1
|
Estay SF, Morales-Moraga C, Vielma AH, Palacios-Muñoz A, Chiu CQ, Chávez AE. Non-canonical type 1 cannabinoid receptor signaling regulates night visual processing in the inner rat retina. iScience 2024; 27:109920. [PMID: 38799553 PMCID: PMC11126983 DOI: 10.1016/j.isci.2024.109920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/18/2024] [Accepted: 05/03/2024] [Indexed: 05/29/2024] Open
Abstract
Type 1 cannabinoid receptors (CB1Rs) are expressed in major retinal neurons within the rod-pathway suggesting a role in regulating night visual processing, but the underlying mechanisms remain poorly understood. Using acute rat retinal slices, we show that CB1R activation reduces glutamate release from rod bipolar cell (RBC) axon terminals onto AII and A17 amacrine cells through a pathway that requires exchange proteins directly activated by cAMP (EPAC1/2) signaling. Consequently, CB1R activation abrogates reciprocal GABAergic feedback inhibition from A17 amacrine cells. Moreover, the activation of CB1Rs in vivo enhances and prolongs the time course of the dim-light rod-driven visual responses, an effect that was eliminated when both GABAA and GABAC receptors were blocked. Altogether, our findings underscore a non-canonical mechanism by which cannabinoid signaling regulates RBC dyad synapses in the inner retina to regulate dim-light visual responses to fine-tune night vision.
Collapse
Affiliation(s)
- Sebastián F. Estay
- Programa de Doctorado en Ciencias, Mención Neurociencia, Valparaíso 2340000, Chile
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Camila Morales-Moraga
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Alex H. Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Angelina Palacios-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Chiayu Q. Chiu
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Andrés E. Chávez
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| |
Collapse
|
2
|
Tempone MH, Borges-Martins VP, César F, Alexandrino-Mattos DP, de Figueiredo CS, Raony Í, dos Santos AA, Duarte-Silva AT, Dias MS, Freitas HR, de Araújo EG, Ribeiro-Resende VT, Cossenza M, P. Silva H, P. de Carvalho R, Ventura ALM, Calaza KC, Silveira MS, Kubrusly RCC, de Melo Reis RA. The Healthy and Diseased Retina Seen through Neuron-Glia Interactions. Int J Mol Sci 2024; 25:1120. [PMID: 38256192 PMCID: PMC10817105 DOI: 10.3390/ijms25021120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
The retina is the sensory tissue responsible for the first stages of visual processing, with a conserved anatomy and functional architecture among vertebrates. To date, retinal eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, glaucoma, and others, affect nearly 170 million people worldwide, resulting in vision loss and blindness. To tackle retinal disorders, the developing retina has been explored as a versatile model to study intercellular signaling, as it presents a broad neurochemical repertoire that has been approached in the last decades in terms of signaling and diseases. Retina, dissociated and arranged as typical cultures, as mixed or neuron- and glia-enriched, and/or organized as neurospheres and/or as organoids, are valuable to understand both neuronal and glial compartments, which have contributed to revealing roles and mechanisms between transmitter systems as well as antioxidants, trophic factors, and extracellular matrix proteins. Overall, contributions in understanding neurogenesis, tissue development, differentiation, connectivity, plasticity, and cell death are widely described. A complete access to the genome of several vertebrates, as well as the recent transcriptome at the single cell level at different stages of development, also anticipates future advances in providing cues to target blinding diseases or retinal dysfunctions.
Collapse
Affiliation(s)
- Matheus H. Tempone
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Vladimir P. Borges-Martins
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Felipe César
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Dio Pablo Alexandrino-Mattos
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Camila S. de Figueiredo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ícaro Raony
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Aline Araujo dos Santos
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Aline Teixeira Duarte-Silva
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana Santana Dias
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Hércules Rezende Freitas
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; (Í.R.); (H.R.F.)
| | - Elisabeth G. de Araújo
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
- National Institute of Science and Technology on Neuroimmunomodulation—INCT-NIM, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-360, Brazil
| | - Victor Tulio Ribeiro-Resende
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| | - Marcelo Cossenza
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Hilda P. Silva
- Laboratory of Gene Therapy and Viral Vectors, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.S.D.); (H.P.S.)
| | - Roberto P. de Carvalho
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Ana L. M. Ventura
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Karin C. Calaza
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Federal Fluminense University, Niterói 24020-141, Brazil; (C.S.d.F.); (A.T.D.-S.); (E.G.d.A.); (R.P.d.C.); (A.L.M.V.); (K.C.C.)
| | - Mariana S. Silveira
- Laboratory for Investigation in Neuroregeneration and Development, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil;
| | - Regina C. C. Kubrusly
- Department of Physiology and Pharmacology, Biomedical Institute and Program of Neurosciences, Federal Fluminense University, Niterói 24020-150, Brazil; (V.P.B.-M.); (A.A.d.S.); (M.C.); (R.C.C.K.)
| | - Ricardo A. de Melo Reis
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro 21949-000, Brazil; (M.H.T.); (F.C.); (D.P.A.-M.); (V.T.R.-R.)
| |
Collapse
|
3
|
Chamorro-Aguirre E, Gaveglio VL, Pascual AC, Pasquaré SJ. The Metabolism of 2-arachidonoylglycerol in Rod Outer Segments Is Modulated by Proteins Involved in the Phototransduction Process. Mol Neurobiol 2023:10.1007/s12035-023-03873-z. [PMID: 38109005 DOI: 10.1007/s12035-023-03873-z] [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: 08/08/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
We previously reported that 2-arachidonoylglycerol (2-AG) synthesis by diacylglycerol lipase (DAGL) and lysophosphatidate phosphohydrolase (LPAP) and hydrolysis by monoacylglycerol lipase (MAGL) in rod outer segments (ROS) from bovine retina were differently modified by light applied to the retina. Based on these findings, the aim of the present research was to evaluate whether 2-AG metabolism could be modulated by proteins involved in the visual process. To this end, ROS kept in darkness (DROS) or obtained in darkness and then subjected to light (BROS) were treated with GTPγS and GDPβS, or with low and moderate ionic strength buffers for detaching soluble and peripheral proteins, or soluble proteins, respectively. Only DAGL activity was stimulated by the application of light to the ROS. GTPγS-stimulated DAGL activity in DROS reached similar values to that observed in BROS. The studies using different ionic strength show that (1) the highest decrease in DROS DAGL activity was observed when both phosphodiesterase (PDE) and transducin α (Tα) are totally membrane-associated; (2) the decrease in BROS DAGL activity does not depend on PDE association to membrane, and that (3) MAGL activity decreases, both in DROS and BROS, when PDE is not associated to the membrane. Our results indicate that the bioavailability of 2-AG under light conditions is favored by G protein-stimulated increase in DAGL activity and hindered principally by Tα/PDE association with the ROS membrane, which decreases DAGL activity.
Collapse
Affiliation(s)
- Estefanía Chamorro-Aguirre
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB, UNS-CONICET), Edificio E1, Camino La Carrindanga Km 7, 8000, Bahía Blanca, Argentina
| | - Virginia L Gaveglio
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB, UNS-CONICET), Edificio E1, Camino La Carrindanga Km 7, 8000, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, 8000, Bahía Blanca, Argentina
| | - Ana C Pascual
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB, UNS-CONICET), Edificio E1, Camino La Carrindanga Km 7, 8000, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, 8000, Bahía Blanca, Argentina
| | - Susana J Pasquaré
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB, UNS-CONICET), Edificio E1, Camino La Carrindanga Km 7, 8000, Bahía Blanca, Argentina.
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, San Juan 670, 8000, Bahía Blanca, Argentina.
| |
Collapse
|
4
|
Papadogkonaki S, Spyridakos D, Lapokonstantaki E, Chaniotakis N, Makriyannis A, Malamas MS, Thermos K. Investigating the Effects of Exogenous and Endogenous 2-Arachidonoylglycerol on Retinal CB1 Cannabinoid Receptors and Reactive Microglia in Naive and Diseased Retina. Int J Mol Sci 2023; 24:15689. [PMID: 37958673 PMCID: PMC10650178 DOI: 10.3390/ijms242115689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/22/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
The endocannabinoid system (ECS) is a new target for the development of retinal disease therapeutics, whose pathophysiology involves neurodegeneration and neuroinflammation. The endocannabinoid 2-arachidonoylglycerol (2-AG) affects neurons and microglia by activating CB1/CB2 cannabinoid receptors (Rs). The aim of this study was to investigate the effects of 2-AG on the CB1R expression/downregulation and retinal neurons/reactive microglia, when administered repeatedly (4 d), in three different paradigms. These involved the 2-AG exogenous administration (a) intraperitoneally (i.p.) and (b) topically and (c) by enhancing the 2-AG endogenous levels via the inhibition (AM11920, i.p.) of its metabolic enzymes (MAGL/ABHD6). Sprague Dawley rats were treated as mentioned above in the presence or absence of CB1/CB2R antagonists and the excitatory amino acid, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Immunohistochemistry, Western blot and a 2-AG level analyses were performed. The 2-AG repeated treatment (i.p.) induced the CB1R downregulation, abolishing its neuroprotective actions. However, 2-AG attenuated the AMPA-induced activation of microglia via the CB2R, as concurred by the AM630 antagonist effect. Topically administered 2-AG was efficacious as a neuroprotectant/antiapoptotic and anti-inflammatory agent. AM11920 increased the 2-AG levels providing neuroprotection against excitotoxicity and reduced microglial activation without affecting the CB1R expression. Our findings show that 2-AG, in the three paradigms studied, displays differential pharmacological profiles in terms of the downregulation of the CB1R and neuroprotection. All treatments, however, attenuated the activation of microglia via the CB2R activation, supporting the anti-inflammatory role of 2-AG in the retina.
