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Vargas Y, Castro Tron AE, Rodríguez Rodríguez A, Uribe RM, Joseph-Bravo P, Charli JL. Thyrotropin-Releasing Hormone and Food Intake in Mammals: An Update. Metabolites 2024; 14:302. [PMID: 38921437 PMCID: PMC11205479 DOI: 10.3390/metabo14060302] [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: 05/05/2024] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 06/27/2024] Open
Abstract
Thyrotropin-releasing hormone (TRH; pGlu-His-Pro-NH2) is an intercellular signal produced mainly by neurons. Among the multiple pharmacological effects of TRH, that on food intake is not well understood. We review studies demonstrating that peripheral injection of TRH generally produces a transient anorexic effect, discuss the pathways that might initiate this effect, and explain its short half-life. In addition, central administration of TRH can produce anorexic or orexigenic effects, depending on the site of injection, that are likely due to interaction with TRH receptor 1. Anorexic effects are most notable when TRH is injected into the hypothalamus and the nucleus accumbens, while the orexigenic effect has only been detected by injection into the brain stem. Functional evidence points to TRH neurons that are prime candidate vectors for TRH action on food intake. These include the caudal raphe nuclei projecting to the dorsal motor nucleus of the vagus, and possibly TRH neurons from the tuberal lateral hypothalamus projecting to the tuberomammillary nuclei. For other TRH neurons, the anatomical or physiological context and impact of TRH in each synaptic domain are still poorly understood. The manipulation of TRH expression in well-defined neuron types will facilitate the discovery of its role in food intake control in each anatomical scene.
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Affiliation(s)
| | | | | | | | | | - Jean-Louis Charli
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Avenida Universidad 2001, Cuernavaca 62210, Mexico; (Y.V.); (A.E.C.T.); (A.R.R.); (R.M.U.); (P.J.-B.)
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2
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Gao C, Gohel CA, Leng Y, Ma J, Goldman D, Levine AJ, Penzo MA. Molecular and spatial profiling of the paraventricular nucleus of the thalamus. eLife 2023; 12:81818. [PMID: 36867023 PMCID: PMC10014079 DOI: 10.7554/elife.81818] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 03/02/2023] [Indexed: 03/04/2023] Open
Abstract
The paraventricular nucleus of the thalamus (PVT) is known to regulate various cognitive and behavioral processes. However, while functional diversity among PVT circuits has often been linked to cellular differences, the molecular identity and spatial distribution of PVT cell types remain unclear. To address this gap, here we used single nucleus RNA sequencing (snRNA-seq) and identified five molecularly distinct PVT neuronal subtypes in the mouse brain. Additionally, multiplex fluorescent in situ hybridization of top marker genes revealed that PVT subtypes are organized by a combination of previously unidentified molecular gradients. Lastly, comparing our dataset with a recently published single-cell sequencing atlas of the thalamus yielded novel insight into the PVT's connectivity with the cortex, including unexpected innervation of auditory and visual areas. This comparison also revealed that our data contains a largely non-overlapping transcriptomic map of multiple midline thalamic nuclei. Collectively, our findings uncover previously unknown features of the molecular diversity and anatomical organization of the PVT and provide a valuable resource for future investigations.
