RESUMO
Neuroinflammation is a recognized complication of immunotherapeutic approaches such as immune checkpoint inhibitor treatment, chimeric antigen receptor therapy, and graft versus host disease (GVHD) occurring after allogeneic hematopoietic stem cell transplantation. While T cells and inflammatory cytokines play a role in this process, the precise interplay between the adaptive and innate arms of the immune system that propagates inflammation in the central nervous system remains incompletely understood. Using a murine model of GVHD, we demonstrate that type 2 cannabinoid receptor (CB2R) signaling plays a critical role in the pathophysiology of neuroinflammation. In these studies, we identify that CB2R expression on microglial cells induces an activated inflammatory phenotype that potentiates the accumulation of donor-derived proinflammatory T cells, regulates chemokine gene regulatory networks, and promotes neuronal cell death. Pharmacological targeting of this receptor with a brain penetrant CB2R inverse agonist/antagonist selectively reduces neuroinflammation without deleteriously affecting systemic GVHD severity. Thus, these findings delineate a therapeutically targetable neuroinflammatory pathway and have implications for the attenuation of neurotoxicity after GVHD and potentially other T cell-based immunotherapeutic approaches.
Assuntos
Doença Enxerto-Hospedeiro , Microglia , Doenças Neuroinflamatórias , Receptor CB2 de Canabinoide , Animais , Camundongos , Aloenxertos , Modelos Animais de Doenças , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/patologia , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/genética , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Camundongos Knockout , Microglia/metabolismo , Microglia/imunologia , Microglia/patologia , Doenças Neuroinflamatórias/imunologia , Doenças Neuroinflamatórias/patologia , Doenças Neuroinflamatórias/metabolismo , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , MasculinoRESUMO
BACKGROUND: Bacterial pneumonia is a major risk factor for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Pseudomonas aeruginosa (PA), an opportunistic pathogen with an increasing resistance acquired against multiple drugs, is one of the main causative agents of ALI and ARDS in diverse clinical settings. Given the anti-inflammatory role of the cannabinoid-2 receptor (CB2R), the effect of CB2R activation in the regulation of PA-induced ALI and inflammation was tested in a mouse model as an alternative to conventional antibiotic therapy. METHODS: In order to activate CB2R, a selective synthetic agonist, JWH133, was administered intraperitoneally (i.p.) to C57BL/6J mice. Furthermore, SR144528 (a selective CB2R antagonist) was administered in combination with JWH133 to test the specificity of the CB2R-mediated effect. PA was administered intratracheally (i.t.) for induction of pneumonia in mice. At 24 h after PA exposure, lung mechanics were measured using the FlexiVent system. The total cell number, protein content, and neutrophil population in the bronchoalveolar lavage fluid (BALF) were determined. The bacterial load in the whole lung was also measured. Lung injury was evaluated by histological examination and PA-induced inflammation was assessed by measuring the levels of BALF cytokines and chemokines. Neutrophil activation (examined by immunofluorescence and immunoblot) and PA-induced inflammatory signaling (analyzed by immunoblot) were also studied. RESULTS: CB2R activation by JWH133 was found to significantly reduce PA-induced ALI and the bacterial burden. CB2R activation also suppressed the PA-induced increase in immune cell infiltration, neutrophil population, and inflammatory cytokines. These effects were abrogated by a CB2R antagonist, SR144528, further confirming the specificity of the CB2R-mediated effects. CB2R-knock out (CB2RKO) mice had a significantly higher level of PA-induced inflammation as compared to that in WT mice. CB2R activation diminished the excess activation of neutrophils, whereas mice lacking CB2R had elevated neutrophil activation. Pharmacological activation of CB2R significantly reduced the PA-induced NF-κB and NLRP3 inflammasome activation, whereas CB2KO mice had elevated NLRP3 inflammasome. CONCLUSION: Our findings indicate that CB2R activation ameliorates PA-induced lung injury and inflammation, thus paving the path for new therapeutic avenues against PA pneumonia.