Collapse
Affiliation(s)
- Sofia Papadogkonaki
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, 71003 Crete, Greece; (S.P.); (D.S.)
| | - Dimitris Spyridakos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, 71003 Crete, Greece; (S.P.); (D.S.)
| | | | - Nikos Chaniotakis
- Department of Chemistry, University of Crete, Heraklion, 71003 Crete, Greece; (E.L.); (N.C.)
| | - Alexandros Makriyannis
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA; (A.M.); (M.S.M.)
| | - Michael S. Malamas
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA; (A.M.); (M.S.M.)
| | - Kyriaki Thermos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, 71003 Crete, Greece; (S.P.); (D.S.)
| |
Collapse
|
5
|
Alswailmi FK. A Cross Talk between the Endocannabinoid System and Different Systems Involved in the Pathogenesis of Hypertensive Retinopathy. Pharmaceuticals (Basel) 2023; 16:ph16030345. [PMID: 36986445 PMCID: PMC10058254 DOI: 10.3390/ph16030345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/26/2023] Open
Abstract
The prognosis of hypertension leads to organ damage by causing nephropathy, stroke, retinopathy, and cardiomegaly. Retinopathy and blood pressure have been extensively discussed in relation to catecholamines of the autonomic nervous system (ANS) and angiotensin II of the renin–angiotensin aldosterone system (RAAS) but very little research has been conducted on the role of the ECS in the regulation of retinopathy and blood pressure. The endocannabinoid system (ECS) is a unique system in the body that can be considered as a master regulator of body functions. It encompasses the endogenous production of its cannabinoids, its degrading enzymes, and functional receptors which innervate and perform various functions in different organs of the body. Hypertensive retinopathy pathologies arise normally due to oxidative stress, ischemia, endothelium dysfunction, inflammation, and an activated renin–angiotensin system (RAS) and catecholamine which are vasoconstrictors in their biological nature. The question arises of which system or agent counterbalances the vasoconstrictors effect of noradrenaline and angiotensin II (Ang II) in normal individuals? In this review article, we discuss the role of the ECS and its contribution to the pathogenesis of hypertensive retinopathy. This review article will also examine the involvement of the RAS and the ANS in the pathogenesis of hypertensive retinopathy and the crosstalk between these three systems in hypertensive retinopathy. This review will also explain that the ECS, which is a vasodilator in its action, either independently counteracts the effect produced with the vasoconstriction of the ANS and Ang II or blocks some of the common pathways shared by the ECS, ANS, and Ang II in the regulation of eye functions and blood pressure. This article concludes that persistent control of blood pressure and normal functions of the eye are maintained either by decreasing systemic catecholamine, ang II, or by upregulation of the ECS which results in the regression of retinopathy induced by hypertension.
Collapse
Affiliation(s)
- Farhan Khashim Alswailmi
- Department of Pharmacy Practice, College of Pharmacy, University of Hafr Al Batin, Hafr Al Batin 39524, Saudi Arabia
| |
Collapse
|
6
|
New Insights into the Identity of the DFNA58 Gene. Genes (Basel) 2022; 13:genes13122274. [PMID: 36553541 PMCID: PMC9777997 DOI: 10.3390/genes13122274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/21/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Hearing loss is the most common sensory deficit, affecting 466 million people worldwide. The vast and diverse genes involved reflect the complexity of auditory physiology, which requires the use of animal models in order to gain a fuller understanding. Among the loci with a yet-to-be validated gene is the DFNA58, in which ~200 Kb genomic duplication, including three protein-coding genes (PLEK, CNRIP1, and PPP3R1's exon1), was found to segregate with autosomal dominant hearing loss. Through whole genome sequencing, the duplication was found to be in tandem and inserted in an intergenic region, without the disruption of the topological domains. Reanalysis of transcriptomes data studies (zebrafish and mouse), and RT-qPCR analysis of adult zebrafish target organs, in order to access their orthologues expression, highlighted promising results with Cnrip1a, corroborated by zebrafish in situ hybridization and immunofluorescence. Mouse data also suggested Cnrip1 as the best candidate for a relevant role in auditory physiology, and its importance in hearing seems to have remained conserved but the cell type exerting its function might have changed, from hair cells to spiral ganglion neurons.
Collapse
|
7
|
Pasquaré SJ, Chamorro-Aguirre E, Gaveglio VL. The endocannabinoid system in the visual process. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022. [DOI: 10.1016/j.jpap.2022.100159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
8
|
Andreis K, Billingsley J, Naimi Shirazi K, Wager-Miller J, Johnson C, Bradshaw H, Straiker A. Cannabinoid CB1 receptors regulate salivation. Sci Rep 2022; 12:14182. [PMID: 35986066 PMCID: PMC9391487 DOI: 10.1038/s41598-022-17987-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/03/2022] [Indexed: 01/30/2023] Open
Abstract
Saliva serves multiple important functions within the body that we typically take for granted, such as helping prepare food for swallowing and defense against oral pathogens. Dry mouth is a primary symptom of Sjӧgren’s syndrome and is a side effect of many drug treatments. Cannabis users frequently report dry mouth, but the basis for this is still unknown. If the effects occur via the endogenous cannabinoid signaling system, then this may represent a novel mechanism for the regulation of salivation. We examined expression of cannabinoid CB1 receptors in submandibular salivary gland using immunohistochemistry and tested regulation of salivation by THC and cannabinoid-related ligands. We now report that CB1 receptors are expressed in the axons of cholinergic neurons innervating the submandibular gland. No staining is seen in submandibular gland epithelial cells (acinar and ductal), or myoepithelial cells (MECs). Treatment with THC (4 mg/kg, IP) or the cannabinoid receptor agonist CP55940 (0.5 mg/kg) reduced salivation in both male and female mice 1 h after treatment. CBD had no effect on its own but reversed the effect of THC in a concentration-dependent manner. Neither the CB1 receptor antagonist SR141716 (4 mg/kg) nor the CB2-selective agonist JWH133 (4 mg/kg) had an effect on salivation. We also found that fatty acid amide hydrolase (FAAH), the enzyme that metabolizes the endocannabinoid anandamide and related lipids, regulates salivation. Salivation was reduced in FAAH knockout mice as well as mice treated with the FAAH blocker URB597 (4 mg/kg). URB597 had no effect in CB1 knockout mice. FAAH protein is detected intracellularly in acinar but not ductal epithelial cells. In lipidomics experiments, we found that FAAH knockout mice chiefly had elevated levels of acylethanolamines, including anandamide, and reduced levels of acyglycines. Our results are consistent with a model wherein endocannabinoids activate CB1 receptors on cholinergic axons innervating the submandibular gland. THC likely acts by plugging into this system, activating CB1 receptors to reduce salivation, thus offering a mechanism underlying the dry mouth reported by cannabis users.
Collapse
|
9
|
Metabotropic Glutamate Receptors at Ribbon Synapses in the Retina and Cochlea. Cells 2022; 11:cells11071097. [PMID: 35406660 PMCID: PMC8998116 DOI: 10.3390/cells11071097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/17/2022] [Accepted: 03/22/2022] [Indexed: 02/01/2023] Open
Abstract
Our senses define our view of the world. They allow us to adapt to environmental stimuli and are essential for communication and social behaviour. For most humans, seeing and hearing are central senses for their daily life. Our eyes and ears respond to an extraordinary broad range of stimuli covering about 12 log units of light intensity or acoustic power, respectively. The cellular basis is represented by sensory cells (photoreceptors in the retina and inner hair cells in the cochlea) that convert sensory inputs into electrical signals. Photoreceptors and inner hair cells have developed a specific pre-synaptic structure, termed synaptic ribbon, that is decorated with numerous vesicles filled with the excitatory neurotransmitter glutamate. At these ribbon synapses, glutamatergic signal transduction is guided by distinct sets of metabotropic glutamate receptors (mGluRs). MGluRs belong to group II and III of the receptor classification can inhibit neuronal activity, thus protecting neurons from overstimulation and subsequent degeneration. Consequently, dysfunction of mGluRs is associated with vision and hearing disorders. In this review, we introduce the principle characteristics of ribbon synapses and describe group II and III mGluRs in these fascinating structures in the retina and cochlea.
Collapse
|
10
|
Lezirovitz K, Vieira-Silva GA, Batissoco AC, Levy D, Kitajima JP, Trouillet A, Ouyang E, Zebarjadi N, Sampaio-Silva J, Pedroso-Campos V, Nascimento LR, Sonoda CY, Borges VM, Vasconcelos LG, Beck RMO, Grasel SS, Jagger DJ, Grillet N, Bento RF, Mingroni-Netto RC, Oiticica J. A rare genomic duplication in 2p14 underlies autosomal dominant hearing loss DFNA58. Hum Mol Genet 2021; 29:1520-1536. [PMID: 32337552 DOI: 10.1093/hmg/ddaa075] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/02/2020] [Accepted: 04/20/2020] [Indexed: 02/07/2023] Open
Abstract
Here we define a ~200 Kb genomic duplication in 2p14 as the genetic signature that segregates with postlingual progressive sensorineural autosomal dominant hearing loss (HL) in 20 affected individuals from the DFNA58 family, first reported in 2009. The duplication includes two entire genes, PLEK and CNRIP1, and the first exon of PPP3R1 (protein coding), in addition to four uncharacterized long non-coding (lnc) RNA genes and part of a novel protein-coding gene. Quantitative analysis of mRNA expression in blood samples revealed selective overexpression of CNRIP1 and of two lncRNA genes (LOC107985892 and LOC102724389) in all affected members tested, but not in unaffected ones. Qualitative analysis of mRNA expression identified also fusion transcripts involving parts of PPP3R1, CNRIP1 and an intergenic region between PLEK and CNRIP1, in the blood of all carriers of the duplication, but were heterogeneous in nature. By in situ hybridization and immunofluorescence, we showed that Cnrip1, Plek and Ppp3r1 genes are all expressed in the adult mouse cochlea including the spiral ganglion neurons, suggesting changes in expression levels of these genes in the hearing organ could underlie the DFNA58 form of deafness. Our study highlights the value of studying rare genomic events leading to HL, such as copy number variations. Further studies will be required to determine which of these genes, either coding proteins or non-coding RNAs, is or are responsible for DFNA58 HL.
Collapse
Affiliation(s)
- Karina Lezirovitz
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Gleiciele A Vieira-Silva
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Ana C Batissoco
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Débora Levy
- Lipids, Oxidation, and Cell Biology Group, Head, Laboratory of Immunology (LIM19), Heart Institute (InCor), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 05403-900, Brazil
| | | | - Alix Trouillet
- Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, CA 94305, USA
| | - Ellen Ouyang
- Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, CA 94305, USA
| | - Navid Zebarjadi
- Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, CA 94305, USA
| | - Juliana Sampaio-Silva
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil
| | - Vinicius Pedroso-Campos
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil
| | - Larissa R Nascimento
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Cindy Y Sonoda
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil
| | - Vinícius M Borges
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Laura G Vasconcelos
- Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Roberto M O Beck
- Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Signe S Grasel
- Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Daniel J Jagger
- UCL Ear Institute, University College London, London WC1E 6BT, UK
| | - Nicolas Grillet
- Department of Otolaryngology - Head and Neck Surgery, Stanford University, Stanford, CA 94305, USA
| | - Ricardo F Bento
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| | - Regina C Mingroni-Netto
- Centro de Pesquisas sobre o Genoma Humano e Células-Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Jeanne Oiticica
- Otorhinolaryngology/LIM32, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo 01246-000, Brazil.,Departamento de Otorrinolaringologia, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo 05403-000, Brazil
| |
Collapse
|
11
|
Heinbockel T, Straiker A. Cannabinoids Regulate Sensory Processing in Early Olfactory and Visual Neural Circuits. Front Neural Circuits 2021; 15:662349. [PMID: 34305536 PMCID: PMC8294086 DOI: 10.3389/fncir.2021.662349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/11/2021] [Indexed: 12/25/2022] Open
Abstract
Our sensory systems such as the olfactory and visual systems are the target of neuromodulatory regulation. This neuromodulation starts at the level of sensory receptors and extends into cortical processing. A relatively new group of neuromodulators includes cannabinoids. These form a group of chemical substances that are found in the cannabis plant. Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main cannabinoids. THC acts in the brain and nervous system like the chemical substances that our body produces, the endogenous cannabinoids or endocannabinoids, also nicknamed the brain's own cannabis. While the function of the endocannabinoid system is understood fairly well in limbic structures such as the hippocampus and the amygdala, this signaling system is less well understood in the olfactory pathway and the visual system. Here, we describe and compare endocannabinoids as signaling molecules in the early processing centers of the olfactory and visual system, the olfactory bulb, and the retina, and the relevance of the endocannabinoid system for synaptic plasticity.