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Affiliation(s)
- Claire Gao
- National Institute of Mental HealthBethesdaUnited States
- Department of Neuroscience, Brown UniversityProvidenceUnited States
| | - Chiraag A Gohel
- National Institute on Alcohol Abuse and AlcoholismRockvilleUnited States
| | - Yan Leng
- National Institute of Mental HealthBethesdaUnited States
| | - Jun Ma
- National Institute of Mental HealthBethesdaUnited States
| | - David Goldman
- National Institute on Alcohol Abuse and AlcoholismRockvilleUnited States
| | - Ariel J Levine
- National Institute of Child Health and Human DevelopmentBethesdaUnited States
| | - Mario A Penzo
- National Institute of Mental HealthBethesdaUnited States
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3
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Sharafi A, Pakkhesal S, Fakhari A, Khajehnasiri N, Ahmadalipour A. Rapid treatments for depression: Endocannabinoid system as a therapeutic target. Neurosci Biobehav Rev 2022; 137:104635. [PMID: 35351488 DOI: 10.1016/j.neubiorev.2022.104635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/19/2022] [Accepted: 03/20/2022] [Indexed: 12/16/2022]
Abstract
Current first-line treatments for major depressive disorder (MDD), i.e., antidepressant drugs and psychotherapy, show delayed onset of therapeutic effect as late as 2-3 weeks or more. In the clinic, the speed of beginning of the actions of antidepressant drugs or other interventions is vital for many reasons. Late-onset means that depression, its related disability, and the potential danger of suicide remain a threat for some patients. There are some rapid-acting antidepressant interventions, such as sleep deprivation, ketamine, acute exercise, which induce a significant response, ranging from a few hours to maximally one week, and most of them share a common characteristic that is the activation of the endocannabinoid (eCB) system. Activation of this system, i.e., augmentation of eCB signaling, appears to have anti-depressant-like actions. This article puts the idea forward that the activation of eCB signaling represents a critical mechanism of rapid-acting therapeutic interventions in MDD, and this system might contribute to the development of novel rapid-acting treatments for MDD.
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Affiliation(s)
- AmirMohammad Sharafi
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sina Pakkhesal
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Fakhari
- Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nazli Khajehnasiri
- Department of Biological Science, Faculty of Basic Science, Higher Education Institute of Rab-Rashid, Tabriz, Iran
| | - Ali Ahmadalipour
- Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Tabriz, Iran; Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran.
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4
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Jeon J, Bu F, Sun G, Tian JB, Ting SM, Li J, Aronowski J, Birnbaumer L, Freichel M, Zhu MX. Contribution of TRPC Channels in Neuronal Excitotoxicity Associated With Neurodegenerative Disease and Ischemic Stroke. Front Cell Dev Biol 2021; 8:618663. [PMID: 33490083 PMCID: PMC7820370 DOI: 10.3389/fcell.2020.618663] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
The seven canonical members of transient receptor potential (TRPC) proteins form cation channels that evoke membrane depolarization and intracellular calcium concentration ([Ca2+] i ) rise, which are not only important for regulating cell function but their deregulation can also lead to cell damage. Recent studies have implicated complex roles of TRPC channels in neurodegenerative diseases including ischemic stroke. Brain ischemia reduces oxygen and glucose supply to neurons, i.e., Oxygen and Glucose Deprivation (OGD), resulting in [Ca2+] i elevation, ion dyshomeostasis, and excitotoxicity, which are also common in many forms of neurodegenerative diseases. Although ionotropic glutamate receptors, e.g., N-methyl-D-aspartate receptors, are well established to play roles in excitotoxicity, the contribution of metabotropic glutamate receptors and their downstream effectors, i.e., TRPC channels, should not be neglected. Here, we summarize the current findings about contributions of TRPC channels in neurodegenerative diseases, with a focus on OGD-induced neuronal death and rodent models of cerebral ischemia/reperfusion. TRPC channels play both detrimental and protective roles to neurodegeneration depending on the TRPC subtype and specific pathological conditions involved. When illustrated the mechanisms by which TRPC channels are involved in neuronal survival or death seem differ greatly, implicating diverse and complex regulation. We provide our own data showing that TRPC1/C4/C5, especially TRPC4, may be generally detrimental in OGD and cerebral ischemia/reperfusion. We propose that although TRPC channels significantly contribute to ischemic neuronal death, detailed mechanisms and specific roles of TRPC subtypes in brain injury at different stages of ischemia/reperfusion and in different brain regions need to be carefully and systematically investigated.
