1
|
Voronin MV, Shangin SV, Litvinova SA, Abramova EV, Kurbanov RD, Rybina IV, Vakhitova YV, Seredenin SB. Pharmacological Analysis of GABA A Receptor and Sigma1R Chaperone Interaction: Research Report I-Investigation of the Anxiolytic, Anticonvulsant and Hypnotic Effects of Allosteric GABA A Receptors' Ligands. Int J Mol Sci 2023; 24:ijms24119580. [PMID: 37298532 DOI: 10.3390/ijms24119580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Two groups of facts have been established in previous drug development studies of the non-benzodiazepine anxiolytic fabomotizole. First, fabomotizole prevents stress-induced decrease in binding ability of the GABAA receptor's benzodiazepine site. Second, fabomotizole is a Sigma1R chaperone agonist, and exposure to Sigma1R antagonists blocks its anxiolytic effect. To prove our main hypothesis of Sigma1R involvement in GABAA receptor-dependent pharmacological effects, we performed a series of experiments on BALB/c and ICR mice using Sigma1R ligands to study anxiolytic effects of benzodiazepine tranquilizers diazepam (1 mg/kg i.p.) and phenazepam (0.1 mg/kg i.p.) in the elevated plus maze test, the anticonvulsant effects of diazepam (1 mg/kg i.p.) in the pentylenetetrazole-induced seizure model, and the hypnotic effects of pentobarbital (50 mg/kg i.p.). Sigma1R antagonists BD-1047 (1, 10, and 20 mg/kg i.p.), NE-100 (1 and 3 mg/kg i.p.), and Sigma1R agonist PRE-084 (1, 5, and 20 mg/kg i.p.) were used in the experiments. Sigma1R antagonists have been found to attenuate while Sigma1R agonists can enhance GABAARs-dependent pharmacological effects.
Collapse
Affiliation(s)
- Mikhail V Voronin
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Stanislav V Shangin
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Svetlana A Litvinova
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Elena V Abramova
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Rustam D Kurbanov
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Inna V Rybina
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Yulia V Vakhitova
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| | - Sergei B Seredenin
- Department of Pharmacogenetics, Federal State Budgetary Institution "Research Zakusov Institute of Pharmacology", Baltiyskaya Street 8, 125315 Moscow, Russia
| |
Collapse
|
2
|
He J, Fang J, Wang Y, Ge C, Liu S, Jiang Y. Discovery of Small-Molecule Antagonists of Orexin 1/2 Receptors from Traditional Chinese Medicinal Plants with a Hypnotic Effect. Pharmaceuticals (Basel) 2023; 16:ph16040542. [PMID: 37111298 PMCID: PMC10146837 DOI: 10.3390/ph16040542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/25/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Insomnia is an important public health problem. The currently available treatments for insomnia can cause some adverse effects. Orexin receptors 1 (OX1R) and 2 (OX2R) are burgeoning targets for insomnia treatment. It is an effective approach to screening OX1R and OX2R antagonists from traditional Chinese medicine, which contains abundant and diverse chemical components. This study established an in-home ligand library of small-molecule compounds from medicinal plants with a definite hypnotic effect, as described in the Chinese Pharmacopoeia. Molecular docking was applied to virtually screen potential orexin receptor antagonists using molecular operating environment software, and surface plasmon resonance (SPR) technology was used to detect the binding affinity between potential active compounds and orexin receptors. Finally, the results of virtual screening and SPR analysis were verified through in vitro assays. We successfully screened one potential lead compound (neferine) as an orexin receptor antagonist from the in-home ligand library, which contained more than 1000 compounds. The screened compound was validated as a potential agent for insomnia treatment through comprehensive biological assays. This research enabled the discovery of a potential small-molecule antagonist of orexin receptors for the treatment of insomnia, providing a novel screening approach for the detection of potential candidate compounds for corresponding targets.