Assuntos
Lesão Pulmonar Aguda , Canabinoides , Inflamação , Infecções por Pseudomonas , Receptor CB2 de Canabinoide , Animais , Camundongos , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/prevenção & controle , Canabinoides/farmacologia , Canabinoides/uso terapêutico , Citocinas , Inflamassomos/genética , Inflamassomos/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/prevenção & controle , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR , Pseudomonas aeruginosa , Receptores de Canabinoides , Síndrome do Desconforto Respiratório , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/imunologia , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/prevenção & controle , Modelos Animais de DoençasRESUMO
The therapeutic potential of Cannabis sativa has been recognized since ancient times. Phytocannabinoids, endocannabinoids and synthetic cannabinoids activate two major G protein-coupled receptors, subtype 1 and 2 (CB1 and CB2). Cannabinoids (CBs) modulate several aspects of cancer cells, such as apoptosis, autophagy, proliferation, migration, epithelial-to-mesenchymal transition and stemness. Moreover, agonists of CB1 and CB2 receptors inhibit angiogenesis and lymphangiogenesis in vitro and in vivo. Low-grade inflammation is a hallmark of cancer in the tumor microenvironment (TME), which contains a plethora of innate and adaptive immune cells. These cells play a central role in tumor initiation and growth and the formation of metastasis. CB2 and, to a lesser extent, CB1 receptors are expressed on a variety of immune cells present in TME (e.g., T cells, macrophages, mast cells, neutrophils, NK cells, dendritic cells, monocytes, eosinophils). The activation of CB receptors modulates a variety of biological effects on cells of the adaptive and innate immune system. The expression of CB2 and CB1 on different subsets of immune cells in TME and hence in tumor development is incompletely characterized. The recent characterization of the human cannabinoid receptor CB2-Gi signaling complex will likely aid to design potent and specific CB2/CB1 ligands with therapeutic potential in cancer.
Assuntos
Endocanabinoides/imunologia , Neoplasias , Receptor CB1 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/imunologia , Microambiente Tumoral/imunologia , Autofagia , Proliferação de Células , Transição Epitelial-Mesenquimal , Humanos , Neoplasias/imunologia , Neoplasias/patologiaRESUMO
The endocannabinoid system is a promising target to mitigate pain as the endocannabinoids are endogenous ligands of the pain-mediating receptors-cannabinoid receptors 1 and 2 (CB1 and CB2) and TRPV1. Herein, we report on a class of lipids formed by the epoxidation of N-arachidonoyl-dopamine (NADA) and N-arachidonoyl-serotonin (NA5HT) by epoxygenases. EpoNADA and epoNA5HT are dual-functional rheostat modulators of the endocannabinoid-TRPV1 axis. EpoNADA and epoNA5HT are stronger modulators of TRPV1 than either NADA or NA5HT, and epoNA5HT displays a significantly stronger inhibition on TRPV1-mediated responses in primary afferent neurons. Moreover, epoNA5HT is a full CB1 agonist. These epoxides reduce the pro-inflammatory biomarkers IL-6, IL-1ß, TNF-α and nitrous oxide and raise anti-inflammatory IL-10 cytokine in activated microglial cells. The epoxides are spontaneously generated by activated microglia cells and their formation is potentiated in the presence of anandamide. Detailed kinetics and molecular dynamics simulation studies provide evidence for this potentiation using the epoxygenase human CYP2J2. Taken together, inflammation leads to an increase in the metabolism of NADA, NA5HT and other eCBs by epoxygenases to form the corresponding epoxides. The epoxide metabolites are bioactive lipids that are potent, multi-faceted molecules, capable of influencing the activity of CB1, CB2 and TRPV1 receptors.
Assuntos
Anti-Inflamatórios/administração & dosagem , Dopamina/administração & dosagem , Dor/tratamento farmacológico , Receptor CB1 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/imunologia , Serotonina/administração & dosagem , Animais , Anti-Inflamatórios/química , Dopamina/química , Endocanabinoides/administração & dosagem , Endocanabinoides/química , Compostos de Epóxi/química , Feminino , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nitroso/imunologia , Dor/genética , Dor/imunologia , Receptor CB1 de Canabinoide/genética , Receptor CB2 de Canabinoide/genética , Serotonina/química , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/imunologiaRESUMO
Graft-versus-host disease (GVHD) pathophysiology is a complex interplay between cells that comprise the adaptive and innate arms of the immune system. Effective prophylactic strategies are therefore contingent upon approaches that address contributions from both immune cell compartments. In the current study, we examined the role of the type 2 cannabinoid receptor (CB2R), which is expressed on nearly all immune cells, and demonstrated that absence of the CB2R on donor CD4+ or CD8+ T cells or administration of a selective CB2R pharmacological antagonist exacerbated acute GVHD lethality. This was accompanied primarily by the expansion of proinflammatory CD8+ T cells, indicating that constitutive CB2R expression on T cells preferentially regulated CD8+ T-cell alloreactivity. Using a novel CB2ReGFP reporter mouse, we observed significant loss of CB2R expression on T cells, but not macrophages, during acute GVHD, indicative of differential alterations in receptor expression under inflammatory conditions. Therapeutic targeting of the CB2R with the agonists Δ9-tetrahydrocannabinol (THC) and JWH-133 revealed that only THC mitigated lethal T cell-mediated acute GVHD. Conversely, only JWH-133 was effective in a sclerodermatous chronic GVHD model where macrophages contributed to disease biology. In vitro, both THC and JWH-133 induced arrestin recruitment and extracellular regulated kinase phosphorylation via CB2R, but THC had no effect on CB2R-mediated inhibition of adenylyl cyclase. This study shows that the CB2R plays a critical role in the regulation of GVHD and suggests that effective therapeutic targeting is dependent upon agonist signaling characteristics and receptor selectivity in conjunction with the composition of pathogenic immune effector cells.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Receptor CB2 de Canabinoide/imunologia , Transdução de Sinais , Doença Aguda , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Doença Crônica , Doença Enxerto-Hospedeiro/patologia , Camundongos Endogâmicos C57BL , Índice de Gravidade de DoençaRESUMO
