Category Archives: Endocannabinoid System

Modulation of Renal GLUT2 by the Cannabinoid-1 Receptor: Implications for the Treatment of Diabetic Nephropathy.

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“Altered glucose reabsorption via the facilitative glucose transporter 2 (GLUT2) during diabetes may lead to renal proximal tubule cell (RPTC) injury, inflammation, and interstitial fibrosis. These pathologies are also triggered by activating the cannabinoid-1 receptor (CB1R), which contributes to the development of diabetic nephropathy (DN). However, the link between CB1R and GLUT2 remains to be determined. Here, we show that chronic peripheral CB1R blockade or genetically inactivating CB1Rs in the RPTCs ameliorated diabetes-induced renal structural and functional changes, kidney inflammation, and tubulointerstitial fibrosis in mice. Inhibition of CB1R also downregulated GLUT2 expression, affected the dynamic translocation of GLUT2 to the brush border membrane of RPTCs, and reduced glucose reabsorption. Thus, targeting peripheral CB1R or inhibiting GLUT2 dynamics in RPTCs has the potential to treat and ameliorate DN. These findings may support the rationale for the clinical testing of peripherally restricted CB1R antagonists or the development of novel renal-specific GLUT2 inhibitors against DN.”

https://www.ncbi.nlm.nih.gov/pubmed/29030466

http://jasn.asnjournals.org/content/early/2017/10/12/ASN.2017040371

Human bone marrow mesenchymal stem cells secrete endocannabinoids that stimulate in vitro hematopoietic stem cell migration effectively comparable to beta adrenergic stimulation.

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Experimental Hematology Home

“Granulocyte Colony-Stimulating Factor (G-CSF) is a well-known hematopoietic stem cell (HSC) mobilizing agent used in both allogeneic and autologous transplantation. However, a proportion of patients or healthy donors fail to mobilize sufficient number of cells. New mobilization agents are therefore needed.

Endocannabinoids (eCBs) are endogenous lipid mediators generated in the brain and peripheral tissues and activate the cannabinoid receptors (CB1, CB2). We suggest that eCBs may act as mobilizers of hematopoietic stem cells (HSC) from the BM under stress conditions as beta adrenergic receptors (Adrβ).

This study demonstrates that bone marrow (BM) mesenchymal stem cells (MSCs) secrete anandamide (AEA) and 2-arachidonylglycerol (2-AG), and peripheral blood (PB) and BM microenvironment contain AEA and 2-AG. 2-AG levels are significantly higher in PB of the G-CSF treated group when compared to BM plasma. BM mononuclear cells (MNCs) and CD34+HSCs, express CB1, CB2 and Adrβ subtypes. CD34+HSCs had higher CB1 and CB2 receptor expression in G-CSF untreated and treated groups when compared to MSCs. MNCs but not MSCs expressed CB1 and CB2 receptors based on qRT-PCR and flow cytometry (FC). AEA and 2-AG stimulated HSC migration was blocked by eCB receptor antagonists in in vitro migration assay.

In conclusion, components of the eCB system and their interaction with Adrβ subtypes were demonstrated on HSCs and MSCs of G-CSF treated and untreated healthy donors in vitro, revealing that eCBs might be potential candidates to enhance or facilitate G-CSF-mediated HSC migration under stress conditions in a clinical setting.”

https://www.ncbi.nlm.nih.gov/pubmed/29030083

http://www.exphem.org/article/S0301-472X(17)30813-5/fulltext

Activation of cannabinoid receptor type II by AM1241 protects adipose-derived mesenchymal stem cells from oxidative damage and enhances their therapeutic efficacy in myocardial infarction mice via Stat3 activation.

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“The poor survival of cells in ischemic sites diminishes the therapeutic efficacy of stem cell therapy. Previously we and others have reported that Cannabinoid receptor type II (CB2) is protective during heart ischemic injury for its anti-oxidative activity. However, whether CB2 activation could improve the survival and therapeutic efficacy of stem cells in ischemic myocardium and the underlying mechanisms remain elusive.

Here, we showed evidence that CB2 agonist AM1241 treatment could improve the functional survival of adipose-derived mesenchymal stem cells (AD-MSCs) in vitro as well as in vivo. Moreover, AD-MSCs adjuvant with AM1241 improved cardiac function, and inhibited cardiac oxidative stress, apoptosis and fibrosis. To unveil possible mechanisms, AD-MSCs were exposed to hydrogen peroxide/serum deprivation to simulate the ischemic environment in myocardium.