Collapse
Affiliation(s)
- Thomas Heinbockel
- Department of Anatomy, Howard University College of Medicine, Washington, DC, United States
| | - Alex Straiker
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States
| |
Collapse
|
12
|
Campbell WA, Blum S, Reske A, Hoang T, Blackshaw S, Fischer AJ. Cannabinoid signaling promotes the de-differentiation and proliferation of Müller glia-derived progenitor cells. Glia 2021; 69:2503-2521. [PMID: 34231253 DOI: 10.1002/glia.24056] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 12/11/2022]
Abstract
Endocannabinoids (eCB) are lipid-based neurotransmitters that are known to influence synaptic function in the visual system. eCBs are also known to suppress neuroinflammation in different pathological states. However, nothing is known about the roles of the eCB system during the transition of Müller glia (MG) into proliferating progenitor-like cells in the retina. Accordingly, we used the chick and mouse model to characterize expression patterns of eCB-related genes and applied pharmacological agents to investigate how the eCB system impacts glial reactivity and the capacity of MG to become Müller glia-derived progenitor cells (MGPCs). We queried single cell RNA-seq libraries to identify eCB-related genes and identify cells with dynamic patterns of expression in damaged retinas. MG and inner retinal neurons expressed the eCB receptor CNR1, as well as enzymes involved in eCB metabolism. In the chick, intraocular injections of cannabinoids, 2-Arachidonoylglycerol (2-AG) and Anandamide (AEA), stimulated the formation of MGPCs. Cannabinoid Receptor 1 (CNR1)-agonists and Monoglyceride Lipase-inhibitor promoted the formation of MGPCs, whereas CNR1-antagonist and inhibitors of eCB synthesis suppressed this process. In damaged mouse retinas where MG activate NFkB-signaling, activation of CNR1 decreased and inhibition of CNR1 increased NFkB, whereas levels of neuronal cell death were unaffected. Surprisingly, retinal microglia were largely unaffected by increases or decreases in eCB-signaling in both chick and mouse retinas. We conclude that the eCB system in the retina influences the reactivity of MG and the formation of proliferating MGPCs, but does not influence the reactivity of immune cells in the retina.
Collapse
Affiliation(s)
- Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Sydney Blum
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Alana Reske
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
13
|
Chen D, Wu H, Feng X, Chen Y, Lv Z, Kota VG, Chen J, Wu W, Lu Y, Liu H, Zhang Y, Zheng S, Wu J. DNA Methylation of Cannabinoid Receptor Interacting Protein 1 Promotes Pathogenesis of Intrahepatic Cholangiocarcinoma Through Suppressing Parkin-Dependent Pyruvate Kinase M2 Ubiquitination. Hepatology 2021; 73:1816-1835. [PMID: 32955740 DOI: 10.1002/hep.31561] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND AIMS Methylation landscape is important for maintaining the silence of cannabinoid receptor-interacting protein 1 (CNRIP1) in some tumors. However, the role of CNRIP1 in intrahepatic cholangiocarcinoma (ICC) remains poorly defined. APPROACH AND RESULTS In our study, we showed that CNRIP1 was down-regulated in ICC tissues, and low expression of CNRIP1 was significantly associated with poor prognosis of patients with ICC in 3-year overall survival and tumor-free survival. Investigating the genomic DNA methylation profile, we disclosed a CpG island site named CNRIP1 MS-2 (CNRIP1 methylation site-2) that contributes to the down-regulation of CNRIP1. In addition, the methylation level of CNRIP1 MS-2 was correlated to the pathological grade, metastasis, and tumor-node-metastasis classification in ICC. Notably, we observed that CNRIP1 suppressed tumor cell migration, invasion, and proliferation by inhibiting the activity of pyruvate kinase M2 (PKM2). Sustained overexpression of CNRIP1 suppressed the in vivo tumor growth in a mouse xenograft model. It was also found that CNRIP1 overexpression activated Parkin (an E3 ubiquitin ligase), which resulted in the protein degradation of PKM2 in ICC cells. CONCLUSIONS We identified that CNRIP1 acted as a putative tumor suppressor in ICC, which suggested that CNRIP1 could be a candidate biomarker for predicting tumor recurrence in patients with ICC. Furthermore, these findings highlight a potential therapeutic approach in targeting the CNRIP1/Parkin/PKM2 pathway for the treatment of ICC.
Collapse
Affiliation(s)
- Diyu Chen
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
- Zhejiang Provincial Research Center for Diagnosis and Treatment of Hepatobiliary Diseases, Hangzhou, Zhejiang, China
| | - Hao Wu
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Xiaode Feng
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Yunhao Chen
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Zhen Lv
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Vishnu Goutham Kota
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Junru Chen
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Wenxuan Wu
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Yuejie Lu
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Hua Liu
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Yanpeng Zhang
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
| | - Shusen Zheng
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
- Zhejiang Provincial Research Center for Diagnosis and Treatment of Hepatobiliary Diseases, Hangzhou, Zhejiang, China
| | - Jian Wu
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Key Laboratory of Combined Multiorgan Transplantation, National Health Commission, Hangzhou, Zhejiang, China
- Key Laboratory of Organ Transplantation, Hangzhou, Zhejiang, China
- Zhejiang Provincial Research Center for Diagnosis and Treatment of Hepatobiliary Diseases, Hangzhou, Zhejiang, China
| |
Collapse
|
14
|
Delayed on- and off-retinal responses of cones pathways in regular cannabis users: An On-Off flash electroretinogram case-control study. J Psychiatr Res 2021; 136:312-318. [PMID: 33636687 DOI: 10.1016/j.jpsychires.2021.02.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 11/20/2022]
Abstract
The retina is considered a useful area for investigating synaptic transmission abnormalities in neuropsychiatric disorders, including as a result of using cannabis, the most widely consumed illicit substance in the developed world. The impact of regular cannabis use on retinal function has already been evaluated, using pattern and flash electroretinogram (ERG) to demonstrate a delay in ganglion and bipolar cell response. Using multifocal ERG, it was showed that the delay to be preferentially located in the central retina. ERG tests do not separately examine the impact of cannabis on the On and Off pathways. The purpose of this study is to assess On and Off pathway function using On-Off ERG. We conducted an On-Off ERG test in 42 regular cannabis users and 26 healthy controls. The protocol was compliant with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Amplitude and peak time were measured for the a-, b- and d-waves. Results in the regular cannabis users showed a significant increase in the latencies of both the b- and the d-wave (p = 0.020, p = 0.022, respectively, Mann-Whitney U test), with no change in the wave amplitudes. A-wave peak time and amplitude were unchanged. These findings are reflective of an effect of regular cannabis use on the On and Off pathways and are consistent with previous findings which also identified increases in retinal neuron response times. We confirm here that regular cannabis use impacts the post-receptoral cones pathway at the level of bipolar cells, affecting the On and Off pathways.
Collapse
|
15
|
Kokona D, Spyridakos D, Tzatzarakis M, Papadogkonaki S, Filidou E, Arvanitidis KI, Kolios G, Lamani M, Makriyannis A, Malamas MS, Thermos K. The endocannabinoid 2-arachidonoylglycerol and dual ABHD6/MAGL enzyme inhibitors display neuroprotective and anti-inflammatory actions in the in vivo retinal model of AMPA excitotoxicity. Neuropharmacology 2021; 185:108450. [PMID: 33450278 DOI: 10.1016/j.neuropharm.2021.108450] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 12/17/2020] [Accepted: 01/03/2021] [Indexed: 12/14/2022]
Abstract
The endocannabinoid system has been shown to be a putative therapeutic target for retinal disease. Here, we aimed to investigate the ability of the endocannabinoid 2-arachidonoylglycerol (2-AG) and novel inhibitors of its metabolic enzymes, α/β-hydrolase domain-containing 6 (ABHD6) and monoacylglycerol lipase (MAGL), a) to protect the retina against excitotoxicity and b) the mechanisms involved in the neuroprotection. Sprague-Dawley rats, wild type and Akt2-/- C57BL/6 mice were intravitreally administered with phosphate-buffered saline or (RS)-α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid hydrobromide (AMPA). 2-AG was intravitreally co-administered with AMPA in the absence and presence of AM251 or AM630 (cannabinoid 1 and 2 receptor antagonists, respectively) or Wortmannin [Phosphoinositide 3-Kinase (PI3K)/Akt inhibitor]. Inhibitors of ABHD6 and dual ABHD6/MAGL (AM12100 and AM11920, respectively) were co-administered with AMPA intravitreally in rats. Immunohistochemistry was performed using antibodies raised against retinal neuronal markers (bNOS), microglia (Iba1) and macroglia (GFAP). TUNEL assay and real-time PCR were also employed. The CB2 receptor was expressed in rat retina (approx. 62% of CB1 expression). 2-AG attenuated the AMPA-induced increase in TUNEL+ cells. 2-AG activation of both CB1 and CB2 receptors and the PI3K/Akt downstream signaling pathway, as substantiated by the use of Akt2-/- mice, afforded neuroprotection against AMPA excitotoxicity. AM12100 and AM11920 attenuated the AMPA-induced glia activation and produced a dose-dependent partial neuroprotection, with the dual inhibitor AM11920 being more efficacious. These results show that 2-AG has the pharmacological profile of a putative therapeutic for retinal diseases characterized by neurodegeneration and neuroinflammation, when administered exogenously or by the inhibition of its metabolic enzymes.
Collapse
Affiliation(s)
- Despina Kokona
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Dimitris Spyridakos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Manolis Tzatzarakis
- Department of Toxicology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Sofia Papadogkonaki
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Eirini Filidou
- Laboratory of Pharmacology, School of Medicine, Democritus University of Thrace, Alexandroupolis, 68100, Greece.
| | - Konstantinos I Arvanitidis
- Laboratory of Pharmacology, School of Medicine, Democritus University of Thrace, Alexandroupolis, 68100, Greece.
| | - George Kolios
- Laboratory of Pharmacology, School of Medicine, Democritus University of Thrace, Alexandroupolis, 68100, Greece.
| | - Manjunath Lamani
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, 02115, USA.
| | - Alexandros Makriyannis
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, 02115, USA.
| | - Michael S Malamas
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology and Pharmaceutical Sciences, Northeastern University, Boston, MA, 02115, USA.
| | - Kyriaki Thermos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| |
Collapse
|
16
|
Oliver EE, Hughes EK, Puckett MK, Chen R, Lowther WT, Howlett AC. Cannabinoid Receptor Interacting Protein 1a (CRIP1a) in Health and Disease. Biomolecules 2020; 10:biom10121609. [PMID: 33261012 PMCID: PMC7761089 DOI: 10.3390/biom10121609] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022] Open
Abstract
Endocannabinoid signaling depends upon the CB1 and CB2 cannabinoid receptors, their endogenous ligands anandamide and 2-arachidonoylglycerol, and intracellular proteins that mediate responses via the C-terminal and other intracellular receptor domains. The CB1 receptor regulates and is regulated by associated G proteins predominantly of the Gi/o subtypes, β-arrestins 1 and 2, and the cannabinoid receptor-interacting protein 1a (CRIP1a). Evidence for a physiological role for CRIP1a is emerging as data regarding the cellular localization and function of CRIP1a are generated. Here we summarize the neuronal distribution and role of CRIP1a in endocannabinoid signaling, as well as discuss investigations linking CRIP1a to development, vision and hearing sensory systems, hippocampus and seizure regulation, and psychiatric disorders including schizophrenia. We also examine the genetic and epigenetic association of CRIP1a within a variety of cancer subtypes. This review provides evidence upon which to base future investigations on the function of CRIP1a in health and disease.