The COVID-19 pandemic caused by SARS-CoV-2 is a deadly disease afflicting millions. The pandemic continues affecting population due to nonavailability of drugs and vaccines. The pathogenesis and complications of infection mainly involve hyperimmune-inflammatory responses. Thus, therapeutic strategies rely on repurposing of drugs aimed at reducing infectivity and inflammation and modulate immunity favourably. Among, numerous therapeutic targets, the endocannabinoid system, particularly activation of cannabinoid type-2 receptors (CB2R) emerged as an important one to suppress the hyperimmune-inflammatory responses. Recently, potent antiinflammatory, antiviral and immunomodulatory properties of CB2R selective ligands of endogenous, plant, and synthetic origin were showed mediating CB2R selective functional agonism. CB2R activation appears to regulate numerous signaling pathways to control immune-inflammatory mediators including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Many CB2R ligands also exhibit off-target effects mediating activation of PPARs, opioids, and TRPV, suggestive of adjuvant use with existing drugs that may maximize efficacy synergistically and minimize therapeutic doses to limit adverse/ side effects. We hypothesize that CB2R agonists, due to immunomodulatory, antiinflammatory, and antiviral properties may show activity against COVID-19. Based on the organoprotective potential, relative safety, lack of psychotropic effects, and druggable properties, CB2R selective ligands might make available promising candidates for further investigation.
Assuntos
Tratamento Farmacológico da COVID-19 , Agonistas de Receptores de Canabinoides/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Imunidade Celular/efeitos dos fármacos , Receptor CB2 de Canabinoide/agonistas , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/metabolismo , COVID-19/imunologia , COVID-19/metabolismo , Agonistas de Receptores de Canabinoides/metabolismo , Humanos , Imunidade Celular/fisiologia , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/metabolismo , Receptor CB2 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/metabolismo , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/metabolismoRESUMO
Microglia are key to maintaining the homeostasis of the brain. These immune cells of the brain can be our biggest ally in fighting infections, but can worsen pathology or hinder recovery when uncontrolled. Thus, understanding how microglia contribute to neuroinflammatory processes and how their activity can be controlled is of great importance. It is known that activation of endocannabinoid system, and especially the cannabinoid type 2 receptor (CB2R), decreases inflammation. Alongside its non-psychoactive effect, it makes the CB2R receptor a perfect target for treating diseases accompanied by neuroinflammation including neurodegenerative diseases. However, the exact mechanisms by which CB2R regulates microglial activity are not yet understood. Here, we review the current knowledge on the roles of microglial CB2R from in vitro and in vivo studies. We look into CB2R function under physiological and pathological conditions and focus on four different disease models representing chronic and acute inflammation. We highlight open questions and controversies and provide an update on the latest discoveries that were enabled by the development of novel technologies. Also, we discuss the recent findings on the role of microglia CB2R in cognition and its role in neuron-microglia communication.
Assuntos
Encéfalo/imunologia , Homeostase/imunologia , Inflamação/imunologia , Receptor CB2 de Canabinoide/imunologia , Transdução de Sinais/imunologia , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Humanos , Imunidade/imunologia , Inflamação/metabolismo , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/metabolismo , Receptor CB2 de Canabinoide/metabolismoRESUMO
This review examines the impact of cannabinoids on viral infections, as well as its effects on the mitochondria of the nervous and immune system. The paper conveys information about the beneficial and negative impacts of cannabinoids on viral infections, especially HIV-1. These include effects on the inflammatory response as well as neuroprotective effects. We also explore non-apoptotic mitochondrial pathways modulated by the activity of cannabinoids, resulting in modifications to cellular functions. As a large part of the literature derives from studies of the nervous system, we first compile the information related to mitochondrial functions in this system, particularly through the CB1 receptor. Finally, we reflect on how this knowledge could complement what has been demonstrated in the immune system, especially in the context of the CB2 receptor and Ca2+ uptake. The overall conclusion of the review is that cannabinoids have the potential to affect a broad range of cell types through mitochondrial modulation, be it through receptor-specific action or not, and that this pathway has a potential implication in cases of viral infection.
