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Anger JT, Case LK, Baranowski AP, Berger A, Craft RM, Damitz LA, Gabriel R, Harrison T, Kaptein K, Lee S, Murphy AZ, Said E, Smith SA, Thomas DA, Valdés Hernández MDC, Trasvina V, Wesselmann U, Yaksh TL. Pain mechanisms in the transgender individual: a review. FRONTIERS IN PAIN RESEARCH 2024; 5:1241015. [PMID: 38601924 PMCID: PMC11004280 DOI: 10.3389/fpain.2024.1241015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 01/25/2024] [Indexed: 04/12/2024] Open
Abstract
Specific Aim Provide an overview of the literature addressing major areas pertinent to pain in transgender persons and to identify areas of primary relevance for future research. Methods A team of scholars that have previously published on different areas of related research met periodically though zoom conferencing between April 2021 and February 2023 to discuss relevant literature with the goal of providing an overview on the incidence, phenotype, and mechanisms of pain in transgender patients. Review sections were written after gathering information from systematic literature searches of published or publicly available electronic literature to be compiled for publication as part of a topical series on gender and pain in the Frontiers in Pain Research. Results While transgender individuals represent a significant and increasingly visible component of the population, many researchers and clinicians are not well informed about the diversity in gender identity, physiology, hormonal status, and gender-affirming medical procedures utilized by transgender and other gender diverse patients. Transgender and cisgender people present with many of the same medical concerns, but research and treatment of these medical needs must reflect an appreciation of how differences in sex, gender, gender-affirming medical procedures, and minoritized status impact pain. Conclusions While significant advances have occurred in our appreciation of pain, the review indicates the need to support more targeted research on treatment and prevention of pain in transgender individuals. This is particularly relevant both for gender-affirming medical interventions and related medical care. Of particular importance is the need for large long-term follow-up studies to ascertain best practices for such procedures. A multi-disciplinary approach with personalized interventions is of particular importance to move forward.
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Affiliation(s)
- Jennifer T. Anger
- Department of Urology, University of California San Diego, San Diego, CA, United States
| | - Laura K. Case
- Department of Anesthesiology, University of California San Diego, San Diego, CA, United States
| | - Andrew P. Baranowski
- Pelvic Pain Medicine and Neuromodulation, University College Hospital Foundation Trust, University College London, London, United Kingdom
| | - Ardin Berger
- Anesthesiology, Perioperative and Pain Medicine, Stanford University, Stanford, CA, United States
| | - Rebecca M. Craft
- Department of Psychology, Washington State University, Pullman, WA, United States
| | - Lyn Ann Damitz
- Division of Plastic and Reconstructive Surgery, University of North Carolina, Chapel Hill, NC, United States
| | - Rodney Gabriel
- Division of Regional Anesthesia, University of California San Diego, San Diego, CA, United States
| | - Tracy Harrison
- Department of OB/GYN & Reproductive Sciences, University of California San Diego, San Diego, CA, United States
| | - Kirsten Kaptein
- Division of Plastic Surgery, University of California San Diego, San Diego, CA, United States
| | - Sanghee Lee
- Department of Urology, University of California San Diego, San Diego, CA, United States
| | - Anne Z. Murphy
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Engy Said
- Division of Regional Anesthesia, University of California San Diego, San Diego, CA, United States
| | - Stacey Abigail Smith
- Division of Infection Disease, The Hope Clinic of Emory University, Atlanta, GA, United States
| | - David A. Thomas
- Office of Research on Women's Health, National Institutes of Health, Bethesda, MD, United States
| | - Maria del C. Valdés Hernández
- Department of Neuroimaging Sciences, Center for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Victor Trasvina
- Department of Urology, University of California San Diego, San Diego, CA, United States
| | - Ursula Wesselmann
- Departments of Anesthesiology and Perioperative Medicine/Division of Pain Medicine, Neurology and Psychology, and Consortium for Neuroengineering and Brain-Computer Interfaces, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Tony L. Yaksh
- Department of Anesthesiology, University of California San Diego, San Diego, CA, United States
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Xu WB, Tang MH, Long JY, Wang WW, Qin JY, Qi XJ, Liu ZY. Antinociceptive effect of gelsenicine, principal toxic alkaloids of gelsemium, on prostaglandin E2-induced hyperalgesia in mice: Comparison with gelsemine and koumine. Biochem Biophys Res Commun 2023; 681:55-61. [PMID: 37757667 DOI: 10.1016/j.bbrc.2023.09.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/10/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023]
Abstract
Gelsemium elegans (G.elegans) is a plant of the Loganiaceae family, known for its indole alkaloids, including gelsemine, koumine, and gelsenicine. Gelsemine and koumine are well-studied active alkaloids with low toxicity, valued for their anti-anxiety and analgesic properties. However, gelsenicine, another important alkaloid, remains underexplored due to its high toxicity. This study focuses on evaluating the analgesic properties of gelsenicine and comparing them with gelsemine and koumine. The results indicate that all three alkaloids exhibit robust analgesic properties, with gelsemine, koumine, and gelsenicine showing ED50 values of 0.82 mg/kg, 0.60 mg/kg, and 8.43 μg/kg, respectively, as assessed by the hot plate method. Notably, the therapeutic dose of gelsenicine was significantly lower than its toxic dose (LD50 = 0.185 mg/kg). The study also investigated the mechanism of action by analyzing the expression levels of GlyRα3 and Gephyrin. The PGE2 model group showed decreased expression levels of GlyRα3 and Gephyrin, while groups treated with gelsemine, koumine, and gelsenicine were able to reverse this decrease. These results suggest that gelsenicine effectively alleviates PGE2-induced hyperalgesia by upregulating the expression of GlyRα3 and Gephyrin, which are key targets of the Gly receptor pathway.