Collapse
Affiliation(s)
- Emily E. Oliver
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC 20157, USA; (E.E.O.); (E.K.H.); (M.K.P.); (R.C.)
- Department of Biochemistry and Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC 20157, USA;
| | - Erin K. Hughes
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC 20157, USA; (E.E.O.); (E.K.H.); (M.K.P.); (R.C.)
- Department of Biochemistry and Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC 20157, USA;
| | - Meaghan K. Puckett
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC 20157, USA; (E.E.O.); (E.K.H.); (M.K.P.); (R.C.)
| | - Rong Chen
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC 20157, USA; (E.E.O.); (E.K.H.); (M.K.P.); (R.C.)
| | - W. Todd Lowther
- Department of Biochemistry and Center for Structural Biology, Wake Forest School of Medicine, Winston-Salem, NC 20157, USA;
| | - Allyn C. Howlett
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Blvd, Winston-Salem, NC 20157, USA; (E.E.O.); (E.K.H.); (M.K.P.); (R.C.)
- Correspondence: ; Tel.: +1-336-716-8545
| |
Collapse
|
17
|
Vielma AH, Tapia F, Alcaino A, Fuenzalida M, Schmachtenberg O, Chávez AE. Cannabinoid Signaling Selectively Modulates GABAergic Inhibitory Input to OFF Bipolar Cells in Rat Retina. Invest Ophthalmol Vis Sci 2020; 61:3. [PMID: 32150246 PMCID: PMC7401570 DOI: 10.1167/iovs.61.3.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In the mammalian retina, cannabinoid type 1 receptors (CB1Rs) are well-positioned to alter inhibitory synaptic function from amacrine cells and, thus, might influence visual signal processing in the inner retina. However, it is not known if CB1R modulates amacrine cells feedback inhibition at retinal bipolar cell (BC) terminals. Methods Using whole-cell voltage-clamp recordings, we examined the pharmacological effect of CB1R activation and inhibition on spontaneous inhibitory postsynaptic currents (sIPSCs) and glutamate-evoked IPSCs (gIPSCs) from identified OFF BCs in light-adapted rat retinal slices. Results Activation of CB1R with WIN55212-2 selectively increased the frequency of GABAergic, but not glycinergic sIPSC in types 2, 3a, and 3b OFF BCs, and had no effect on inhibitory activity in type 4 OFF BCs. The increase in GABAergic activity was eliminated in axotomized BCs and can be suppressed by blocking CB1R with AM251 or GABAA and GABAρ receptors with SR-95531 and TPMPA, respectively. In all OFF BC types tested, a brief application of glutamate to the outer plexiform layer elicited gIPSCs comprising GABAergic and glycinergic components that were unaffected by CB1R activation. However, blocking CB1R selectively increased GABAergic gIPSCs, supporting a role for endocannabinoid signaling in the regulation of glutamate-evoked GABAergic inhibitory feedback to OFF BCs. Conclusions CB1R activation shape types 2, 3a, and 3b OFF BC responses by selectively regulate GABAergic feedback inhibition at their axon terminals, thus cannabinoid signaling might play an important role in the fine-tuning of visual signal processing in the mammalian inner retina.
Collapse
|
18
|
Klotz L, Wendler O, Frischknecht R, Shigemoto R, Schulze H, Enz R. Localization of group II and III metabotropic glutamate receptors at pre- and postsynaptic sites of inner hair cell ribbon synapses. FASEB J 2019; 33:13734-13746. [PMID: 31585509 DOI: 10.1096/fj.201901543r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the CNS binding to a variety of glutamate receptors. Metabotropic glutamate receptors (mGluR1 to mGluR8) can act excitatory or inhibitory, depending on associated signal cascades. Expression and localization of inhibitory acting mGluRs at inner hair cells (IHCs) in the cochlea are largely unknown. Here, we analyzed expression of mGluR2, mGluR3, mGluR4, mGluR6, mGluR7, and mGluR8 and investigated their localization with respect to the presynaptic ribbon of IHC synapses. We detected transcripts for mGluR2, mGluR3, and mGluR4 as well as for mGluR7a, mGluR7b, mGluR8a, and mGluR8b splice variants. Using receptor-specific antibodies in cochlear wholemounts, we found expression of mGluR2, mGluR4, and mGluR8b close to presynaptic ribbons. Super resolution and confocal microscopy in combination with 3-dimensional reconstructions indicated a postsynaptic localization of mGluR2 that overlaps with postsynaptic density protein 95 on dendrites of afferent type I spiral ganglion neurons. In contrast, mGluR4 and mGluR8b were expressed at the presynapse close to IHC ribbons. In summary, we localized in detail 3 mGluR types at IHC ribbon synapses, providing a fundament for new therapeutical strategies that could protect the cochlea against noxious stimuli and excitotoxicity.-Klotz, L., Wendler, O., Frischknecht, R., Shigemoto, R., Schulze, H., Enz, R. Localization of group II and III metabotropic glutamate receptors at pre- and postsynaptic sites of inner hair cell ribbon synapses.
Collapse
Affiliation(s)
- Lisa Klotz
- Institute for Biochemistry (Emil-Fischer-Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Olaf Wendler
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Head and Neck Surgery, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Renato Frischknecht
- Department of Biology, Animal Physiology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Holger Schulze
- Department of Otorhinolaryngology, Head and Neck Surgery, Experimental Otolaryngology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Ralf Enz
- Institute for Biochemistry (Emil-Fischer-Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
19
|
The Endocannabinoid System Is Present in Rod Outer Segments from Retina and Is Modulated by Light. Mol Neurobiol 2019; 56:7284-7295. [PMID: 31016476 DOI: 10.1007/s12035-019-1603-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
Abstract
The aim of the present research was to evaluate if the endocannabinoid system (enzymes and receptors) could be modulated by light in rod outer segment (ROS) from bovine retina. First, we analyzed endocannabinoid 2-arachidonoylglycerol (2-AG) metabolism in purified ROS obtained from dark-adapted (DROS) or light-adapted (LROS) retinas. To this end, diacylglycerol lipase (DAGL), monoacylglycerol lipase (MAGL), and lysophosphatidate phosphohydrolase (LPAP) enzymatic activities were analyzed using radioactive substrates. The protein content of these enzymes and of the receptors to which cannabinoids bind was determined by immunoblotting under light stimulus. Our results indicate that whereas DAGL and MAGL activities were stimulated in retinas exposed to light, no changes were observed in LPAP activity. Interestingly, the protein content of the main enzymes involved in 2-AG metabolism, phospholipase C β1 (PLCβ1), and DAGLα (synthesis), and MAGL (hydrolysis), was also modified by light. PLCβ1 content was increased, while that of lipases was decreased. On the other hand, light produced an increase in the cannabinoid receptors CB1 and CB2 and a decrease in GPR55 protein levels. Taken together, our results indicate that the endocannabinoid system (enzymes and receptors) depends on the illumination state of the retina, suggesting that proteins related to phototransduction phenomena could be involved in the effects observed.
Collapse
|
20
|
Lafreniere J, Kelly M. Potential for endocannabinoid system modulation in ocular pain and inflammation: filling the gaps in current pharmacological options. Neuronal Signal 2018; 2:NS20170144. [PMID: 32714590 PMCID: PMC7373237 DOI: 10.1042/ns20170144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 02/06/2023] Open
Abstract
Challenges in the management of ocular pain are an underappreciated topic. Currently available therapeutics lack both efficacy and clear guidelines for their use, with many also possessing unacceptable side effects. Promising novel agents would offer analgesic, anti-inflammatory, and possibly neuroprotective actions; have favorable ocular safety profiles; and show potential in managing neuropathic pain. Growing evidence supports a link between the endocannabinoid system (ECS) and a range of physiological and disease processes, notably those involving inflammation and pain. Both preclinical and clinical data suggest analgesic and anti-inflammatory actions of cannabinoids and ECS-modifying drugs in chronic pain conditions, including those of neuropathic origin. This review will examine existing evidence for the anatomical and physiological basis of ocular pain, specifically, ocular surface disease and the development of chronic ocular pain. The mechanism of action, efficacy, and limitations of currently available treatments will be discussed, and current knowledge related to ECS-modulation of ocular pain and inflammatory disease will be summarized. A perspective will be provided on the future directions of ECS research in terms of developing cannabinoid therapeutics for ocular pain.
Collapse
Affiliation(s)
| | - Melanie E.M. Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
21
|
Rapino C, Tortolani D, Scipioni L, Maccarrone M. Neuroprotection by (endo)Cannabinoids in Glaucoma and Retinal Neurodegenerative Diseases. Curr Neuropharmacol 2018; 16:959-970. [PMID: 28738764 PMCID: PMC6120105 DOI: 10.2174/1570159x15666170724104305] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/14/2017] [Accepted: 07/21/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Emerging neuroprotective strategies are being explored to preserve the retina from degeneration, that occurs in eye pathologies like glaucoma, diabetic retinopathy, age-related macular degeneration, and retinitis pigmentosa. Incidentally, neuroprotection of retina is a defending mechanism designed to prevent or delay neuronal cell death, and to maintain neural function following an initial insult, thus avoiding loss of vision. METHODS Numerous studies have investigated potential neuroprotective properties of plant-derived phytocannabinoids, as well as of their endogenous counterparts collectively termed endocannabinoids (eCBs), in several degenerative diseases of the retina. eCBs are a group of neuromodulators that, mainly by activating G protein-coupled type-1 and type-2 cannabinoid (CB1 and CB2) receptors, trigger multiple signal transduction cascades that modulate central and peripheral cell functions. A fine balance between biosynthetic and degrading enzymes that control the right concentration of eCBs has been shown to provide neuroprotection in traumatic, ischemic, inflammatory and neurotoxic damage of the brain. RESULTS Since the existence of eCBs and their binding receptors was documented in the retina of numerous species (from fishes to primates), their involvement in the visual processing has been demonstrated, more recently with a focus on retinal neurodegeneration and neuroprotection. CONCLUSION The aim of this review is to present a modern view of the endocannabinoid system, in order to discuss in a better perspective available data from preclinical studies on the use of eCBs as new neuroprotective agents, potentially useful to prevent glaucoma and retinal neurodegenerative diseases.