Collapse
Affiliation(s)
- Jia He
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Jing Fang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yuxin Wang
- College of Pharmacy, Dali University, Dali 671000, China
| | - Chengyu Ge
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Shao Liu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yueping Jiang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| |
Collapse
|
3
|
Zhang T, Ruan HZ, Wang YC, Shao YQ, Zhou W, Weng SJ, Zhong YM. Signaling Mechanism for Modulation by GLP-1 and Exendin-4 of GABA Receptors on Rat Retinal Ganglion Cells. Neurosci Bull 2022; 38:622-636. [PMID: 35278196 PMCID: PMC9206055 DOI: 10.1007/s12264-022-00826-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/10/2021] [Indexed: 11/29/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is expressed in retinal neurons, but its role in the retina is largely unknown. Here, we demonstrated that GLP-1 or the GLP-1 receptor (GLP-1R; a G protein-coupled receptor) agonist exendin-4 suppressed γ-aminobutyric acid receptor (GABAR)-mediated currents through GLP-1Rs in isolated rat retinal ganglion cells (GCs). Pre-incubation with the stimulatory G protein (Gs) inhibitor NF 449 abolished the exendin-4 effect. The exendin-4-induced suppression was mimicked by perfusion with 8-Br-cAMP (a cAMP analog), but was eliminated by the protein kinase A (PKA) inhibitor Rp-cAMP/KT-5720. The exendin-4 effect was accompanied by an increase in [Ca2+]i of GCs through the IP3-sensitive pathway and was blocked in Ca2+-free solution. Furthermore, when the activity of calmodulin (CaM) and CaM-dependent protein kinase II (CaMKII) was inhibited, the exendin-4 effect was eliminated. Consistent with this, exendin-4 suppressed GABAR-mediated light-evoked inhibitory postsynaptic currents in GCs in rat retinal slices. These results suggest that exendin-4-induced suppression may be mediated by a distinct Gs/cAMP-PKA/IP3/Ca2+/CaM/CaMKII signaling pathway, following the activation of GLP-1Rs.
Collapse
Affiliation(s)
- Tao Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Hang-Ze Ruan
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yong-Chen Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yu-Qi Shao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Wei Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Shi-Jun Weng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yong-Mei Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
| |
Collapse
|
4
|
Qin J, Wei T, Chen H, Lin X, Qin D, Wei F, Liu P, Ye W, Su J. Salicylate Induced GABAAR Internalization by Dopamine D1-Like Receptors Involving Protein Kinase C (PKC) in Spiral Ganglion Neurons. Med Sci Monit 2021; 27:e933278. [PMID: 34657931 PMCID: PMC8532520 DOI: 10.12659/msm.933278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Sodium salicylate (SS) induces excitotoxicity of spiral ganglion neurons (SGNs) by inhibiting the response of γ-aminobutyric acid type A receptors (GABAARs). Our previous studies have shown that SS can increase the internalization of GABAARs on SGNs, which involves dopamine D1-like receptors (D1Rs) and related signaling pathways. In this study, we aimed to explore the role of D1Rs and their downstream molecule protein kinase C (PKC) in the process of SS inhibiting GABAARs. MATERIAL AND METHODS The expression of D1Rs and GABARγ2 on rat cochlear SGNs cultured in vitro was tested by immunofluorescence. Then, the SGNs were exposed to SS, D1R agonist (SKF38393), D1R antagonist (SCH23390), clathrin/dynamin-mediated endocytosis inhibitor (dynasore), and PKC inhibitor (Bisindolylmaleimide I). Western blotting and whole-cell patch clamp technique were used to assess the changes of surface and total protein of GABARγ2 and GABA-activated currents. RESULTS Immunofluorescence showed that D1 receptors (DRD1) were expressed on SGNs. Data from western blotting showed that SS promoted the internalization of cell surface GABAARs, and activating D1Rs had the same result. Inhibiting D1Rs and PKC decreased the internalization of GABAARs. Meanwhile, the phosphorylation level of GABAARγ2 S327 affected by PKC was positively correlated with the degree of internalization of GABAARs. Moreover, whole-cell patch clamp recording showed that inhibition of D1Rs or co-inhibition of D1Rs and PKC attenuated the inhibitory effect of SS on GABA-activated currents. CONCLUSIONS D1Rs mediate the GABAAR internalization induced by SS via a PKC-dependent manner and participate in the excitotoxic process of SGNs.