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Affiliation(s)
- Wen-Bo Xu
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Mo-Huan Tang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Jiang-Yu Long
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Wei-Wei Wang
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Jiao-Yan Qin
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Xue-Jia Qi
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China
| | - Zhao-Ying Liu
- College of Veterinary Medicine, Hunan Agricultural University, Changsha, 410128, China; Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha, 410128, China.
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3
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Vitku J, Hill M, Kolatorova L, Kubala Havrdova E, Kancheva R. Steroid Sulfation in Neurodegenerative Diseases. Front Mol Biosci 2022; 9:839887. [PMID: 35281259 PMCID: PMC8904904 DOI: 10.3389/fmolb.2022.839887] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/20/2022] [Indexed: 11/13/2022] Open
Abstract
Steroid sulfation and desulfation participates in the regulation of steroid bioactivity, metabolism and transport. The authors focused on sulfation and desulfation balance in three neurodegenerative diseases: Alzheimer´s disease (AD), Parkinson´s disease (PD), and multiple sclerosis (MS). Circulating steroid conjugates dominate their unconjugated counterparts, but unconjugated steroids outweigh their conjugated counterparts in the brain. Apart from the neurosteroid synthesis in the central nervous system (CNS), most brain steroids cross the blood-brain barrier (BBB) from the periphery and then may be further metabolized. Therefore, steroid levels in the periphery partly reflect the situation in the brain. The CNS steroids subsequently influence the neuronal excitability and have neuroprotective, neuroexcitatory, antidepressant and memory enhancing effects. They also exert anti-inflammatory and immunoprotective actions. Like the unconjugated steroids, the sulfated ones modulate various ligand-gated ion channels. Conjugation by sulfotransferases increases steroid water solubility and facilitates steroid transport. Steroid sulfates, having greater half-lives than their unconjugated counterparts, also serve as a steroid stock pool. Sulfotransferases are ubiquitous enzymes providing massive steroid sulfation in adrenal zona reticularis and zona fasciculata.. Steroid sulfatase hydrolyzing the steroid conjugates is exceedingly expressed in placenta but is ubiquitous in low amounts including brain capillaries of BBB which can rapidly hydrolyze the steroid sulfates coming across the BBB from the periphery. Lower dehydroepiandrosterone sulfate (DHEAS) plasma levels and reduced sulfotransferase activity are considered as risk factors in AD patients. The shifted balance towards unconjugated steroids can participate in the pathophysiology of PD and anti-inflammatory effects of DHEAS may counteract the MS.
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Affiliation(s)
- Jana Vitku
- Department of Steroids and Proteofactors, Institute of Endocrinology, Prague, Czechia
- *Correspondence: Jana Vitku,
| | - Martin Hill
- Department of Steroids and Proteofactors, Institute of Endocrinology, Prague, Czechia
| | - Lucie Kolatorova
- Department of Steroids and Proteofactors, Institute of Endocrinology, Prague, Czechia
| | - Eva Kubala Havrdova
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Radmila Kancheva
- Department of Steroids and Proteofactors, Institute of Endocrinology, Prague, Czechia
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McHann MC, Blanton HL, Guindon J. Role of sex hormones in modulating breast and ovarian cancer associated pain. Mol Cell Endocrinol 2021; 533:111320. [PMID: 34033890 PMCID: PMC8263503 DOI: 10.1016/j.mce.2021.111320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 04/16/2021] [Accepted: 05/09/2021] [Indexed: 01/18/2023]
Abstract
According to the National Cancer Institute in 2020 there will be an estimated 21,750 new ovarian cancer cases and 276,480 new breast cancer cases. Both breast and ovarian cancer are hormone dependent cancers, meaning they cannot grow without the presence of hormones. The two most studied hormones in these two cancers are estrogen and progesterone, which are also involved in the modulation of pain. The incidence of pain in breast and ovarian cancer is very high. Research about mechanisms involved in modulation of pain by hormones are still being debated, as some studies find estrogen to be anti-nociceptive and others pro-nociceptive in pain studies. Moreover, analgesic treatments for breast and ovarian cancer-associated pain are limited and often ineffective. In this review, we will focus on estrogen and progesterone mechanisms of action in modulation of pain and cancer. We will also discuss new treatment options for these types of cancer and associated-pain.
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Affiliation(s)
- Melissa C McHann
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA
| | - Henry L Blanton
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA
| | - Josée Guindon
- Department of Pharmacology and Neuroscience at Texas Tech University Health Sciences Center, USA.
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Rapid effects of neurosteroids on neuronal plasticity and their physiological and pathological implications. Neurosci Lett 2021; 750:135771. [PMID: 33636284 DOI: 10.1016/j.neulet.2021.135771] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/15/2021] [Accepted: 02/20/2021] [Indexed: 11/22/2022]
Abstract
Current neuroscience research on neurosteroids and their synthetic analogues - neuroactive steroids - clearly demonstrate their drug likeness in a variety of neurological and psychiatric conditions. Moreover, research on neurosteroids continues to provide novel mechanistic insights into receptor activation or inhibition of various receptors. This mini-review will provide a high-level overview of the research area and discuss the various classes of potential physiological and pathological implications discovered so far.