Collapse
Affiliation(s)
- Cinzia Rapino
- Address correspondence to these authors at the Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; Tel: +39 0861 266842;, E-mail: and the Department of Medicine, Campus Bio-Medico University of Rome, 00128 Rome, Italy; Tel: +39 06 225419169;, E-mail:
| | | | | | - Mauro Maccarrone
- Address correspondence to these authors at the Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; Tel: +39 0861 266842;, E-mail: and the Department of Medicine, Campus Bio-Medico University of Rome, 00128 Rome, Italy; Tel: +39 06 225419169;, E-mail:
| |
Collapse
|
22
|
Chen Y, Luo X, Liu S, Shen Y. Neuroprotective effect of cannabinoid receptor 1 antagonist in the MNU-induced retinal degeneration model. Exp Eye Res 2017; 167:145-151. [PMID: 29126840 DOI: 10.1016/j.exer.2017.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 11/16/2022]
Abstract
Endocannabinoid system involves in neuroprotective effects on the central neural system. The cannabinoid receptor 1 (CB1R) is widely expressed in the mouse retina. However, the role of cannabinoid receptors in the retina remains unclear. In this work, we established a photoreceptor degeneration mouse model via N-methyl-N-nitrosourea (MNU) administration to identify the neuroprotective effects of cannabinoid receptors. The MNU-induced retinal degeneration behaves similarly to that in the human retinitis pigmentosa (RP). Administration of the CB1R antagonist SR141716A distinctly recovered the photoreceptor loss, decreased glial reactivity and reduced abnormal vascular complexes in an MNU-induced mouse model. The BC dendrites were shrunk in the MNU-treated retina with eliminated ON-BCs responses and partially diminished OFF-BCs responses in patch-clamp recordings. In the MNU + SR1 group, both the function and structure of ON-BCs recovered. Taken together, our study showed that the inhibition of CB1R can effectively prevent MNU-induced retinal degeneration, suggesting a potential therapeutic effect of the CB1R antagonist SR1 in retinal degeneration diseases.
Collapse
Affiliation(s)
- Yuanyuan Chen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Xue Luo
- Eye Center, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Shiliang Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, 430030, PR China
| | - Yin Shen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan 430060, PR China.
| |
Collapse
|
23
|
Singh P, Ganjiwale A, Howlett AC, Cowsik SM. In silico interaction analysis of cannabinoid receptor interacting protein 1b (CRIP1b) - CB1 cannabinoid receptor. J Mol Graph Model 2017; 77:311-321. [PMID: 28918320 PMCID: PMC5816684 DOI: 10.1016/j.jmgm.2017.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/01/2017] [Accepted: 09/02/2017] [Indexed: 01/16/2023]
Abstract
Cannabinoid Receptor Interacting Protein isoform 1b (CRIP1b) is known to interact with the CB1 receptor. Alternative splicing of the CNRIP1 gene produces CRIP1a and CRIP1b with a difference in the third exon only. Exons 1 and 2 encode for a functional domain in both proteins. CRIP1a is involved in regulating CB1 receptor internalization, but the function of CRIP1b is not very well characterized. Since there are significant identities in functional domains of these proteins, CRIP1b is a potential target for drug discovery. We report here predicted structure of CRIP1b followed by its interaction analysis with CB1 receptor by in-silico methods A number of complementary computational techniques, including, homology modeling, ab-initio and protein threading, were applied to generate three-dimensional molecular models for CRIP1b. The computed model of CRIP1b was refined, followed by docking with C terminus of CB1 receptor to generate a model for the CRIP1b- CB1 receptor interaction. The structure of CRIP1b obtained by homology modelling using RHO_GDI-2 as template is a sandwich fold structure having beta sheets connected by loops, similar to predicted CRIP1a structure. The best scoring refined model of CRIP1b in complex with the CB1 receptor C terminus peptide showed favourable polar interactions. The overall binding pocket of CRIP1b was found to be overlapping to that of CRIP1a. The Arg82 and Cys126 of CRIP1b are involved in the majority of hydrogen bond interactions with the CB1 receptor and are possible key residues required for interactions between the CB1 receptor and CRIP1b.
Collapse
Affiliation(s)
- Pratishtha Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Anjali Ganjiwale
- Department of Life Sciences, Bangalore University, Bangalore 560056, India
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Sudha M Cowsik
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| |
Collapse
|
24
|
The Cannabinoid Receptor Interacting Proteins 1 of zebrafish are not required for morphological development, viability or fertility. Sci Rep 2017; 7:4858. [PMID: 28687732 PMCID: PMC5501828 DOI: 10.1038/s41598-017-05017-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/23/2017] [Indexed: 01/10/2023] Open
Abstract
The Cannabinoid Receptor Interacting Protein 1 (Cnrip1) was discovered as an interactor with the intracellular region of Cannabinoid Receptor 1 (CB1R, also known as Cnr1 or CB1). Functional assays in mouse show cannabinoid sensitivity changes and Cnrip1 has recently been suggested to control eye development in Xenopus laevis. Two Cnrip1 genes are described in zebrafish, cnrip1a and cnrip1b. In situ mRNA hybridisation revealed accumulation of mRNA encoding each gene primarily in brain and spinal cord, but also elsewhere. For example, cnrip1b is expressed in forming skeletal muscle. CRISPR/Cas9 genome editing generated predicted null mutations in cnrip1a and cnrip1b. Each mutation triggered nonsense-mediated decay of the respective mRNA transcript. No morphological or behavioural phenotype was observed in either mutant. Moreover, fish lacking both Cnrip1a and Cnrip1b both maternally and zygotically are viable and fertile and no phenotype has so far been detected despite strong evolutionary conservation over at least 400 Myr.
Collapse
|
25
|
Miller S, Leishman E, Hu SS, Elghouche A, Daily L, Murataeva N, Bradshaw H, Straiker A. Harnessing the Endocannabinoid 2-Arachidonoylglycerol to Lower Intraocular Pressure in a Murine Model. Invest Ophthalmol Vis Sci 2017; 57:3287-96. [PMID: 27333182 PMCID: PMC4961057 DOI: 10.1167/iovs.16-19356] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Purpose Cannabinoids, such as Δ9-THC, act through an endogenous signaling system in the vertebrate eye that reduces IOP via CB1 receptors. Endogenous cannabinoid (eCB) ligand, 2-arachidonoyl glycerol (2-AG), likewise activates CB1 and is metabolized by monoacylglycerol lipase (MAGL). We investigated ocular 2-AG and its regulation by MAGL and the therapeutic potential of harnessing eCBs to lower IOP. Methods We tested the effect of topical application of 2-AG and MAGL blockers in normotensive mice and examined changes in eCB-related lipid species in the eyes and spinal cord of MAGL knockout (MAGL−/−) mice using high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). We also examined the protein distribution of MAGL in the mouse anterior chamber. Results 2-Arachidonoyl glycerol reliably lowered IOP in a CB1- and concentration-dependent manner. Monoacylglycerol lipase is expressed prominently in nonpigmented ciliary epithelium. The MAGL blocker KML29, but not JZL184, lowered IOP. The ability of CB1 to lower IOP is not desensitized in MAGL−/− mice. Ocular monoacylglycerols, including 2-AG, are elevated in MAGL−/− mice but, in contrast to the spinal cord, arachidonic acid and prostaglandins are not changed. Conclusions Our data confirm a central role for MAGL in metabolism of ocular 2-AG and related lipid species, and that endogenous 2-AG can be harnessed to reduce IOP. The MAGL blocker KML29 has promise as a therapeutic agent, while JZL184 may have difficulty crossing the cornea. These data, combined with the relative specificity of MAGL for ocular monoacylglycerols and the lack of desensitization in MAGL−/− mice, suggest that the development of an optimized MAGL blocker offers therapeutic potential for treatment of elevated IOP.
Collapse
Affiliation(s)
- Sally Miller
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Emma Leishman
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Sherry Shujung Hu
- Department of Psychology, National Cheng Kung University, Tainan, Taiwan
| | - Alhasan Elghouche
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Laura Daily
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Natalia Murataeva
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Heather Bradshaw
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Alex Straiker
- Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| |
Collapse
|
26
|
Cairns EA, Toguri JT, Porter RF, Szczesniak AM, Kelly MEM. Seeing over the horizon - targeting the endocannabinoid system for the treatment of ocular disease. J Basic Clin Physiol Pharmacol 2017; 27:253-65. [PMID: 26565550 DOI: 10.1515/jbcpp-2015-0065] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/25/2015] [Indexed: 01/09/2023]
Abstract
The observation that marijuana reduces intraocular pressure was made by Hepler and Frank in the 1970s. Since then, there has been a significant body of work investigating cannabinoids for their potential use as therapeutics. To date, no endocannabinoid system (ECS)-modulating drug has been approved for clinical use in the eye; however, recent advances in our understanding of the ECS, as well as new pharmacological tools, has renewed interest in the development of ocular ECS-based therapeutics. This review summarizes the current state-of-affairs for the use of ECS-modulating drugs for the treatment of glaucoma and ocular inflammatory and ischemic disease.
Collapse
|
27
|
Mascia F, Klotz L, Lerch J, Ahmed MH, Zhang Y, Enz R. CRIP1a inhibits endocytosis of G-protein coupled receptors activated by endocannabinoids and glutamate by a common molecular mechanism. J Neurochem 2017; 141:577-591. [PMID: 28295323 DOI: 10.1111/jnc.14021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/17/2017] [Accepted: 03/10/2017] [Indexed: 01/20/2023]
Abstract
The excitability of the central nervous system depends largely on the surface density of neurotransmitter receptors. The endocannabinoid receptor 1 (CB1 R) and the metabotropic glutamate receptor mGlu8 R are expressed pre-synaptically where they reduce glutamate release into the synaptic cleft. Recently, the CB1 R interacting protein cannabinoid receptor interacting protein 1a (CRIP1a) was identified and characterized to regulate CB1 R activity in neurons. However, underlying molecular mechanisms are largely unknown. Here, we identified a common mechanism used by CRIP1a to regulate the cell surface density of two different types of G-protein coupled receptors, CB1 R and mGlu8a R. Five amino acids within the CB1 R C-terminus were required and sufficient to reduce constitutive CB1 R endocytosis by about 72% in the presence of CRIP1a. Interestingly, a similar sequence is present in mGlu8a R and consistently, endocytosis of mGlu8a R depended on CRIP1a, as well. Docking analysis and molecular dynamics simulations identified a conserved serine in CB1 R (S468) and mGlu8a R (S894) that forms a hydrogen bond with the peptide backbone of CRIP1a at position R82. In contrast to mGlu8a R, the closely related mGlu8b R splice-variant carries a lysine (K894) at this position, and indeed, mGlu8b R endocytosis was not affected by CRIP1a. Chimeric constructs between CB1 R, mGlu8a R, and mGlu8b R underline the role of the identified five CRIP1a sensitive amino acids. In summary, we suggest that CRIP1a negatively regulates endocytosis of two different G-protein coupled receptor types, CB1 R and mGlu8a R.
