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Sbrini G, Mutti V, Bono F, Tomasoni Z, Fadel D, Missale C, Fiorentini C. 17-β-estradiol potentiates the neurotrophic and neuroprotective effects mediated by the dopamine D3/acetylcholine nicotinic receptor heteromer in dopaminergic neurons. Eur J Pharmacol 2024; 976:176678. [PMID: 38821163 DOI: 10.1016/j.ejphar.2024.176678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/10/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
Dopaminergic neurons express a heteromer composed of the dopamine D3 receptor and the α4β2 nicotinic acetylcholine receptor, the D3R-nAChR heteromer, activated by both nicotine and dopamine D2 and D3 receptors agonists, such as quinpirole, and crucial for dopaminergic neuron homeostasis. We now report that D3R-nAChR heteromer activity is potentiated by 17-β-estradiol which acts as a positive allosteric modulator by binding a specific domain on the α4 subunit of the nicotinic receptor protomer. In mouse dopaminergic neurons, in fact, 17-β-estradiol significantly increased the ability of nicotine and quinpirole in promoting neuron dendritic remodeling and in protecting neurons against the accumulation of α-synuclein induced by deprivation of glucose, with a mechanism that does not involve the classical estrogen receptors. The potentiation induced by 17-β-estradiol required the D3R-nAChR heteromer since either nicotinic receptor or dopamine D3 receptor antagonists and interfering TAT-peptides, but not the estrogen receptor antagonist fulvestrant, specifically prevented 17-β-estradiol effects. Evidence of estrogens neuroprotection, mainly mediated by genomic mechanisms, have been provided, which is in line with epidemiological data reporting that females are less likely to develop Parkinson's Disease than males. Therefore, potentiation of D3R-nAChR heteromer activity may represent a further mechanism by which 17-β-estradiol reduces dopaminergic neuron vulnerability.
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Affiliation(s)
- Giulia Sbrini
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Veronica Mutti
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Federica Bono
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Zaira Tomasoni
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Dounia Fadel
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Cristina Missale
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Chiara Fiorentini
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy.
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2
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Munawar Cheema M, Macakova Kotrbova Z, Hrcka Krausova B, Adla SK, Slavikova B, Chodounska H, Kratochvil M, Vondrasek J, Sedlak D, Balastik M, Kudova E. 5β-reduced neuroactive steroids as modulators of growth and viability of postnatal neurons and glia. J Steroid Biochem Mol Biol 2024; 239:106464. [PMID: 38246201 DOI: 10.1016/j.jsbmb.2024.106464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 01/23/2024]
Abstract
Endogenous neurosteroids (NS) and their synthetic analogs, neuroactive steroids (NAS), are potentially useful drug-like compounds affecting the pathophysiology of miscellaneous central nervous system disorders (e.g. Alzheimer´s disease, epilepsy, depression, etc.). Additionally, NS have been shown to promote neuron viability and neurite outgrowth upon injury. The molecular, structural and physicochemical basis of the NS effect on neurons is so far not fully understood, and the development of new, biologically relevant assays is essential for their comparative analysis and for assessment of their mechanism of action. Here, we report the development of a novel, plate-based, high-content in vitro assay for screening of NS and newly synthesized, 5β-reduced NAS for the promotion of postnatal neuron survival and neurite growth using fluorescent, postnatal mixed cortical neuron cultures isolated from thy1-YFP transgenic mice. The screen allows a detailed time course analysis of different parameters, such as the number of neurons or neurite lengths of 7-day, in vitro neuron cultures. Using the screen, we identify a new NAS, compound 42, that promotes the survival and growth of postnatal neurons significantly better than several endogenous NS (dehydroepiandrosterone, progesterone, and allopregnanolone). Interestingly, we demonstrate that compound 42 also promotes the proliferation of glia (in particular oligodendrocytes) and that the glial function is critical for its neuron growth support. Computational analysis of the biological data and calculated physicochemical properties of tested NS and NAS demonstrated that their biological activity is proportional to their lipophilicity. Together, the screen proves useful for the selection of neuron-active NAS and the comparative evaluation of their biologically relevant structural and physicochemical features.
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Affiliation(s)
- Marie Munawar Cheema
- Laboratory of Molecular Neurobiology, Institute of Physiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Zuzana Macakova Kotrbova
- CZ-OPENSCREEN: National Infrastructure for Chemical Biology, Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Barbora Hrcka Krausova
- Laboratory of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Santosh Kumar Adla
- Dept. of Neurosteroids, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic
| | - Barbora Slavikova
- Dept. of Neurosteroids, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic
| | - Hana Chodounska
- Dept. of Neurosteroids, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic
| | - Miroslav Kratochvil
- Dept. of Bioinformatics, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic
| | - Jiri Vondrasek
- Dept. of Bioinformatics, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic
| | - David Sedlak
- CZ-OPENSCREEN: National Infrastructure for Chemical Biology, Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic
| | - Martin Balastik
- Laboratory of Molecular Neurobiology, Institute of Physiology, Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, Czech Republic.
| | - Eva Kudova
- Dept. of Neurosteroids, Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo namesti 2, 16610 Prague 6, Czech Republic.
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Covey DF, Evers AS, Izumi Y, Maguire JL, Mennerick SJ, Zorumski CF. Neurosteroid enantiomers as potentially novel neurotherapeutics. Neurosci Biobehav Rev 2023; 149:105191. [PMID: 37085023 PMCID: PMC10750765 DOI: 10.1016/j.neubiorev.2023.105191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/23/2023]
Abstract
Endogenous neurosteroids and synthetic neuroactive steroids (NAS) are important targets for therapeutic development in neuropsychiatric disorders. These steroids modulate major signaling systems in the brain and intracellular processes including inflammation, cellular stress and autophagy. In this review, we describe studies performed using unnatural enantiomers of key neurosteroids, which are physiochemically identical to their natural counterparts except for rotation of polarized light. These studies led to insights in how NAS interact with receptors, ion channels and intracellular sites of action. Certain effects of NAS show high enantioselectivity, consistent with actions in chiral environments and likely direct interactions with signaling proteins. Other effects show no enantioselectivity and even reverse enantioselectivity. The spectrum of effects of NAS enantiomers raises the possibility that these agents, once considered only as tools for preclinical studies, have therapeutic potential that complements and in some cases may exceed their natural counterparts. Here we review studies of NAS enantiomers from the perspective of their potential development as novel neurotherapeutics.
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Affiliation(s)
- Douglas F Covey
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA; Anesthesiology Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Alex S Evers
- Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA; Anesthesiology Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Yukitoshi Izumi
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Jamie L Maguire
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Steven J Mennerick
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F Zorumski
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA; The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA.
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Maher EE, Strzelecki AM, Weafer JJ, Gipson CD. The importance of translationally evaluating steroid hormone contributions to substance use. Front Neuroendocrinol 2023; 69:101059. [PMID: 36758769 PMCID: PMC10182261 DOI: 10.1016/j.yfrne.2023.101059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023]
Abstract
Clinically, women appear to be more susceptible to certain aspects of substance use disorders (SUDs). The steroid hormones 17β-estradiol (E2) and progesterone (Pg) have been linked to women-specific drug behaviors. Here, we review clinical and preclinical studies investigating how cycling ovarian hormones affect nicotine-, cocaine-, and opioid-related behaviors. We also highlight gaps in the literature regarding how synthetic steroid hormone use may influence drug-related behaviors. In addition, we explore how E2 and Pg are known to interact in brain reward pathways and provide evidence of how these interactions may influence drug-related behaviors. The synthesis of this review demonstrates the critical need to study women-specific factors that may influence aspects of SUDs, which may play important roles in addiction processes in a sex-specific fashion. It is important to understand factors that impact women's health and may be key to moving the field forward toward more efficacious and individualized treatment strategies.
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Affiliation(s)
- Erin E Maher
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, United States
| | - Ashley M Strzelecki
- Department of Psychology, University of Kentucky, Lexington, KY, United States
| | - Jessica J Weafer
- Department of Psychology, University of Kentucky, Lexington, KY, United States
| | - Cassandra D Gipson
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, United States.
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5
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Novick AM, Duffy KA, Johnson RL, Sammel MD, Cao W, Strasser AA, Sofuoglu M, Kuzma A, Loughead J, Epperson CN. Progesterone Increases Nicotine Withdrawal and Anxiety in Male but Not Female Smokers During Brief Abstinence. Nicotine Tob Res 2022; 24:1898-1905. [PMID: 35713950 PMCID: PMC9653080 DOI: 10.1093/ntr/ntac146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 05/08/2022] [Accepted: 06/14/2022] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Although exogenous progesterone may hold promise as a treatment for nicotine use disorders, it is unclear whether it is similarly effective in males and females. This study examined the effects of progesterone on nicotine use disorder comprehensively using behavioral, psychological, and neural measures in male and female smokers exposed to brief abstinence. AIMS AND METHODS Thirty-three male and 33 female non-treatment-seeking smokers participated in a double-blind, randomized, placebo-controlled crossover study of 200 mg of progesterone or placebo daily over a four-day abstinence period. Smoking behavior and subjective effects of nicotine were assessed at baseline and after final drug administration. Nicotine withdrawal, smoking urges, mood states, and neural response to smoking cues were measured at baseline, after the first drug administration, and after the final drug administration. RESULTS No main effect of drug (progesterone vs. placebo) emerged for any outcome. Significant sex by drug interactions emerged for nicotine withdrawal (p = .020), perceived strength of nicotine (p = .040), and perceived bad effects of nicotine (p = .029). Males receiving progesterone reported worse nicotine withdrawal (p = .046) and a trend towards decreased bad effects of nicotine (p = .070). Males on progesterone also reported greater tension and anxiety relative to placebo (p = .021). Females on progesterone perceived nicotine's effects as being stronger relative to placebo (p = .046). CONCLUSIONS Progesterone causes sex-dependent effects on smoking-related outcomes during brief abstinence. Specifically, progesterone in males may increase rather than decrease nicotine withdrawal and negative affect during abstinence, potentially hindering efforts to quit smoking. IMPLICATIONS In male and female smokers undergoing a brief period of abstinence, we examined the effects of progesterone on smoking outcomes. While progesterone had limited effects in female smokers, in males, it worsened nicotine withdrawal and negative affect. Our findings emphasize the importance of analyzing sex differences in future studies examining progesterone as a potential treatment and suggest that progesterone in males could potentially exacerbate aspects of nicotine dependence. CLINICALTRIALS.GOV REGISTRATION NCT01954966. https://clinicaltrials.gov/ct2/show/NCT01954966.