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Chen Z, Wang X, Liao H, Sheng T, Chen P, Zhou H, Pan Y, Liu W, Yao H. Glycine attenuates cerebrovascular remodeling via glycine receptor alpha 2 and vascular endothelial growth factor receptor 2 after stroke. Am J Transl Res 2020; 12:6895-6907. [PMID: 33194080 PMCID: PMC7653569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/01/2020] [Indexed: 06/11/2023]
Abstract
As a dual-acting neurotransmitter, glycine plays critical roles in cerebral ischemia by activating both glycine receptors (GlyRs) and N-methyl-D-aspartate acid receptors (NMDARs). However, the involvement of glycine receptor alpha 2 (GlyRa2) in cerebral ischemia has not been explored. The objective of this study was to determine the mechanism of action of GlyRa2 in cerebrovascular remodeling. After induction of rat tMCAO, levels of the GLRA2 gene and GlyRa2 protein were examined using q-PCR, western blot, and immunohistochemical analyses. Blood-brain barrier permeability, and the presence of hemorrhage and arteriosclerosis were also analyzed. The underlying mechanism of vascular remodeling was examined using immunohistochemical and immunofluorescence analyses. Both the GLRA2 gene and GlyRa2 protein were altered sharply after stroke. GlyRa2 of vascular origin appears to play a protective role after glycine treatment for ischemia. Blockade of GlyRa2 by the addition of cyclothiazide was found to abolish previous improvements in cerebrovascular survival after glycine treatment for tMCAO in rats. GlyRa2-dependent neurovascular remodeling was found to be correlated with the vascular endothelial growth factor receptor 2 (VEGFR2) pathways. These results suggest that vascular-derived GlyRa2 protects against post-ischemic injury. Vascular protection via GlyRa2 is due to VEGFR2/pSTAT3 signaling.
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Affiliation(s)
- Zheng Chen
- Schools of Medicine, Huzhou University, Huzhou Central HospitalHuzhou, PR China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou Central HospitalHuzhou, PR China
- Division of Vascular Surgery, East Hospital, Tongji University School of MedicineShanghai, 200120, PR China
| | - Xiang Wang
- Division of Vascular Surgery, East Hospital, Tongji University School of MedicineShanghai, 200120, PR China
| | - Haikang Liao
- Institute of Life Sciences and Institute of Neuroscience, Wenzhou UniversityWenzhou, PR China
| | - Tao Sheng
- Schools of Medicine, Huzhou University, Huzhou Central HospitalHuzhou, PR China
| | - Panhong Chen
- Schools of Medicine, Huzhou University, Huzhou Central HospitalHuzhou, PR China
| | - Hongchang Zhou
- Schools of Medicine, Huzhou University, Huzhou Central HospitalHuzhou, PR China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou Central HospitalHuzhou, PR China
| | - Yongliang Pan
- Schools of Medicine, Huzhou University, Huzhou Central HospitalHuzhou, PR China
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou University, Huzhou Central HospitalHuzhou, PR China
| | - Weiqin Liu
- The Affiliated Ganzhou Hospital of Nanchang UniversityGanzhou, PR China
| | - Hua Yao
- Guangxi Key Laboratory of Brain and Cognitive Neuroscience, Guilin Medical UniversityGuilin, PR China
- Institute of Life Sciences and Institute of Neuroscience, Wenzhou UniversityWenzhou, PR China
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7
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San Martin L, Gallegos S, Araya A, Romero N, Morelli G, Comhair J, Harvey RJ, Rigo J, Brone B, Aguayo LG. Ethanol consumption and sedation are altered in mice lacking the glycine receptor α2 subunit. Br J Pharmacol 2020; 177:3941-3956. [PMID: 32436225 PMCID: PMC7429487 DOI: 10.1111/bph.15136] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/31/2020] [Accepted: 05/09/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE The precise mechanism/s of action of ethanol, although studied for many years, are not well understood. Like other drugs of abuse, ethanol affects dopamine levels in the nucleus accumbens (nAc), an important region of the mesolimbic system, causing a reinforcing effect. It has been shown that glycine receptors (GlyRs) present in the nAc are potentiated by clinically relevant concentrations of ethanol, where α1 and α2 are the predominant subunits expressed. EXPERIMENTAL APPROACH Using a combination of electrophysiology and behavioural assays, we studied the involvement of GlyR α2 subunits on the effects of low and high doses of ethanol, as well as on consumption using mice lacking the GlyR α2 subunit (male Glra2-/Y and female Glra2-/- ). KEY RESULTS GlyR α2 subunits exist in accumbal neurons, since the glycine-evoked currents and glycinergic miniature inhibitory postsynaptic currents (mIPSCs) in Glra2-/Y mice were drastically decreased. In behavioural studies, differences in ethanol consumption and sedation were observed between wild-type (WT) and Glra2 knockout (KO) mice. Using the drinking in the dark (DID) paradigm, we found that Glra2-/Y mice presented a binge-like drinking behaviour immediately when exposed to ethanol rather than the gradual consumption seen in WT animals. Interestingly, the effect of knocking out Glra2 in female (Glra2-/- ) mice was less evident, since WT female mice already showed higher DID. CONCLUSION AND IMPLICATIONS The differences in ethanol consumption between WT and KO mice provide additional evidence supporting the conclusion that GlyRs are biologically relevant targets for the sedative and rewarding properties of ethanol.