Assuntos
Canabinoides/imunologia , Imunomodulação , Mitocôndrias/efeitos dos fármacos , Viroses/imunologia , Animais , Canabinoides/administração & dosagem , Humanos , Sistema Imunitário/efeitos dos fármacos , Camundongos , Mitocôndrias/fisiologia , Sistema Nervoso/efeitos dos fármacos , Receptor CB1 de Canabinoide/imunologia , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/metabolismoRESUMO
Cannabis use is an emergent risk factor for periodontitis, a chronic bacterial-induced disease of the supporting structures of the teeth. However, the mechanisms by which marijuana exposure predisposes to periodontal tissue destruction have yet to be elucidated. Therefore, we examined the influence of physiologically relevant doses of major marijuana-derived phytocannabinoid subtypes (cannabidiol [CBD]; cannabinol [CBN]; and tetrahydrocannabinol [THC], 1.0 µg/ml) on the interactions of three ultrastructurally variant oral pathogens, Porphyromonas gingivalis, Filifactor alocis, and Treponema denticola with the immune system. CBD, CBN, and THC each suppressed P. gingivalis-induced IL-12 p40, IL-6, IL-8, and TNF release while enhancing the anti-inflammatory cytokine, IL-10, from human innate cells. Similar phenomena were observed in F. alocis- and T. denticola-exposed human monocytes and human gingival keratinocytes. Higher phytocannabinoid doses (≥5.0 µg/ml) compromised innate cell viability and inhibited the growth of P. gingivalis and F. alocis, relative to unexposed bacteria. T. denticola, however, was resistant to all cannabinoid doses tested (up to 10.0 µg/ml). Pharmaceutical inhibition and efficient gene silencing indicated that a common CB2/PI3K axis of immune suppression is triggered by phytocannabinoids in vitro. This pathway does not appear to perpetuate through the canonical GSK3ß-dependent cholinergic anti-inflammatory pathway, the predominant endogenous inflammatory control system. In a repetitive, transient oral infection model, CBD also suppressed P. gingivalis-induced innate immune markers in wild-type mice, but not in CB2-/- mice. If such phenomena occur in humans in situ, environmental cannabinoids may enhance periodontitis via direct toxic effects on specific oral bacteria; by compromising innate cell vitality; and/or through a suppressed innate response to periodontal pathogens involving a CB2/PI3K signaling lineage.
Assuntos
Infecções Bacterianas/imunologia , Canabinoides/farmacologia , Cannabis/química , Imunidade Inata/efeitos dos fármacos , Doenças da Boca/imunologia , Fosfatidilinositol 3-Quinases/imunologia , Receptor CB2 de Canabinoide/imunologia , Transdução de Sinais/efeitos dos fármacos , Animais , Bactérias/imunologia , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Infecções Bacterianas/patologia , Canabinoides/química , Linhagem Celular Tumoral , Humanos , Imunidade Inata/genética , Queratinócitos/imunologia , Queratinócitos/patologia , Masculino , Camundongos , Camundongos Knockout , Monócitos/imunologia , Monócitos/patologia , Doenças da Boca/genética , Doenças da Boca/microbiologia , Doenças da Boca/patologia , Fosfatidilinositol 3-Quinases/genética , Receptor CB2 de Canabinoide/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologiaRESUMO
OBJECTIVE: Cannabinoid CB2 receptors (CB2Rs) are mainly present on immune cells including mast cells, which participate in 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD). In this study, we aimed to investigate whether inhibition of mast cell degranulation was involved in the anti-ACD effect of electroacupuncture (EA) at ST36 via CB2R. METHODS: Sprague-Dawley rats were sensitised and challenged with DNFB following EA stimulation for 1 week. Ear swelling, serum IgE levels, local cytokine production and mast cell infiltration were evaluated. Additionally, rat peritoneal mast cells (RPMCs) were isolated and cultured for detection of CB2R expression, mitogen-activated protein kinase (MAPK) signalling activation and mast cell degranulation (including ß-hexosaminidase and histamine release) in the presence or absence of CB2R antagonists. RESULTS: EA treatment inhibited ear swelling, suppressed IgE and cytokine production, decreased the number of mast cells and curbed mast cell degranulation, which was associated with the inhibition of p38 phosphorylation in DNFB-induced ACD. Importantly, EA enhanced the expression of CB2R mRNA and protein in the RPMCs. CB2R antagonist AM630 but not CB1R antagonist AM251 effectively reversed the suppressive effect of EA on p38 activation, mast cell infiltration and degranulation. CONCLUSION: These findings provide more evidence to support the hypothesis that EA promotes CB2R expression in mast cells, which is followed by inhibition of the p38 MAPK pathway, potentially resulting in the anti-ACD effect of EA. This suggests that EA at ST36 may be an effective candidate therapy for treating inflammatory skin diseases such as ACD.