Collapse
Affiliation(s)
- Jiangyuan Qin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Tingjia Wei
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Huiying Chen
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Xiaoyu Lin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Danxue Qin
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Fangyu Wei
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Peiqiang Liu
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Wenhua Ye
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| | - Jiping Su
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China (mainland)
| |
Collapse
|
5
|
Regulation of GABA A Receptors Induced by the Activation of L-Type Voltage-Gated Calcium Channels. MEMBRANES 2021; 11:membranes11070486. [PMID: 34209589 PMCID: PMC8304739 DOI: 10.3390/membranes11070486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 12/30/2022]
Abstract
GABAA receptors are pentameric ion channels that mediate most synaptic and tonic extrasynaptic inhibitory transmissions in the central nervous system. There are multiple GABAA receptor subtypes constructed from 19 different subunits in mammals that exhibit different regional and subcellular distributions and distinct pharmacological properties. Dysfunctional alterations of GABAA receptors are associated with various neuropsychiatric disorders. Short- and long-term plastic changes in GABAA receptors can be induced by the activation of different intracellular signaling pathways that are triggered, under physiological and pathological conditions, by calcium entering through voltage-gated calcium channels. This review discusses several mechanisms of regulation of GABAA receptor function that result from the activation of L-type voltage gated calcium channels. Calcium influx via these channels activates different signaling cascades that lead to changes in GABAA receptor transcription, phosphorylation, trafficking, and synaptic clustering, thus regulating the inhibitory synaptic strength. These plastic mechanisms regulate the interplay of synaptic excitation and inhibition that is crucial for the normal function of neuronal circuits.
Collapse
|
6
|
Yang X, Zhu S, Jin N, Li Y, Zhen C, Zhang H, Xu A, Wang M, Zheng C. [Orexin-A inhibits γ-aminobutyric acid current of neonatal rat spinal cord ventral horn neurons by activating OX 1R, OX 2R and Ca 2+-independent PKC]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2021; 41:694-701. [PMID: 34134956 DOI: 10.12122/j.issn.1673-4254.2021.05.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the effect of orexin-A on the functionality of ionotropic γ-aminobutyric acid (GABA) receptors in spinal cord ventral horn neurons and its mechanisms. OBJECTIVE The spinal cord containing the lumbosacral enlargement was isolated from neonatal SD rats (7-12 days old) and sliced. The slices were digested with papain (in 0.18 g/30 mL artificial cerebrospinal fluid) for 40-60 min, and the ventral horn neurons were separated acutely using fire-polished Pasteur pipettes. After the cells adhered to the bottom of Petri dishes, patch-clamp experiments combined with pharmacological methods were performed to test the effects of orexin-A on GABA currents of the neurons treated with SB334867 (a selective OX1R antagonist), TCSOX229 (a selective OX2R antagonist), Bis-Ⅳ (a PKC inhibitor), PMA (a PKC agonist), Rp-cAMP (a PKA inhibitor), or BAPTA (Ca2+ chelator). OBJECTIVE The isolated neurons maintained good morphologies with diverse shapes of cell body and long protrusions. Treatment with orexin-A significantly inhibited the amplitude of GABA-induced current (P < 0.001, n=49) with an inhibition rate of (67.48±12.50)%. SB334867 and TCSOX229, when applied simultaneously, completely abolished the suppressive effect of orexin-A on the GABA currents (P=0.93, n=6), and their separate use partially relieved the suppressive effect of orexin-A (P=0.001, n=8; P=0.02, n=8). The application of Bis-Ⅳ also abolished the suppressive effect of orexin-A on GABA currents (P=0.31, n=5). PMA mimicked the effect of orexin-A in these neurons and significantly inhibited GABA currents with an inhibition rate of (60.79±10.94)%, and the application of orexin-A did not cause further suppression of GABA currents in PMA-treated neurons (P=0.15, n=6). Orexin-A was still capable of suppressing GABA currents in Rp-cAMP-treated neurons (P=0.001, n=5). The extracellular Ca2+-free solution (P=0.004, n=8) or the presence of BAPTA (P=0.04, n=7) did not significantly affect the inhibitory effect of orexin-A on GABA currents. OBJECTIVE Orexin-A inhibits GABA currents in the ventral horn neurons of rat spinal cord probably by activating OX1R, OX2R and Ca2+-independent PKC.