Collapse
Affiliation(s)
- Fabrizio Mascia
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lisa Klotz
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Judith Lerch
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mostafa H Ahmed
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ralf Enz
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
28
|
Kelly MEM, Lehmann C, Zhou J. The Endocannabinoid System in Local and Systemic Inflammation. ACTA ACUST UNITED AC 2017. [DOI: 10.4199/c00151ed1v01y201702isp074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
29
|
Imamura T, Tsuruma K, Inoue Y, Otsuka T, Ohno Y, Ogami S, Yamane S, Shimazawa M, Hara H. Rimonabant, a selective cannabinoid 1 receptor antagonist, protects against light-induced retinal degeneration in vitro and in vivo. Eur J Pharmacol 2017; 803:78-83. [PMID: 28315677 DOI: 10.1016/j.ejphar.2017.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 03/07/2017] [Accepted: 03/13/2017] [Indexed: 01/01/2023]
Abstract
The endocannabinoid system is involved in some neurodegenerative diseases such as Alzheimer's disease. An endogenous constellation of proteins related to cannabinoid1 receptor signaling, including free fatty acids, diacylglycerol lipase, and N-acylethanolamine-hydrolyzing acid amidase, are localized in the murine retina. Moreover, the expression levels of endogenous agonists of cannabinoid receptors are changed in the vitreous fluid. However, the role of the endocannabinoid system in the retina, particularly in the light-induced photoreceptor degeneration, remains unknown. Therefore, we investigated involvement of the cannabinoid1 receptor in light-induced retinal degeneration using in vitro and in vivo models. To evaluate the effect of cannabinoid1 receptors in light irradiation-induced cell death, the mouse retinal cone-cell line (661W) was treated with a cannabinoid1 receptor antagonist, rimonabant. Time-dependent changes of expression and localization of retinal cannabinoid1 receptors were measured using Western blot and immunostaining. Retinal damage was induced in mice by exposure to light, followed by intravitreal injection of rimonabant. Electroretinograms and histologic analyses were performed. Rimonabant suppressed light-induced photoreceptor cell death. Cannabinoid1 receptor expression was upregulated by light exposure. Treatment with rimonabant improved both a- and b-wave amplitudes and the thickness of the outer nuclear layer. These results suggest that the cannabinoid1 receptor is involved in light-induced retinal degeneration and it may represent a therapeutic target in the light-induced photoreceptor degeneration related diseases.
Collapse
Affiliation(s)
- Tomoyo Imamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Kazuhiro Tsuruma
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Yuki Inoue
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Tomohiro Otsuka
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Yuta Ohno
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Shiho Ogami
- Discovery Research Laboratories III, Ono Pharmaceutical Co., Ltd., Osaka, Japan.
| | - Shinsaku Yamane
- Discovery Research Laboratories III, Ono Pharmaceutical Co., Ltd., Osaka, Japan.
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
| |
Collapse
|
30
|
The arguments for and against cannabinoids application in glaucomatous retinopathy. Biomed Pharmacother 2016; 86:620-627. [PMID: 28027538 DOI: 10.1016/j.biopha.2016.11.106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 11/21/2016] [Accepted: 11/27/2016] [Indexed: 01/22/2023] Open
Abstract
Glaucoma represents several optic neuropathies leading to irreversible blindness through progressive retinal ganglion cell (RGC) loss. Reduction of intraocular pressure (IOP) is known as the only modifiable factor in the treatment of this disorder. Application of exogenous cannabinoids to lower IOP has attracted attention of scientists as potential agents for the treatment of glaucoma. Accordingly, neuroprotective effect of these agents has been recently described through modulation of endocannabinoid system in the eye. In the present work, pertinent information regarding ocular endocannabinoid system, mechanism of exogenous cannabinoids interaction with the ocular endocannabinoid system to reduce IOP, and neuroprotection property of cannabinoids will be discussed according to current scientific literature. In addition to experimental studies, bioavailability of cannabinoids, clinical surveys, and adverse effects of application of cannabinoids in glaucoma will be reviewed.
Collapse
|
31
|
Toguri JT, Caldwell M, Kelly MEM. Turning Down the Thermostat: Modulating the Endocannabinoid System in Ocular Inflammation and Pain. Front Pharmacol 2016; 7:304. [PMID: 27695415 PMCID: PMC5024674 DOI: 10.3389/fphar.2016.00304] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/26/2016] [Indexed: 11/13/2022] Open
Abstract
The endocannabinoid system (ECS) has emerged as an important regulator of both physiological and pathological processes. Notably, this endogenous system plays a key role in the modulation of pain and inflammation in a number of tissues. The components of the ECS, including endocannabinoids, their cognate enzymes and cannabinoid receptors, are localized in the eye, and evidence indicates that ECS modulation plays a role in ocular disease states. Of these diseases, ocular inflammation presents a significant medical problem, given that current clinical treatments can be ineffective or are associated with intolerable side-effects. Furthermore, a prominent comorbidity of ocular inflammation is pain, including neuropathic pain, for which therapeutic options remain limited. Recent evidence supports the use of drugs targeting the ECS for the treatment of ocular inflammation and pain in animal models; however, the potential for therapeutic use of cannabinoid drugs in the eye has not been thoroughly investigated at this time. This review will highlight evidence from experimental studies identifying components of the ocular ECS and discuss the functional role of the ECS during different ocular inflammatory disease states, including uveitis and corneal keratitis. Candidate ECS targeted therapies will be discussed, drawing on experimental results obtained from both ocular and non-ocular tissue(s), together with their potential application for the treatment of ocular inflammation and pain.
Collapse
Affiliation(s)
- James T. Toguri
- Department of Pharmacology, Dalhousie University, HalifaxNS, Canada
| | - Meggie Caldwell
- Department of Pharmacology, Dalhousie University, HalifaxNS, Canada
| | - Melanie E. M. Kelly
- Department of Pharmacology, Dalhousie University, HalifaxNS, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University, HalifaxNS, Canada
- Anesthesia, Pain Management & Perioperative Medicine, Dalhousie University, HalifaxNS, Canada
| |
Collapse
|
32
|
A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys. Neural Plast 2016; 2016:3127658. [PMID: 26977322 PMCID: PMC4761687 DOI: 10.1155/2016/3127658] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/06/2016] [Indexed: 11/24/2022] Open
Abstract
The endocannabinoid (eCB) system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system in the retina of mice, tree shrews, and monkeys. We found that CB1R and FAAH distributions are well-preserved among these species. However, expression of NAPE-PLD is circumscribed to the photoreceptor layer only in monkeys. In contrast, CB2R expression is variable across these species; in mice, CB2R is found in retinal neurons but not in glial cells; in tree shrews, CB2R is expressed in Müller cell processes of the outer retina and in retinal neurons of the inner retina; in monkeys, CB2R is restricted to Müller cells. Finally, the expression patterns of MAGL and DAGLα are differently expressed across species. Overall, these results provide evidence that the eCB system is differently expressed in the retina of these mammals and suggest a distinctive role of eCBs in visual processing.
Collapse
|
33
|
Cairns EA, Baldridge WH, Kelly MEM. The Endocannabinoid System as a Therapeutic Target in Glaucoma. Neural Plast 2016; 2016:9364091. [PMID: 26881140 PMCID: PMC4737462 DOI: 10.1155/2016/9364091] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 11/10/2015] [Indexed: 11/17/2022] Open
Abstract
Glaucoma is an irreversible blinding eye disease which produces progressive retinal ganglion cell (RGC) loss. Intraocular pressure (IOP) is currently the only modifiable risk factor, and lowering IOP results in reduced risk of progression of the disorder. The endocannabinoid system (ECS) has attracted considerable attention as a potential target for the treatment of glaucoma, largely due to the observed IOP lowering effects seen after administration of exogenous cannabinoids. However, recent evidence has suggested that modulation of the ECS may also be neuroprotective. This paper will review the use of cannabinoids in glaucoma, presenting pertinent information regarding the pathophysiology of glaucoma and how alterations in cannabinoid signalling may contribute to glaucoma pathology. Additionally, the mechanisms and potential for the use of cannabinoids and other novel agents that target the endocannabinoid system in the treatment of glaucoma will be discussed.
Collapse
Affiliation(s)
- Elizabeth A. Cairns
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - William H. Baldridge
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada B3H 4R2
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - Melanie E. M. Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada B3H 4R2
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2
| |
Collapse
|
34
|
The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications. Neural Plast 2016; 2016:2916732. [PMID: 26881099 PMCID: PMC4736597 DOI: 10.1155/2016/2916732] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/23/2015] [Indexed: 01/11/2023] Open
Abstract
Cannabis is one of the most prevalent drugs used in industrialized countries. The main effects of Cannabis are mediated by two major exogenous cannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2. Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes. This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system. As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology. This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection. Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases. Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing.
Collapse
|
35
|
Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease. Neural Plast 2016; 2016:8373020. [PMID: 26881135 PMCID: PMC4736800 DOI: 10.1155/2016/8373020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 11/16/2015] [Accepted: 12/01/2015] [Indexed: 11/25/2022] Open
Abstract
The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease.
Collapse
|
36
|
Expression and Function of the Endocannabinoid System in the Retina and the Visual Brain. Neural Plast 2015; 2016:9247057. [PMID: 26839718 PMCID: PMC4709729 DOI: 10.1155/2016/9247057] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/24/2015] [Accepted: 09/27/2015] [Indexed: 12/16/2022] Open
Abstract
Endocannabinoids are important retrograde modulators of synaptic transmission throughout the nervous system. Cannabinoid receptors are seven transmembrane G-protein coupled receptors favoring Gi/o protein. They are known to play an important role in various processes, including metabolic regulation, craving, pain, anxiety, and immune function. In the last decade, there has been a growing interest for endocannabinoids in the retina and their role in visual processing. The purpose of this review is to characterize the expression and physiological functions of the endocannabinoid system in the visual system, from the retina to the primary visual cortex, with a main interest regarding the retina, which is the best-described area in this system so far. It will show that the endocannabinoid system is widely present in the retina, mostly in the through pathway where it can modulate neurotransmitter release and ion channel activity, although some evidence also indicates possible mechanisms via amacrine, horizontal, and Müller cells. The presence of multiple endocannabinoid ligands, synthesizing and catabolizing enzymes, and receptors highlights various pharmacological targets for novel therapeutic application to retinal diseases.
Collapse
|
37
|
Abstract
The endocannabinoid system consists of endogenous cannabinoids (endocannabinoids), the enzymes that synthesize and degrade endocannabinoids, and the receptors that transduce the effects of endocannabinoids. Much of what we know about the function of endocannabinoids comes from studies that combine localization of endocannabinoid system components with physiological or behavioral approaches. This review will focus on the localization of the best-known components of the endocannabinoid system for which the strongest anatomical evidence exists.