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Affiliation(s)
- Jaepyo Jeon
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Fan Bu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Guanghua Sun
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jin-Bin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Shun-Ming Ting
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jun Li
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jaroslaw Aronowski
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Lutz Birnbaumer
- Institute for Biomedical Research (BIOMED UCA-CONICET), Buenos Aires, Argentina.,School of Medical Sciences, Catholic University of Argentina (UCA), Buenos Aires, Argentina.,Neurobiology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Marc Freichel
- Department of Pharmacology, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States
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Yang S, Hu B, Wang Z, Zhang C, Jiao H, Mao Z, Wei L, Jia J, Zhao J. Cannabinoid CB1 receptor agonist ACEA alleviates brain ischemia/reperfusion injury via CB1-Drp1 pathway. Cell Death Discov 2020; 6:102. [PMID: 33083022 PMCID: PMC7548964 DOI: 10.1038/s41420-020-00338-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/23/2020] [Indexed: 12/16/2022] Open
Abstract
Activation of the cannabinoid CB1 receptor induces neuroprotection against brain ischemia/reperfusion injury (IRI); however, the mechanism is still unknown. In this study, we used oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in neuronal cells and middle cerebral artery occlusion (MCAO)-induced brain IRI in rats to mimic ischemic brain injury, and hypothesized that the CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA) would protect ischemic neurons by inhibiting mitochondrial fission via dynamin-related protein 1 (Drp1). We found that OGD/R injury reduced cell viability and mitochondrial function, increased lactate dehydrogenase (LDH) release, and increased cell apoptosis, and mitochondrial fission. Notably, ACEA significantly abolished the OGD/R-induced neuronal injuries described above. Similarly, ACEA significantly reversed MCAO-induced increases in brain infarct volume, neuronal apoptosis and mitochondrial fission, leading to the recovery of neurological functions. The neuroprotective effects of ACEA were obviously blocked by coadministration of the CB1 receptor antagonist AM251 or by the upregulation of Drp1 expression, indicating that ACEA alleviates brain IRI via the CB1-Drp1 pathway. Our findings suggest that the CB1 receptor links aberrant mitochondrial fission to brain IRI, providing a new therapeutic target for brain IRI treatment.
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Affiliation(s)
- Shuai Yang
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Bin Hu
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zongming Wang
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Changming Zhang
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Haosen Jiao
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zhigang Mao
- Department of Neurosurgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Liguang Wei
- Department of Neurosurgery, The Second People’s Hospital of Qinzhou City, Qinzhou, China
| | - Ji Jia
- Department of Anesthesiology, General Hospital of Southern Theatre Command of PLA, Guangzhou, China
| | - Jingling Zhao
- Department of Burns, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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6
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Wei F, Zhao L, Jing Y. Signaling molecules targeting cannabinoid receptors: Hemopressin and related peptides. Neuropeptides 2020; 79:101998. [PMID: 31831183 DOI: 10.1016/j.npep.2019.101998] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 11/21/2019] [Accepted: 11/21/2019] [Indexed: 12/23/2022]
Abstract
Cannabinoid receptors (CBRs) are part of the endocannabinoid system, which is involved in various physiological processes such as nociception, inflammation, appetite, stress, and emotion regulation. Many studies have linked the endocannabinoid system to neuroinflammatory and neurodegenerative disorders such as Parkinson's disease, Huntington's chorea, Alzheimer's disease, and multiple sclerosis. Hemopressin [Hp; a fragment of the hemoglobin α1 chain (95-103 amino acids)] and related peptides [VD-Hpα and RVD-Hpα] are peptides that bind to CBRs. Hp acts as an inverse agonist to CB1 receptor (CB1R), VD-Hpα acts as an agonist to CB1R, and RVD-Hpα acts as a negative allosteric modulator of CB1R and a positive allosteric modulator of CB2R. Because of the critical roles of CBRs in numerous physiological processes, it is appealing to use Hp and related peptides for therapeutic purposes. This review discusses their discovery, structure, metabolism, brain exposure, self-assembly characteristics, pharmacological characterization, and pharmacological activities.
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Affiliation(s)
- Fengmei Wei
- Department of Physiology and Psychology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu Province 730000, PR China
| | - Long Zhao
- Department of Orthopaedics, Lanzhou University First Affiliated Hospital, Lanzhou, Gansu Province 730000, PR China
| | - Yuhong Jing
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu 730000, PR China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, Gansu 730000, PR China.