Collapse
Affiliation(s)
- X Yang
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - S Zhu
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - N Jin
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - Y Li
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - C Zhen
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - H Zhang
- Psychophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - A Xu
- Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - M Wang
- Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - C Zheng
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| |
Collapse
|
7
|
Sadanandan SM, Kreko-Pierce T, Khatri SN, Pugh JR. Cannabinoid type 2 receptors inhibit GABAA receptor-mediated currents in cerebellar Purkinje cells of juvenile mice. PLoS One 2020; 15:e0233020. [PMID: 32437355 PMCID: PMC7241750 DOI: 10.1371/journal.pone.0233020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 04/28/2020] [Indexed: 12/15/2022] Open
Abstract
Signaling through the endocannabinoid system is critical to proper functioning of the cerebellar circuit. However, most studies have focused on signaling through cannabinoid type 1 (CB1) receptors, while relatively little is known about signaling through type 2 (CB2) receptors. We show that functional CB2 receptors are expressed in Purkinje cells using a combination of immunohistochemistry and patch-clamp electrophysiology in juvenile mice. Pharmacological activation of CB2 receptors significantly reduces inhibitory synaptic responses and currents mediated by photolytic uncaging of RuBi-GABA in Purkinje cells. CB2 receptor activation does not change the paired-pulse ratio of inhibitory responses and its effects are blocked by inclusion of GDP-β-S in the internal solution, indicating a postsynaptic mechanism of action. However, CB2 receptors do not contribute to depolarization induced suppression of inhibition (DSI), indicating they are not activated by endocannabinoids synthesized and released from Purkinje cells using this protocol. This work demonstrates that CB2 receptors inhibit postsynaptic GABAA receptors by a postsynaptic mechanism in Purkinje cells. This represents a novel mechanism by which CB2 receptors may modulate neuronal and circuit function in the central nervous system.
Collapse
Affiliation(s)
- Sriity Melley Sadanandan
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Tabita Kreko-Pierce
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Shailesh N. Khatri
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Jason R. Pugh
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
- Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| |
Collapse
|
8
|
Mechanisms of GABA B receptor enhancement of extrasynaptic GABA A receptor currents in cerebellar granule cells. Sci Rep 2019; 9:16683. [PMID: 31723152 PMCID: PMC6853962 DOI: 10.1038/s41598-019-53087-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/26/2019] [Indexed: 12/31/2022] Open
Abstract
Many neurons, including cerebellar granule cells, exhibit a tonic GABA current mediated by extrasynaptic GABAA receptors. This current is a critical regulator of firing and the target of many clinically relevant compounds. Using a combination of patch clamp electrophysiology and photolytic uncaging of RuBi-GABA we show that GABAB receptors are tonically active and enhance extrasynaptic GABAA receptor currents in cerebellar granule cells. This enhancement is not associated with meaningful changes in GABAA receptor potency, mean channel open-time, open probability, or single-channel current. However, there was a significant (~40%) decrease in the number of channels participating in the GABA uncaging current and an increase in receptor desensitization. Furthermore, we find that adenylate cyclase, PKA, CaMKII, and release of Ca2+ from intracellular stores are necessary for modulation of GABAA receptors. Overall, this work reveals crosstalk between postsynaptic GABAA and GABAB receptors and identifies the signaling pathways and mechanisms involved.
