids. The following is an overview of findings that assess how pregnenolone and/or allopregnanolone concentrations are altered in animal models of stress and after consumption of alcohol or cannabis-type drugs, as well as in patients with depression, anxiety, post-traumatic stress disorder or psychosis and/or in those diagnosed with alcohol or cannabis use disorders. Preclinical and clinical evidence shows that pregnenolone and allopregnanolone, operating according to a different or common pharmacological profile involving GABAergic and/or endocannabinoid system, may be relevant biomarkers of psychiatric disorders for therapeutic purposes. Hence, ongoing clinical trials implicate synthetic analogs of pregnenolone or allopregnanolone, and also modulators of neurosteroidogenesis.
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Affiliation(s)
- Giovanni Tomaselli
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", 146 Rue Léo Saignat, 33000 Bordeaux, France; University of Bordeaux, 33000 Bordeaux, France
| | - Monique Vallée
- INSERM U1215, Neurocentre Magendie, Group "Physiopathology and Therapeutic Approaches of Stress-Related Disease", 146 Rue Léo Saignat, 33000 Bordeaux, France; University of Bordeaux, 33000 Bordeaux, France.
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Blaine SK, Milivojevic V, Fox H, Sinha R. Alcohol Effects on Stress Pathways: Impact on Craving and Relapse Risk. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2016; 61:145-53. [PMID: 27254089 PMCID: PMC4813419 DOI: 10.1177/0706743716632512] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A significant amount of neurobiological research regarding the development of alcohol use disorders (AUDs) has focused on alcohol-related activation and long-term alterations in the mesocortical dopaminergic reward pathways. However, alcohol does not only interact with brain reward systems. Many of its acute and chronic effects may be related to allostatic adaptations in hypothalamic and extrahypothalamic stress regulation pathways. For example, acute binge intoxication is associated with hypothalamically driven increases in blood cortisol, norepinephrine, and sex steroid metabolite levels. This may contribute to the development of mesocortical sensitization to alcohol. Furthermore, chronic alcohol exposure is associated with systemic dysregulation of the hypothalamic pituitary adrenal axis, sympathetic adrenal medullary system, and sex steroid systems. This dysregulation appears to manifest as neuroendocrine tolerance. In this review, we first summarize the literature suggesting that alcohol-induced alterations in these hypothalamic systems influence craving and contribute to the development of AUDs. We note that for women, the effects of alcohol on these neuroendocrine stress regulation systems may be influenced by the rhythmic variations of hormones and steroids across the menstrual cycle. Second, we discuss how changes in these systems may indicate progression of AUDs and increased risk of relapse in both sexes. Specifically, neuroendocrine tolerance may contribute to mesocortical sensitization, which in turn may lead to decreased prefrontal inhibitory control of the dopaminergic reward and hypothalamic stress systems. Thus, pharmacological strategies that counteract alcohol-associated changes in hypothalamic and extrahypothalamic stress regulation pathways may slow the development and progression of AUDs.
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Affiliation(s)
- Sara K Blaine
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Verica Milivojevic
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Helen Fox
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Rajita Sinha
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
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Porcu P, Barron AM, Frye CA, Walf AA, Yang SY, He XY, Morrow AL, Panzica GC, Melcangi RC. Neurosteroidogenesis Today: Novel Targets for Neuroactive Steroid Synthesis and Action and Their Relevance for Translational Research. J Neuroendocrinol 2016; 28:12351. [PMID: 26681259 PMCID: PMC4769676 DOI: 10.1111/jne.12351] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 12/12/2015] [Accepted: 12/12/2015] [Indexed: 12/19/2022]
Abstract
Neuroactive steroids are endogenous neuromodulators synthesised in the brain that rapidly alter neuronal excitability by binding to membrane receptors, in addition to the regulation of gene expression via intracellular steroid receptors. Neuroactive steroids induce potent anxiolytic, antidepressant, anticonvulsant, sedative, analgesic and amnesic effects, mainly through interaction with the GABAA receptor. They also exert neuroprotective, neurotrophic and antiapoptotic effects in several animal models of neurodegenerative diseases. Neuroactive steroids regulate many physiological functions, such as the stress response, puberty, the ovarian cycle, pregnancy and reward. Their levels are altered in several neuropsychiatric and neurological diseases and both preclinical and clinical studies emphasise a therapeutic potential of neuroactive steroids for these diseases, whereby symptomatology ameliorates upon restoration of neuroactive steroid concentrations. However, direct administration of neuroactive steroids has several challenges, including pharmacokinetics, low bioavailability, addiction potential, safety and tolerability, which limit its therapeutic use. Therefore, modulation of neurosteroidogenesis to restore the altered endogenous neuroactive steroid tone may represent a better therapeutic approach. This review summarises recent approaches that target the neuroactive steroid biosynthetic pathway at different levels aiming to promote neurosteroidogenesis. These include modulation of neurosteroidogenesis through ligands of the translocator protein 18 kDa and the pregnane xenobiotic receptor, as well as targeting of specific neurosteroidogenic enzymes such as 17β-hydroxysteroid dehydrogenase type 10 or P450 side chain cleavage. Enhanced neurosteroidogenesis through these targets may be beneficial not only for neurodegenerative diseases, such as Alzheimer's disease and age-related dementia, but also for neuropsychiatric diseases, including alcohol use disorders.
