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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.)
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.
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Spyridakos D, Papadogkonaki S, Dionysopoulou S, Mastrodimou N, Polioudaki H, Thermos K. Effect of acute and subchronic administration of (R)-WIN55,212-2 induced neuroprotection and anti inflammatory actions in rat retina: CB1 and CB2 receptor involvement. Neurochem Int 2020; 142:104907. [PMID: 33220388 DOI: 10.1016/j.neuint.2020.104907] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/30/2020] [Accepted: 11/15/2020] [Indexed: 01/09/2023]
Abstract
Cannabinoids have been shown to protect the retina from ischemic/excitotoxic insults. The aim of the present study was to investigate the neuroprotective and anti-inflammatory properties of the synthetic cannabinoid (R)-WIN55,212-2 (CB1/CB2 receptor agonist) when administered acutely or subchronically in control and AMPA treated retinas. Sprague-Dawley rats were intravitreally administered (acutely) with vehicle or AMPA, in the absence or presence of (R)-WIN55,212-2 (10-7-10-4M) alone or in combination with AM251 [CB1 receptor antagonist/inverse agonist,10-4M] and AM630 (CB2 receptor antagonist,10-4M). In addition, AMPA was co-administered with the racemic (R,S)-WIN55,212 (10-4Μ). (R)-WIN55,212-2 was also administered subchronically (25,100 μg/kg,i.p.,4d) in control and AMPA treated rats. Immunohistochemical studies were performed using antibodies against the CB1R, and retinal markers for retinal neurons (brain nitric oxide synthetase, bNOS) and microglia (ionized calcium binding adaptor molecule 1, Iba1). ELISA assay was employed to assess TNFα levels in AMPA treated retinas. Intravitreal administration of (R)-WIN55,212-2 reversed the AMPA induced loss of bNOS expressing amacrine cells, an effect that was blocked by both AM251 and AM630. (R,S)WIN55,212 had no effect. (R)-WIN55,212-2 also reduced a) the AMPA induced activation of microglia, by activating CB2 receptors that were shown to be colocalized with Iba1+ reactive microglial cells, and b) TNFα levels in retina. (R)-WIN55,212-2 administered subchronically led to the downregulation of CB1 receptors at the high dose of 100 μg/kg(i.p.), and to the attenuation of the WIN55,212-2 induced neuroprotection of amacrine cells. At the same dose, (R)-WIN55,212-2 did not attenuate the AMPA induced increase in the number of reactive microglia cells, suggesting CB2 receptor downregulation under subchronic conditions. This study provides new findings regarding the role of CB1 and CB2 receptor activation by the synthetic cannabinoid (R)-WIN55,212-2, administered acutely or sub-chronically, on neuron viability and microglia activation in healthy and diseased retina.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/administration & dosage
- Benzoxazines/administration & dosage
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Female
- Male
- Morpholines/administration & dosage
- Naphthalenes/administration & dosage
- Neuroprotective Agents/administration & dosage
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/metabolism
- Retina/drug effects
- Retina/metabolism
- alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/toxicity
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Affiliation(s)
- Dimitris Spyridakos
- Department of Pharmacology, 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.
| | - Stavroula Dionysopoulou
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Niki Mastrodimou
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Hara Polioudaki
- Department of Biochemistry, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
| | - Kyriaki Thermos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, 71003, Greece.