Collapse
|
38
|
Murataeva N, Li S, Oehler O, Miller S, Dhopeshwarkar A, Hu SSJ, Bonanno JA, Bradshaw H, Mackie K, McHugh D, Straiker A. Cannabinoid-induced chemotaxis in bovine corneal epithelial cells. Invest Ophthalmol Vis Sci 2015; 56:3304-13. [PMID: 26024113 DOI: 10.1167/iovs.14-15675] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Cannabinoid CB1 receptors are found in abundance in the vertebrate eye, with most tissue types expressing this receptor. However, the function of CB1 receptors in corneal epithelial cells (CECs) is poorly understood. Interestingly, the corneas of CB1 knockout mice heal more slowly after injury via a mechanism proposed to involve protein kinase B (Akt) activation, chemokinesis, and cell proliferation. The current study examined the role of cannabinoids in CEC migration in greater detail. METHODS We determined the role of CB1 receptors in corneal healing. We examined the consequences of their activation on migration and proliferation in bovine CECs (bCECs). We additionally examined the mRNA profile of cannabinoid-related genes and CB1 protein expression as well as CB1 signaling in bovine CECs. RESULTS We now report that activation of CB1 with physiologically relevant concentrations of the synthetic agonist WIN55212-2 (WIN) induces bCEC migration via chemotaxis, an effect fully blocked by the CB1 receptor antagonist SR141716. The endogenous agonist 2-arachidonoylglycerol (2-AG) also enhances migration. Separately, mRNA for most cannabinoid-related proteins are present in bovine corneal epithelium and cultured bCECs. Notably absent are CB2 receptors and the 2-AG synthesizing enzyme diglycerol lipase-α (DAGLα). The signaling profile of CB1 activation is complex, with inactivation of mitogen-activated protein kinase (MAPK). Lastly, CB1 activation does not induce bCEC proliferation, but may instead antagonize EGF-induced proliferation. CONCLUSIONS In summary, we find that CB1-based signaling machinery is present in bovine cornea and that activation of this system induces chemotaxis.
Collapse
Affiliation(s)
- Natalia Murataeva
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Shimin Li
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Olivia Oehler
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Sally Miller
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Amey Dhopeshwarkar
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Sherry Shu-Jung Hu
- Department of Psychology, National Cheng Kung University, Tainan, Taiwan
| | - Joseph A Bonanno
- School of Optometry, Indiana University, Bloomington, Indiana, United States
| | - Heather Bradshaw
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Ken Mackie
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| | - Douglas McHugh
- Frank H. Netter MD School of Medicine, Quinnipiac University, North Haven, Connecticut, United States
| | - Alex Straiker
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States
| |
Collapse
|
39
|
Kokona D, Thermos K. Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways. Exp Eye Res 2015; 136:45-58. [DOI: 10.1016/j.exer.2015.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 11/29/2022]
|
40
|
Zheng X, Suzuki T, Takahashi C, Nishida E, Kusakabe M. cnrip1 is a regulator of eye and neural development in Xenopus laevis. Genes Cells 2015; 20:324-39. [PMID: 25652037 DOI: 10.1111/gtc.12225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 12/22/2014] [Indexed: 01/26/2023]
Abstract
Cannabinoid receptor interacting protein 1 (CNRIP1), which has been originally identified as the binding partner of cannabinoid receptor 1 (CNR1), is evolutionarily conserved throughout vertebrates, but its physiological function has been unknown. Here, we identify a developmental role of CNRIP1 using Xenopus laevis embryos. During early embryogenesis, expression of Xenopus laevis cnrip1 is highly restricted to the animal region of gastrulae where neural and eye induction occur, and afterward it is seen in neural and other tissues with a temporally and spatially regulated pattern. Morpholino-mediated knockdown experiments indicate that cnrip1 has an essential role in early eye and neural development by regulating the onset of expression of key transcription factor genes, sox2, otx2, pax6 and rax. Also, over-expression experiments suggest that cnrip1 has a potential to expand sox2, otx2, pax6 and rax expression. These results suggest an instructive role of Xenopus laevis cnrip1 in early eye and neural development. Furthermore, Xenopus laevis cnr1 knockdown leads to eye defects, which are partly similar to, but milder than, those caused by cnrip1 knockdown, suggesting a possible functional similarity between CNRIP1 and CNR1. This study is the first characterization of an in vivo role of CNRIP1 in the context of whole organisms.
Collapse
Affiliation(s)
- Xiaona Zheng
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | | | | | | | | |
Collapse
|
41
|
Smith TH, Blume LC, Straiker A, Cox JO, David BG, McVoy JRS, Sayers KW, Poklis JL, Abdullah RA, Egertová M, Chen CK, Mackie K, Elphick MR, Howlett AC, Selley DE. Cannabinoid receptor-interacting protein 1a modulates CB1 receptor signaling and regulation. Mol Pharmacol 2015; 87:747-65. [PMID: 25657338 DOI: 10.1124/mol.114.096495] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cannabinoid CB1 receptors (CB1Rs) mediate the presynaptic effects of endocannabinoids in the central nervous system (CNS) and most behavioral effects of exogenous cannabinoids. Cannabinoid receptor-interacting protein 1a (CRIP1a) binds to the CB1R C-terminus and can attenuate constitutive CB1R-mediated inhibition of Ca(2+) channel activity. We now demonstrate cellular colocalization of CRIP1a at neuronal elements in the CNS and show that CRIP1a inhibits both constitutive and agonist-stimulated CB1R-mediated guanine nucleotide-binding regulatory protein (G-protein) activity. Stable overexpression of CRIP1a in human embryonic kidney (HEK)-293 cells stably expressing CB1Rs (CB1-HEK), or in N18TG2 cells endogenously expressing CB1Rs, decreased CB1R-mediated G-protein activation (measured by agonist-stimulated [(35)S]GTPγS (guanylyl-5'-[O-thio]-triphosphate) binding) in both cell lines and attenuated inverse agonism by rimonabant in CB1-HEK cells. Conversely, small-interfering RNA-mediated knockdown of CRIP1a in N18TG2 cells enhanced CB1R-mediated G-protein activation. These effects were not attributable to differences in CB1R expression or endocannabinoid tone because CB1R levels did not differ between cell lines varying in CRIP1a expression, and endocannabinoid levels were undetectable (CB1-HEK) or unchanged (N18TG2) by CRIP1a overexpression. In CB1-HEK cells, 4-hour pretreatment with cannabinoid agonists downregulated CB1Rs and desensitized agonist-stimulated [(35)S]GTPγS binding. CRIP1a overexpression attenuated CB1R downregulation without altering CB1R desensitization. Finally, in cultured autaptic hippocampal neurons, CRIP1a overexpression attenuated both depolarization-induced suppression of excitation and inhibition of excitatory synaptic activity induced by exogenous application of cannabinoid but not by adenosine A1 agonists. These results confirm that CRIP1a inhibits constitutive CB1R activity and demonstrate that CRIP1a can also inhibit agonist-stimulated CB1R signaling and downregulation of CB1Rs. Thus, CRIP1a appears to act as a broad negative regulator of CB1R function.
Collapse
Affiliation(s)
- Tricia H Smith
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Lawrence C Blume
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Alex Straiker
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Jordan O Cox
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Bethany G David
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Julie R Secor McVoy
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Katherine W Sayers
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Justin L Poklis
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Rehab A Abdullah
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Michaela Egertová
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Ching-Kang Chen
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Ken Mackie
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Maurice R Elphick
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Allyn C Howlett
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| | - Dana E Selley
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies (T.H.S., J.O.C., B.G.D., J.R.S.M., J.L.P., R.A.A., D.E.S.), Department of Anatomy and Neurobiology (K.W.S.), Department of Biochemistry and Molecular Biology (C.-K.C.), Virginia Commonwealth University School of Medicine, Richmond, Virginia; Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina (L.C.B., A.C.H.); The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana (A.S., K.M.); and School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom (M.E., M.R.E.)
| |
Collapse
|
42
|
Cabral GA, Ferreira GA, Jamerson MJ. Endocannabinoids and the Immune System in Health and Disease. Handb Exp Pharmacol 2015; 231:185-211. [PMID: 26408161 DOI: 10.1007/978-3-319-20825-1_6] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Endocannabinoids are bioactive lipids that have the potential to signal through cannabinoid receptors to modulate the functional activities of a variety of immune cells. Their activation of these seven-transmembranal, G protein-coupled receptors sets in motion a series of signal transductional events that converge at the transcriptional level to regulate cell migration and the production of cytokines and chemokines. There is a large body of data that supports a functional relevance for 2-arachidonoylglycerol (2-AG) as acting through the cannabinoid receptor type 2 (CB2R) to inhibit migratory activities for a diverse array of immune cell types. However, unequivocal data that supports a functional linkage of anandamide (AEA) to a cannabinoid receptor in immune modulation remains to be obtained. Endocannabinoids, as typical bioactive lipids, have a short half-life and appear to act in an autocrine and paracrine fashion. Their immediate effective action on immune function may be at localized sites in the periphery and within the central nervous system. It is speculated that endocannabinoids play an important role in maintaining the overall "fine-tuning" of the immune homeostatic balance within the host.
Collapse
Affiliation(s)
- Guy A Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA.
| | - Gabriela A Ferreira
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Melissa J Jamerson
- Department of Clinical Laboratory Sciences, Virginia Commonwealth University, Richmond, VA, USA
| |
Collapse
|
43
|
Cécyre B, Monette M, Beudjekian L, Casanova C, Bouchard JF. Localization of diacylglycerol lipase alpha and monoacylglycerol lipase during postnatal development of the rat retina. Front Neuroanat 2014; 8:150. [PMID: 25565975 PMCID: PMC4266045 DOI: 10.3389/fnana.2014.00150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/22/2014] [Indexed: 12/12/2022] Open
Abstract
In recent decades, there has been increased interest in the physiological roles of the endocannabinoid (eCB) system and its receptors, the cannabinoid receptor types 1 (CB1R) and 2 (CB2R). Exposure to cannabinoids during development results in neurofunctional alterations, which implies that the eCB system is involved in the developmental processes of the brain. Because of their lipophilic nature, eCBs are synthesized on demand and are not stored in vesicles. Consequently, the enzymes responsible for their synthesis and degradation are key regulators of their physiological actions. Therefore, knowing the localization of these enzymes during development is crucial for a better understanding of the role played by eCBs during the formation of the central nervous system. In this study, we investigated the developmental protein localization of the synthesizing and catabolic enzymes of the principal eCB, 2-arachidonoylglycerol (2-AG) in the retinas of young and adult rats. The distribution of the enzymes responsible for the synthesis (DAGLα) and the degradation (MAGL) of 2-AG was determined for every retinal cell type from birth to adulthood. Our results indicate that DAGLα is present early in postnatal development. It is highly expressed in photoreceptor, horizontal, amacrine, and ganglion cells. MAGL appears later during the development of the retina and its presence is limited to amacrine and Müller cells. Overall, these results suggest that 2-AG is strongly present in early retinal development and might be involved in the regulation of the structural and functional maturation of the retina.