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Affiliation(s)
- Patrizia Porcu
- Neuroscience Institute, National Research Council of Italy (CNR), Cagliari, Italy
| | - Anna M. Barron
- Molecular Imaging Center, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba, Japan
| | - Cheryl Anne Frye
- Institute of Arctic Biology, The University of Alaska–Fairbanks, Fairbanks, AK, USA
- The University at Albany, Albany, NY, USA
| | - Alicia A. Walf
- Institute of Arctic Biology, The University of Alaska–Fairbanks, Fairbanks, AK, USA
- The University at Albany, Albany, NY, USA
- Department of Cognitive Science, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Song-Yu Yang
- Department of Developmental Biochemistry, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Xue-Ying He
- Department of Developmental Biochemistry, NYS Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - A. Leslie Morrow
- Departments of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Gian Carlo Panzica
- Department of Neuroscience, University of Turin, and NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy
| | - Roberto C. Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
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Porcu P, Morrow AL. Divergent neuroactive steroid responses to stress and ethanol in rat and mouse strains: relevance for human studies. Psychopharmacology (Berl) 2014; 231:3257-72. [PMID: 24770626 PMCID: PMC4135033 DOI: 10.1007/s00213-014-3564-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/25/2014] [Indexed: 01/09/2023]
Abstract
RATIONALE Neuroactive steroids are endogenous or synthetic steroids that rapidly alter neuronal excitability via membrane receptors, primarily γ-aminobutyric acid type A (GABAA) receptors. Neuroactive steroids regulate many physiological processes including hypothalamic-pituitary-adrenal (HPA) axis function, ovarian cycle, pregnancy, aging, and reward. Moreover, alterations in neuroactive steroid synthesis are implicated in several neuropsychiatric disorders. OBJECTIVES This review will summarize the pharmacological properties and physiological regulation of neuroactive steroids, with a particular focus on divergent neuroactive steroid responses to stress and ethanol in rats, mice, and humans. RESULTS GABAergic neuroactive steroids exert a homeostatic regulation of the HPA axis in rats and humans, whereby the increase in neuroactive steroid levels following acute stress counteracts HPA axis hyperactivity and restores homeostasis. In contrast, in C57BL/6J mice, acute stress decreases neurosteroidogenesis and neuroactive steroids exert paradoxical excitatory effects upon the HPA axis. Rats, mice, and humans also differ in the neuroactive steroid responses to ethanol. Genetic variation in neurosteroidogenesis may explain the different neuroactive steroid responses to stress or ethanol. CONCLUSIONS Rats and mouse strains show divergent effects of stress and ethanol on neuroactive steroids in both plasma and brain. The study of genetic variation in the various processes that determine neuroactive steroids levels as well as their effects on cell signaling may underlie these differences and may play a relevant role for the potential therapeutic benefits of neuroactive steroids.