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7
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de Araujo CB, Heimann AS, Remer RA, Russo LC, Colquhoun A, Forti FL, Ferro ES. Intracellular Peptides in Cell Biology and Pharmacology. Biomolecules 2019; 9:biom9040150. [PMID: 30995799 PMCID: PMC6523763 DOI: 10.3390/biom9040150] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/02/2019] [Accepted: 04/12/2019] [Indexed: 12/11/2022] Open
Abstract
Intracellular peptides are produced by proteasomes following degradation of nuclear, cytosolic, and mitochondrial proteins, and can be further processed by additional peptidases generating a larger pool of peptides within cells. Thousands of intracellular peptides have been sequenced in plants, yeast, zebrafish, rodents, and in human cells and tissues. Relative levels of intracellular peptides undergo changes in human diseases and also when cells are stimulated, corroborating their biological function. However, only a few intracellular peptides have been pharmacologically characterized and their biological significance and mechanism of action remains elusive. Here, some historical and general aspects on intracellular peptides' biology and pharmacology are presented. Hemopressin and Pep19 are examples of intracellular peptides pharmacologically characterized as inverse agonists to cannabinoid type 1 G-protein coupled receptors (CB1R), and hemopressin fragment NFKF is shown herein to attenuate the symptoms of pilocarpine-induced epileptic seizures. Intracellular peptides EL28 (derived from proteasome 26S protease regulatory subunit 4; Rpt2), PepH (derived from Histone H2B type 1-H), and Pep5 (derived from G1/S-specific cyclin D2) are examples of peptides that function intracellularly. Intracellular peptides are suggested as biological functional molecules, and are also promising prototypes for new drug development.
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Affiliation(s)
- Christiane B de Araujo
- Special Laboratory of Cell Cycle, Center of Toxins, Immune Response and Cell Signaling - CeTICS, Butantan Institute, São Paulo SP 05503-900, Brazil.
| | | | | | - Lilian C Russo
- Department of Biochemistry, Chemistry Institute, University of São Paulo 1111, São Paulo 05508-000, Brazil.
| | - Alison Colquhoun
- Department of Cell and Developmental Biology, University of São Paulo (USP), São Paulo 05508-000, Brazil.
| | - Fábio L Forti
- Department of Biochemistry, Chemistry Institute, University of São Paulo 1111, São Paulo 05508-000, Brazil.
| | - Emer S Ferro
- Department of Pharmacology, Biomedical Sciences Institute, University of São Paulo (USP), São Paulo 05508-000, Brazil.
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Sánchez-Zavaleta R, Cortés H, Avalos-Fuentes JA, García U, Segovia Vila J, Erlij D, Florán B. Presynaptic cannabinoid CB2 receptors modulate [ 3 H]-Glutamate release at subthalamo-nigral terminals of the rat. Synapse 2018; 72:e22061. [PMID: 30022523 DOI: 10.1002/syn.22061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 11/08/2022]
Abstract
Recent studies suggested the expression of CB2 receptors in neurons of the CNS, however, most of these studies have only explored one aspect of the receptors, i.e., expression of protein, messenger RNA, or functional response, and more complete studies appear to be needed to establish adequately their role in the neuronal function. Electron microscopy studies showed the presence of CB2r in asymmetric terminals of the substantia nigra pars reticulata (SNr), and its mRNA appeared is expressed in the subthalamic nucleus. Here, we explore the expression, source, and functional effects of such receptors by different experimental approaches. Through PCR and immunochemistry, we showed mRNA and protein for CB2rs in slices and primary neuronal cultures from subthalamus. GW833972A, GW405833, and JHW 133, three CB2r agonists dose-dependent inhibited K+ -induced [3 H]-Glutamate release in slices of SNr, and the two antagonist/inverse agonists, JTE-907 and AM630, but not AM281, a CB1r antagonist, prevented GW833972A effect. Subthalamus lesions with kainic acid prevented GW833972A inhibition on release and decreased CB2r protein in nigral synaptosomes, thus nigral CB2rs originate in subthalamus. Inhibition of [3 H]-Glutamate release was PTX- and gallein-sensitive, suggesting a Giβγ -mediated effect. P/Q Ca2+ -type channel blocker, ω-Agatoxin-TK, also inhibited the [3 H]-Glutamate release, this effect was occluded with GW833972A inhibition, indicating that the βγ subunit effect is exerted on Ca2+ channel activity. Finally, microinjections of GW833972A in SNr induced contralateral turning. Our data showed that presynaptic CB2rs inhibit [3 H]-Glutamate release in subthalamo-nigral terminals by P/Q-channels modulation through the Giβγ subunit and suggested their participation in motor behavior.