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Affiliation(s)
- Loreto San Martin
- Laboratory of Neurophysiology, Department of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Scarlet Gallegos
- Laboratory of Neurophysiology, Department of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Anibal Araya
- Laboratory of Neurophysiology, Department of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Nicol Romero
- Laboratory of Neurophysiology, Department of PhysiologyUniversidad de ConcepciónConcepciónChile
| | | | | | - Robert J. Harvey
- School of Health and Sport SciencesUniversity of the Sunshine CoastMaroochydore DCQueenslandAustralia
- Sunshine Coast Health InstituteBirtinyaQueenslandAustralia
| | | | | | - Luis G. Aguayo
- Laboratory of Neurophysiology, Department of PhysiologyUniversidad de ConcepciónConcepciónChile
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Bukanova JV, Solntseva EI, Kudova E. Neurosteroids as Selective Inhibitors of Glycine Receptor Activity: Structure-Activity Relationship Study on Endogenous Androstanes and Androstenes. Front Mol Neurosci 2020; 13:44. [PMID: 32265652 PMCID: PMC7098970 DOI: 10.3389/fnmol.2020.00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/04/2020] [Indexed: 12/21/2022] Open
Abstract
The ability of androstane and androstene neurosteroids with modifications at C-17, C-5, and C-3 (compounds 1-9) to influence the functional activity of inhibitory glycine and γ-aminobutyric acid (GABA) receptors was estimated. The glycine- and GABA-induced chloride current (IGly and IGABA) were measured in isolated pyramidal neurons of the rat hippocampus and isolated rat cerebellar Purkinje cells, correspondingly, using the patch-clamp technique. Our results demonstrate that all the nine neurosteroids display similar biological activity, namely, they strongly inhibited IGly and weakly inhibited IGABA. The threshold concentration of neurosteroids inducing effects on IGly was 0.1 μM, and for effects on IGABA was 10–50 μM. Moreover, our compounds accelerated desensitization of the IGly with the IC50 values varying from 0.12 to 0.49 μM and decreased the peak amplitude with IC50 values varying from 16 to 22 μM. Interestingly, our study revealed that only compounds 4 (epiandrosterone) and 8 (dehydroepiandrosterone) were able to cause a significant change in IGABA in 10 μM concentration. Moreover, compounds 3 (testosterone), 5 (epitestosterone), 6 (dihydroandrostenedione), and 9 (etiocholanedione) did not modulate IGABA up to the concentration of 50 μM. Thus, we conclude that compounds 3, 5, 6, and 9 may be identified as selective modulators of IGly. Our results offer new avenues of investigation in the field of drug-like selective modulators of IGly.
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Affiliation(s)
| | | | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
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9
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Bukanova JV, Solntseva EI, Kolbaev SN, Kudova E. Modulation of GABA and glycine receptors in rat pyramidal hippocampal neurones by 3α5β-pregnanolone derivatives. Neurochem Int 2018; 118:145-151. [PMID: 29886074 DOI: 10.1016/j.neuint.2018.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/25/2018] [Accepted: 06/06/2018] [Indexed: 12/28/2022]
Abstract
The ability of pregnanolone glutamate (PA-Glu), pregnanolone hemisuccinate (PA-hSuc) and pregnanolone hemipimelate (PA-hPim), neuroactive steroids with a negative modulatory effect on excitatory N-methyl-d-aspartate receptors, to influence the functional activity of inhibitory γ-aminobutyric acid and glycine receptors was estimated. The GABA- and glycine-induced chloride currents (IGABA and IGly) were measured in isolated pyramidal neurons of the rat hippocampus using the patch-clamp technique. Compound PA-Glu was found to potentiate IGABA and to inhibit IGly, while PA-hSuc and PA-hPim inhibited both IGABA and IGly. Moreover, PA-Glu, PA-hSuc, and PA-hPim had a greater effect on desensitization than on the peak amplitude of IGly. At a high concentration of glycine (500 μM), the effect of neurosteroids on the peak amplitude of IGly disappeared, and the acceleration of desensitization remained. The conversion of PA-Glu into androstane glutamate (AND-Glu), an analogue that lacks the C-17 acetyl moiety, completely eliminated the effects on these receptors. Our results indicate that the C-17 acetyl moiety is crucial for the action on IGABA and IGly. Our results indicate that the pregnanolone derivatives, in contrast to the androstane analogues, modulate IGABA and IGly at low micromolar concentrations and this family of neurosteroids can be useful for future structure-activity relationship studies of the steroid modulation of other receptor types.
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Affiliation(s)
| | | | | | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.
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Rebas E, Radzik T, Boczek T, Zylinska L. Calcium-engaged Mechanisms of Nongenomic Action of Neurosteroids. Curr Neuropharmacol 2017; 15:1174-1191. [PMID: 28356049 PMCID: PMC5725547 DOI: 10.2174/1570159x15666170329091935] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/01/1970] [Accepted: 03/25/2017] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Neurosteroids form the unique group because of their dual mechanism of action. Classically, they bind to specific intracellular and/or nuclear receptors, and next modify genes transcription. Another mode of action is linked with the rapid effects induced at the plasma membrane level within seconds or milliseconds. The key molecules in neurotransmission are calcium ions, thereby we focus on the recent advances in understanding of complex signaling crosstalk between action of neurosteroids and calcium-engaged events. METHODS Short-time effects of neurosteroids action have been reviewed for GABAA receptor complex, glycine receptor, NMDA receptor, AMPA receptor, G protein-coupled receptors and sigma-1 receptor, as well as for several membrane ion channels and plasma membrane enzymes, based on available published research. RESULTS The physiological relevance of neurosteroids results from the fact that they can be synthesized and accumulated in the central nervous system, independently from peripheral sources. Fast action of neurosteroids is a prerequisite for genomic effects and these early events can significantly modify intracellular downstream signaling pathways. Since they may exert either positive or negative effects on calcium homeostasis, their role in monitoring of spatio-temporal Ca2+ dynamics, and subsequently, Ca2+-dependent physiological processes or initiation of pathological events, is evident. CONCLUSION Neurosteroids and calcium appear to be the integrated elements of signaling systems in neuronal cells under physiological and pathological conditions. A better understanding of cellular and molecular mechanisms of nongenomic, calcium-engaged neurosteroids action could open new ways for therapeutic interventions aimed to restore neuronal function in many neurological and psychiatric diseases.