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Affiliation(s)
- Patrizia Porcu
- Neuroscience Institute, National Research Council of Italy (CNR), Cittadella Universitaria, 09042, Monserrato, Cagliari, Italy,
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Cook JB, Nelli SM, Neighbors MR, Morrow DH, O'Buckley TK, Maldonado-Devincci AM, Morrow AL. Ethanol alters local cellular levels of (3α,5α)-3-hydroxypregnan-20-one (3α,5α-THP) independent of the adrenals in subcortical brain regions. Neuropsychopharmacology 2014; 39:1978-87. [PMID: 24566803 PMCID: PMC4059907 DOI: 10.1038/npp.2014.46] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 01/14/2014] [Accepted: 02/03/2014] [Indexed: 11/09/2022]
Abstract
The neuroactive steroid (3α,5α)-3-hydroxypregnan-20-one (3α,5α-THP or allopregnanolone) is a positive modulator of GABAA receptors synthesized in the brain, adrenal glands, and gonads. In rats, ethanol activates the hypothalamic-pituitary-adrenal axis and elevates 3α,5α-THP in plasma, cerebral cortex, and hippocampus. In vivo, these effects are dependent on both the pituitary and adrenal glands. In vitro, however, ethanol locally increases 3α,5α-THP in hippocampal slices, in the absence of adrenal influence. Therefore, it is not known whether ethanol can change local brain levels of 3α,5α-THP in vivo, independent of the adrenals. To directly address this controversy, we administered ethanol (2 g/kg) or saline to rats that underwent adrenalectomy (ADX) or received sham surgery and performed immunohistochemistry for 3α,5α-THP. In the medial prefrontal cortex (mPFC), ethanol increased 3α,5α-THP after sham surgery, compared with saline controls, with no ethanol-induced change in 3α,5α-THP following ADX. In subcortical regions, 3α,5α-THP was increased independent of adrenals in the CA1 pyramidal cell layer, dentate gyrus polymorphic layer, bed nucleus of the stria terminalis, and paraventricular nucleus of the hypothalamus. Furthermore, ethanol decreased 3α,5α-THP labeling in the nucleus accumbens shore and central nucleus of the amygdala, independent of the adrenal glands. These data indicate that ethanol dynamically regulates local 3α,5α-THP levels in several subcortical regions; however, the adrenal glands contribute to 3α,5α-THP elevations in the mPFC. Using double immunofluorescent labeling we determined that adrenal dependence of 3α,5α-THP induction by ethanol is not due to a lack of colocalization of 3α,5α-THP with the cholesterol transporters steroidogenic acute regulatory protein (StAR) or translocator protein (TSPO).
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Affiliation(s)
- Jason B Cook
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Stephanie M Nelli
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mackenzie R Neighbors
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Danielle H Morrow
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Todd K O'Buckley
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - A Leslie Morrow
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Department of Psychiatry and Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA,Department of Psychiatry and Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, 3027 Thurston Bowles CB no. 7178, Chapel Hill, NC 27599, USA, Tel: +1 919 966 7682, Fax: +1 919 966 9099, E-mail:
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Porcu P, Locci A, Santoru F, Berretti R, Morrow AL, Concas A. Failure of acute ethanol administration to alter cerebrocortical and hippocampal allopregnanolone levels in C57BL/6J and DBA/2J mice. Alcohol Clin Exp Res 2014; 38:948-58. [PMID: 24428156 DOI: 10.1111/acer.12329] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/25/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ethanol (EtOH) administration increases brain allopregnanolone levels in rats, and this increase contributes to sensitivity to EtOH's behavioral effects. However, EtOH's effects on allopregnanolone may differ across species. We investigated the effects of acute EtOH administration on allopregnanolone, progesterone, and corticosterone levels in cerebral cortex and hippocampus of C57BL/6J and DBA/2J mice, 2 inbred strains with different alcohol sensitivity. METHODS Naïve male C57BL/6J and DBA/2J mice received EtOH (1, 2, 3, or 4 g/kg, intraperitoneally [i.p.]) or saline and were euthanized 1 hour later. For the time-course study, mice received EtOH (2 g/kg, i.p.) and were euthanized 15, 30, 60, and 120 minutes later. Steroids were measured by radioimmunoassay. RESULTS Acute EtOH administration did not alter cerebrocortical and hippocampal levels of allopregnanolone and progesterone in these strains at any of the doses and time points examined. Acute EtOH dose-dependently increased cerebrocortical corticosterone levels by 319, 347, and 459% in C57BL/6J mice at the doses of 2, 3, and 4 g/kg, and by 371, 507, 533, and 692% in DBA/2J mice at the doses of 1, 2, 3, and 4 g/kg, respectively. Similar changes were observed in the hippocampus. EtOH's effects on cerebrocortical corticosterone levels were also time dependent in both strains. Moreover, acute EtOH administration time-dependently increased plasma levels of progesterone and corticosterone. Finally, morphine administration increased cerebrocortical allopregnanolone levels in C57BL/6J (+77, +93, and +88% at 5, 10, and 30 mg/kg, respectively) and DBA/2J mice (+81% at 5 mg/kg), suggesting that the impairment in brain neurosteroidogenesis may be specific to EtOH. CONCLUSIONS These results underline important species differences on EtOH-induced brain neurosteroidogenesis. Acute EtOH increases brain and plasma corticosterone levels but does not alter cerebrocortical and hippocampal concentrations of allopregnanolone and progesterone in naïve C57BL/6J and DBA/2J mice.