Assuntos
Dermatite Alérgica de Contato/terapia , Eletroacupuntura , Mastócitos/imunologia , Receptor CB2 de Canabinoide/imunologia , Pontos de Acupuntura , Animais , Degranulação Celular , Citocinas/genética , Citocinas/imunologia , Dermatite Alérgica de Contato/genética , Dermatite Alérgica de Contato/imunologia , Humanos , Imunoglobulina E/imunologia , Masculino , Mastócitos/citologia , Ratos , Ratos Sprague-Dawley , Receptor CB2 de Canabinoide/genética , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/imunologiaRESUMO
This study evaluated the participation of CB1 and CB2 receptors in the antiresorptive effect of electroacupuncture (EA) on an experimental model of inflammatory bone loss in rats. 30 rats were divided into five groups: C (control); EP (experimental periodontitis); EA (C+ EA); EP-EA (EP+ EA in the acupoints LI4, LG11, ST36, ST44); EP - EA-sham (EP+ EA in sham acupoints). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. Animals were euthanized at day 11. Histometric analysis was performed to evaluate the percentage of bone area in the furcation area. Immunolabeling patterns in the periodontal tissues and immunofluorescent staining in the trigeminal ganglia and in the trigeminal spinal tract for CB1 and CB2 receptors were performed. It was observed increased bone loss in the furcation in the EP and EP-EA-sham groups, in comparison to the other groups (pâ¯<â¯0.05). Enhanced CB2 immunolabeling was observed in the periodontal tissues in the EP-EA group, when compared to the EP and EP-EA-sham groups (pâ¯<â¯0.05). Increased CB1 immunofluorescent staining was observed in the neural tissues in the EA treated group in comparison with the other groups (pâ¯<â¯0.05), while no expression of CB2 was observed in those regions. Our study showed that in the presence of inflammatory bone disease, EA treatment reduced bone erosion and increased the immunoexpression of CB1 in the neural tissues and CB2 in the periodontal tissues.
Assuntos
Reabsorção Óssea/imunologia , Reabsorção Óssea/terapia , Eletroacupuntura , Inflamação/patologia , Receptor CB1 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/imunologia , Animais , Masculino , Periodonto/metabolismo , Ratos Wistar , Gânglio Trigeminal/metabolismoRESUMO
Management of pain in the treatment of rheumatoid arthritis (RA) is a priority that is not fully addressed by the conventional therapies. In the present study, we evaluated the efficacy of cannabinoid receptor 2 (CB2) agonist JWH-015 using RA synovial fibroblasts (RASFs) obtained from patients diagnosed with RA and in a rat adjuvant-induced arthritis (AIA) model of RA. Pretreatment of human RASFs with JWH-015 (10-20 µM) markedly inhibited the ability of pro-inflammatory cytokine interleukin-1ß (IL-1ß) to induce production of IL-6 and IL-8 and cellular expression of inflammatory cyclooxygenase-2 (COX-2). JWH-015 was effective in reducing IL-1ß-induced phosphorylation of TAK1 (Thr184/187) and JNK/SAPK in human RASFs. While the knockdown of CB2 in RASFs using siRNA method reduced IL-1ß-induced inflammation, JWH-015 was still effective in eliciting its anti-inflammatory effects despite the absence of CB2, suggesting the role of non-canonical or an off-target receptor. Computational studies using molecular docking and molecular dynamics simulations showed that JWH-105 favorably binds to glucocorticoid receptor (GR) with the binding pose and interactions similar to its well-known ligand dexamethasone. Furthermore, knockdown of GR using siRNA abrogated JWH-015's ability to reduce IL-1ß-induced IL-6 and IL-8 production. In vivo, administration of JWH-015 (5 mg/kg, daily i.p. for 7 days at the onset of arthritis) significantly ameliorated AIA in rats. Pain assessment studies using von Frey method showed a marked antinociception in AIA rats treated with JWH-015. In addition, JWH-015 treatment inhibited bone destruction as evident from micro-CT scanning and bone analysis on the harvested joints and modulated serum RANKL and OPG levels. Overall, our findings suggest that CB2 agonist JWH-015 elicits anti-inflammatory effects partly through GR. This compound could further be tested as an adjunct therapy for the management of pain and tissue destruction as a non-opioid for RA.