Collapse
Affiliation(s)
- Bruno Cécyre
- Laboratoire de Neuropharmacologie, École d'Optométrie, Université de Montréal Montréal, QC, Canada ; Laboratoire des Neurosciences de la vision, École d'Optométrie, Université de Montréal Montréal, QC, Canada
| | - Marjorie Monette
- Laboratoire de Neuropharmacologie, École d'Optométrie, Université de Montréal Montréal, QC, Canada
| | - Liza Beudjekian
- Laboratoire de Neuropharmacologie, École d'Optométrie, Université de Montréal Montréal, QC, Canada
| | - Christian Casanova
- Laboratoire des Neurosciences de la vision, École d'Optométrie, Université de Montréal Montréal, QC, Canada
| | - Jean-François Bouchard
- Laboratoire de Neuropharmacologie, École d'Optométrie, Université de Montréal Montréal, QC, Canada
| |
Collapse
|
44
|
Blume LC, Eldeeb K, Bass CE, Selley DE, Howlett AC. Cannabinoid receptor interacting protein (CRIP1a) attenuates CB1R signaling in neuronal cells. Cell Signal 2014; 27:716-726. [PMID: 25446256 DOI: 10.1016/j.cellsig.2014.11.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/23/2014] [Accepted: 11/08/2014] [Indexed: 01/12/2023]
Abstract
CB1 cannabinoid receptors (CB1R) are one of the most abundantly expressed G protein coupled receptors (GPCR) in the CNS and regulate diverse neuronal functions. The identification of GPCR interacting proteins has provided additional insight into the fine-tuning and regulation of numerous GPCRs. The cannabinoid receptor interacting protein 1a (CRIP1a) binds to the distal carboxy terminus of CB1R, and has been shown to alter CB1R-mediated neuronal function [1]. The mechanisms by which CRIP1a regulates CB1R activity have not yet been identified; therefore the focus of this investigation is to examine the cellular effects of CRIP1a on CB1R signaling using neuronal N18TG2 cells stably transfected with CRIP1a over-expressing and CRIP1a knockdown constructs. Modulation of endogenous CRIP1a expression did not alter total levels of CB1R, ERK, or forskolin-activated adenylyl cyclase activity. When compared to WT cells, CRIP1a over-expression reduced basal phosphoERK levels, whereas depletion of CRIP1a augmented basal phosphoERK levels. Stimulation of phosphoERK by the CB1R agonists WIN55212-2, CP55940 or methanandamide was unaltered in CRIP1a over-expressing clones compared with WT. However, CRIP1a knockdown clones exhibited enhanced ERK phosphorylation efficacy in response to CP55940. In addition, CRIP1a knockdown clones displayed a leftward shift in CP55940-mediated inhibition of forskolin-stimulated cAMP accumulation. CB1R-mediated Gi3 and Go activation by CP99540 was attenuated by CRIP1a over-expression, but robustly enhanced in cells depleted of CRIP1a. Conversely, CP55940-mediated Gi1 and Gi2 activation was significant enhanced in cells over-expressing CRIP1a, but not in cells deficient of CRIP1a. These studies suggest a mechanism by which endogenous levels of CRIP1a modulate CB1R-mediated signal transduction by facilitating a Gi/o protein subtype preference for Gi1 and Gi2, accompanied by an overall suppression of G-protein-mediated signaling in neuronal cells.
Collapse
Affiliation(s)
- Lawrence C Blume
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 USA
| | - Khalil Eldeeb
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 USA
| | - Caroline E Bass
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 USA
| | - Dana E Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298 USA
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157 USA
| |
Collapse
|
45
|
Caldwell MD, Hu SSJ, Viswanathan S, Bradshaw H, Kelly MEM, Straiker A. A GPR18-based signalling system regulates IOP in murine eye. Br J Pharmacol 2014; 169:834-43. [PMID: 23461720 DOI: 10.1111/bph.12136] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 01/17/2013] [Accepted: 02/07/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE GPR18 is a recently deorphaned lipid receptor that is activated by the endogenous lipid N-arachidonoyl glycine (NAGly) as well the behaviourally inactive atypical cannabinoid, abnormal cannabidiol (Abn-CBD). The presence and/or function of any GPR18-based ocular signalling system remain essentially unstudied. The objectives of this research are: (i) to determine the disposition of GPR18 receptors and ligands in anterior murine eye, (ii) examine the effect of GPR18 activation on intraocular pressure (IOP) in a murine model, including knockout mice for CB₁, CB₂ and GPR55. EXPERIMENTAL APPROACH IOP was measured in mice following topical application of Abn-CBD, NAGly or the GPR55/GPR18 agonist O-1602, alone or with injection of the GPR18 antagonist, O-1918. GPR18 protein localization was assessed with immunohistochemistry. Endocannabinoids were measured using LC/MS-MS. KEY RESULTS GPR18 protein was expressed most prominently in the ciliary epithelium and the corneal epithelium and, interestingly, in the trabecular meshwork. The GPR18 ligand, NAGly, was also detected in mouse eye at a level comparable to that seen in the brain. Abn-CBD and NAGly, but not O-1602, significantly reduced IOP in all mice tested. The antagonist, O-1918, blocked the effects of Abn-CBD and NAGly. CONCLUSIONS AND IMPLICATIONS We present evidence for a functional GPR18-based signalling system in the murine anterior eye, including receptors and ligands. GPR18 agonists, Abn-CBD and NAGly, reduce IOP independently of CB₁, CB₂ or GPR55. These findings suggest that GPR18 may serve as a desirable target for the development of novel ocular hypotensive medications.
Collapse
Affiliation(s)
- Meggie D Caldwell
- Department of Clinical Vision Science, Dalhousie University, Halifax, NS, Canada
| | | | | | | | | | | |
Collapse
|
46
|
Ryskamp DA, Redmon S, Jo AO, Križaj D. TRPV1 and Endocannabinoids: Emerging Molecular Signals that Modulate Mammalian Vision. Cells 2014; 3:914-38. [PMID: 25222270 PMCID: PMC4197638 DOI: 10.3390/cells3030914] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 08/27/2014] [Accepted: 09/05/2014] [Indexed: 01/18/2023] Open
Abstract
Transient Receptor Potential Vanilloid 1 (TRPV1) subunits form a polymodal cation channel responsive to capsaicin, heat, acidity and endogenous metabolites of polyunsaturated fatty acids. While originally reported to serve as a pain and heat detector in the peripheral nervous system, TRPV1 has been implicated in the modulation of blood flow and osmoregulation but also neurotransmission, postsynaptic neuronal excitability and synaptic plasticity within the central nervous system. In addition to its central role in nociception, evidence is accumulating that TRPV1 contributes to stimulus transduction and/or processing in other sensory modalities, including thermosensation, mechanotransduction and vision. For example, TRPV1, in conjunction with intrinsic cannabinoid signaling, might contribute to retinal ganglion cell (RGC) axonal transport and excitability, cytokine release from microglial cells and regulation of retinal vasculature. While excessive TRPV1 activity was proposed to induce RGC excitotoxicity, physiological TRPV1 activity might serve a neuroprotective function within the complex context of retinal endocannabinoid signaling. In this review we evaluate the current evidence for localization and function of TRPV1 channels within the mammalian retina and explore the potential interaction of this intriguing nociceptor with endogenous agonists and modulators.
Collapse
Affiliation(s)
- Daniel A Ryskamp
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
| | - Sarah Redmon
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
| | - Andrew O Jo
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, Moran Eye Institute, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
| |
Collapse
|
47
|
Cannabinoid and lipid-mediated vasorelaxation in retinal microvasculature. Eur J Pharmacol 2014; 735:105-14. [DOI: 10.1016/j.ejphar.2014.03.055] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 03/07/2014] [Accepted: 03/19/2014] [Indexed: 11/21/2022]
|
48
|
Murataeva N, Straiker A, Mackie K. Parsing the players: 2-arachidonoylglycerol synthesis and degradation in the CNS. Br J Pharmacol 2014; 171:1379-91. [PMID: 24102242 PMCID: PMC3954479 DOI: 10.1111/bph.12411] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/29/2013] [Accepted: 09/08/2013] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED The endogenous cannabinoid signalling system, composed of endogenous cannabinoids, cannabinoid receptors and the enzymes that synthesize and degrade the endogenous cannabinoids, is much more complex than initially conceptualized. 2-Arachidonoylglycerol (2-AG) is the most abundant endocannabinoid and plays a major role in CNS development and synaptic plasticity. Over the past decade, many key players in 2-AG synthesis and degradation have been identified and characterized. Most 2-AG is synthesized from membrane phospholipids via sequential activation of a phospholipase Cβ and a diacylglycerol lipase, although other pathways may contribute in specialized settings. 2-AG breakdown is more complicated with at least eight different enzymes participating. These enzymes can either degrade 2-AG into its components, arachidonic acid and glycerol, or transform 2-AG into highly bioactive signal molecules. The implications of the precise temporal and spatial control of the expression and function of these pleiotropic metabolizing enzymes have only recently come to be appreciated. In this review, we will focus on the primary organization of the synthetic and degradative pathways of 2-AG and then discuss more recent findings and their implications, with an eye towards the biological and therapeutic implications of manipulating 2-AG synthesis and metabolism. LINKED ARTICLES This article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-6.
Collapse
Affiliation(s)
- N Murataeva
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
| | - A Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
| | - K Mackie
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana UniversityBloomington, IN, USA
| |
Collapse
|
49
|
Ahmed MH, Kellogg GE, Selley DE, Safo MK, Zhang Y. Predicting the molecular interactions of CRIP1a-cannabinoid 1 receptor with integrated molecular modeling approaches. Bioorg Med Chem Lett 2014; 24:1158-65. [PMID: 24461351 PMCID: PMC4353595 DOI: 10.1016/j.bmcl.2013.12.119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/26/2013] [Accepted: 12/29/2013] [Indexed: 12/14/2022]
Abstract
Cannabinoid receptors are a family of G-protein coupled receptors that are involved in a wide variety of physiological processes and diseases. One of the key regulators that are unique to cannabinoid receptors is the cannabinoid receptor interacting proteins (CRIPs). Among them CRIP1a was found to decrease the constitutive activity of the cannabinoid type-1 receptor (CB1R). The aim of this study is to gain an understanding of the interaction between CRIP1a and CB1R through using different computational techniques. The generated model demonstrated several key putative interactions between CRIP1a and CB1R, including the critical involvement of Lys130 in CRIP1a.
Collapse
Affiliation(s)
- Mostafa H Ahmed
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Glen E Kellogg
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, USA; Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Dana E Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Martin K Safo
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, VA 23298, USA.
| |
Collapse
|
50
|
The fatty acid amide hydrolase inhibitor, URB597, promotes retinal ganglion cell neuroprotection in a rat model of optic nerve axotomy. Neuropharmacology 2013; 72:116-25. [DOI: 10.1016/j.neuropharm.2013.04.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 11/19/2022]
|