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Affiliation(s)
- Patrizia Porcu
- Institute of Neuroscience, National Research Council of Italy (CNR), Cagliari, Italy
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Social rank, chronic ethanol self-administration, and diurnal pituitary-adrenal activity in cynomolgus monkeys. Psychopharmacology (Berl) 2012; 224:133-43. [PMID: 22526537 PMCID: PMC3469782 DOI: 10.1007/s00213-012-2707-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 03/24/2012] [Indexed: 12/20/2022]
Abstract
RATIONALE Dominance hierarchies affect ethanol self-administration, with greater intake among subordinate animals compared to dominant animals. Excessive ethanol intake disrupts circadian rhythms. Diurnal rhythms of the hypothalamic-pituitary-adrenal axis have not been characterized in the context of ethanol self-administration with regard to social rank. OBJECTIVE This study aimed to determine whether diurnal pituitary-adrenal hormonal rhythms account for differences between social ranks in ethanol self-administration or are differentially affected by ethanol self-administration between social ranks. METHODS During alternating individual (n = 11-12) and social (n = 3 groups) housing of male cynomolgus monkeys (Macaca fascicularis), diurnal measures of cortisol and adrenocorticotropic hormone (ACTH) were obtained from plasma samples three times per week. Social rank was determined, ethanol (4 %, w/v) self-administration was induced, and then the monkeys were allowed a choice of water or ethanol for 22 h/day for 49 weeks. RESULTS For all social ranks, plasma ACTH was elevated during social housing, but cortisol was stable, although greater among dominant monkeys. Ethanol self-administration blunted the effect of social housing, cortisol, and the diurnal rhythm for both hormones, regardless of daily ethanol intake (1.2-4.2 g/kg/day). Peak ACTH and cortisol were more likely to be observed in the morning during ethanol access. Ethanol, not vehicle, intake was lower during social housing across social ranks. Only dominant monkeys showed significantly lower blood-ethanol concentration during social housing. CONCLUSIONS There was a low threshold for disruption of diurnal pituitary rhythms by ethanol drinking, but sustained adrenal corticosteroid rhythms. Protection against heavy drinking among dominant monkeys may have constrained ethanol intoxication, possibly to preserve dominance rank.
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Helms CM, Rossi DJ, Grant KA. Neurosteroid influences on sensitivity to ethanol. Front Endocrinol (Lausanne) 2012; 3:10. [PMID: 22654852 PMCID: PMC3356014 DOI: 10.3389/fendo.2012.00010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/11/2012] [Indexed: 12/23/2022] Open
Abstract
This review will highlight a variety of mechanisms by which neurosteroids affect sensitivity to ethanol, including physiological states associated with activity of the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes, and the effects of chronic exposure to ethanol, in addition to behavioral implications. To date, γ-aminobutyric acid (GABA(A)) receptor mechanisms are a major focus of the modulation of ethanol effects by neuroactive steroids. While NMDA receptor mechanisms are gaining prominence in the literature, these complex data would be best discussed separately. Accordingly, GABA(A) receptor mechanisms are emphasized in this review with brief mention of some NMDA receptor mechanisms to point out contrasting neuroactive steroid pharmacology. Overall, the data suggest that neurosteroids are virtually ubiquitous modulators of inhibitory neurotransmission. Neurosteroids appear to affect sensitivity to ethanol in specific brain regions and, consequently, specific behavioral tests, possibly related to the efficacy and potency of ethanol to potentiate the release of GABA and increase neurosteroid concentrations. Although direct interaction of ethanol and neuroactive steroids at common receptor binding sites has been suggested in some studies, this proposition is still controversial. It is currently difficult to assign a specific mechanism by which neuroactive steroids could modulate the effects of ethanol in particular behavioral tasks.