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Affiliation(s)
- Andrew M Novick
- Corresponding Author: Andrew M. Novick, MD, PhD, Department of Psychiatry, University of Colorado-Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO 80045, USA. Telephone: 303-724-5656; Fax: 844-886-1892; E-mail:
| | - Korrina A Duffy
- Department of Psychiatry, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
| | - Rachel L Johnson
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
| | - Mary D Sammel
- Department of Psychiatry, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
| | - Wen Cao
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrew A Strasser
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mehmet Sofuoglu
- Department of Psychiatry, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Alexandra Kuzma
- Larner College of Medicine, University of Vermont, Burlington, VM, USA
| | - James Loughead
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - C Neill Epperson
- Department of Psychiatry, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
- Department of Family Medicine, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, CO, USA
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6
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Novick AM, Duffy KA, Johnson RL, Sammel MD, Cao W, Strasser AA, Sofuoglu M, Kuzma A, Loughead J, Morrow AL, Epperson CN. Effect of progesterone administration in male and female smokers on nicotine withdrawal and neural response to smoking cues: role of progesterone conversion to allopregnanolone. Biol Sex Differ 2022; 13:60. [PMID: 36274158 PMCID: PMC9590190 DOI: 10.1186/s13293-022-00472-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 10/15/2022] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Progesterone administration has therapeutic effects in tobacco use disorder (TUD), with females benefiting more than males. Conversion of progesterone to the neurosteroid allopregnanolone is hypothesized to partly underlie the therapeutic effects of progesterone; however, this has not been investigated clinically. METHODS Smokers (n = 18 males, n = 21 females) participated in a randomized, double-blind, placebo-controlled crossover study of 200 mg progesterone daily across 4 days of abstinence. The ratio of allopregnanolone:progesterone was analyzed in relationship to nicotine withdrawal, smoking urges, mood states, subjective nicotine effects, and neural response to smoking cues. RESULTS Allopregnanolone:progesterone ratio interacted with sex to predict withdrawal symptoms (p = 0.047), such that females with higher allopregnanolone:progesterone ratios reported lower withdrawal severity (b = - 0.98 [- 1.95, - 0.01]; p = 0.048). In addition, allopregnanolone:progesterone ratio interacted with sex to predict confusion (p = 0.014) and fatigue (p = 0.034), such that females with higher allopregnanolone:progesterone ratios reported less confusion (b = - 0.45 [- 0.78, - 0.12]; p = 0.008) and marginally lower fatigue (b = - 0.50 [- 1.03, 0.02]; p = 0.062. Irrespective of sex, higher ratios of allopregnanolone:progesterone were associated with stronger "good effects" of nicotine (b = 8.39 [2.58, 14.20]); p = 0.005) and weaker "bad effects" of nicotine (b = - 7.13 [- 13.53, - 0.73]; p = 0.029). CONCLUSIONS Conversion of progesterone to allopregnanolone correlated with smoking-related outcomes in both sex-dependent and sex-independent ways. Sex-dependent effects suggest that conversion of progesterone to allopregnanolone may contribute to greater therapeutic benefits in females but not males with TUD. Trial registration Clinicaltrials.gov registration, retrospectively registered: NCT01954966; https://clinicaltrials.gov/ct2/show/NCT01954966 \.
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Affiliation(s)
- Andrew M Novick
- Department of Psychiatry, School of Medicine, University of CO-Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO, 80045, USA.
| | - Korrina A Duffy
- Department of Psychiatry, School of Medicine, University of CO-Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO, 80045, USA
| | - Rachel L Johnson
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of CO-Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Mary D Sammel
- Department of Psychiatry, School of Medicine, University of CO-Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO, 80045, USA
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of CO-Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Wen Cao
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Andrew A Strasser
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Mehmet Sofuoglu
- Department of Psychiatry, Yale School of Medicine, Yale University, New Haven, CT, 06511, USA
| | - Alexandra Kuzma
- Larner College of Medicine, University of Vermont, Burlington, VM, 05405, USA
| | - James Loughead
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - A Leslie Morrow
- Departments of Psychiatry and Pharmacology and the Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, 27514, USA
| | - C Neill Epperson
- Department of Psychiatry, School of Medicine, University of CO-Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO, 80045, USA
- Department of Family Medicine, School of Medicine, University of CO-Anschutz Medical Campus, Aurora, CO, 80045, USA
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Hill M, Pařízek A, Šimják P, Koucký M, Anderlová K, Krejčí H, Vejražková D, Ondřejíková L, Černý A, Kancheva R. Steroids, steroid associated substances and gestational diabetes mellitus. Physiol Res 2021. [DOI: 10.33549//physiolres.934794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
As gestational diabetes mellitus (GDM) is both a frequent and serious complication, steroid levels in pregnancy are extremely elevated and their role in pregnancy is crucial, this review focuses on the role of steroids and related substances in the GDM pathophysiology. Low SHBG levels are associated with insulin resistance and hyperinsulinemia, while also predicting a predisposition to GDM. Other relevant agents are placental hormones such as kisspeptin and CRH, playing also an important role beyond pregnancy, but which are synthesized here in smaller amounts in the hypothalamus. These hormones affect both the course of pregnancy as well as the synthesis of pregnancy steroids and may also be involved in the GDM pathophysiology. Steroids, whose biosynthesis is mainly provided by the fetal adrenal glands, placenta, maternal adrenal glands, and both maternal and fetal livers, are also synthesized in limited amounts directly in the pancreas and may influence the development of GDM. These substances involve the sulfated Δ5 steroids primarily acting via modulating different ion channels and influencing the development of GDM in different directions, mostly diabetogenic progesterone and predominantly anti-diabetic estradiol acting both in genomic and non-genomic way, androgens associated with IR and hyperinsulinemia, neuroactive steroids affecting the pituitary functioning, and cortisol whose production is stimulated by CRH but which suppresses its pro-inflammatory effects. Due to the complex actions of steroids, studies assessing their predominant effect and studies assessing their predictive values for estimating predisposition to GDM are needed.
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Affiliation(s)
- M Hill
- Institute of Endocrinology, Prague, Czech Republic.
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Ondřejíková L, Pařízek A, Šimják P, Vejražková D, Velíková M, Anderlová K, Vosátková M, Krejčí H, Koucký M, Kancheva R, Dušková M, Vaňková M, Bulant J, Hill M. Altered Steroidome in Women with Gestational Diabetes Mellitus: Focus on Neuroactive and Immunomodulatory Steroids from the 24th Week of Pregnancy to Labor. Biomolecules 2021; 11:biom11121746. [PMID: 34944390 PMCID: PMC8698588 DOI: 10.3390/biom11121746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/12/2021] [Accepted: 11/20/2021] [Indexed: 12/19/2022] Open
Abstract
Gestational diabetes mellitus (GDM) is a complication in pregnancy, but studies focused on the steroidome in patients with GDM are not available in the public domain. This article evaluates the steroidome in GDM+ and GDM- women and its changes from 24 weeks (± of gestation) to labor. The study included GDM+ (n = 44) and GDM- women (n = 33), in weeks 24-28, 30-36 of gestation and at labor and mixed umbilical blood after delivery. Steroidomic data (101 steroids quantified by GC-MS/MS) support the concept that the increasing diabetogenic effects with the approaching term are associated with mounting progesterone levels. The GDM+ group showed lower levels of testosterone (due to reduced AKR1C3 activity), estradiol (due to a shift from the HSD17B1 towards HSD17B2 activity), 7-oxygenated androgens (competing with cortisone for HSD11B1 and shifting the balance from diabetogenic cortisol towards the inactive cortisone), reduced activities of SRD5As, and CYP17A1 in the hydroxylase but higher CYP17A1 activity in the lyase step. With the approaching term, the authors found rising activities of CYP3A7, AKR1C1, CYP17A1 in its hydroxylase step, but a decline in its lyase step, rising conjugation of neuroinhibitory and pregnancy-stabilizing steroids and weakening AKR1D1 activity.
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Affiliation(s)
- Leona Ondřejíková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Antonín Pařízek
- Department of Gynecology and Obstetrics, First Faculty of Medicine, General University Hospital in Prague, Charles University in Prague, 128 08 Prague, Czech Republic; (A.P.); (P.Š.); (K.A.); (H.K.); (M.K.)
| | - Patrik Šimják
- Department of Gynecology and Obstetrics, First Faculty of Medicine, General University Hospital in Prague, Charles University in Prague, 128 08 Prague, Czech Republic; (A.P.); (P.Š.); (K.A.); (H.K.); (M.K.)
| | - Daniela Vejražková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Marta Velíková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Kateřina Anderlová
- Department of Gynecology and Obstetrics, First Faculty of Medicine, General University Hospital in Prague, Charles University in Prague, 128 08 Prague, Czech Republic; (A.P.); (P.Š.); (K.A.); (H.K.); (M.K.)
| | - Michala Vosátková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Hana Krejčí
- Department of Gynecology and Obstetrics, First Faculty of Medicine, General University Hospital in Prague, Charles University in Prague, 128 08 Prague, Czech Republic; (A.P.); (P.Š.); (K.A.); (H.K.); (M.K.)
| | - Michal Koucký
- Department of Gynecology and Obstetrics, First Faculty of Medicine, General University Hospital in Prague, Charles University in Prague, 128 08 Prague, Czech Republic; (A.P.); (P.Š.); (K.A.); (H.K.); (M.K.)
| | - Radmila Kancheva
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Michaela Dušková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Markéta Vaňková
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Josef Bulant
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
| | - Martin Hill
- Institute of Endocrinology, 116 94 Prague, Czech Republic; (L.O.); (D.V.); (M.V.); (M.V.); (R.K.); (M.D.); (M.V.); (J.B.)
- Correspondence: ; Tel.: +420-224-905-246
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Moen JK, Lee AM. Sex Differences in the Nicotinic Acetylcholine Receptor System of Rodents: Impacts on Nicotine and Alcohol Reward Behaviors. Front Neurosci 2021; 15:745783. [PMID: 34621155 PMCID: PMC8490611 DOI: 10.3389/fnins.2021.745783] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/31/2021] [Indexed: 12/20/2022] Open
Abstract
Alcohol and nicotine are the two most widely used and misused drugs around the world, and co-consumption of both substances is highly prevalent. Multiple lines of evidence show a profound effect of sex in many aspects of alcohol and nicotine reward, with women having more difficulty quitting smoking and showing a faster progression toward developing alcohol use disorder compared with men. Both alcohol and nicotine require neuronal nicotinic acetylcholine receptors (nAChRs) to elicit rewarding effects within the mesolimbic system, representing a shared molecular pathway that likely contributes to the frequent comorbidity of alcohol and nicotine dependence. However, the majority of preclinical studies on the mechanisms of alcohol and nicotine reward behaviors utilize only male rodents, and thus our understanding of alcohol and nicotine neuropharmacology relies heavily on male data. As preclinical research informs the development and refinement of therapies to help patients reduce drug consumption, it is critical to understand the way biological sex and sex hormones influence the rewarding properties of alcohol and nicotine. In this review, we summarize what is known about sex differences in rodent models of alcohol and nicotine reward behaviors with a focus on neuronal nAChRs, highlighting exciting areas for future research. Additionally, we discuss the way circulating sex hormones may interact with neuronal nAChRs to influence reward-related behavior.