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Papadogkonaki S, Theodorakis Κ, Thermos K. Endogenous and synthetic cannabinoids induce the downregulation of cannabinoid CB1 receptor in retina. Exp Eye Res 2019; 185:107694. [DOI: 10.1016/j.exer.2019.107694] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/20/2019] [Accepted: 06/10/2019] [Indexed: 10/26/2022]
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Ibán-Arias R, Lisa S, Mastrodimou N, Kokona D, Koulakis E, Iordanidou P, Kouvarakis A, Fothiadaki M, Papadogkonaki S, Sotiriou A, Katerinopoulos HE, Gravanis A, Charalampopoulos I, Thermos K. The Synthetic Microneurotrophin BNN27 Affects Retinal Function in Rats With Streptozotocin-Induced Diabetes. Diabetes 2018; 67:321-333. [PMID: 29208634 DOI: 10.2337/db17-0391] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 11/18/2017] [Indexed: 11/13/2022]
Abstract
BNN27, a C17-spiroepoxy derivative of DHEA, was shown to have antiapoptotic properties via mechanisms involving the nerve growth factor receptors (tropomyosin-related kinase A [TrkA]/neurotrophin receptor p75 [p75NTR]). In this study, we examined the effects of BNN27 on neural/glial cell function, apoptosis, and inflammation in the experimental rat streptozotocin (STZ) model of diabetic retinopathy (DR). The ability of BNN27 to activate the TrkA receptor and regulate p75NTR expression was investigated. BNN27 (2,10, and 50 mg/kg i.p. for 7 days) administration 4 weeks post-STZ injection (paradigm A) reversed the diabetes-induced glial activation and loss of function of amacrine cells (brain nitric oxide synthetase/tyrosine hydroxylase expression) and ganglion cell axons via a TrkA receptor (TrkAR)-dependent mechanism. BNN27 activated/phosphorylated the TrkAY490 residue in the absence but not the presence of TrkAR inhibitor and abolished the diabetes-induced increase in p75NTR expression. However, it had no effect on retinal cell death (TUNEL+ cells). A similar result was observed when BNN27 (10 mg/kg i.p.) was administered at the onset of diabetes, every other day for 4 weeks (paradigm B). However, BNN27 decreased the activation of caspase-3 in both paradigms. Finally, BNN27 reduced the proinflammatory (TNFα and IL-1β) and increased the anti-inflammatory (IL-10 and IL-4) cytokine levels. These findings suggest that BNN27 has the pharmacological profile of a therapeutic for DR, since it targets both the neurodegenerative and inflammatory components of the disease.
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MESH Headings
- Amacrine Cells/drug effects
- Amacrine Cells/immunology
- Amacrine Cells/metabolism
- Amacrine Cells/pathology
- Animals
- Anti-Inflammatory Agents/administration & dosage
- Anti-Inflammatory Agents/therapeutic use
- Axons/drug effects
- Axons/immunology
- Axons/metabolism
- Axons/pathology
- Dehydroepiandrosterone/administration & dosage
- Dehydroepiandrosterone/therapeutic use
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/physiopathology
- Diabetic Retinopathy/immunology
- Diabetic Retinopathy/metabolism
- Diabetic Retinopathy/pathology
- Diabetic Retinopathy/prevention & control
- Dose-Response Relationship, Drug
- Eye Proteins/agonists
- Eye Proteins/metabolism
- Female
- Ganglia, Sensory/drug effects
- Ganglia, Sensory/immunology
- Ganglia, Sensory/metabolism
- Ganglia, Sensory/pathology
- Male
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/metabolism
- Neuroglia/drug effects
- Neuroglia/immunology
- Neuroglia/metabolism
- Neuroglia/pathology
- Neuroprotective Agents/administration & dosage
- Neuroprotective Agents/therapeutic use
- Phosphorylation/drug effects
- Protein Processing, Post-Translational/drug effects
- Rats, Sprague-Dawley
- Receptor, Nerve Growth Factor/agonists
- Receptor, Nerve Growth Factor/metabolism
- Receptor, trkA/agonists
- Receptor, trkA/metabolism
- Retina/drug effects
- Retina/immunology
- Retina/pathology
- Retina/physiopathology
- Streptozocin
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Affiliation(s)
- Ruth Ibán-Arias
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Silvia Lisa
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Niki Mastrodimou
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Despina Kokona
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Emmanuil Koulakis
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Panagiota Iordanidou
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Antonis Kouvarakis
- Laboratory of Environmental Chemical Processes, Department of Chemistry, University of Crete, Heraklion, Crete, Greece
| | - Myrto Fothiadaki
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Sofia Papadogkonaki
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Aggeliki Sotiriou
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
| | | | - Achille Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research & Technology-Hellas, University of Crete, Crete, Greece
| | | | - Kyriaki Thermos
- Department of Pharmacology, School of Medicine, University of Crete, Heraklion, Crete, Greece
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