Collapse
|
9
|
Davoudi M, Vijeepallam K, Azizi H, Mirnajafi-Zadeh J, Semnanian S. PKC inhibitor reversed the suppressive effect of orexin-A on IPSCs of locus coeruleus neurons in naloxone-induced morphine withdrawal. J Neural Transm (Vienna) 2019; 126:1425-1435. [PMID: 31493096 DOI: 10.1007/s00702-019-02064-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/09/2019] [Indexed: 11/26/2022]
Abstract
The locus coeruleus (LC) as a target of addictive drugs receives a dense projection of orexinergic fibres from the lateral hypothalamus (LH) and is accordingly a candidate site for the expression of the somatic aspects of morphine withdrawal. Recently it has been shown that the inhibitory synaptic currents of LC neurons decrease partly through orexin type 1 receptors in the context of naloxone-induced morphine withdrawal; however, its cellular mechanism remains unclear. In this study, whole-cell patch clamp recordings of LC neurons in brainstem slices were used to investigate the impact of protein kinase C (PKC) on GABAergic inhibitory post-synaptic currents (IPSCs) in the context of naloxone-induced morphine withdrawal. Male Wistar rats (P14-P21) received morphine (20 mg/kg, i.p.) daily for 7 consecutive days to induce morphine dependency. Our results showed that the application of PKC inhibitor (Go 6983; 1 µM) alone did not decrease the probability of GABA release in the LC neurons of the morphine-treated rats in the presence of naloxone. Although, Go 6983 reversed the reduction of the amplitude of evoked IPSCs (eIPSCs) and spontaneous IPSCs (sIPSCs) frequency induced by orexin-A but did not change the sIPSCs amplitude. These results indicate that the suppressive effect of orexin-A on IPSCs is probably reversed by PKC inhibitor in the LC neurons of morphine-treated rats in the context of naloxone withdrawal.
Collapse
Affiliation(s)
- Mahnaz Davoudi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Kamini Vijeepallam
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| |
Collapse
|
10
|
Davoudi M, Azizi H, Mirnajafi-Zadeh J, Semnanian S. Decrease of inhibitory synaptic currents of locus coeruleus neurons via orexin type 1 receptors in the context of naloxone-induced morphine withdrawal. J Physiol Sci 2019; 69:281-293. [PMID: 30406600 PMCID: PMC10717061 DOI: 10.1007/s12576-018-0645-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/25/2018] [Indexed: 10/27/2022]
Abstract
Acute opioid withdrawal syndrome is a series of neurological symptoms caused by the abrupt cessation of the chronic administration of opioids such as morphine. The locus coeruleus (LC) in the brain stem receives a dense projection of orexinergic fibers from the hypothalamus and is a candidate site for the expression of the somatic aspects of morphine withdrawal. Previous studies have shown that orexin-A contributes to the behavioral symptoms of naloxone-induced morphine withdrawal, partly by reducing the activity of GABAergic neurons, suggesting that orexin-A may negatively modulate fast GABAergic neurotransmission during morphine withdrawal. We used whole-cell patch-clamp recordings of LC neurons in brainstem slices to investigate the effect of orexin-A on bicuculline-sensitive GABAergic inhibitory postsynaptic currents (IPSCs) during naloxone-induced morphine withdrawal. Male Wistar rats (P14-P21) were given morphine (20 mg/kg, i.p.) daily for seven consecutive days to create dependency on the drug. The application of naloxone (1 µM) to brain slices of morphine-treated rats reduced the amplitude of evoked IPSCs (eIPSCs) as well as spontaneous IPSCs (sIPSCs) frequency but did not change sIPSCs amplitude. Orexin-A (100 nM) significantly enhanced the suppressive effect of naloxone on eIPSCs amplitude and sIPSCs frequency but had no effect on the presence of the orexin type 1 receptor (OX1R) antagonist, SB-334867. Orexin-A alone had no significant effect on eIPSCs and sIPSCs in the absence of naloxone. In summary, our results show that orexin-A, via OX1R, potentiates the suppressive effect of naloxone on GABAergic IPSCs of LC neurons in morphine-treated rats. We conclude that orexins may have a critical role in regulating GABAergic neurotransmission to LC neurons during naloxone-induced morphine withdrawal.