Assuntos
Artrite Experimental/tratamento farmacológico , Fibroblastos/imunologia , Indóis/farmacologia , Interleucina-1beta/imunologia , Receptor CB2 de Canabinoide/agonistas , Receptores de Esteroides/imunologia , Membrana Sinovial/imunologia , Animais , Artrite Experimental/induzido quimicamente , Artrite Experimental/imunologia , Artrite Experimental/patologia , Feminino , Fibroblastos/patologia , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/imunologia , Inflamação/patologia , Ratos , Ratos Endogâmicos Lew , Receptor CB2 de Canabinoide/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Membrana Sinovial/patologiaRESUMO
Mast cells (MCs) contribute to the control of local inflammatory reactions and become hyporesponsive after prolonged TLR4 activation by bacterial LPS. The molecular mechanisms involved in endotoxin tolerance (ET) induction in MCs are not fully understood. In this study, we demonstrate that the endocannabinoid 2-arachidonoylglycerol (2-AG) and its receptor, cannabinoid receptor 2 (CB2), play a role in the establishment of ET in bone marrow-derived MCs from C57BL/6J mice. We found that CB2 antagonism prevented the development of ET and that bone marrow-derived MCs produce 2-AG in a TLR4-dependent fashion. Exogenous 2-AG induced ET similarly to LPS, blocking the phosphorylation of IKK and the p65 subunit of NF-κB and inducing the synthesis of molecular markers of ET. LPS caused CB2 receptor trafficking in Rab11-, Rab7-, and Lamp2-positive vesicles, indicating recycling and degradation of the receptor. 2-AG also prevented LPS-induced TNF secretion in vivo, in a MC-dependent model of endotoxemia, demonstrating that TLR4 engagement leads to 2-AG secretion, which contributes to the negative control of MCs activation. Our study uncovers a functional role for the endocannabinoid system in the inhibition of MC-dependent innate immune responses in vivo.
Assuntos
Ácidos Araquidônicos/farmacologia , Endocanabinoides/farmacologia , Glicerídeos/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Mastócitos/imunologia , Receptor CB2 de Canabinoide/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Tolerância Imunológica/imunologia , Proteína 2 de Membrana Associada ao Lisossomo/genética , Proteína 2 de Membrana Associada ao Lisossomo/imunologia , Camundongos , Camundongos Knockout , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/genética , Transporte Proteico/imunologia , Receptor CB2 de Canabinoide/genética , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/imunologia , proteínas de unión al GTP Rab7RESUMO
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, characterized by loss of tolerance toward self nuclear Ags. Systemic induction of type I IFNs plays a pivotal role in SLE, a major source of type I IFNs being the plasmacytoid dendritic cells (pDCs). Several genes have been linked with susceptibility to SLE in genome-wide association studies. We aimed at exploring the role of one such gene, α/ß-hydrolase domain-containing 6 (ABHD6), in regulation of IFN-α induction in SLE patients. We discovered a regulatory role of ABHD6 in human pDCs through modulating the local abundance of its substrate, the endocannabinoid 2-arachidonyl glycerol (2-AG), and elucidated a hitherto unknown cannabinoid receptor 2 (CB2)-mediated regulatory role of 2-AG on IFN-α induction by pDCs. We also identified an ABHD6High SLE endophenotype wherein reduced local abundance of 2-AG relieves the CB2-mediated steady-state resistive tuning on IFN-α induction by pDCs, thereby contributing to SLE pathogenesis.
Assuntos
Células Dendríticas/imunologia , Endocanabinoides/metabolismo , Interferon gama/biossíntese , Lúpus Eritematoso Sistêmico/imunologia , Monoacilglicerol Lipases/imunologia , Adulto , Ácidos Araquidônicos/imunologia , Ácidos Araquidônicos/metabolismo , Células Dendríticas/metabolismo , Endocanabinoides/imunologia , Endofenótipos , Feminino , Regulação da Expressão Gênica/imunologia , Glicerídeos/imunologia , Glicerídeos/metabolismo , Humanos , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/metabolismo , Masculino , Pessoa de Meia-Idade , Monoacilglicerol Lipases/genética , Receptor CB2 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/metabolismoRESUMO
Cannabinoids are known to possess anti-inflammatory and immunomodulatory properties, but the mechanisms involved are not fully understood. CB2 is the cannabinoid receptor that is expressed primarily on hematopoietic cells and mediates the immunoregulatory functions of cannabinoids. In order to study the effect of JTE907, a selective/inverse agonist of CB2 with anti-inflammatory properties, on the differentiation of T cell subtypes, we used an in vitro system of Th lineage-specific differentiation of naïve CD4+ T lymphocytes isolated from the mouse spleen. The results indicate that JTE907 was able to induce the differentiation of Th0 cells into the Treg cell phenotype, which was characterized by the expression of FoxP3, TGF-ß and IL-10. P38 phosphorylation and STAT5A activation were found to mediate the signaling pathway triggered by JTE907 via the CB2 receptor in Th0 lymphocytes. In mice with DNBS-induced colitis, JTE907 treatment was able to induce an increase in the number of CD4+CD25+FoxP3+ cells in the lamina propria after 24 h of disease onset and reduce disease severity after 48 h. Further, longer JTE907 treatment resulted in less severe colitis even when administered orally, resulting in less body weight loss, reduction of the disease score, prevention of NF-κB activation, and reduction of the expression of adhesion molecules. Collectively, the results of this study indicate that specific signals delivered through the CB2 receptor can drive the immune response towards the Treg cell phenotype. Thus, ligands such as JTE907 may have use as potential therapeutic agents in autoimmune and inflammatory diseases.