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Affiliation(s)
- Janna K Moen
- Graduate Program in Neuroscience, University of Minnesota Twin Cities, Minneapolis, MN, United States
| | - Anna M Lee
- Graduate Program in Neuroscience, University of Minnesota Twin Cities, Minneapolis, MN, United States.,Department of Pharmacology, University of Minnesota Twin Cities, Minneapolis, MN, United States
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10
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Moffett SX, Klein EA, Brannigan G, Martin JV. L-3,3',5-triiodothyronine and pregnenolone sulfate inhibit Torpedo nicotinic acetylcholine receptors. PLoS One 2019; 14:e0223272. [PMID: 31584962 PMCID: PMC6777777 DOI: 10.1371/journal.pone.0223272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 09/17/2019] [Indexed: 11/19/2022] Open
Abstract
The nicotinic acetylcholine receptor (nAChR) is an excitatory pentameric ligand-gated ion channel (pLGIC), homologous to the inhibitory γ-aminobutyric acid (GABA) type A receptor targeted by pharmaceuticals and endogenous sedatives. Activation of the GABAA receptor by the neurosteroid allopregnanolone can be inhibited competitively by thyroid hormone (L-3,3’,5-triiodothyronine, or T3), but modulation of nAChR by T3 or neurosteroids has not been investigated. Here we show that allopregnanolone inhibits the nAChR from Torpedo californica at micromolar concentrations, as do T3 and the anionic neurosteroid pregnenolone sulfate (PS). We test for the role of protein and ligand charge in mediated receptor inhibition by varying pH in a narrow range around physiological pH. We find that both T3 and PS become less potent with increasing pH, with remarkably similar trends in IC50 when T3 is neutral at pH < 7.3. After deprotonation of T3 (but no additional deprotonation of PS) at pH 7.3, T3 loses potency more slowly with increasing pH than PS. We interpret this result as indicating the negative charge is not required for inhibition but does increase activity. Finally, we show that both T3 and PS affect nAChR channel desensitization, which may implicate a binding site homologous to one that was recently indicated for accelerated desensitization of the GABAA receptor by PS.
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Affiliation(s)
- Steven X. Moffett
- Center for Computational and Integrative Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
| | - Eric A. Klein
- Center for Computational and Integrative Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
- Department of Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
| | - Grace Brannigan
- Center for Computational and Integrative Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
- Department of Physics, Rutgers University—Camden, Camden, New Jersey, United States of America
| | - Joseph V. Martin
- Center for Computational and Integrative Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
- Department of Biology, Rutgers University—Camden, Camden, New Jersey, United States of America
- * E-mail:
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11
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Yu Z, Chiara DC, Savechenkov PY, Bruzik KS, Cohen JB. A photoreactive analog of allopregnanolone enables identification of steroid-binding sites in a nicotinic acetylcholine receptor. J Biol Chem 2019; 294:7892-7903. [PMID: 30923128 DOI: 10.1074/jbc.ra118.007172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/27/2019] [Indexed: 11/06/2022] Open
Abstract
Many neuroactive steroids potently and allosterically modulate pentameric ligand-gated ion channels, including GABAA receptors (GABAAR) and nicotinic acetylcholine receptors (nAChRs). Allopregnanolone and its synthetic analog alphaxalone are GABAAR-positive allosteric modulators (PAMs), whereas alphaxalone and most neuroactive steroids are nAChR inhibitors. In this report, we used 11β-(p-azidotetrafluorobenzoyloxy)allopregnanolone (F4N3Bzoxy-AP), a general anesthetic and photoreactive allopregnanolone analog that is a potent GABAAR PAM, to characterize steroid-binding sites in the Torpedo α2βγδ nAChR in its native membrane environment. We found that F4N3Bzoxy-AP (IC50 = 31 μm) is 7-fold more potent than alphaxalone in inhibiting binding of the channel blocker [3H]tenocyclidine to nAChRs in the desensitized state. At 300 μm, neither steroid inhibited binding of [3H]tetracaine, a closed-state selective channel blocker, or of [3H]acetylcholine. Photolabeling identified three distinct [3H]F4N3Bzoxy-AP-binding sites in the nAChR transmembrane domain: 1) in the ion channel, identified by photolabeling in the M2 helices of βVal-261 and δVal-269 (position M2-13'); 2) at the interface between the αM1 and αM4 helices, identified by photolabeling in αM1 (αCys-222/αLeu-223); and 3) at the lipid-protein interface involving γTrp-453 (M4), a residue photolabeled by small lipophilic probes and promegestone, a steroid nAChR antagonist. Photolabeling in the ion channel and αM1 was higher in the nAChR-desensitized state than in the resting state and inhibitable by promegestone. These results directly indicate a steroid-binding site in the nAChR ion channel and identify additional steroid-binding sites also occupied by other lipophilic nAChR antagonists.
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Affiliation(s)
- Zhiyi Yu
- From the Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - David C Chiara
- From the Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - Pavel Y Savechenkov
- the Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois 60612
| | - Karol S Bruzik
- the Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois 60612
| | - Jonathan B Cohen
- From the Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115 and
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12
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Cheng WWL, Chen ZW, Bracamontes JR, Budelier MM, Krishnan K, Shin DJ, Wang C, Jiang X, Covey DF, Akk G, Evers AS. Mapping two neurosteroid-modulatory sites in the prototypic pentameric ligand-gated ion channel GLIC. J Biol Chem 2018; 293:3013-3027. [PMID: 29301936 DOI: 10.1074/jbc.ra117.000359] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/21/2017] [Indexed: 12/20/2022] Open
Abstract
Neurosteroids are endogenous sterols that potentiate or inhibit pentameric ligand-gated ion channels (pLGICs) and can be effective anesthetics, analgesics, or anti-epileptic drugs. The complex effects of neurosteroids on pLGICs suggest the presence of multiple binding sites in these receptors. Here, using a series of novel neurosteroid-photolabeling reagents combined with top-down and middle-down mass spectrometry, we have determined the stoichiometry, sites, and orientation of binding for 3α,5α-pregnane neurosteroids in the Gloeobacter ligand-gated ion channel (GLIC), a prototypic pLGIC. The neurosteroid-based reagents photolabeled two sites per GLIC subunit, both within the transmembrane domain; one site was an intrasubunit site, and the other was located in the interface between subunits. By using reagents with photoreactive groups positioned throughout the neurosteroid backbone, we precisely map the orientation of neurosteroid binding within each site. Amino acid substitutions introduced at either site altered neurosteroid modulation of GLIC channel activity, demonstrating the functional role of both sites. These results provide a detailed molecular model of multisite neurosteroid modulation of GLIC, which may be applicable to other mammalian pLGICs.
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Affiliation(s)
| | - Zi-Wei Chen
- Department of Anesthesiology; Taylor Family Institute for Innovative Psychiatric Research, Washington University, St. Louis, Missouri 63110
| | | | | | | | | | | | | | - Douglas F Covey
- Department of Anesthesiology; Taylor Family Institute for Innovative Psychiatric Research, Washington University, St. Louis, Missouri 63110; Department of Developmental Biology; Department of Psychiatry
| | - Gustav Akk
- Department of Anesthesiology; Taylor Family Institute for Innovative Psychiatric Research, Washington University, St. Louis, Missouri 63110
| | - Alex S Evers
- Department of Anesthesiology; Taylor Family Institute for Innovative Psychiatric Research, Washington University, St. Louis, Missouri 63110; Department of Developmental Biology.
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13
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Cross SJ, Linker KE, Leslie FM. Sex-dependent effects of nicotine on the developing brain. J Neurosci Res 2017; 95:422-436. [PMID: 27870426 DOI: 10.1002/jnr.23878] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/08/2016] [Accepted: 07/14/2016] [Indexed: 02/06/2023]
Abstract
The use of tobacco products represents a major public health concern, especially among women. Epidemiological data have consistently demonstrated that women have less success quitting tobacco use and a higher risk for developing tobacco-related diseases. The deleterious effects of nicotine are not restricted to adulthood, as nicotinic acetylcholine receptors regulate critical aspects of neural development. However, the exact mechanisms underlying the particular sensitivity of women to develop tobacco dependence have not been well elucidated. In this mini-review, we show that gonadal hormone-mediated sexual differentiation of the brain may be an important determinant of sex differences in the effects of nicotine. We highlight direct interactions between sex steroid hormones and ligand-gated ion channels critical for brain maturation, and discuss the extended and profound sexual differentiation of the brain. We emphasize that nicotine exposure during the perinatal and adolescent periods interferes with normal sexual differentiation and can induce long-lasting, sex-dependent alterations in neuronal structure, cognitive and executive function, learning and memory, and reward processing. We stress important age and sex differences in nicotine's effects and emphasize the importance of including these factors in preclinical research that models tobacco dependence. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Sarah J Cross
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California
| | - Kay E Linker
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California
| | - Frances M Leslie
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California.,Department of Pharmacology, School of Medicine, University of California, Irvine, California
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14
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Jin X, Steinbach JH. Potentiation of Neuronal Nicotinic Receptors by 17β-Estradiol: Roles of the Carboxy-Terminal and the Amino-Terminal Extracellular Domains. PLoS One 2015; 10:e0144631. [PMID: 26684647 PMCID: PMC4684330 DOI: 10.1371/journal.pone.0144631] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/21/2015] [Indexed: 01/21/2023] Open
Abstract
The endogenous steroid 17β-estradiol (βEST) potentiates activation of neuronal nicotinic receptors containing α4 subunits. Previous work has shown that the final 4 residues of the α4 subunit are required for potentiation. However, receptors containing the α2 subunit are not potentiated although it has these 4 residues, and only one amino acid difference in the C-terminal tail (FLAGMI vs. WLAGMI). Previous work had indicated that the tryptophan residue was involved in binding an analog of βEST, but not in potentiation by βEST. To determine the structural basis for the loss of potentiation we analyzed data from chimeric subunits, which indicated that the major factor underlying the difference between α2 and α4 is the tryptophan/phenylalanine difference, while the N-terminal extracellular domain is a less significant factor. When the tryptophan in α4 was mutated, both phenylalanine and tyrosine conferred lower potentiation while lysine and leucine did not. The reduction reflected a reduced maximal magnitude of potentiation, indicating that the tryptophan is involved in transduction of steroid effects. The regions of the α4 N-terminal extracellular domain involved in potentiation lie near the agonist-binding pocket, rather than close to the membrane or the C-terminal tail, and appear to be involved in transduction rather than binding. These observations indicate that the C-terminal region is involved in both steroid binding (AGMI residues) and transduction (W). The role of the N-terminus appears to be independent of the C-terminal tryptophan and likely reflects an influence on conformational changes caused during channel activation by agonist and potentiation by estradiol.