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Affiliation(s)
- Christa M. Helms
- Division of Neuroscience, Oregon National Primate Research CenterBeaverton, OR, USA
- *Correspondence: Christa M. Helms, Division of Neuroscience, Oregon National Primate Research Center, L-584, 505 North-West 185th Avenue, Beaverton, OR 97006, USA. e-mail:
| | - David J. Rossi
- Department of Behavioral Neuroscience, Oregon Health and Science UniversityPortland, OR, USA
| | - Kathleen A. Grant
- Division of Neuroscience, Oregon National Primate Research CenterBeaverton, OR, USA
- Department of Behavioral Neuroscience, Oregon Health and Science UniversityPortland, OR, USA
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Porcu P, O'Buckley TK, Song SC, Harenza JL, Lu L, Wang X, Williams RW, Miles MF, Morrow AL. Genetic analysis of the neurosteroid deoxycorticosterone and its relation to alcohol phenotypes: identification of QTLs and downstream gene regulation. PLoS One 2011; 6:e18405. [PMID: 21494628 PMCID: PMC3072994 DOI: 10.1371/journal.pone.0018405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 03/07/2011] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Deoxycorticosterone (DOC) is an endogenous neurosteroid found in brain and serum, precursor of the GABAergic neuroactive steroid (3α,5α)-3,21-dihydroxypregnan-20-one (tetrahydrodeoxycorticosterone, THDOC) and the glucocorticoid corticosterone. These steroids are elevated following stress or ethanol administration, contribute to ethanol sensitivity, and their elevation is blunted in ethanol dependence. METHODOLOGY/PRINCIPAL FINDINGS To systematically define the genetic basis, regulation, and behavioral significance of DOC levels in plasma and cerebral cortex we examined such levels across 47 young adult males from C57BL/6J (B6)×DBA/2J (D2) (BXD) mouse strains for quantitative trait loci (QTL) and bioinformatics analyses of behavior and gene regulation. Mice were injected with saline or 0.075 mg/kg dexamethasone sodium salt at 8:00 am and were sacrificed 6 hours later. DOC levels were measured by radioimmunoassay. Basal cerebral cortical DOC levels ranged between 1.4 and 12.2 ng/g (8.7-fold variation, p<0.0001) with a heritability of ∼0.37. Basal plasma DOC levels ranged between 2.8 and 12.1 ng/ml (4.3-fold variation, p<0.0001) with heritability of ∼0.32. QTLs for basal DOC levels were identified on chromosomes 4 (cerebral cortex) and 14 (plasma). Dexamethasone-induced changes in DOC levels showed a 4.4-fold variation in cerebral cortex and a 4.1-fold variation in plasma, but no QTLs were identified. DOC levels across BXD strains were further shown to be co-regulated with networks of genes linked to neuronal, immune, and endocrine function. DOC levels and its responses to dexamethasone were associated with several behavioral measures of ethanol sensitivity previously determined across the BXD strains by multiple laboratories. CONCLUSIONS/SIGNIFICANCE Both basal and dexamethasone-suppressed DOC levels are positively correlated with ethanol sensitivity suggesting that the neurosteroid DOC may be a putative biomarker of alcohol phenotypes. DOC levels were also strongly correlated with networks of genes associated with neuronal function, innate immune pathways, and steroid metabolism, likely linked to behavioral phenotypes.
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Affiliation(s)
- Patrizia Porcu
- Department of Psychiatry, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America.
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10
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Porcu P, O'Buckley TK, Alward SE, Song SC, Grant KA, de Wit H, Leslie Morrow A. Differential effects of ethanol on serum GABAergic 3alpha,5alpha/3alpha,5beta neuroactive steroids in mice, rats, cynomolgus monkeys, and humans. Alcohol Clin Exp Res 2009; 34:432-42. [PMID: 20028362 DOI: 10.1111/j.1530-0277.2009.01123.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Acute ethanol administration increases plasma and brain levels of progesterone and deoxycorticosterone-derived neuroactive steroids (3alpha,5alpha)-3-hydroxypregnan-20-one (3alpha,5alpha-THP) and (3alpha,5alpha)-3,21-dihydroxypregnan-20-one (3alpha,5alpha-THDOC) in rats. However, little is known about ethanol effects on GABAergic neuroactive steroids in mice, nonhuman primates, or humans. We investigated the effects of ethanol on plasma levels of 3alpha,5alpha- and 3alpha,5beta-reduced GABAergic neuroactive steroids derived from progesterone, deoxycorticosterone, dehydroepiandrosterone, and testosterone using gas chromatography-mass spectrometry. METHODS Serum levels of GABAergic neuroactive steroids and pregnenolone were measured in male rats, C57BL/6J and DBA/2J mice, cynomolgus monkeys, and humans following ethanol administration. Rats and mice were injected with ethanol (0.8 to 2.0 g/kg), cynomolgus monkeys received ethanol (1.5 g/kg) intragastrically, and healthy men consumed a beverage containing 0.8 g/kg ethanol. Steroids were measured after 60 minutes in all species and also after 120 minutes in monkeys and humans. RESULTS Ethanol administration to rats increased levels of 3alpha,5alpha-THP, 3alpha,5alpha-THDOC, and pregnenolone at the doses of 1.5 g/kg (+228, +134, and +860%, respectively, p < 0.001) and 2.0 g/kg (+399, +174, and +1125%, respectively, p < 0.001), but not at the dose of 0.8 g/kg. Ethanol did not alter levels of the other neuroactive steroids. In contrast, C57BL/6J mice exhibited a 27% decrease in serum 3alpha,5alpha-THP levels (p < 0.01), while DBA/2J mice showed no significant effect of ethanol, although both mouse strains exhibited substantial increases in precursor steroids. Ethanol did not alter any of the neuroactive steroids in cynomolgus monkeys at doses comparable to those studied in rats. Finally, no effect of ethanol (0.8 g/kg) was observed in men. CONCLUSIONS These studies show clear species differences among rats, mice, and cynomolgus monkeys in the effects of ethanol administration on circulating neuroactive steroids. Rats are unique in their pronounced elevation of GABAergic neuroactive steroids, while this effect was not observed in mice or cynomolgus monkeys at comparable ethanol doses.