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Affiliation(s)
- Elzbieta Rebas
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, Poland
| | - Tomasz Radzik
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, Poland
| | - Tomasz Boczek
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, Poland
- Boston Children’s Hospital and Harvard Medical School, Boston, USA
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Faculty of Health Sciences, Medical University of Lodz, Poland
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11
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Rodinsky AG, Tkachenko SS. [BIOELECTRIC ACTIVITY OF INTERNEURONES OF SPINAL CORD IN THE EXPERIMENTAL MENOPAUSE IN FEMAL RATS]. ACTA ACUST UNITED AC 2016; 61:28-34. [PMID: 26845841 DOI: 10.15407/fz61.05.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We analyzed the amplitude-time characteristics of the components of the potential dorsal surface of the spinal cord (PDS SC) in experimental menopause. The excitation threshold increased at 102.14% and the latent period at 94.12% in animals with experimental menopause. In the context of supramaximal stimulation of dorsal root L5 identified N1 amplitude growth at 10.14%, N2 at 11.82%, N3 at 48.28%, and P-wave 31.58% and to increase component N3 26.54% in the experimental group. At condition of paired stimulation pulses on the time interval from 2 to 3 ms there was a significant increase, and from 6 to 30 ms--a depression of N1-component of the second PDS SC in the group of animals with experimental menopause. Thus, our results suggest the presence of changes in nerve structures of the posterior horn of the spinal cord at conditions of estrogen deficiency.
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Activation of glycine and extrasynaptic GABA(A) receptors by taurine on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis. Neural Plast 2013; 2013:740581. [PMID: 24379976 PMCID: PMC3863572 DOI: 10.1155/2013/740581] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/05/2013] [Accepted: 11/12/2013] [Indexed: 11/23/2022] Open
Abstract
The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been known for the processing and transmission of orofacial nociceptive information. Taurine, one of the most plentiful free amino-acids in humans, has proved to be involved in pain modulation. In this study, using whole-cell patch clamp technique, we investigated the direct membrane effects of taurine and the action mechanism behind taurine-mediated responses on the SG neurons of the Vc. Taurine showed non-desensitizing and repeatable membrane depolarizations and inward currents which remained in the presence of amino-acid receptors blocking cocktail (AARBC) with tetrodotoxin, indicating that taurine acts directly on the postsynaptic SG neurons. Further, application of taurine at different doses (10 μM to 3 mM) showed a concentration dependent depolarizations and inward currents with the EC50 of 84.3 μM and 723 μM, respectively. Taurine-mediated responses were partially blocked by picrotoxin (50 μM) and almost completely blocked by strychnine (2 μM), suggesting that taurine-mediated responses are via glycine receptor (GlyR) activation. In addition, taurine (1 mM) activated extrasynaptic GABAA receptor (GABAAR)-mediated currents. Taken together, our results indicate that taurine can be a target molecule for orofacial pain modulation through the activation of GlyRs and/or extrasynaptic GABAARs on the SG neurons.
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14
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Zhang Y, Lü N, Zhao ZQ, Zhang YQ. Involvement of estrogen in rapid pain modulation in the rat spinal cord. Neurochem Res 2012; 37:2697-705. [PMID: 22903468 DOI: 10.1007/s11064-012-0859-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/17/2012] [Accepted: 07/28/2012] [Indexed: 12/16/2022]
Abstract
The pivotal role of estrogens in the pain sensitivity has been investigated in many ways. Traditionally, it is ascribed to the slow genomic changes mediated by classical nuclear estrogen receptors (ER), ERα and ERβ, depending on peripheral estrogens. Recently, it has become clear that estrogens can also signal through membrane ERs (mERs), such as G-protein-coupled ER1 (GPER1), mediating the non-genomic effects. However, the spinal specific role played by ERs and the underlying cellular mechanisms remain elusive. The present study investigated the rapid estrogenic regulation of nociception at the spinal level. Spinal administration of 17β-estradiol (E2), the most potent natural estrogen, acutely produced a remarkable mechanical allodynia and thermal hyperalgesia without significant differences among male, female and ovariectomized (Ovx) rats. E2-induced the pro-nociceptive effects were partially abrogated by ICI 182,780 (ERs antagonist), and mimicked by E2-BSA (a mER agonist). Inhibition of local E2 synthesis by 1,4,6-Androstatrien-3,17-dione (ATD, a potent irreversible aromatase inhibitor), or blockade of ERs by ICI 182,780 produced an inhibitory effect on the late phase of formalin nociceptive responses. Notably, lumbar puncture injection of G15 (a selective GPER1 antagonist) resulted in similar but more efficient inhibition of formalin nociceptive responses as compared with ICI 182,780. At the cellular level, the amplitude and decay time of spontaneous inhibitory postsynaptic currents were attenuated by short E2 or E2-BSA treatment in spinal slices. These results indicate that estrogen acutely facilitates nociceptive transmission in the spinal cord via activation of membrane-bound estrogen receptors.