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Affiliation(s)
- Rodolfo Sánchez-Zavaleta
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, México
| | - Hernán Cortés
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Ciudad de México, México
| | - José Arturo Avalos-Fuentes
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, México
| | - Ubaldo García
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, México
| | - José Segovia Vila
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, México
| | - David Erlij
- Department of Physiology, SUNY Downstate Medical Center, Brooklyn, New York
| | - Benjamín Florán
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, México
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Lindström JB, Pierce NT, Latz MI. Role of TRP Channels in Dinoflagellate Mechanotransduction. THE BIOLOGICAL BULLETIN 2017; 233:151-167. [PMID: 29373067 DOI: 10.1086/695421] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Transient receptor potential (TRP) ion channels are common components of mechanosensing pathways, mainly described in mammals and other multicellular organisms. To gain insight into the evolutionary origins of eukaryotic mechanosensory proteins, we investigated the involvement of TRP channels in mechanosensing in a unicellular eukaryotic protist, the dinoflagellate Lingulodinium polyedra. BLASTP analysis of the protein sequences predicted from the L. polyedra transcriptome revealed six sequences with high similarity to human TRPM2, TRPM8, TRPML2, TRPP1, and TRPP2; and characteristic TRP domains were identified in all sequences. In a phylogenetic tree including all mammalian TRP subfamilies and TRP channel sequences from unicellular and multicellular organisms, the L. polyedra sequences grouped with the TRPM, TPPML, and TRPP clades. In pharmacological experiments, we used the intrinsic bioluminescence of L. polyedra as a reporter of mechanoresponsivity. Capsaicin and RN1734, agonists of mammalian TRPV, and arachidonic acid, an agonist of mammalian TRPV, TRPA, TRPM, and Drosophila TRP, all stimulated bioluminescence in L. polyedra. Mechanical stimulation of bioluminescence, but not capsaicin-stimulated bioluminescence, was inhibited by gadolinium (Gd3+), a general inhibitor of mechanosensitive ion channels, and the phospholipase C (PLC) inhibitor U73122. These pharmacological results are consistent with the involvement of TRP-like channels in mechanosensing by L. polyedra. The TRP channels do not appear to be mechanoreceptors but rather are components of the mechanotransduction signaling pathway and may be activated via a PLC-dependent mechanism. The presence and function of TRP channels in a dinoflagellate emphasize the evolutionary conservation of both the channel structures and their functions.
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Key Words
- AA, amino acids
- AMTB hydrochloride, N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide hydrochloride
- Ce, Caenorhabditis elegans
- Cr, Chlamydomonas reinhardtii
- DMSO, dimethyl sulfoxide
- Dm, Drosophila melanogaster
- Dr, Danio rerio
- FSW, filtered seawater
- Gd3+, gadolinium
- GsMTx4, Grammostola spatulata mechanotoxin 4
- HC067047, 2-Methyl-1-[3-(4-morpholinyl)propyl]-5-phenyl-N-[3-(trifluoromethyl)phenyl]-1H-pyrrole-3-carboxamide
- HMM, Hidden Markov Model
- Hs, Homo sapiens
- Lp, Lingulodinium polyedra
- ML204, 4-Methyl-2-(1-piperidinyl)-quinoline
- Mb, Monosiga brevicollis
- ORF, open reading frame
- PIP2, Phosphatidylinositol 4,5-bisphosphate
- PLC, phospholipase C
- Pt, Paramecium tetraurelia
- RHC80267, O,O′-[1,6-Hexanediylbis(iminocarbonyl)]dioxime cyclohexanone
- RN1734, 2,4-Dichloro-N-isopropyl-N-(2-isopropylaminoethyl)benzenesulfonamide
- RN1747, 1-(4-Chloro-2-nitrophenyl)sulfonyl-4-benzylpiperazine
- TMHMM, transmembrane helix prediction
- TRP, transient receptor potential channel
- U73122, 1-[6-[((17β)-3-Methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione
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Console-Bram LM, Zhao P, Abood ME. Protocols and Good Operating Practices in the Study of Cannabinoid Receptors. Methods Enzymol 2017; 593:23-42. [PMID: 28750805 DOI: 10.1016/bs.mie.2017.06.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
With the approach of the 30th year since the pioneering discovery of a cannabinoid receptor in rat brain (Devane et al., 1988), the field of cannabinoid pharmacology and physiology has impacted human physiology at multiple levels. The development of highly specific and potent orthosteric ligands, as well as the blossoming field of allosteric ligand development, has placed the endocannabinoid system in the forefront as a modulator of a multitude of physiologic processes. Reproducibility among laboratories is especially important due to the development of novel tools to investigate the role(s) of the endocannabinoid system in human physiology, and to clarify the roles for medicinal marijuana. Any definitive role in normal, or diseased states, must be satisfied through the demonstration of a specific receptor-mediated event. This chapter provides working protocols for the study of cannabinoid receptor-ligand binding, as well as immediate and downstream G protein-dependent signaling assays to assess receptor function.