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Affiliation(s)
- Patrizia Porcu
- Department of Psychiatry and Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7178, USA
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Boyd KN, Kumar S, O'Buckley TK, Porcu P, Morrow AL. Ethanol induction of steroidogenesis in rat adrenal and brain is dependent upon pituitary ACTH release and de novo adrenal StAR synthesis. J Neurochem 2009; 112:784-96. [PMID: 20021565 DOI: 10.1111/j.1471-4159.2009.06509.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanisms of ethanol actions that produce its behavioral sequelae involve the synthesis of potent GABAergic neuroactive steroids, specifically the GABAergic metabolites of progesterone, (3alpha,5alpha)-3-hydroxypregnan-20-one (3alpha,5alpha-THP), and deoxycorticosterone, (3alpha,5alpha)-3,21-dihydroxypregnan-20-one. We investigated the mechanisms that underlie the effect of ethanol on adrenal steroidogenesis. We found that ethanol effects on plasma pregnenolone, progesterone, 3alpha,5alpha-THP and cortical 3alpha,5alpha-THP are highly correlated, exhibit a threshold of 1.5 g/kg, but show no dose dependence. Ethanol increases plasma adrenocorticotropic hormone (ACTH), adrenal steroidogenic acute regulatory protein (StAR), and adrenal StAR phosphorylation, but does not alter levels of other adrenal cholesterol transporters. The inhibition of ACTH release, de novo adrenal StAR synthesis or cytochrome P450 side chain cleavage activity prevents ethanol-induced increases in GABAergic steroids in plasma and brain. ACTH release and de novo StAR synthesis are independently regulated following ethanol administration and both are necessary, but not sufficient, for ethanol-induced elevation of plasma and brain neuroactive steroids. As GABAergic steroids contribute to ethanol actions and ethanol sensitivity, the mechanisms of this effect of ethanol may be important factors that contribute to the behavioral actions of ethanol and risk for alcohol abuse disorders.
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Affiliation(s)
- Kevin N Boyd
- Curriculum in Toxicology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Kumar S, Porcu P, Werner DF, Matthews DB, Diaz-Granados JL, Helfand RS, Morrow AL. The role of GABA(A) receptors in the acute and chronic effects of ethanol: a decade of progress. Psychopharmacology (Berl) 2009; 205:529-64. [PMID: 19455309 PMCID: PMC2814770 DOI: 10.1007/s00213-009-1562-z] [Citation(s) in RCA: 342] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 04/30/2009] [Indexed: 12/12/2022]
Abstract
The past decade has brought many advances in our understanding of GABA(A) receptor-mediated ethanol action in the central nervous system. We now know that specific GABA(A) receptor subtypes are sensitive to ethanol at doses attained during social drinking while other subtypes respond to ethanol at doses attained by severe intoxication. Furthermore, ethanol increases GABAergic neurotransmission through indirect effects, including the elevation of endogenous GABAergic neuroactive steroids, presynaptic release of GABA, and dephosphorylation of GABA(A) receptors promoting increases in GABA sensitivity. Ethanol's effects on intracellular signaling also influence GABAergic transmission in multiple ways that vary across brain regions and cell types. The effects of chronic ethanol administration are influenced by adaptations in GABA(A) receptor function, expression, trafficking, and subcellular localization that contribute to ethanol tolerance, dependence, and withdrawal hyperexcitability. Adolescents exhibit altered sensitivity to ethanol actions, the tendency for higher drinking and longer lasting GABAergic adaptations to chronic ethanol administration. The elucidation of the mechanisms that underlie adaptations to ethanol exposure are leading to a better understanding of the regulation of inhibitory transmission and new targets for therapies to support recovery from ethanol withdrawal and alcoholism.