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Affiliation(s)
- Yan Zhang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
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15
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Zhang Y, Xiao X, Zhang XM, Zhao ZQ, Zhang YQ. Estrogen facilitates spinal cord synaptic transmission via membrane-bound estrogen receptors: implications for pain hypersensitivity. J Biol Chem 2012; 287:33268-81. [PMID: 22869379 DOI: 10.1074/jbc.m112.368142] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Recent evidence suggests that estrogen is synthesized in the spinal dorsal horn and plays a role in nociceptive processes. However, the cellular and molecular mechanisms underlying these effects remain unclear. Using electrophysiological, biochemical, and morphological techniques, we here demonstrate that 17β-estradiol (E2), a major form of estrogen, can directly modulate spinal cord synaptic transmission by 1) enhancing NMDA receptor-mediated synaptic transmission in dorsal horn neurons, 2) increasing glutamate release from primary afferent terminals, 3) increasing dendritic spine density in cultured spinal cord dorsal horn neurons, and 4) potentiating spinal cord long term potentiation (LTP) evoked by high frequency stimulation (HFS) of Lissauer's tract. Notably, E2-BSA, a ligand that acts only on membrane estrogen receptors, can mimic E2-induced facilitation of HFS-LTP, suggesting a nongenomic action of this neurosteroid. Consistently, cell surface biotinylation demonstrated that three types of ERs (ERα, ERβ, and GPER1) are localized on the plasma membrane of dorsal horn neurons. Furthermore, the ERα and ERβ antagonist ICI 182,780 completely abrogates the E2-induced facilitation of LTP. ERβ (but not ERα) activation can recapitulate E2-induced persistent increases in synaptic transmission (NMDA-dependent) and dendritic spine density, indicating a critical role of ERβ in spinal synaptic plasticity. E2 also increases the phosphorylation of ERK, PKA, and NR2B, and spinal HFS-LTP is prevented by blockade of PKA, ERK, or NR2B activation. Finally, HFS increases E2 release in spinal cord slices, which can be prevented by aromatase inhibitor androstatrienedione, suggesting activity-dependent local synthesis and release of endogenous E2.
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Affiliation(s)
- Yan Zhang
- Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
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16
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Deliu E, Brailoiu GC, Arterburn JB, Oprea TI, Benamar K, Dun NJ, Brailoiu E. Mechanisms of G protein-coupled estrogen receptor-mediated spinal nociception. THE JOURNAL OF PAIN 2012; 13:742-54. [PMID: 22858342 PMCID: PMC3412047 DOI: 10.1016/j.jpain.2012.05.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 03/26/2012] [Accepted: 05/17/2012] [Indexed: 01/15/2023]
Abstract
UNLABELLED Human and animal studies suggest that estrogens are involved in the processing of nociceptive sensory information and analgesic responses in the central nervous system. Rapid pronociceptive estrogenic effects have been reported, some of which likely involve G protein-coupled estrogen receptor (GPER) activation. Membrane depolarization and increases in cytosolic calcium and reactive oxygen species (ROS) levels are markers of neuronal activation, underlying pain sensitization in the spinal cord. Using behavioral, electrophysiological, and fluorescent imaging studies, we evaluated GPER involvement in spinal nociceptive processing. Intrathecal challenging of mice with the GPER agonist G-1 results in pain-related behaviors. GPER antagonism with G15 reduces the G-1-induced response. Electrophysiological recordings from superficial dorsal horn neurons indicate neuronal membrane depolarization with G-1 application, which is G15 sensitive. In cultured spinal sensory neurons, G-1 increases intracellular calcium concentration and induces mitochondrial and cytosolic ROS accumulation. In the presence of G15, G-1 does not elicit the calcium and ROS responses, confirming specific GPER involvement in this process. Cytosolic calcium concentration elevates faster and with higher amplitude following G-1 intracellular microinjections compared to extracellular exposure, suggesting subcellular GPER functionality. Thus, GPER activation results in spinal nociception, and the downstream mechanisms involve cytosolic calcium increase, ROS accumulation, and neuronal membrane depolarization. PERSPECTIVE Our results suggest that GPER modulates pain processing in spinal sensory neurons via cytosolic calcium increase and ROS accumulation. These findings extend the current knowledge on GPER involvement in physiology and disease, providing the first evidence of its pronociceptive effects at central levels and characterizing some of the underlying mechanisms.