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Affiliation(s)
- Xiaochun Jin
- Department of Anesthesiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Joe Henry Steinbach
- Department of Anesthesiology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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15
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Ton HT, Smart AE, Aguilar BL, Olson TT, Kellar KJ, Ahern GP. Menthol Enhances the Desensitization of Human α3β4 Nicotinic Acetylcholine Receptors. Mol Pharmacol 2015; 88:256-64. [PMID: 25964258 DOI: 10.1124/mol.115.098285] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/11/2015] [Indexed: 11/22/2022] Open
Abstract
The α3β4 nicotinic acetylcholine receptor (nAChR) subtype is widely expressed in the peripheral and central nervous systems, including in airway sensory nerves. The nAChR subtype transduces the irritant effects of nicotine in tobacco smoke and, in certain brain areas, may be involved in nicotine addiction and/or withdrawal. Menthol, a widely used additive in cigarettes, is a potential analgesic and/or counterirritant at sensory nerves and may also influence nicotine's actions in the brain. We examined menthol's effects on recombinant human α3β4 nAChRs and native nAChRs in mouse sensory neurons. Menthol markedly decreased nAChR activity as assessed by Ca(2+) imaging, (86)Rb(+) efflux, and voltage-clamp measurements. Coapplication of menthol with acetylcholine or nicotine increased desensitization, demonstrated by an increase in the rate and magnitude of the current decay and a reduction of the current integral. These effects increased with agonist concentration. Pretreatment with menthol followed by its washout did not affect agonist-induced desensitization, suggesting that menthol must be present during the application of agonist to augment desensitization. Notably, menthol acted in a voltage-independent manner and reduced the mean open time of single channels without affecting their conductance, arguing against a simple channel-blocking effect. Further, menthol slowed or prevented the recovery of nAChRs from desensitization, indicating that it probably stabilizes a desensitized state. Moreover, menthol at concentrations up to 1 mM did not compete for the orthosteric nAChR binding site labeled by [(3)H]epibatidine. Taken together, these data indicate that menthol promotes desensitization of α3β4 nAChRs by an allosteric action.
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Affiliation(s)
- Hoai T Ton
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
| | - Amanda E Smart
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
| | - Brittany L Aguilar
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
| | - Thao T Olson
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
| | - Kenneth J Kellar
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
| | - Gerard P Ahern
- Department of Pharmacology and Physiology, Georgetown University, Washington, District of Columbia
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16
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Barrantes FJ. Phylogenetic conservation of protein-lipid motifs in pentameric ligand-gated ion channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1796-805. [PMID: 25839355 DOI: 10.1016/j.bbamem.2015.03.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/20/2015] [Accepted: 03/25/2015] [Indexed: 12/13/2022]
Abstract
Using the crosstalk between the nicotinic acetylcholine receptor (nAChR) and its lipid microenvironment as a paradigm, this short overview analyzes the occurrence of structural motifs which appear not only to be conserved within the nAChR family and contemporary eukaryotic members of the pentameric ligand-gated ion channel (pLGIC) superfamily, but also extend to prokaryotic homologues found in bacteria. The evolutionarily conserved design is manifested in: 1) the concentric three-ring architecture of the transmembrane region, 2) the occurrence in this region of distinct lipid consensus motifs in prokaryotic and eukaryotic pLGIC and 3) the key participation of the outer TM4 ring in conveying the influence of the lipid membrane environment to the middle TM1-TM3 ring and this, in turn, to the inner TM2 channel-lining ring, which determines the ion selectivity of the channel. The preservation of these constant structural-functional features throughout such a long phylogenetic span likely points to the successful gain-of-function conferred by their early acquisition. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Institute for Biomedical Research (BIOMED), Faculty of Medical Sciences, UCA-CONICET, Av. Alicia Moreau de Justo 1600, C1107AFF Buenos Aires, Argentina.
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17
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Hill M, Dušková M, Stárka L. Dehydroepiandrosterone, its metabolites and ion channels. J Steroid Biochem Mol Biol 2015; 145:293-314. [PMID: 24846830 DOI: 10.1016/j.jsbmb.2014.05.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 05/06/2014] [Accepted: 05/11/2014] [Indexed: 11/20/2022]
Abstract
This review is focused on the physiological and pathophysiological relevance of steroids influencing the activities of the central and peripheral nervous systems with regard to their concentrations in body fluids and tissues in various stages of human life like the fetal development or pregnancy. The data summarized in this review shows that DHEA and its unconjugated and sulfated metabolites are physiologically and pathophysiologically relevant in modulating numerous ion channels and participate in vital functions of the human organism. DHEA and its unconjugated and sulfated metabolites including 5α/β-reduced androstane steroids participate in various physiological and pathophysiological processes like the management of GnRH cyclic release, regulation of glandular and neurotransmitter secretions, maintenance of glucose homeostasis on one hand and insulin insensitivity on the other hand, control of skeletal muscle and smooth muscle activities including vasoregulation, promotion of tolerance to ischemia and other neuroprotective effects. In respect of prevalence of steroid sulfates over unconjugated steroids in the periphery and the opposite situation in the CNS, the sulfated androgens and androgen metabolites reach relevance in peripheral organs. The unconjugated androgens and estrogens are relevant in periphery and so much the more in the CNS due to higher concentrations of most unconjugated steroids in the CNS tissues than in circulation and peripheral organs. This article is part of a Special Issue entitled "Essential role of DHEA".
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Affiliation(s)
- M Hill
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - M Dušková
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - L Stárka
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
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18
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Neurosteroids, stress and depression: potential therapeutic opportunities. Neurosci Biobehav Rev 2012; 37:109-22. [PMID: 23085210 DOI: 10.1016/j.neubiorev.2012.10.005] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/28/2012] [Accepted: 10/02/2012] [Indexed: 12/19/2022]
Abstract
Neurosteroids are potent and effective neuromodulators that are synthesized from cholesterol in the brain. These agents and their synthetic derivatives influence the function of multiple signaling pathways including receptors for γ-aminobutyric acid (GABA) and glutamate, the major inhibitory and excitatory neurotransmitters in the central nervous system (CNS). Increasing evidence indicates that dysregulation of neurosteroid production plays a role in the pathophysiology of stress and stress-related psychiatric disorders, including mood and anxiety disorders. In this paper, we review the mechanisms of neurosteroid action in brain with an emphasis on those neurosteroids that potently modulate the function of GABA(A) receptors. We then discuss evidence indicating a role for GABA and neurosteroids in stress and depression, and focus on potential strategies that can be used to manipulate CNS neurosteroid synthesis and function for therapeutic purposes.
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19
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Large conductance, calcium- and voltage-gated potassium (BK) channels: regulation by cholesterol. Pharmacol Ther 2012; 135:133-50. [PMID: 22584144 DOI: 10.1016/j.pharmthera.2012.05.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 04/09/2012] [Indexed: 11/21/2022]
Abstract
Cholesterol (CLR) is an essential component of eukaryotic plasma membranes. CLR regulates the membrane physical state, microdomain formation and the activity of membrane-spanning proteins, including ion channels. Large conductance, voltage- and Ca²⁺-gated K⁺ (BK) channels link membrane potential to cell Ca²⁺ homeostasis. Thus, they control many physiological processes and participate in pathophysiological mechanisms leading to human disease. Because plasmalemma BK channels cluster in CLR-rich membrane microdomains, a major driving force for studying BK channel-CLR interactions is determining how membrane CLR controls the BK current phenotype, including its pharmacology, channel sorting, distribution, and role in cell physiology. Since both BK channels and CLR tissue levels play a pathophysiological role in human disease, identifying functional and structural aspects of the CLR-BK channel interaction may open new avenues for therapeutic intervention. Here, we review the studies documenting membrane CLR-BK channel interactions, dissecting out the many factors that determine the final BK current response to changes in membrane CLR content. We also summarize work in reductionist systems where recombinant BK protein is studied in artificial lipid bilayers, which documents a direct inhibition of BK channel activity by CLR and builds a strong case for a direct interaction between CLR and the BK channel-forming protein. Bilayer lipid-mediated mechanisms in CLR action are also discussed. Finally, we review studies of BK channel function during hypercholesterolemia, and underscore the many consequences that the CLR-BK channel interaction brings to cell physiology and human disease.
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20
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Use of concatemers of ligand-gated ion channel subunits to study mechanisms of steroid potentiation. Anesthesiology 2012; 115:1328-37. [PMID: 21926904 DOI: 10.1097/aln.0b013e318233046a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Synaptic receptors of the nicotinic receptor gene family are pentamers of subunits. This modular structure creates problems in studies of drug actions, related to the number of copies of a subunit that are present and their position. A separate issue concerns the mechanism of action of many anesthetics, which involves potentiation of responses to neurotransmitters. Potentiation requires an interaction between a transmitter and a potentiator, mediated through the target receptor. We have studied the mechanism by which neurosteroids potentiate transmitter responses, using concatemers of covalently linked subunits to control the number and position of subunits in the assembled receptor and to selectively introduce mutations into positionally defined copies of a subunit. We found that the steroid needs to interact with only one site to produce potentiation, that the native sites for steroid interaction have indistinguishable properties, and that steroid potentiation appears to result from a global effect on receptor function.
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21
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Pandya A, Yakel JL. Allosteric modulators of the α4β2 subtype of neuronal nicotinic acetylcholine receptors. Biochem Pharmacol 2011; 82:952-8. [PMID: 21596025 PMCID: PMC3162104 DOI: 10.1016/j.bcp.2011.04.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 04/28/2011] [Accepted: 04/29/2011] [Indexed: 02/07/2023]
Abstract
Nicotinic acetylcholine receptors are ligand-gated ion conducting transmembrane channels from the Cys-loop receptor super-family. The α4β2 subtype is the predominant heteromeric subtype of nicotinic receptors found in the brain. Allosteric modulators for α4β2 receptors interact at a site other than the orthosteric site where acetylcholine binds. Many compounds which act as allosteric modulators of the α4β2 receptors have been identified, with both positive and negative effects. Such allosteric modulators either increase or decrease the response induced by agonist on the α4β2 receptors. Here we discuss the concept of allosterism as it pertains to the α4β2 receptors and summarize the important features of allosteric modulators for this nicotinic receptor subtype.
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Affiliation(s)
- Anshul Pandya
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
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22
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Williams DK, Wang J, Papke RL. Positive allosteric modulators as an approach to nicotinic acetylcholine receptor-targeted therapeutics: advantages and limitations. Biochem Pharmacol 2011; 82:915-30. [PMID: 21575610 DOI: 10.1016/j.bcp.2011.05.001] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 04/28/2011] [Accepted: 05/02/2011] [Indexed: 11/16/2022]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChR), recognized targets for drug development in cognitive and neuro-degenerative disorders, are allosteric proteins with dynamic interconversions between multiple functional states. Activation of the nAChR ion channel is primarily controlled by the binding of ligands (agonists, partial agonists, competitive antagonists) at conventional agonist binding sites, but is also regulated in either negative or positive ways by the binding of ligands to other modulatory sites. In this review, we discuss models for the activation and desensitization of nAChR, and the discovery of multiple types of ligands that influence those processes in both heteromeric nAChR, such as the high-affinity nicotine receptors of the brain, and homomeric α7-type receptors. In recent years, α7 nAChRs have been identified as a potential target for therapeutic indications leading to the development of α7-selective agonists and partial agonists. However, unique properties of α7 nAChR, including low probability of channel opening and rapid desensitization, may limit the therapeutic usefulness of ligands binding exclusively to conventional agonist binding sites. New enthusiasm for the therapeutic targeting of α7 has come from the identification of α7-selective positive allosteric modulators (PAMs) that work effectively on the intrinsic factors that limit α7 ion channel activation. While these new drugs appear promising for therapeutic development, we also consider potential caveats and possible limitations for their use, including PAM-insensitive forms of desensitization and cytotoxicity issues.