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Affiliation(s)
- Sandeep Kumar
- Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, 3027 Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599-7178, USA
| | - Patrizia Porcu
- Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, 3027 Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599-7178, USA
| | - David F. Werner
- Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, 3027 Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599-7178, USA
| | | | | | - Rebecca S. Helfand
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, USA
| | - A. Leslie Morrow
- Department of Psychiatry, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, 3027 Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599-7178, USA, Department of Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, 3027 Thurston-Bowles Building, CB #7178, Chapel Hill, NC 27599-7178, USA
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Biggio G, Concas A, Follesa P, Sanna E, Serra M. Stress, ethanol, and neuroactive steroids. Pharmacol Ther 2007; 116:140-71. [PMID: 17555824 PMCID: PMC3000046 DOI: 10.1016/j.pharmthera.2007.04.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 04/06/2007] [Indexed: 12/27/2022]
Abstract
Neurosteroids play a crucial role in stress, alcohol dependence and withdrawal, and other physiological and pharmacological actions by potentiating or inhibiting neurotransmitter action. This review article focuses on data showing that the interaction among stress, ethanol, and neuroactive steroids may result in plastic molecular and functional changes of GABAergic inhibitory neurotransmission. The molecular mechanisms by which stress-ethanol-neuroactive steroids interactions can produce plastic changes in GABA(A) receptors have been studied using different experimental models in vivo and in vitro in order to provide useful evidence and new insights into the mechanisms through which acute and chronic ethanol and stress exposure modulate the activity of GABAergic synapses. We show detailed data on a) the effect of acute and chronic stress on peripheral and brain neurosteroid levels and GABA(A) receptor gene expression and function; b) ethanol-stimulated brain steroidogenesis; c) plasticity of GABA(A) receptor after acute and chronic ethanol exposure. The implications of these new mechanistic insights to our understanding of the effects of ethanol during stress are also discussed. The understanding of these neurochemical and molecular mechanisms may shed new light on the physiopathology of diseases, such as anxiety, in which GABAergic transmission plays a pivotal role. These data may also lead to the need for new anxiolytic, hypnotic and anticonvulsant selective drugs devoid of side effects.
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Affiliation(s)
- Giovanni Biggio
- Department of Experimental Biology, Center of Excellence for the Neurobiology of Dependence, University of Cagliari, Cagliari, Italy.
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14
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Abstract
Gamma-hydroxybutyrate (GHB) is a drug of abuse that causes euphoria, anxiolysis, and hypnosis. The recent rise in the recreational intake of GHB, as well as its association with 'drug rape', has turned the attention to GHB in acute hospital settings. Acutely admitted GHB intoxicated patients may display various levels of sedation or coma, but may also show paradoxical agitation, combativeness, or self-injurious behaviors. The symptoms can be nonspecific and the definite diagnosis therefore normally relies on the detection of GHB in blood or body fluids, which is an analysis that may not be promptly available. As a basis for understanding the clinical features of GHB intoxication and abuse, we here review the pharmacological and neurophysiological knowledge about GHB, which stems from decades of clinical and basic GHB research. In addition, we discuss the latest discoveries in the quest for distinct GHB receptors in the brain, and their possible implications for future therapies of GHB abuse.
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Affiliation(s)
- K R Drasbek
- Institute of Physiology and Biophysics, Faculty of Health Sciences, University of Aarhus, Aarhus, Denmark
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15
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Follesa P, Biggio F, Talani G, Murru L, Serra M, Sanna E, Biggio G. Neurosteroids, GABAA receptors, and ethanol dependence. Psychopharmacology (Berl) 2006; 186:267-80. [PMID: 16163526 DOI: 10.1007/s00213-005-0126-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 06/21/2005] [Indexed: 11/26/2022]
Abstract
RATIONALE Changes in the expression of type A receptors for gamma-aminobutyric acid (GABA) represent one of the mechanisms implicated in the development of tolerance to and dependence on ethanol. The impact of such changes on the function and pharmacological sensitivity of GABAA receptors (GABAARs) has remained unclear, however. Certain behavioral and electrophysiological actions of ethanol are mediated by an increase in the concentration of neuroactive steroids in the brain that results from stimulation of the hypothalamic-pituitary-adrenal (HPA) axis. Such steroids include potent modulators of GABAAR function. OBJECTIVES We have investigated the effect of ethanol exposure and withdrawal on subunit expression and receptor function evaluated by subunit selective compounds, as well as the effects of short-term exposure to ethanol on both neurosteroid synthesis and GABAAR function, in isolated neurons and brain tissue. RESULTS Chronic treatment with and subsequent withdrawal from ethanol alter the expression of genes for specific GABAAR subunits in cultured rat neurons, and these changes are associated with alterations in receptor function and pharmacological sensitivity to neurosteroids, zaleplon, and flumazenil. Acute ethanol exposure increases the amount of 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone) in hippocampal slices by a local action independent of the activity of the HPA axis. This effect of ethanol was associated with an increased amplitude of GABAAR-mediated miniature inhibitory postsynaptic currents recorded from CA1 pyramidal neurons in such slices. CONCLUSIONS Chronic ethanol exposure elicits changes in the subunit composition of GABAARs, which, in turn, likely contribute to changes in receptor function associated with the altered pharmacological and behavioral sensitivity characteristic of ethanol tolerance and dependence. Ethanol may also modulate GABAAR function by increasing the de novo synthesis of neurosteroids in the brain in a manner independent of the HPA axis. This latter mechanism may play an important role in the central effects of ethanol.