Assuntos
Anti-Inflamatórios/farmacologia , Colite/imunologia , Dioxóis/farmacologia , Quinolonas/farmacologia , Receptor CB2 de Canabinoide/imunologia , Linfócitos T/efeitos dos fármacos , Animais , Diferenciação Celular , Colite/patologia , Colo/efeitos dos fármacos , Colo/patologia , Citocinas/imunologia , Modelos Animais de Doenças , Inflamação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Masculino , Camundongos Endogâmicos C57BL , Fenótipo , Baço/citologia , Linfócitos T/citologia , Linfócitos T/imunologiaRESUMO
Cannabinoid CB1 receptors are highly expressed in the brain and functionally modulate presynaptic neurotransmitter release, while cannabinoid CB2 receptors (CB2Rs) were initially identified in the spleen and regarded as peripheral cannabinoid receptors. Recently, growing evidence indicates the presence of functional CB2Rs in the brain. However, this finding is disputed because of the specificity of CB2R antibody signals. We used two strains of currently available partial CB2-knockout (CB2-KO) mice as controls, four anti-rat or anti-mouse CB2R antibodies, and mRNA quantification to further address this issue. Western blot assays using the four antibodies detected a CB2R-like band at ~40 kD in both the brain and spleen. Notably, more bands were detected in the brain than in the spleen, and specific immune peptides blocked band detection. Immunohistochemical assays also detected CB2-like immunostaining in mouse midbrain dopamine neurons. CB2R deletion in CB2-KO mice may reduce or leave CB2R-like immunoreactivity unaltered depending on antibody epitope. Antibodies with epitopes at the receptor-deleted region detected a significant reduction in CB2R band density and immunostaining in N-terminal-deleted Deltagen and C-terminal-deleted Zimmer strain CB2-KO mice. Other antibodies with epitopes at the predicted receptor-undeleted regions detected similar band densities and immunostaining in wild-type and CB2-KO mice. Quantitative RT-PCR assays detected CB2 mRNA expression using probes that targeted upstream or downstream gene sequences but not the probe that targeted the gene-deleted sequence in Deltagen or Zimmer CB2-KO mice. These findings suggest that none of the tested four polyclonal antibodies are highly mouse CB2R-specific. Non-specific binding may be related to the expression of mutant or truncated CB2R-like proteins in partial CB2-KO mice and the use of anti-rat CB2 antibodies because the epitopes are different between rat and mouse CB2Rs.
Assuntos
Anticorpos/imunologia , Receptor CB2 de Canabinoide/imunologia , Receptor CB2 de Canabinoide/metabolismo , Animais , Western Blotting , Neurônios Dopaminérgicos/metabolismo , Técnicas de Inativação de Genes , Imuno-Histoquímica , Mesencéfalo/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Receptor CB2 de Canabinoide/genética , Baço/metabolismoRESUMO
Metabolic reprogramming greatly contributes to the regulation of macrophage activation. However, the mechanism of lipid accumulation and the corresponding function in tumor-associated macrophages (TAMs) remain unclear. With primary investigation in colon cancer and confirmation in other cancer models, here we determine that deficiency of monoacylglycerol lipase (MGLL) results in lipid overload in TAMs. Functionally, macrophage MGLL inhibits CB2 cannabinoid receptor-dependent tumor progression in inoculated and genetic cancer models. Mechanistically, MGLL deficiency promotes CB2/TLR4-dependent macrophage activation, which further suppresses the function of tumor-associated CD8+ T cells. Treatment with CB2 antagonists delays tumor progression in inoculated and genetic cancer models. Finally, we verify that expression of macrophage MGLL is decreased in cancer tissues and positively correlated with the survival of cancer patients. Taken together, our findings identify MGLL as a switch for CB2/TLR4-dependent macrophage activation and provide potential targets for cancer therapy.