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Affiliation(s)
- Dustin K Williams
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL Neurocypres, United States
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23
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A novel mechanism of modulation of 5-HT₃A receptors by hydrocortisone. Biophys J 2011; 100:42-51. [PMID: 21190655 DOI: 10.1016/j.bpj.2010.10.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 10/19/2010] [Accepted: 10/27/2010] [Indexed: 11/24/2022] Open
Abstract
Modulation of Cys-loop receptors by steroids is of physiological and therapeutical relevance. Nonetheless, its molecular mechanism has not been elucidated for serotonin (5-HT) type 3 receptors. We deciphered the mechanism of action of hydrocortisone (HC) at 5-HT type 3A receptors. Single-channel currents from the high-conductance form (∼4.7 pA, -70 mV) appear as a series of long opening events forming bursts, which group into long clusters. Although they are very infrequent, subconductance events (∼2.4 pA) are detected within clusters. HC produces a significant concentration-dependent reduction in open and burst durations, demonstrating open-channel block. In addition, it increases the appearance of subconductance levels in a concentration- and slightly voltage-dependent manner. The amplitude of the subconductance level does not change with HC concentration and its open duration is briefer than that of full amplitude events, indicating lower open-channel stability. Dual effects are distinguished from macroscopic responses: HC reduces amplitude by acting from either open or closed states, and it increases decay rates from the open state. Thus, HC acts as a negative modulator of 5-HT type 3A receptors by different mechanisms: It acts as an open-channel blocker and it favors opening to a preexisting subconductance level. The latter constitutes a novel, to our knowledge, mechanism of channel modulation, which might be applicable to other steroids and channels.
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Kandi P, Hayslett R. Nicotine and 17β-estradiol produce an antidepressant-like effect in female ovariectomized rats. Brain Res Bull 2011; 84:224-8. [DOI: 10.1016/j.brainresbull.2010.12.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/17/2010] [Accepted: 12/20/2010] [Indexed: 10/18/2022]
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Rammouz G, Lecanu L, Papadopoulos V. Oxidative Stress-Mediated Brain Dehydroepiandrosterone (DHEA) Formation in Alzheimer's Disease Diagnosis. Front Endocrinol (Lausanne) 2011; 2:69. [PMID: 22654823 PMCID: PMC3356139 DOI: 10.3389/fendo.2011.00069] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 10/19/2011] [Indexed: 02/06/2023] Open
Abstract
Neurosteroids are steroids made by brain cells independently of peripheral steroidogenic sources. The biosynthesis of most neurosteroids is mediated by proteins and enzymes similar to those identified in the steroidogenic pathway of adrenal and gonadal cells. Dehydroepiandrosterone (DHEA) is a major neurosteroid identified in the brain. Over the years we have reported that, unlike other neurosteroids, DHEA biosynthesis in rat, bovine, and human brain is mediated by an oxidative stress-mediated mechanism, independent of the cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) enzyme activity found in the periphery. This alternative pathway is induced by pro-oxidant agents, such as Fe(2+) and β-amyloid peptide. Neurosteroids are involved in many aspects of brain function, and as such, are involved in various neuropathologies, including Alzheimer's disease (AD). AD is a progressive, yet irreversible neurodegenerative disease for which there are limited means for ante-mortem diagnosis. Using brain tissue specimens from control and AD patients, we provided evidence that DHEA is formed in the AD brain by the oxidative stress-mediated metabolism of an unidentified precursor, thus depleting levels of the precursor in the blood stream. We tested for the presence of this DHEA precursor in human serum using a Fe(2+)-based reaction and determined the amounts of DHEA formed. Fe(2+) treatment of the serum resulted in a dramatic increase in DHEA levels in control patients, whereas only a moderate or no increase was observed in AD patients. The DHEA variation after oxidation correlated with the patients' cognitive and mental status. In this review, we present the cumulative evidence for oxidative stress as a natural regulator of DHEA formation and the use of this concept to develop a blood-based diagnostic tool for neurodegenerative diseases linked to oxidative stress, such as AD.
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Affiliation(s)
- Georges Rammouz
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
| | - Laurent Lecanu
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
| | - Vassilios Papadopoulos
- Department of Medicine, The Research Institute of the McGill University Health Centre, McGill UniversityMontreal, QC, Canada
- Department of Biochemistry, McGill UniversityMontreal, QC, Canada
- Department of Pharmacology and Therapeutics, McGill UniversityMontreal, QC, Canada
- *Correspondence: Vassilios Papadopoulos, The Research Institute of the McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, C10-148, Montreal, QC, Canada H3G 1A4. e-mail:
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Bukiya AN, Belani JD, Rychnovsky S, Dopico AM. Specificity of cholesterol and analogs to modulate BK channels points to direct sterol-channel protein interactions. J Gen Physiol 2011; 137:93-110. [PMID: 21149543 PMCID: PMC3010061 DOI: 10.1085/jgp.201010519] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 11/22/2010] [Indexed: 11/26/2022] Open
Abstract
The activity (Po) of large-conductance voltage/Ca(2+)-gated K(+) (BK) channels is blunted by cholesterol levels within the range found in natural membranes. We probed BK channel-forming α (cbv1) subunits in phospholipid bilayers with cholesterol and related monohydroxysterols and performed computational dynamics to pinpoint the structural requirements for monohydroxysterols to reduce BK Po and obtain insights into cholesterol's mechanism of action. Cholesterol, cholestanol, and coprostanol reduced Po by shortening mean open and lengthening mean closed times, whereas epicholesterol, epicholestanol, epicoprostanol, and cholesterol trisnorcholenic acid were ineffective. Thus, channel inhibition by monohydroxysterols requires the β configuration of the C3 hydroxyl and is favored by the hydrophobic nature of the side chain, while having lax requirements on the sterol A/B ring fusion. Destabilization of BK channel open state(s) has been previously interpreted as reflecting increased bilayer lateral stress by cholesterol. Lateral stress is controlled by the sterol molecular area and lipid monolayer lateral tension, the latter being related to the sterol ability to adopt a planar conformation in lipid media. However, we found that the differential efficacies of monohydroxysterols to reduce Po (cholesterol≥coprostanol≥cholestanol>>>epicholesterol) did not follow molecular area rank (coprostanol>>epicholesterol>cholesterol>cholestanol). In addition, computationally predicted energies for cholesterol (effective BK inhibitor) and epicholesterol (ineffective) to adopt a planar conformation were similar. Finally, cholesterol and coprostanol reduced Po, yet these sterols have opposite effects on tight lipid packing and, likely, on lateral stress. Collectively, these findings suggest that an increase in bilayer lateral stress is unlikely to underlie the differential ability of cholesterol and related steroids to inhibit BK channels. Remarkably, ent-cholesterol (cholesterol mirror image) failed to reduce Po, indicating that cholesterol efficacy requires sterol stereospecific recognition by a protein surface. The BK channel phenotype resembled that of α homotetramers. Thus, we hypothesize that a cholesterol-recognizing protein surface resides at the BK α subunit itself.
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Affiliation(s)
- Anna N. Bukiya
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163
| | | | - Scott Rychnovsky
- Department of Chemistry, University of California, Irvine, CA 92697
| | - Alex M. Dopico
- Department of Pharmacology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163
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Sofuoglu M, Mouratidis M, Mooney M. Progesterone improves cognitive performance and attenuates smoking urges in abstinent smokers. Psychoneuroendocrinology 2011; 36:123-32. [PMID: 20675057 PMCID: PMC2987547 DOI: 10.1016/j.psyneuen.2010.07.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 01/08/2023]
Abstract
BACKGROUND Progesterone, a steroid hormone, has been implicated in many CNS functions including reward, cognition, and neuroprotection. The goal of this study was to examine the dose-dependent effects of progesterone on cognitive performance, smoking urges, and smoking behavior in smokers. METHODS Thirty female and thirty-four male smokers participated in a double-blind, placebo-controlled study. Female smokers were in the early follicular phase of their menstrual cycle during study participation. Smokers were randomly assigned to either 200 or 400mg/day of progesterone or placebo, given in two separate doses, during clinic visit. The first 3 days of the treatment period, smokers abstained from smoking, which was verified with breath CO levels. Smokers attended an experimental session on day 4 where the number of cigarettes smoked were recorded starting 2h after the medication treatment. RESULTS Progesterone treatment, 200mg/day, significantly improved cognitive performance in the Stroop and the Digit Symbol Substitution Test. Progesterone at 400mg/day was associated with reduced urges for smoking but did not change ad lib smoking behavior. CONCLUSIONS These findings suggest a potential therapeutic value of progesterone for smoking cessation.
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Affiliation(s)
- Mehmet Sofuoglu
- Yale University, School of Medicine, Department of Psychiatry, VA Connecticut Healthcare System, West Haven, CT, USA.
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Li P, Steinbach JH. The neuronal nicotinic alpha4beta2 receptor has a high maximal probability of being open. Br J Pharmacol 2010; 160:1906-15. [PMID: 20649589 DOI: 10.1111/j.1476-5381.2010.00761.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE A fundamental property of transmitter-gated ion channels is the probability a channel will be open (P(open)) when stimulated by a concentration of agonist that elicits a maximal response. This value is critical for interpreting steady-state concentration-response relationships in terms of channel activation, and for understanding the actions of drugs that potentiate responses. We used analysis of non-stationary noise to estimate the maximal probability the nicotinic alpha4beta2 receptor is open. EXPERIMENTAL APPROACH HEK293 cells stably transfected to express human alpha4beta2 nicotinic receptors were studied using whole-cell voltage clamp. Nicotinic agonists (acetylcholine, nicotine, cytisine and 5-iodo A-85380) were applied, and the relationship between variance of the elicited whole-cell current and mean current was analysed. KEY RESULTS The variance did not increase linearly with the mean current. For acetylcholine and nicotine the relationship between variance and mean indicates that the maximal P(open) is greater than 0.8. The number of agonist-activatable channels was estimated to be about 1000 per cell. The mean single channel conductance at -60 mV was indistinguishable when currents were elicited by acetylcholine (18 pS), nicotine (17 pS) or 5-iodo A-85380 (17 pS), whereas the value for cytisine was larger (24 pS). CONCLUSIONS AND IMPLICATIONS The neuronal nicotinic alpha4beta2 receptor has a maximal probability of being open that is greater than 0.8. This conclusion applies to the receptor containing three alpha4 and two beta2 subunits (the low-sensitivity stoichiometry), but may not apply to the receptor containing two alpha4 and three beta2 subunits (the high-sensitivity stoichiometry).