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Affiliation(s)
- Linda M Console-Bram
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Pingwei Zhao
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Mary E Abood
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
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Actions and Regulation of Ionotropic Cannabinoid Receptors. ADVANCES IN PHARMACOLOGY 2017; 80:249-289. [PMID: 28826537 DOI: 10.1016/bs.apha.2017.04.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Almost three decades have passed since the identification of the two specific metabotropic receptors mediating cannabinoid pharmacology. Thereafter, many cannabinoid effects, both at central and peripheral levels, have been well documented and characterized. However, numerous evidences demonstrated that these pharmacological actions could not be attributable solely to the activation of CB1 and CB2 receptors since several important cannabimimetic actions have been found in biological systems lacking CB1 or CB2 gene such as in specific cell lines or transgenic mice. It is now well accepted that, beyond their receptor-mediated effects, these molecules can act also via CB1/CB2-receptor-independent mechanism. Cannabinoids have been demonstrated to modulate several voltage-gated channels (including Ca2+, Na+, and various type of K+ channels), ligand-gated ion channels (i.e., GABA, glycine), and ion-transporting membranes proteins such as transient potential receptor class (TRP) channels. The first direct, cannabinoid receptor-independent interaction was reported on the function of serotonin 5-HT3 receptor-ion channel complex. Similar effects were reported also on the other above mentioned ion channels. In the early ninety, studies searching for endogenous modulators of L-type Ca2+ channels identified anandamide as ligand for L-type Ca2+ channel. Later investigations indicated that other types of Ca2+ currents are also affected by endocannabinoids, and, in the late ninety, it was discovered that endocannabinoids activate the vanilloid receptor subtype 1 (TRPV1), and nowadays, it is known that (endo)cannabinoids gate at least five distinct TRP channels. This chapter focuses on cannabinoid regulation of ion channels and lays special emphasis on their action at transient receptor channels.
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Kolaj M, Zhang L, Renaud LP. L-type calcium channels and MAP kinase contribute to thyrotropin-releasing hormone-induced depolarization in thalamic paraventricular nucleus neurons. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1120-7. [PMID: 27009047 PMCID: PMC4935505 DOI: 10.1152/ajpregu.00082.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 03/18/2016] [Indexed: 12/11/2022]
Abstract
In rat paraventricular thalamic nucleus (PVT) neurons, activation of thyrotropin-releasing hormone (TRH) receptors enhances neuronal excitability via concurrent decrease in a G protein-coupled inwardly rectifying K (GIRK)-like conductance and opening of a cannabinoid receptor-sensitive transient receptor potential canonical (TRPC)-like conductance. Here, we investigated the calcium (Ca(2+)) contribution to the components of this TRH-induced response. TRH-induced membrane depolarization was reduced in the presence of intracellular BAPTA, also in media containing nominally zero [Ca(2+)]o, suggesting a critical role for both intracellular Ca(2+) release and Ca(2+) influx. TRH-induced inward current was unchanged by T-type Ca(2+) channel blockade, but was decreased by blockade of high-voltage-activated Ca(2+) channels (HVACCs). Both the pharmacologically isolated GIRK-like and the TRPC-like components of the TRH-induced response were decreased by nifedipine and increased by BayK8644, implying Ca(2+) influx via L-type Ca(2+) channels. Only the TRPC-like conductance was reduced by either thapsigargin or dantrolene, suggesting a role for ryanodine receptors and Ca(2+)-induced Ca(2+) release in this component of the TRH-induced response. In pituitary and other cell lines, TRH stimulates MAPK. In PVT neurons, only the GIRK-like component of the TRH-induced current was selectively decreased in the presence of PD98059, a MAPK inhibitor. Collectively, the data imply that TRH-induced depolarization and inward current in PVT neurons involve both a dependency on extracellular Ca(2+) influx via opening of L-type Ca(2+) channels, a sensitivity of a TRPC-like component to intracellular Ca(2+) release via ryanodine channels, and a modulation by MAPK of a GIRK-like conductance component.