Collapse
Affiliation(s)
- Mahnaz Davoudi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| |
Collapse
|
11
|
Raoof M, Soofiabadi S, Abbasnejad M, Kooshki R, Esmaeili-Mahani S, Mansoori M. Activation of orexin-1 receptors in the ventrolateral periaqueductal grey matter (vlPAG) modulates pulpal nociception and the induction of substance P in vlPAG and trigeminal nucleus caudalis. Int Endod J 2018; 52:318-328. [PMID: 30152877 DOI: 10.1111/iej.13007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/24/2018] [Indexed: 12/24/2022]
Abstract
AIM To characterize the role of orexin-1 receptors (OX1Rs) in ventrolateral periaqueductal grey matter (vlPAG) on modulation of capsaicin-induced pulpal nociception in rats. METHODOLOGY Sixty-six adult male Wistar rats (2 months old) weighing between 230 and 260 g were used. The animals were cannulated for microinjection of drugs into the vlPAG matter. Pulpalgia was induced by intradental application of capsaicin solution (100 μg) into the incisor teeth of the rats. Ten min prior to capsaicin application, orexin-A (50, 100 and 150 pmol L-1 per rat) was administered. Orexin-A (150 pmol L-1 ) was also co-administrated with SB-334867 (40 nmol L-1 per rat), an OX1Rs antagonist; or bicuculline (1 μg per rat), a GABAA receptors antagonist. Moreover, treatment effects on the release of pro-nociceptive modulator substance P (SP) in vlPAG and trigeminal nucleus caudalis (Vc) of rats were explored using an immunofluorescence technique. One-way analysis of variance was used for the statistical analysis. RESULTS Orexin-A dose-dependently decreased capsaicin-induced nociceptive behaviour. However, SB-334867 (40 nmol L-1 per rat) pretreatment (P < 0.05), but not bicuculline (1 μg per rat), attenuated the analgesic effect of orexin-A (150 pmol L-1 ). The level of SP was significantly increased in Vc and decreased in vlPAG of capsaicin-treated rats (P < 0.05). Capsaicin-induced changes in SP levels, however, were prohibited by orexin-A treatment (150 pmol L-1 ) (P < 0.05). CONCLUSIONS Orexin-A administration into the vlPAG was associated with an inhibitory effect on capsaicin-induced pulpal nociception and bidirectional effects on the induction of SP in vlPAG and Vc of rats. Central activation of OX1Rs is a potential therapeutic tool for pulpalgia.
Collapse
Affiliation(s)
- M Raoof
- Endodontology Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - S Soofiabadi
- Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - M Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - R Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - S Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - M Mansoori
- Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| |
Collapse
|
12
|
Activation of orexin system facilitates anesthesia emergence and pain control. Proc Natl Acad Sci U S A 2018; 115:E10740-E10747. [PMID: 30348769 DOI: 10.1073/pnas.1808622115] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Orexin (also known as hypocretin) neurons in the hypothalamus play an essential role in sleep-wake control, feeding, reward, and energy homeostasis. The likelihood of anesthesia and sleep sharing common pathways notwithstanding, it is important to understand the processes underlying emergence from anesthesia. In this study, we investigated the role of the orexin system in anesthesia emergence, by specifically activating orexin neurons utilizing the designer receptors exclusively activated by designer drugs (DREADD) chemogenetic approach. With injection of adeno-associated virus into the orexin-Cre transgenic mouse brain, we expressed the DREADD receptor hM3Dq specifically in orexin neurons and applied the hM3Dq ligand clozapine to activate orexin neurons. We monitored orexin neuronal activities by c-Fos staining and whole-cell patch-clamp recording and examined the consequence of orexin neuronal activation via EEG recording. Our results revealed that the orexin-DREADD mice with activated orexin neurons emerged from anesthesia with significantly shorter latency than the control mice. As an indication of reduced pain sensitivity, these orexin-DREADD mice took longer to respond to the 55 °C thermal stimuli in the hot plate test and exhibited significantly less frequent licking of the formalin-injected paw in the formalin test. Our study suggests that approaches to activate the orexin system can be beneficial in postoperative recovery.