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Affiliation(s)
- Paolo Follesa
- Department of Experimental Biology Bernardo Loddo, University of Cagliari, Cagliari, 09123, Italy
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16
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Concas A, Sogliano C, Porcu P, Marra C, Brundu A, Biggio G. Neurosteroids in nicotine and morphine dependence. Psychopharmacology (Berl) 2006; 186:281-92. [PMID: 16133140 DOI: 10.1007/s00213-005-0111-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Accepted: 06/20/2005] [Indexed: 11/25/2022]
Abstract
RATIONALE Neurosteroids are implicated in various stages of drug dependence, including the acquisition phase, tolerance, and withdrawal. The neurosteroid allopregnanolone is also able to substitute for drugs with abuse potential and possesses reinforcing properties. OBJECTIVES The effects of acute treatment with, and discontinuation of, chronic exposure to nicotine or morphine on the concentrations of allopregnanolone and its precursors, pregnenolone and progesterone, in the cerebral cortex and plasma of rats were investigated. The role of the hypothalamic-pituitary-adrenal (HPA) axis in, and the development of tolerance to, such effects were also examined. METHODS Nicotine or morphine was administered acutely or chronically, and withdrawal syndrome was induced by spontaneous discontinuation of drug treatment or by administration of a corresponding receptor antagonist (mecamylamine and naloxone, respectively). Neurosteroids were extracted from the cerebral cortex and plasma, fractionated by high-performance liquid chromatography, and quantitated by radioimmunoassay. RESULTS Acute intraperitoneal administration of nicotine (0.3-2 mg kg-1) or morphine (5-30 mg kg-1) induced dose- and time-dependent increases in the cerebrocortical and plasma concentrations of pregnenolone, progesterone, and allopregnanolone. The effects of both drugs were abolished by adrenalectomy-orchiectomy. Spontaneous or naloxone-precipitated morphine withdrawal and mecamylamine-precipitated (but not spontaneous) nicotine withdrawal also increased neurosteroid concentrations in the brain and plasma. A challenge dose of nicotine or morphine, administered 14 or 24 h after the last drug injection in chronic ally treated rats, failed to increase cerebrocortical neurosteroid concentrations. CONCLUSIONS Changes in neurosteroid concentrations mediated by activation of the HPA axis may both contribute to the early acquisition phase of nicotine or morphine addiction and serve to counteract the anxiety-like behavior associated with nicotine or morphine withdrawal. However, the evidence that nicotine withdrawal did not increase neurosteroids, unless precipitated by mecamylamine, suggests that the role of these neurosteroids in spontaneous nicotine withdrawal may not be clear.
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Affiliation(s)
- Alessandra Concas
- Department of Experimental Biology, Center of Excellence for Neurobiology of Dependence, University of Cagliari, Cagliari, Italy.
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Khisti RT, Boyd KN, Kumar S, Morrow AL. Systemic ethanol administration elevates deoxycorticosterone levels and chronic ethanol exposure attenuates this response. Brain Res 2005; 1049:104-11. [PMID: 15936001 DOI: 10.1016/j.brainres.2005.05.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2005] [Revised: 05/03/2005] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
Systemic ethanol administration is known to elevate levels of the GABAergic neuroactive steroid 3alpha,21-dihydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THDOC). 3alpha,5alpha-THDOC is synthesized from deoxycorticosterone (DOC) by metabolism in adrenals and brain. The present study investigated DOC levels in plasma and brain following ethanol administration to naïve and ethanol-exposed rats. Rats were administered ethanol (2 g/kg, i.p.) or saline and DOC levels were measured in plasma and brain regions by radioimmunoassay. Chronic ethanol-exposed rats were administered an ethanol challenge (2 g/kg, i.p.) following 15 days of ethanol liquid diet consumption. Ethanol administration markedly increased DOC levels in plasma, cerebral cortex, hippocampus, hypothalamus, cerebellum, and olfactory tubercle of naïve rats. Ethanol challenge produced an attenuated elevation of DOC in rat plasma and brain following chronic ethanol consumption for 2 weeks. These findings suggest that acute ethanol increases DOC levels in ethanol naïve rats and chronic ethanol consumption induces tolerance to ethanol-induced increases in DOC levels.
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Affiliation(s)
- Rahul T Khisti
- Department of Psychiatry and Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7178, USA
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