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Affiliation(s)
- Ping Li
- Department of Anesthesiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
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Sofuoglu M, Mitchell E, Mooney M. Progesterone effects on subjective and physiological responses to intravenous nicotine in male and female smokers. Hum Psychopharmacol 2009; 24:559-64. [PMID: 19743227 PMCID: PMC2785078 DOI: 10.1002/hup.1055] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Previous studies suggest possible modulatory effects of progesterone on nicotine addiction. The goal of this study was to determine the effects of progesterone, on acute physiological and subjective responses to intravenous (IV) nicotine in overnight abstinent male and female smokers. METHODS Twelve smokers, six males and six females, participated in a double-blind, placebo-controlled, crossover study, which consisted of two experimental sessions. Before each session, subjects were treated orally with a single dose of either 200 mg progesterone or placebo. Starting 2 h following the medication treatment, subjects received an IV saline injection, followed by 0.5 and 1.0 mg/70 kg IV nicotine. RESULTS Progesterone treatment, compared to placebo, enhanced the ratings of "bad effects," from IV nicotine and attenuated the rating of "drug liking." Progesterone also enhanced suppression of smoking urges by nicotine as assessed by the Brief Questionnaire on Smoking Urges (BQSU). CONCLUSIONS These results suggest that progesterone may alter the subjective effects of nicotine as well as urges to smoke cigarettes. Further studies are warranted to examine the modulation of nicotine's effects by gonadal hormones.
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Affiliation(s)
- Mehmet Sofuoglu
- Department of Psychiatry and VA Connecticut Healthcare System, Yale University School of Medicine, West Haven, Connecticut 06516, USA.
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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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Covey DF. ent-Steroids: novel tools for studies of signaling pathways. Steroids 2009; 74:577-85. [PMID: 19103212 PMCID: PMC2668732 DOI: 10.1016/j.steroids.2008.11.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 11/21/2008] [Accepted: 11/24/2008] [Indexed: 12/24/2022]
Abstract
Membrane receptors are often modulated by steroids and it is necessary to distinguish the effects of steroids at these receptors from effects occurring at nuclear receptors. Additionally, it may also be mechanistically important to distinguish between direct effects caused by binding of steroids to membrane receptors and indirect effects on membrane receptor function caused by steroid perturbation of the membrane containing the receptor. In this regard, ent-steroids, the mirror images of naturally occurring steroids, are novel tools for distinguishing between these various actions of steroids. The review provides a background for understanding the different actions that can be expected of steroids and ent-steroids in biological systems, references for the preparation of ent-steroids, a short discussion about relevant forms of stereoisomerism and the requirements that need to be fulfilled for the interaction between two molecules to be enantioselective. The review then summarizes results of biophysical, biochemical and pharmacological studies published since 1992 in which ent-steroids have been used to investigate the actions of steroids in membranes and/or receptor-mediated signaling pathways.
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Affiliation(s)
- Douglas F Covey
- Department of Developmental Biology, Campus Box 8103, Washington Univ. in St. Louis, School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, United States.
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Chen Y, Cui Y, Lin JW, Xiang QL, Liu WF, Wang TH. Modulatory role of estradiol in nicotinic antinociception in adult female rats. Life Sci 2009; 85:91-6. [DOI: 10.1016/j.lfs.2009.04.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/30/2009] [Accepted: 04/30/2009] [Indexed: 10/20/2022]
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Soltész S, Mencke T, Stunz M, Diefenbach C, Ziegeler S, Molter GP. Attenuation of a rocuronium-induced neuromuscular block in patients receiving prednisolone. Acta Anaesthesiol Scand 2009; 53:443-8. [PMID: 19317861 DOI: 10.1111/j.1399-6576.2009.01908.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND This study tested the influence of continuous medication (more than 4 weeks) with prednisolone on a rocuronium-induced neuromuscular block. METHODS The time course of a rocuronium-induced neuromuscular blockade (0.3 mg/kg) was investigated in 40 patients with chronic inflammatory bowel disease undergoing elective abdominal surgery. The primary end point was the time from the start of injection of rocuronium until recovery of the TOF ratio to 0.9. Twenty patients received continuous medication with prednisolone (group A), and 20 were without glucocorticoid medication (group B). Additionally, another 20 patients without inflammatory bowel disease and without glucocorticoid medication served as control (group C). RESULTS The onset time was prolonged in group A [253 (51.2) s] compared with group B [187 (61.3) s]. Twitch height at the onset of the block was higher in group A [16.5 (0-61)%] than that in group B [5.0 (0-33)%]. The duration to 25% twitch height was shorter in group A [12.6 (0-20.7) min] compared with group B [16.7 (0-25.3) min] and group C [16.9 (0-29.3) min]. The recovery to a train-of-four ratio of 0.9 was reduced in group A [25.7 (23-34.3) min] compared with group B [34.7 (32.7-44.2) min] and group C [36.5 (31.7-42.3) min]. CONCLUSIONS Prednisolone treatment in patients with inflammatory bowel disease is associated with a delayed onset and a shorter duration of action of rocuronium. The presence of an inflammatory bowel disease did not influence the neuromuscular block.
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Affiliation(s)
- S Soltész
- Department of Anaesthesia and Intensive Care, Hospital Leverkusen, Am Gesundheitspark 11, Leverkusen, Germany.
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Martín-García E, Pallarés M. A post-training intrahippocampal anxiogenic dose of the neurosteroid pregnenolone sulfate impairs passive avoidance retention. Exp Brain Res 2008; 191:123-31. [DOI: 10.1007/s00221-008-1506-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 07/02/2008] [Indexed: 01/04/2023]
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Soltész S, Mencke T, Mey C, Röhrig S, Diefenbach C, Molter GP. Influence of a continuous prednisolone medication on the time course of neuromuscular block of atracurium in patients with chronic inflammatory bowel disease. Br J Anaesth 2008; 100:798-802. [PMID: 18400809 DOI: 10.1093/bja/aen084] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Corticosteroids interact with neuromuscular blocking agents. However, experimental data are contradictory: enhancement and attenuation of the neuromuscular block has been observed. This study tested the influence of long-term medication with prednisolone on atracurium-induced neuromuscular block. METHODS Sixty patients with chronic inflammatory bowel disease undergoing elective abdominal surgery were investigated. Thirty patients received a long-term medication with prednisolone (Group A) and 30 were without corticoid medication (Group B). Additionally, another 30 patients without inflammatory bowel disease and without corticoid medication served as control (Group C). The following parameters of an atracurium-induced neuromuscular block (0.25 mg kg(-1)) were measured: onset time, maximum block, recovery to 25% first twitch height, recovery index (time from 25% until 75% recovery of first twitch), duration to recovery to a train-of-four (TOF) rate of 0.7 and 0.9. RESULTS The groups did not differ with regard to onset time, maximum block, and recovery index. The duration to 25% twitch height was significantly lower in Group A [18.1 (0-30.7) min] compared with Group B [23.5 (0-36.7) min; P<0.05]. Duration to a TOF rate of 0.7 and 0.9, respectively, were significantly reduced in Group A [36.1 (7.9) and 40.9 (9.0 min)] compared with Group B [47.9 (7.6) and 53.4 (9.2) min; P<0.001]. CONCLUSIONS Long-term medication with prednisolone resulted in a shorter duration of an atracurium-induced neuromuscular block in patients with Crohn's disease or ulcerative colitis. The presence of the inflammatory bowel disease did not influence the time course of the neuromuscular block.
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Affiliation(s)
- S Soltész
- Department of Anaesthesia and Intensive Care, Hospital Leverkusen, Am Gesundheitspark 11, D-51375 Leverkusen, Germany.
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Hamouda AK, Sanghvi M, Chiara DC, Cohen JB, Blanton MP. Identifying the lipid-protein interface of the alpha4beta2 neuronal nicotinic acetylcholine receptor: hydrophobic photolabeling studies with 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine. Biochemistry 2007; 46:13837-46. [PMID: 17994769 DOI: 10.1021/bi701705r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Using an acetylcholine-derivatized affinity column, we have purified human alpha4beta2 neuronal nicotinic acetylcholine receptors (nAChRs) from a stably transfected HEK-293 cell line. Both the quantity and the quality of the purified receptor are suitable for applying biochemical methods to directly study the structure of the alpha4beta2 nAChR. In this first study, the lipid-protein interface of purified and lipid-reconstituted alpha4beta2 nAChRs was directly examined using photoaffinity labeling with the hydrophobic probe 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID). [125I]TID photoincorporated into both alpha4 and beta2 subunits, and for each subunit the labeling was initially mapped to fragments containing the M4 and M1-M3 transmembrane segments. For both the alpha4 and beta2 subunits, approximately 60% of the total labeling was localized within fragments that contain the M4 segment, which suggests that the M4 segment has the greatest exposure to lipid. Within M4 segments, [125I]TID labeled homologous amino acids alpha4-Cys582/beta2-Cys445, which are also homologous to the [125I]TID-labeled residues alpha1-Cys418 and beta1-Cys447 in the lipid-exposed face of Torpedo nAChR alpha1M4 and beta1M4, respectively. Within the alpha4M1 segment, [125I]TID labeled residues Cys226 and Cys231, which correspond to the [125I]TID-labeled residues Cys222 and Phe227 at the lipid-exposed face of the Torpedo alpha1M1 segment. In beta2M1, [125I]TID labeled beta2-Cys220, which is homologous to alpha4-Cys226. We conclude from these studies that the alpha4beta2 nAChR can be purified from stably transfected HEK-293 cells in sufficient quantity and purity for structural studies and that the lipid-protein interfaces of the neuronal alpha4beta2 nAChR and the Torpedo nAChR display a high degree of structural homology.
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Affiliation(s)
- Ayman K Hamouda
- Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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Li W, Jin X, Covey DF, Steinbach JH. Neuroactive steroids and human recombinant rho1 GABAC receptors. J Pharmacol Exp Ther 2007; 323:236-47. [PMID: 17636008 DOI: 10.1124/jpet.107.127365] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The gamma-aminobutyric acid type C (GABAC) receptor is structurally related to the GABAA receptors, yet quite distinct physiologically and pharmacologically. Neuroactive steroids are known to be potent and efficacious modulators of the GABAA receptor, but they are less well characterized in their actions on the GABAC receptor. We have examined the actions of neuroactive steroids and analogs on rho1 (GABAC) receptors expressed in Xenopus laevis oocytes, with two goals in mind. First, we tested a larger number of endogenous steroids, to determine whether particularly potent steroids could be found. Second, we examined the structure-activity relationship for steroid actions, and some mechanistic features, to determine the possible numbers of steroid binding sites and mechanisms of action. In total, 41 compounds were examined. Estradiols are inhibitors, essentially equipotent with picrotoxinin. No endogenous steroid tested was highly efficacious at potentiation. The results of the structure-activity studies and the effects of two mutations to the second transmembrane region of the rho1 GABAC receptor indicate that there are several mechanisms by which steroids can inhibit the receptor. Surprisingly, estradiol shares some features with picrotoxin. Inhibition by negatively charged compounds was not sensitive to membrane potential, and inhibition by all compounds tested was reduced at higher concentrations of GABA. The data indicate that the binding sites mediating potentiation and inhibition differ from each other and that there are several (three or more) mechanisms for producing inhibition.