Results delineated that AM1241 blocked the apoptosis, oxidative damage and promoted the paracrine effects of AD-MSCs. Mechanistically, AM1241 activated signal transducers and activators of transcription 3 (Stat3) through the phosphorylation of Akt and ERK1/2. Moreover, the administration of AM630, LY294002, U0126 and AG490 (inhibitors for CB2, Akt, ERK1/2 and Stat3, respectively) could abolish the beneficial actions of AM1241.

Our result support the promise of CB2 activation as an effective strategy to optimize stem cell-based therapy possibly through Stat3 activation.”

 https://www.ncbi.nlm.nih.gov/pubmed/29029396
http://www.impactjournals.com/oncotarget/index.php?journal=oncotarget&page=article&op=view&path[]=17614&path[]=56386

Cannabinoid CB1 receptor overactivity contributes to the pathogenesis of idiopathic pulmonary fibrosis.

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“Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease without effective treatment, highlighting the need for identifying new targets and treatment modalities. The pathogenesis of IPF is complex, and engaging multiple targets simultaneously might improve therapeutic efficacy.

To assess the role of the endocannabinoid/cannabinoid receptor 1 (endocannabinoid/CB1R) system in IPF and its interaction with inducible nitric oxide synthase (iNOS) as dual therapeutic targets, we analyzed lung fibrosis and the status of the endocannabinoid/CB1R system and iNOS in mice with bleomycin-induced pulmonary fibrosis (PF) and in lung tissue and bronchoalveolar lavage fluid (BALF) from patients with IPF, as well as controls. In addition, we investigated the antifibrotic efficacy in the mouse PF model of an orally bioavailable and peripherally restricted CB1R/iNOS hybrid inhibitor.

We report that increased activity of the endocannabinoid/CB1R system parallels disease progression in the lungs of patients with idiopathic PF and in mice with bleomycin-induced PF and is associated with increased tissue levels of interferon regulatory factor-5. Furthermore, we demonstrate that simultaneous engagement of the secondary target iNOS by the hybrid CB1R/iNOS inhibitor has greater antifibrotic efficacy than inhibition of CB1R alone. This hybrid antagonist also arrests the progression of established fibrosis in mice, thus making it a viable candidate for future translational studies in IPF.”  https://www.ncbi.nlm.nih.gov/pubmed/28422760

 “The limited success of medications with a single target suggests that multitargeted therapies may be more effective, considering the multifactorial pathology of IPF. Here, we report that a dual-target hybrid inhibitor of peripheral CB1R and iNOS completely arrested the progression of BL-PF and dramatically improved the survival rate in a progression arrest treatment paradigm, providing proof of principle for a polypharmacology approach in this preclinical model of IPF. “
 https://insight.jci.org/articles/view/92281

“Our results show that CB1 signaling plays a key pathological role in the development of radiation-induced pulmonary inflammation and fibrosis, and peripherally restricted CB1 antagonists may represent a novel therapeutic approach against this devastating complication of radiotherapy/irradiation. In summary, we provide the first evidence on the key pathological role of CB1 signaling in radiation-induced pulmonary fibrogenesis and show that peripherally restricted CB1 antagonists may represent a novel therapeutic approach against this devastating and untreatable complication of radiotherapy/irradiation. Our results also suggest that targeting CB1 may provide benefits in other lung diseases associated with inflammation and fibrosis.”  http://www.atsjournals.org/doi/10.1165/rcmb.2014-0331OC

“Pure Δ9-tetrahydrocannabivarin and a Cannabis sativa extract with high content in Δ9-tetrahydrocannabivarin inhibit nitrite production in murine peritoneal macrophages. THCV down-regulated the over-expression of inducible nitric oxide synthase (iNOS). THCV counteracted LPS-induced up-regulation of CB1 receptors.  Cannabis use has immunomodulatory and anti-inflammatory effects.”  http://www.ncbi.nlm.nih.gov/pubmed/27498155

 “As a class, the cannabinoids are generally free from the adverse effects associated with NSAIDs. Their clinical development thus provides a new approach to treatment of diseases characterized by acute and chronic inflammation and fibrosis. The review concludes with a presentation of a possible mechanism for the anti-inflammatory and antifibrotic actions of these substances. Thus, several cannabinoids may be considered candidates for development as anti-inflammatory and antifibrotic agents.”  https://www.ncbi.nlm.nih.gov/pubmed/27435265

Cannabinoid receptor 2 as a novel target for promotion of renal cell carcinoma prognosis and progression.