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MESH Headings
- Action Potentials/drug effects
- Analgesics, Opioid/administration & dosage
- Animals
- Animals, Newborn
- Behavior, Animal/drug effects
- Benzodioxoles/administration & dosage
- Calcium/metabolism
- Cells, Cultured
- Cyclopentanes/pharmacology
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Drug Interactions
- Female
- Gene Expression Regulation/drug effects
- In Vitro Techniques
- Male
- Mice
- Mice, Inbred ICR
- Microinjections
- Morphine/administration & dosage
- Neurons/drug effects
- Neurons/physiology
- Nociception/drug effects
- Nociception/physiology
- Nociceptive Pain/drug therapy
- Nociceptive Pain/metabolism
- Nociceptive Pain/pathology
- Pain Measurement
- Patch-Clamp Techniques
- Quinolines/administration & dosage
- Quinolines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
- Receptors, Estrogen/antagonists & inhibitors
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Spinal Cord/cytology
- Spinal Cord/pathology
- Superoxides/metabolism
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Affiliation(s)
- Elena Deliu
- Department of Pharmacology, Temple University School of Medicine Philadelphia, PA 19140
| | - G. Cristina Brailoiu
- Department of Pharmacology, Temple University School of Medicine Philadelphia, PA 19140
| | - Jeffrey B. Arterburn
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003
| | - Tudor I. Oprea
- Division of Biocomputing, Department Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM 87131
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Kemitorvet, Building 208, Lyngby, DK-2800, Denmark
| | - Khalid Benamar
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, 19140
| | - Nae J. Dun
- Department of Pharmacology, Temple University School of Medicine Philadelphia, PA 19140
| | - Eugen Brailoiu
- Department of Pharmacology, Temple University School of Medicine Philadelphia, PA 19140
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17
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Lu Y, Li Z, Li HJ, Du D, Wang LP, Yu LH, Burnstock G, Chen A, Ma B. A comparative study of the effect of 17β-estradiol and estriol on peripheral pain behavior in rats. Steroids 2012; 77:241-9. [PMID: 22198527 DOI: 10.1016/j.steroids.2011.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 11/07/2011] [Accepted: 11/24/2011] [Indexed: 12/26/2022]
Abstract
Although estradiol has been reported to influence pain sensitivity, the role of estriol (an estradiol metabolite and another widely used female sex hormone) remains unclear. In this study, pain behavior tests, whole-cell patch clamp recording and Western blotting were used to determine whether estriol plays a role in pain signal transduction and transmission. Either systemic or local administration of 17β-estradiol produced a significant rise of mechanical pain threshold, while estriol lacked this effect in normal and ovariectomized (OVX) rats following estriol replacement. Local administration of 17β-estradiol or estriol significantly decreased ATP-induced spontaneous hind-paw withdrawal duration (PWD), which was blocked by an estrogen receptor antagonist, ICI 182, 780. However, systemic application of estriol in normal or OVX rats lacked this similar effect. In cultured dorsal root ganglion neurons, estriol attenuated α,β-methylene ATP-induced transient currents which were blocked by ICI 182, 780. In complete Freund's adjuvant treated (CFA) rats, systemic application of 17β-estradiol or estriol decreased the mechanical pain threshold significantly, but did not change the inflammatory process. Similar effects were observed after estriol replacement in OVX rats. The expression of c-fos in lumbosacral spinal cord dorsal horn (SCDH) was increased significantly by administration of 17β-estradiol but not estriol, and not by estriol replacement in OVX rats. These results suggest that 17β-estradiol but not estriol plays an anti-hyperalgesic role in physiological pain. However, both peripheral 17β-estradiol and estriol play anti-hyperalgesic roles in ATP-induced inflammatory pain. Systemic application of estriol as well as 17β-estradiol plays hyperalgesic roles in CFA-induced chronic pain.
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Affiliation(s)
- Yi Lu
- Department of Physiology and Key Laboratory of Molecular Neurobiology, Ministry of Education, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
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18
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Puri J, Bellinger LL, Kramer PR. Estrogen in cycling rats alters gene expression in the temporomandibular joint, trigeminal ganglia and trigeminal subnucleus caudalis/upper cervical cord junction. J Cell Physiol 2011; 226:3169-80. [PMID: 21321935 DOI: 10.1002/jcp.22671] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Females report temporomandibular joint (TMJ) pain more than men and studies suggest estrogen modulates this pain response. Our goal in this study was to determine genes that are modulated by physiological levels of 17β-estradiol that could have a role in TMJ pain. To complete this goal, saline or complete Freund's adjuvant was injected in the TMJ when plasma 17β-estradiol was low or when it was at a high proestrus level. TMJ, trigeminal ganglion, and trigeminal subnucleus caudalis/upper cervical cord junction (Vc/C(1-2) ) tissues were isolated from the treated rats and expression of 184 genes was quantitated in each tissue using real-time PCR. Significant changes in the amount of specific transcripts were observed in the TMJ tissues, trigeminal ganglia, and Vc/C(1-2) region when comparing rats with high and low estrogen. GABA A receptor subunit α6 (Gabra6) and the glycine receptor α2 (Glra2) were two genes of interest because of their direct function in neuronal activity and a >29-fold increase in the trigeminal ganglia was observed in proestrus rats with TMJ inflammation. Immunohistochemical studies showed that Gabrα6 and Glrα2 neuronal and not glial expression increased when comparing rats with high and low estrogen. Estrogen receptors α and β are present in neurons of the trigeminal ganglia, whereby 17β-estradiol can alter expression of Gabrα6 and Glrα2. Also, estrogen receptor α (ERα) but not ERβ was observed in satellite glial cells of the trigeminal ganglia. These results demonstrate that genes associated with neurogenic inflammation or neuronal excitability were altered by changes in the concentration of 17β-estradiol.