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Affiliation(s)
- Wenjun Li
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO, USA
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Akk G, Covey DF, Evers AS, Steinbach JH, Zorumski CF, Mennerick S. Mechanisms of neurosteroid interactions with GABA(A) receptors. Pharmacol Ther 2007; 116:35-57. [PMID: 17524487 PMCID: PMC2047817 DOI: 10.1016/j.pharmthera.2007.03.004] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 03/29/2007] [Indexed: 11/20/2022]
Abstract
Neuroactive steroids have some of their most potent actions by augmenting the function of GABA(A) receptors. Endogenous steroid actions on GABA(A) receptors may underlie important effects on mood and behavior. Exogenous neuroactive steroids have potential as anesthetics, anticonvulsants, and neuroprotectants. We have taken multiple approaches to understand more completely the interaction of neuroactive steroids with GABA(A) receptors. We have developed many novel steroid analogues in this effort. Recent work has resulted in synthesis of new enantiomer analogue pairs, novel ligands that probe various properties of the steroid pharmacophore, fluorescent neuroactive steroid analogues, and photoaffinity labels. Using these tools, combined with receptor binding and electrophysiological assays, we have begun to untangle the complexity of steroid actions at this important class of ligand-gated ion channel.
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Affiliation(s)
- Gustav Akk
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
| | - Douglas F. Covey
- Department of Molecular Biology & Pharmacology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
| | - Alex S. Evers
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
- Department of Molecular Biology & Pharmacology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
| | - Joe Henry Steinbach
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
- Department of Anatomy & Neurobiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
| | - Charles F. Zorumski
- Department of Anatomy & Neurobiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
| | - Steven Mennerick
- Department of Anatomy & Neurobiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
- Department of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110
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39
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Azam L, Chen Y, Leslie FM. Developmental regulation of nicotinic acetylcholine receptors within midbrain dopamine neurons. Neuroscience 2006; 144:1347-60. [PMID: 17197101 PMCID: PMC2020843 DOI: 10.1016/j.neuroscience.2006.11.011] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 10/11/2006] [Accepted: 11/08/2006] [Indexed: 11/24/2022]
Abstract
We have combined anatomical and functional methodologies to provide a comprehensive analysis of the properties of nicotinic acetylcholine receptors (nAChRs) on developing dopamine (DA) neurons of Sprague-Dawley rats. Double-labeling in situ hybridization was used to examine the expression of nAChR subunit mRNAs within developing midbrain DA neurons. As brain maturation progressed there was a change in the pattern of subunit mRNA expression within DA neurons, such that alpha3 and alpha4 subunits declined and alpha6 mRNA increased. Although there were strong similarities in subunit mRNA expression in substantia nigra (SNc) and ventral tegmental area (VTA), there was higher expression of alpha4 mRNA in SNc than VTA at gestational day (G) 15, and of alpha5, alpha6 and beta3 mRNAs during postnatal development. Using a superfusion neurotransmitter release paradigm to functionally characterize nicotine-stimulated release of [(3)H]DA from striatal slices, the properties of the nAChRs on DA terminals were also found to change with age. Functional nAChRs were detected on striatal terminals at G18. There was a decrease in maximal release in the first postnatal week, followed by an increase in nicotine efficacy and potency during the second and third postnatal weeks. In the transition from adolescence (postnatal days (P) 30 and 40) to adulthood, there was a complex pattern of functional maturation of nAChRs in ventral, but not dorsal, striatum. In males, but not females, there were significant changes in both nicotine potency and efficacy during this developmental period. These findings suggest that nAChRs may play critical functional roles throughout DA neuronal maturation.
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Affiliation(s)
- L Azam
- Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112, USA.
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40
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Li W, Covey DF, Alakoskela JM, Kinnunen PKJ, Steinbach JH. Enantiomers of neuroactive steroids support a specific interaction with the GABA-C receptor as the mechanism of steroid action. Mol Pharmacol 2006; 69:1779-82. [PMID: 16527905 DOI: 10.1124/mol.106.022863] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuroactive steroids can either potentiate or inhibit a variety of membrane channels. Most studies have suggested that the effects are mediated by specific association of the steroid with the affected channel. However, a recent study of the rho1 (GABA-C) receptor (Mol Pharmacol 66:56-69, 2004) concluded that the actions were consistent with an action of the steroid in the lipid bilayer to alter the lateral pressure profile in the membrane. The enantiomers of an optically active compound are expected to have identical physical properties, including interactions with hydrophobic portions of the cell membrane. We have used two pairs of enantiomers (pregnanolone and ent-pregnanolone, allopregnanolone and ent-allopregnanolone) and show that the ability to potentiate (allopregnanolone) or inhibit (pregnanolone) the rho1 receptor is enantioselective. Therefore, these results strongly suggest that the actions of these neuroactive steroids are mediated by interactions with chiral regions of the target protein, rather than by a change in membrane properties (including lateral pressure).
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Affiliation(s)
- Wenjun Li
- Department of Anesthesiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA
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41
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Arias HR, Bhumireddy P, Bouzat C. Molecular mechanisms and binding site locations for noncompetitive antagonists of nicotinic acetylcholine receptors. Int J Biochem Cell Biol 2006; 38:1254-76. [PMID: 16520081 DOI: 10.1016/j.biocel.2006.01.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 01/03/2006] [Accepted: 01/12/2006] [Indexed: 01/16/2023]
Abstract
Nicotinic acetylcholine receptors are pentameric proteins that belong to the Cys-loop receptor superfamily. Their essential mechanism of functioning is to couple neurotransmitter binding, which occurs at the extracellular domain, to the opening of the membrane-spanning cation channel. The function of these receptors can be modulated by structurally different compounds called noncompetitive antagonists. Noncompetitive antagonists may act at least by two different mechanisms: a steric and/or an allosteric mechanism. The simplest idea representing a steric mechanism is that the antagonist molecule physically blocks the ion channel. On the other hand, there exist distinct allosteric mechanisms. For example, noncompetitive antagonists may bind to the receptor and stabilize a nonconducting conformational state (e.g., resting or desensitized state), and/or increase the receptor desensitization rate. Barbiturates, dissociative anesthetics, antidepressants, and neurosteroids have been shown to inhibit nicotinic receptors by allosteric mechanisms and/or by open- and closed-channel blockade. Receptor modulation has proved to be highly complex for most noncompetitive antagonists. Noncompetitive antagonists may act by more than one mechanism and at distinct sites in the same receptor subtype. The binding site location for one particular molecule depends on the conformational state of the receptor. The mechanisms of action and binding affinities of noncompetitive antagonists differ among nicotinic receptor subtypes. Knowledge of the structure of the nicotinic acetylcholine receptor, the location of its noncompetitive antagonist binding sites, and the mechanisms of inhibition will aid the design of new and more efficacious drugs for treatment of neurological diseases.
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Affiliation(s)
- Hugo R Arias
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 E. Second Street, Pomona, CA 91766-1854, USA.
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42
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Martin-Garcia E, Pallares M. The intrahippocampal administration of the neurosteroid allopregnanolone blocks the audiogenic seizures induced by nicotine. Brain Res 2005; 1062:144-50. [PMID: 16256958 DOI: 10.1016/j.brainres.2005.09.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 09/02/2005] [Accepted: 09/25/2005] [Indexed: 10/25/2022]
Abstract
Allopregnanolone (AlloP), GABA(A) positive modulator, has efficacy as anticonvulsant. In contrast, nicotine and pregnenolone sulfate (PregS) act as potent convulsants. The present study aims to evaluate whether a promnesic dose of PregS and/or an anxiolytic dose of AlloP administered in the hippocampus can affect the audiogenic seizures induced by nicotine administration. Rats were assigned at random to six groups that received two consecutive intrahippocampal (dorsal CA1) injections once a week during three consecutive weeks. First injection: nicotine (4.6 microg, 20 mM) or saline, second injection: PregS (5 ng, 24 microM), AlloP (0.2 microg, 1.26 microM) or saline. After the last injections, locomotor activity and audiogenic seizures were tested. AlloP decreased the horizontal and vertical activity, suggesting sedative effects. Nicotine induced behavioral convulsions and AlloP acted as an anticonvulsant. AlloP reversed the seizures induced by nicotine and decreased the audiogenic convulsions in comparison with the controls. PregS also reversed the nicotine-induced audiogenic seizures in the nicotine group but not in the control group. These results suggest that anticonvulsive effects of AlloP and PregS are mediated by different action mechanisms such as GABA(A) positive modulation, or negative modulatory action on neural nicotinic acetylcholine receptors. Even though several brain structures could be involved, these results highlight the important role played by hippocampal cholinergic and GABAergic activities, as well as neurosteroids, especially AlloP, in preventing convulsive behavior.
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Affiliation(s)
- Elena Martin-Garcia
- Area de Psicobiologia, Institut de Neurociències, Departament de Psicobiologia i Metodologia de les Ciències de la Salut, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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43
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Armstrong SM, Stuenkel EL. Progesterone regulation of catecholamine secretion from chromaffin cells. Brain Res 2005; 1043:76-86. [PMID: 15862520 DOI: 10.1016/j.brainres.2005.02.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 02/14/2005] [Accepted: 02/15/2005] [Indexed: 11/20/2022]
Abstract
Stress stimulates the adrenal medulla to rapidly secrete catecholamines (CAs), and the adrenal cortex to release progesterone (PROG), which may locally regulate stress-induced CA release. We used bovine chromaffin cells to investigate the effects of PROG on CA secretion. PROG dose-dependently inhibited CA secretion induced by nicotinic acetylcholine receptor (nAChR) agonist 1,1-dimethyl-4-phenlypiperazinium iodide (DMPP) up to 77%. Pre-incubation with PROG up to 1 h increased this inhibition. 3alpha,5alpha-Tetrahydroprogesterone (3alpha,5alpha-THP) and dexamethasone were less potent inhibitors. Patch-clamp techniques revealed that PROG co-applied with DMPP inhibited peak DMPP-induced current up to 68% and with 3 min pre-incubation inhibited both peak and integrated current up to approximately 95%. Monitoring of FURA-2 showed that PROG similarly inhibited parallel changes in intracellular-free Ca(++) concentration. PROG also inhibited CA secretion elicited by elevated K(+) (38%), and, in single cells, suppressed Ca(++) current evoked by step depolarization, inhibiting amplitude by 15%, and reducing the time constant of current decay during depolarization by 57%. In contrast to the immediate inhibition of nicotinic current, inhibition of Ca(++) current became statistically significant only after 1 min exposure to PROG. PROG did not inhibit secretion stimulated by high Ca(++) perfusion of permeabilized cells. These data suggest that PROG inhibits CA secretion from chromaffin cells predominantly by rapidly inhibiting nAChRs, and by gradually enhancing the inactivation of voltage-dependent Ca(++) channels (VDCCs), but not by affecting secretory processes downstream of Ca(++) influx. This study supports a role for adrenocortical PROG in the regulation of CA secretion during stress.
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Affiliation(s)
- Siobhan M Armstrong
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-0622, USA.