Collapse
|
13
|
Jurek B, Neumann ID. The Oxytocin Receptor: From Intracellular Signaling to Behavior. Physiol Rev 2018; 98:1805-1908. [DOI: 10.1152/physrev.00031.2017] [Citation(s) in RCA: 408] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The many facets of the oxytocin (OXT) system of the brain and periphery elicited nearly 25,000 publications since 1930 (see FIGURE 1 , as listed in PubMed), which revealed central roles for OXT and its receptor (OXTR) in reproduction, and social and emotional behaviors in animal and human studies focusing on mental and physical health and disease. In this review, we discuss the mechanisms of OXT expression and release, expression and binding of the OXTR in brain and periphery, OXTR-coupled signaling cascades, and their involvement in behavioral outcomes to assemble a comprehensive picture of the central and peripheral OXT system. Traditionally known for its role in milk let-down and uterine contraction during labor, OXT also has implications in physiological, and also behavioral, aspects of reproduction, such as sexual and maternal behaviors and pair bonding, but also anxiety, trust, sociability, food intake, or even drug abuse. The many facets of OXT are, on a molecular basis, brought about by a single receptor. The OXTR, a 7-transmembrane G protein-coupled receptor capable of binding to either Gαior Gαqproteins, activates a set of signaling cascades, such as the MAPK, PKC, PLC, or CaMK pathways, which converge on transcription factors like CREB or MEF-2. The cellular response to OXT includes regulation of neurite outgrowth, cellular viability, and increased survival. OXTergic projections in the brain represent anxiety and stress-regulating circuits connecting the paraventricular nucleus of the hypothalamus, amygdala, bed nucleus of the stria terminalis, or the medial prefrontal cortex. Which OXT-induced patterns finally alter the behavior of an animal or a human being is still poorly understood, and studying those OXTR-coupled signaling cascades is one initial step toward a better understanding of the molecular background of those behavioral effects.
Collapse
Affiliation(s)
- Benjamin Jurek
- Department of Behavioural and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany
| | - Inga D. Neumann
- Department of Behavioural and Molecular Neurobiology, Institute of Zoology, University of Regensburg, Regensburg, Germany
| |
Collapse
|
14
|
Chrobok L, Palus-Chramiec K, Chrzanowska A, Kepczynski M, Lewandowski MH. Multiple excitatory actions of orexins upon thalamo-cortical neurons in dorsal lateral geniculate nucleus - implications for vision modulation by arousal. Sci Rep 2017; 7:7713. [PMID: 28794459 PMCID: PMC5550457 DOI: 10.1038/s41598-017-08202-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 07/06/2017] [Indexed: 01/08/2023] Open
Abstract
The orexinergic system of the lateral hypothalamus plays a crucial role in maintaining wakefulness and mediating arousal in a circadian time-dependent manner. Due to the extensive connections of orexinergic neurons, both orexins (OXA and OXB) exert mainly excitatory effects upon remote brain areas, including the thalamus. The dorsal lateral geniculate nucleus (DLG) is a relay thalamic centre for the visual system. Its thalamo-cortical (TC) neurons convey photic information from the retina to the primary visual cortex. The present study shows that orexins are powerful modulators of neuronal activity in the DLG. OXA directly depolarised the majority of neurons tested, acting predominately on postsynaptic OX2 receptors. Moreover, OXA was found to increase excitability and enhance neuronal responses to both glutamate and γ-aminobutyric acid (GABA). Mechanistic studies showed the involvement of voltage-gated calcium currents and GIRK channels in the observed depolarisations. Immunohistochemical staining showed sparse orexinergic innervation of the DLG during the light phase, with increased density at night. We hypothesise that the depolarising effects of orexins upon DLG neurons may facilitate signal transmission through the visual thalamo-cortical pathway during behavioural arousal. Thus, the action of orexin on DLG TC neurons may underlie the circadian/behavioural modulation of vision.
Collapse
Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa 9 Street, 30-387, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa 9 Street, 30-387, Krakow, Poland
| | - Anna Chrzanowska
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa 9 Street, 30-387, Krakow, Poland
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University in Krakow, Ingardena 3 Street, 30-060, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Gronostajowa 9 Street, 30-387, Krakow, Poland.
| |
Collapse
|