Assuntos
Macrófagos/imunologia , Monoacilglicerol Lipases/metabolismo , Neoplasias/patologia , Receptor CB2 de Canabinoide/metabolismo , Idoso , Animais , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Humanos , Metabolismo dos Lipídeos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Monoacilglicerol Lipases/genética , Neoplasias/imunologia , Cultura Primária de Células , Células RAW 264.7 , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/imunologia , Receptor 4 Toll-Like/metabolismoRESUMO
CB2 cannabinoid receptor (CB2R) gene is associated with depression. We investigated the gene-environment interaction between CB2R function and diverse stressors. First, anxiety-like behavior during chronic-mild-stress (CMS) was evaluated in C57BL/6JJmsSlc mice following treatment with CB2R agonist JWH015 or inverse-agonist AM630. Second, locomotor activity and anxiety-like behavior were measured following exposure to an immune poly I:C stressor. Gene expressions of HPA axis related molecules, Fkbp5, Nr3c1 and Crf and pro-inflammatory cytokine Il-1b, as well as Bdnf as a key neurotrophin that supports neuron health, function, and synaptic plasticity, were determined in hippocampus of Cnr2 knockout mice, as indicators of stressful environment. CMS-induced anxiety-like behavior was enhanced by AM630 and reduced by JWH015 and fluvoxamine. Poly I:C reduced locomotor activity and increased anxiety-like behavior, and these effects were pronounced in the heterozygote than in the wild type mice. Fkbp5 and Nr3c1 expression were lower in the Cnr2 heterozygotes than in the wild type mice with Poly I:C treatment. These findings indicate that interaction between CB2R gene and stressors increases the risk of depression-like behaviors that may be linked with neuro-immune crosstalk. Further studies in human subjects are necessary to determine the role of CB2R and environmental interaction in the development of depression.
Assuntos
Ansiedade/genética , Depressão/genética , Interação Gene-Ambiente , Sistema Hipotálamo-Hipofisário/imunologia , Sistema Hipófise-Suprarrenal/imunologia , Receptor CB2 de Canabinoide/genética , Animais , Ansiedade/induzido quimicamente , Ansiedade/imunologia , Ansiedade/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/imunologia , Agonistas de Receptores de Canabinoides/farmacologia , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/imunologia , Depressão/induzido quimicamente , Depressão/imunologia , Depressão/fisiopatologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/imunologia , Hipocampo/fisiopatologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Fatores Imunológicos/administração & dosagem , Indóis/farmacologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/fisiopatologia , Poli I-C/administração & dosagem , Receptor CB2 de Canabinoide/deficiência , Receptor CB2 de Canabinoide/imunologia , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/imunologia , Transdução de Sinais , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/imunologiaRESUMO
Astrocytes are involved in non-cell-autonomous pathogenic cascades in amyotrophic lateral sclerosis (ALS); however, their role is still debated. We show that astrocytic NF-κB activation drives microglial proliferation and leukocyte infiltration in the SOD1 (G93A) ALS model. This response prolongs the presymptomatic phase, delaying muscle denervation and decreasing disease burden, but turns detrimental in the symptomatic phase, accelerating disease progression. The transition corresponds to a shift in the microglial phenotype showing two effects that can be dissociated by temporally controlling NF-κB activation. While NF-κB activation in astrocytes induced a Wnt-dependent microglial proliferation in the presymptomatic phase with neuroprotective effects on motoneurons, in later stage, astrocyte NF-κB-dependent microglial activation caused an accelerated disease progression. Notably, suppression of the early microglial response by CB2R agonists had acute detrimental effects. These data identify astrocytes as important regulators of microglia expansion and immune response. Therefore, stage-dependent microglia modulation may be an effective therapeutic strategy in ALS.
Assuntos
Esclerose Lateral Amiotrófica/imunologia , Astrócitos/imunologia , NF-kappa B/imunologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/terapia , Animais , Astrócitos/patologia , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Microglia/imunologia , Microglia/patologia , Neurônios Motores/imunologia , Neurônios Motores/patologia , NF-kappa B/genética , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/imunologia , Superóxido Dismutase/genética , Superóxido Dismutase/imunologia , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/imunologiaRESUMO
The hallmark of vaccines is their ability to prevent the spread of infectious pathogens and thereby serve as invaluable public health tool. Despite their medical relevance, there is a gap in our understanding of the physiological factors that mediate innate and adaptive immune response to vaccines. The endocannabinoid (eCB) system is a critical modulator of homeostasis in vertebrates. Our results indicate that macrophages and dendritic cells produce the endocannabinoid, 2-arachidonoyl-sn-glycerol (2-AG) upon antigen activation. We have also established that 2-AG levels are upregulated in the serum and in the lymph node of mice during vaccination. We hypothesized that the intrinsic release of eCBs from immune cells during activation by pathogenic antigens mitigate inflammation, but also suppress overall innate and adaptive immune response. Here we demonstrate, for the first time, that transient administration of the cannabinoid receptor 2 antagonist AM630 (10 mg/kg) or inverse agonist JTE907 (3 mg/kg) during immunization heightens the intensity and breadth of antigen-specific immune responses in young and aged mice through the upregulation of immunomodulatory genes in secondary lymphoid tissues.