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44
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Barrantes FJ. Structural basis for lipid modulation of nicotinic acetylcholine receptor function. ACTA ACUST UNITED AC 2004; 47:71-95. [PMID: 15572164 DOI: 10.1016/j.brainresrev.2004.06.008] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2004] [Indexed: 11/22/2022]
Abstract
The nicotinic acetylcholine receptor (AChR) is the archetype molecule in the superfamily of ligand-gated ion channels (LGIC). Members of this superfamily mediate fast intercellular communication in response to endogenous neurotransmitters. This review is focused on the structural and functional crosstalk between the AChR and lipids in the membrane microenvironment, and the modulation exerted by the latter on ligand binding and ion translocation. Experimental approaches using Laurdan extrinsic fluorescence and Förster-type resonance energy transfer (FRET) that led to the characterization of the polarity and molecular dynamics of the liquid-ordered phase AChR-vicinal lipids and the bulk membrane lipids, and the asymmetry of the AChR-rich membrane are reviewed first. The topological relationship between protein and lipid moieties and the changes in physical properties induced by exogenous lipids are discussed next. This background information lays the basis for understanding the occurrence of lipid sites in the AChR transmembrane region, and the selectivity of the protein-lipid interactions. Changes in FRET efficiency induced by fatty acids, phospholipid and cholesterol (Chol), led to the identification of discrete sites for these lipids on the AChR protein, and electron-spin resonance (ESR) spectroscopy has recently facilitated determination of the stoichiometry and selectivity for the AChR of the shell lipid. The influence of lipids on AChR function is discussed next. Combined single-channel and site-directed mutagenesis data fostered the recognition of lipid-sensitive residues in the transmembrane region, dissecting their contribution to ligand binding and channel gating, opening and closing. Experimental evidence supports the notion that the interface between the protein moiety and the adjacent lipid shell is the locus of a variety of pharmacologically relevant processes, including the action of steroids and other lipids.
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Affiliation(s)
- F J Barrantes
- UNESCO Chair of Biophysics and Molecular Neurobiology.
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45
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Hogg RC, Raggenbass M, Bertrand D. Nicotinic acetylcholine receptors: from structure to brain function. Rev Physiol Biochem Pharmacol 2003; 147:1-46. [PMID: 12783266 DOI: 10.1007/s10254-003-0005-1] [Citation(s) in RCA: 365] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels and can be divided into two groups: muscle receptors, which are found at the skeletal neuromuscular junction where they mediate neuromuscular transmission, and neuronal receptors, which are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. nAChRs are pentameric structures that are made up of combinations of individual subunits. Twelve neuronal nAChR subunits have been described, alpha2-alpha10 and beta2-beta4; these are differentially expressed throughout the nervous system and combine to form nAChRs with a wide range of physiological and pharmacological profiles. The nAChR has been proposed as a model of an allosteric protein in which effects arising from the binding of a ligand to a site on the protein can lead to changes in another part of the molecule. A great deal is known about the structure of the pentameric receptor. The extracellular domain contains binding sites for numerous ligands, which alter receptor behavior through allosteric mechanisms. Functional studies have revealed that nAChRs contribute to the control of resting membrane potential, modulation of synaptic transmission and mediation of fast excitatory transmission. To date, ten genes have been identified in the human genome coding for the nAChRs. nAChRs have been demonstrated to be involved in cognitive processes such as learning and memory and control of movement in normal subjects. Recent data from knockout animals has extended the understanding of nAChR function. Dysfunction of nAChR has been linked to a number of human diseases such as schizophrenia, Alzheimer's and Parkinson's diseases. nAChRs also play a significant role in nicotine addiction, which is a major public health concern. A genetically transmissible epilepsy, ADNFLE, has been associated with specific mutations in the gene coding for the alpha4 or beta2 subunits, which leads to altered receptor properties.
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Affiliation(s)
- R C Hogg
- Department of Physiology, CMU, 1 rue Michel Servet, 1211 Geneva 4, Switzerland.
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46
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Arias HR, Kem WR, Trudell JR, Blanton MP. Unique general anesthetic binding sites within distinct conformational states of the nicotinic acetylcholine receptor. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 54:1-50. [PMID: 12785284 DOI: 10.1016/s0074-7742(03)54002-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
General anesthesia is a complex behavioral state provoked by the pharmacological action of a broad range of structurally different hydrophobic molecules called general anesthetics (GAs) on receptor members of the genetically linked ligand-gated ion channel (LGIC) superfamily. This superfamily includes nicotinic acetylcholine (AChRs), type A and C gamma-aminobutyric acid (GABAAR and GABACR), glycine (GlyR), and type 3 5-hydroxytryptamine (5-HT3R) receptors. This review focuses on recent advances in the localization of GA binding sites on conformationally and compositionally distinct AChRs. The experimental evidence outlined in this review suggests that: 1. Several neuronal-type AChRs might be targets for the pharmacological action of distinct GAs. 2. The molecular components of a specific GA binding site on a certain receptor subtype are different from the structural determinants of the locus for the same GA on a different receptor subtype. 3. There are unique binding sites for distinct GAs in the same receptor protein. 4. A GA can activate, potentiate, or inhibit an ion channel, indicating the existence of more than one binding site for the same GA. 5. The affinity of a specific GA depends on the conformational state of the receptor. 6. GAs inhibition channels by at least two mechanisms, an open-channel-blocking and/or an allosteric mechanism. 7. Certain GAs may inhibit AChR function by competing for the agonist binding sites or by augmenting the desensitization rate.
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Affiliation(s)
- Hugo R Arias
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, California 91766, USA
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47
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Romanelli MN, Gualtieri F. Cholinergic nicotinic receptors: competitive ligands, allosteric modulators, and their potential applications. Med Res Rev 2003; 23:393-426. [PMID: 12710018 DOI: 10.1002/med.10037] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Discovery of the important role played by nicotinic acetylcholine receptors (nAChRs) in several CNS disorders has called attention to these membrane proteins and to ligands able to modulate their functions. The existence of different subtypes at multiple levels has complicated the understanding of this receptor's physiological role, but at the same time has increased the efforts to discover selective compounds in order to improve the pharmacological characterization of this kind of receptor and to make the possible therapeutical use of its modulators safer. This review focuses on the structure of new ligands for nAChRs, agonists, antagonists and allosteric modulators, and on their possible applications.
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Affiliation(s)
- M Novella Romanelli
- Dipartimento di Scienze Farmaceutiche, Università di Firenze, via Gino Capponi 9, 50121 Firenze, Italy.
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Losel RM, Falkenstein E, Feuring M, Schultz A, Tillmann HC, Rossol-Haseroth K, Wehling M. Nongenomic steroid action: controversies, questions, and answers. Physiol Rev 2003; 83:965-1016. [PMID: 12843413 DOI: 10.1152/physrev.00003.2003] [Citation(s) in RCA: 392] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Steroids may exert their action in living cells by several ways: 1). the well-known genomic pathway, involving hormone binding to cytosolic (classic) receptors and subsequent modulation of gene expression followed by protein synthesis. 2). Alternatively, pathways are operating that do not act on the genome, therefore indicating nongenomic action. Although it is comparatively easy to confirm the nongenomic nature of a particular phenomenon observed, e.g., by using inhibitors of transcription or translation, considerable controversy exists about the identity of receptors that mediate these responses. Many different approaches have been employed to answer this question, including pharmacology, knock-out animals, and numerous biochemical studies. Evidence is presented for and against both the participation of classic receptors, or proteins closely related to them, as well as for the involvement of yet poorly understood, novel membrane steroid receptors. In addition, clinical implications for a wide array of nongenomic steroid actions are outlined.
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Affiliation(s)
- Ralf M Losel
- Institut für klinische Pharmakologie, Klinikum Mannheim, Theodor-Kutzer-Ufer, D-68167 Mannheim, Germany
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49
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Darbandi-Tonkabon R, Hastings WR, Zeng CM, Akk G, Manion BD, Bracamontes JR, Steinbach JH, Mennerick SJ, Covey DF, Evers AS. Photoaffinity labeling with a neuroactive steroid analogue. 6-azi-pregnanolone labels voltage-dependent anion channel-1 in rat brain. J Biol Chem 2003; 278:13196-206. [PMID: 12560326 DOI: 10.1074/jbc.m213168200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuroactive steroids modulate the function of gamma-aminobutyric acid, type A (GABA(A)) receptors in the central nervous system by an unknown mechanism. In this study we have used a novel neuroactive steroid analogue, 3 alpha,5 beta-6-azi-3-hydroxypregnan-20-one (6-AziP), as a photoaffinity labeling reagent to identify neuroactive steroid binding sites in rat brain. 6-AziP is an effective modulator of GABA(A) receptors as evidenced by its ability to inhibit binding of [(35)S]t-butylbicyclophosphorothionate to rat brain membranes and to potentiate GABA-elicited currents in Xenopus oocytes and human endothelial kidney 293 cells expressing GABA(A) receptor subunits (alpha(1)beta(2)gamma(2)). [(3)H]6-AziP produced time- and concentration-dependent photolabeling of protein bands of approximately 35 and 60 kDa in rat brain membranes. The 35-kDa band was half-maximally labeled at a [(3)H]6-AziP concentration of 1.9 microM, whereas the 60-kDa band was labeled at higher concentrations. The photolabeled 35-kDa protein was isolated from rat brain by two-dimensional PAGE and identified as voltage-dependent anion channel-1 (VDAC-1) by both matrix-assisted laser desorption ionization time-of-flight and ESI-tandem mass spectrometry. Monoclonal antibody directed against the N terminus of VDAC-1 immunoprecipitated labeled 35-kDa protein from a lysate of rat brain membranes, confirming that VDAC-1 is the species labeled by [(3)H]6-AziP. The beta(2) and beta(3) subunits of the GABA(A) receptor were co-immunoprecipitated by the VDAC-1 antibody suggesting a physical association between VDAC-1 and GABA(A) receptors in rat brain membranes. These data suggest that neuroactive steroid effects on the GABA(A) receptor may be mediated by binding to an accessory protein, VDAC-1.
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Affiliation(s)
- Ramin Darbandi-Tonkabon
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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50
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Pereira EFR, Hilmas C, Santos MD, Alkondon M, Maelicke A, Albuquerque EX. Unconventional ligands and modulators of nicotinic receptors. JOURNAL OF NEUROBIOLOGY 2002; 53:479-500. [PMID: 12436414 DOI: 10.1002/neu.10146] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Evidence gathered from epidemiologic and behavioral studies have indicated that neuronal nicotinic receptors (nAChRs) are intimately involved in the pathogenesis of a number of neurologic disorders, including Alzheimer's disease, Parkinson's disease, and schizophrenia. In the mammalian brain, neuronal nAChRs, in addition to mediating fast synaptic transmission, modulate fast synaptic transmission mediated by the major excitatory and inhibitory neurotransmitters glutamate and GABA, respectively. Of major interest, however, is the fact that the activity of the different subtypes of neuronal nAChR is also subject to modulation by substances of endogenous origin such as choline, the tryptophan metabolite kynurenic acid, neurosteroids, and beta-amyloid peptides and by exogenous substances, including the so-called nicotinic allosteric potentiating ligands, of which galantamine is the prototype, and psychotomimetic drugs such as phencyclidine and ketamine. The present article reviews and discusses the effects of unconventional ligands on nAChR activity and briefly describes the potential benefits of using some of these compounds in the treatment of neuropathologic conditions in which nAChR function/expression is known to be altered.
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Affiliation(s)
- Edna F R Pereira
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, 655 W Baltimore St Baltimore, Maryland 21201, USA
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