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Affiliation(s)
- Jyoti Puri
- Department of Biomedical Sciences, Texas A&M Health Science Center, Baylor College of Dentistry, Dallas, Texas 75246, USA
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19
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Tashiro A, Okamoto K, Bereiter DA. Rapid estrogenic effects on TMJ-responsive brainstem neurons. J Dent Res 2011; 91:210-4. [PMID: 22058119 DOI: 10.1177/0022034511428156] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Estrogen status is a risk factor for temporomandibular muscle and joint disorders (TMJD) and other craniofacial pain conditions. The basis for estrogen modulation of pain is poorly understood and has often been attributed to long-term genomic effects. However, estrogens also act rapidly through membrane-initiated mechanisms to alter neural activity. To assess if estrogens act rapidly to affect TMJ-responsive neurons, we applied 17β-estradiol (E2) directly at the spinomedullary (Vc/C(1-2)) region, the initial brainstem site for synaptic integration of TMJ sensory signals, while recording single neuron activity. In ovariectomized female rats, E2 rapidly (within 10 minutes) and reversibly reduced TMJ-evoked neural activity at the Vc/C(1-2) region. The effect was estrogen receptor (ER) subtype-specific, since ERβ agonists inhibited, while an ERβ agonist enhanced, evoked activity. A membrane-mediated mechanism was indicated, since the membrane-impermeable analogue, E(2)-BSA, mimicked the inhibitory effect of E2 and was prevented by an ER antagonist. This study demonstrated that E2 acted rapidly, through membrane-mediated pathways, and locally at the Vc/C(1-2) region, to modulate sensory signals from the TMJ region. These results were consistent with the hypothesis that estrogens can act rapidly at the level of the trigeminal brainstem complex to influence sensory integration of TMJ-related information.
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Affiliation(s)
- A Tashiro
- Dept. of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, USA
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20
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Zhong YQ, Li KC, Zhang X. Potentiation of excitatory transmission in substantia gelatinosa neurons of rat spinal cord by inhibition of estrogen receptor alpha. Mol Pain 2010; 6:92. [PMID: 21143988 PMCID: PMC3016347 DOI: 10.1186/1744-8069-6-92] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 12/11/2010] [Indexed: 01/23/2023] Open
Abstract
Background It has been shown that estrogen is synthesized in the spinal dorsal horn and plays a role in modulating pain transmission. One of the estrogen receptor (ER) subtypes, estrogen receptor alpha (ERα), is expressed in the spinal laminae I-V, including substantia gelatinosa (SG, lamina II). However, it is unclear how ERs are involved in the modulation of nociceptive transmission. Results In the present study, a selective ERα antagonist, methyl-piperidino-pyrazole (MPP), was used to test the potential functional roles of spinal ERα in the nociceptive transmission. Using the whole-cell patch-clamp technique, we examined the effects of MPP on SG neurons in the dorsal root-attached spinal cord slice prepared from adult rats. We found that MPP increased glutamatergic excitatory postsynaptic currents (EPSCs) evoked by the stimulation of either Aδ- or C-afferent fibers. Further studies showed that MPP treatment dose-dependently increased spontaneous EPSCs frequency in SG neurons, while not affecting the amplitude. In addition, the PKC was involved in the MPP-induced enhancement of synaptic transmission. Conclusions These results suggest that the selective ERα antagonist MPP pre-synaptically facilitates the excitatory synaptic transmission to SG neurons. The nociceptive transmission evoked by Aδ- and C-fiber stimulation could be potentiated by blocking ERα in the spinal neurons. Thus, the spinal estrogen may negatively regulate the nociceptive transmission through the activation of ERα.
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Affiliation(s)
- Yan-Qing Zhong
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences
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21
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Codocedo JF, Rodríguez FE, Huidobro-Toro JP. Neurosteroids differentially modulate P2X ATP-gated channels through non-genomic interactions. J Neurochem 2009; 110:734-44. [PMID: 19457083 DOI: 10.1111/j.1471-4159.2009.06166.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As neuroactive steroids modulate several ionotropic receptors, we assessed whether the ATP-gated currents elicited by P2X(4) receptors are modulated by these compounds. We transfected HEK293 cells or injected Xenopus laevis oocytes with the cDNA coding for rat P2X(4) receptor. Application of 0.1-10 microM alfaxolone potentiated within 60-s the 1 microM ATP-evoked currents with a maximal potentiation of 1.8 and 2.6-fold in HEK293 or oocytes cells respectively. Allopregnalolone or 3alpha, 21-dihydroxy-5alpha-pregnan-20-one (THDOC) also potentiated the ATP-gated currents but with a maximal effect only averaging 1.25 and 1.35-fold respectively. In contrast, 0.3-10 microM pregnanolone, but not its sulfated derivative, inhibited the ATP-gated currents; the maximal inhibition reached 40% in both cell types. THDOC, but not other neurosteroids increased significantly the tau(off) of the ATP-evoked currents, revealing another mode of neurosteroid modulation. Sexual steroids such as 17beta-estradiol or progesterone were inactive revealing explicit structural requirements. Alfaxolone or THDOC at concentrations 30- to 100-fold larger than required to modulate the receptor, gated the P2X(4) receptor eliciting ATP-like currents that were reduced with suramin or brilliant blue G, but potentiated the P2X(4) receptor more than 10-fold by 10 microM zinc. In conclusion, neurosteroids rapidly modulate via non-genomic mechanisms and with nanomolar potencies, the P2X4 receptor interacting likely at distinct modulator sites.
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Affiliation(s)
- Juan Francisco Codocedo
- Departamento de Fisiología, Centro de Regulación Celular y Patología, Instituto Milenio de Biología Fundamental y Aplicada, MIFAB, Pontificia Universidad Católica de Chile, Santiago, Chile
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