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Affiliation(s)
- Miloslav Kolaj
- Ottawa Hospital Research Institute, Neuroscience Program and University of Ottawa, Department of Medicine, Ottawa, Ontario, Canada
| | - Li Zhang
- Ottawa Hospital Research Institute, Neuroscience Program and University of Ottawa, Department of Medicine, Ottawa, Ontario, Canada
| | - Leo P Renaud
- Ottawa Hospital Research Institute, Neuroscience Program and University of Ottawa, Department of Medicine, Ottawa, Ontario, Canada
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Zhang L, Kolaj M, Renaud LP. Endocannabinoid 2-AG and intracellular cannabinoid receptors modulate a low-threshold calcium spike-induced slow depolarizing afterpotential in rat thalamic paraventricular nucleus neurons. Neuroscience 2016; 322:308-19. [PMID: 26924019 DOI: 10.1016/j.neuroscience.2016.02.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/18/2016] [Accepted: 02/19/2016] [Indexed: 12/01/2022]
Abstract
In rat paraventricular thalamic nucleus (PVT) neurons, activation of low-threshold calcium (Ca(2+)) channels triggers a low-threshold spike (LTS) which may be followed by slow afterpotentials that can dramatically influence action potential patterning. Using gluconate-based internal recording solutions, we investigated the properties of a LTS-induced slow afterdepolarization (sADP) observed in a subpopulation of PVT neurons recorded in brain slice preparations. This LTS-induced sADP required T-type Ca(2+) channel opening, exhibited variable magnitudes between neurons and a voltage dependency with a maximum near -50 mV. The area under the sADP remained stable during control monitoring, but displayed gradual suppression in media where strontium replaced Ca(2+). The sADP was suppressed following bath application of 2-APB or ML204, suggesting engagement of transient receptor potential canonical (TRPC)-like channels. Further investigation revealed a reversible suppression during bath applications of membrane permeable cannabinoid receptor (CBR) blockers rimonabant, AM630 or SR144528 suggesting the presence of both CB1Rs and CB2Rs. Similar results were achieved by intracellular, but not bath application of the membrane impermeant CB1R blocker hemopressin, suggesting an intracellular localization of CB1Rs. Data from pharmacologic manipulation of endocannabinoid biosynthetic pathways suggested 2-arachidonlyglycerol (2-AG) as the endogenous cannabinoid ligand, derived via hydrolysis of diacylglycerol (DAG), with the latter formed from the pathway involving phosphatidylcholine-specific phospholipase D and phosphatic acid phosphohydrolase. The sADP suppression observed during recordings with pipettes containing LY294002, a PI3-kinase inhibitor, suggested a role for PI3kinase in the translocation of these TRPC-like channels to the plasma membrane. Drug-induced attenuation of the availability of 2-AG influences the number of action potentials that surmount the LTS evoked in PVT neurons, implying an ongoing intracellular CBR modulation of neuronal excitability during LTS-induced bursting behavior.
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Affiliation(s)
- L Zhang
- Neuroscience Program, Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa, 725 Parkdale Avenue, Ottawa, Ontario K1Y 4E9, Canada
| | - M Kolaj
- Neuroscience Program, Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa, 725 Parkdale Avenue, Ottawa, Ontario K1Y 4E9, Canada
| | - L P Renaud
- Neuroscience Program, Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa, 725 Parkdale Avenue, Ottawa, Ontario K1Y 4E9, Canada.
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