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Journal of Cancer Research and Clinical Oncology

“Renal cell carcinoma (RCC) is the most common malignancy of urogenital system, and patients with RCC may face a poor prognosis. However, limited curable therapeutic options are currently available.

The aim of this study is to investigate the role of Cannabinoid receptor 2 (CB2) in RCC progression.

CB2 expression is functionally related to cellular proliferation, migration, and cell cycle of RCC cells.

Our data suggest that CB2 might be a potential therapeutic target for RCC.”

https://www.ncbi.nlm.nih.gov/pubmed/28993942
https://link.springer.com/article/10.1007%2Fs00432-017-2527-y

Effects of cannabinoid receptor type 2 in respiratory syncytial virus infection in human subjects and mice.

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“An accumulating body of evidence suggests that the endocannabinoid system plays a significant role in pathophysiological processes and impacts disease severity. Here we investigate the possible role of a cannabinoid receptor type 2 (CB2) functional variant in determining disease severity and the potential pharmacological therapeutic effects of CB2 activation in viral respiratory infection. The common missense variant (CAA/CGG; Q63R) of the gene-encoding CB2 receptor (CNR2) was evaluated in 90 inpatient and 90 outpatient children with acute respiratory tract infection (ARTI). The frequency distribution of respiratory syncytial virus (RSV)-the main cause of severe cases of bronchiolitis and pneumonia in children-was studied in all collected samples. The mechanism through which CB2 affects clinical outcomes in case of RSV infection was studied in Balb/c mice model using AM630 as a CB2 antagonist. The potential therapeutic effect of CB2 activation during RSV infection was studied using a selective agonist, JWH133. The CB2 Q63R variation was associated with increased risk of hospitalization in children with ARTI. Children carrying the QQ genotype were more prone to developing severe ARTI (OR = 3.275, 95% CI: 1.221-8.705; p = 0.019). Of all the children enrolled in the study, 83 patients (46.1%) were found positive for RSV infection. The associated risk of developing severe ARTI following RSV infection increased more than two-fold in children carrying the Q allele (OR = 2.148, 95% CI: 1.092-4.224; p = 0.026). In mice, the blockade of CB2 by AM630 during RSV infection enhanced the influx of BAL cells and production of cytokines/chemokines while exaggerating lung pathology. CB2 activation by JWH133 reduces the influx of BAL cells and production of cytokines/chemokines while alleviating lung pathology. Collectively, CB2 is associated with RSV severity during infancy and may serve as a therapeutic target in RSV infection through the alleviation of virus-associated immunopathology.”

 https://www.ncbi.nlm.nih.gov/pubmed/28992427
http://www.tandfonline.com/doi/abs/10.1080/21505594.2017.1389369?journalCode=kvir20

Endocannabinoid-related compounds in gastrointestinal diseases.

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Journal of Cellular and Molecular Medicine

“The endocannabinoid system (ECS) is an endogenous signalling pathway involved in the control of several gastrointestinal (GI) functions at both peripheral and central levels. In recent years, it has become apparent that the ECS is pivotal in the regulation of GI motility, secretion and sensitivity, but endocannabinoids (ECs) are also involved in the regulation of intestinal inflammation and mucosal barrier permeability, suggesting their role in the pathophysiology of both functional and organic GI disorders. Genetic studies in patients with irritable bowel syndrome (IBS) or inflammatory bowel disease have indeed shown significant associations with polymorphisms or mutation in genes encoding for cannabinoid receptor or enzyme responsible for their catabolism, respectively. Furthermore, ongoing clinical trials are testing EC agonists/antagonists in the achievement of symptomatic relief from a number of GI symptoms. Despite this evidence, there is a lack of supportive RCTs and relevant data in human beings, and hence, the possible therapeutic application of these compounds is raising ethical, political and economic concerns. More recently, the identification of several EC-like compounds able to modulate ECS function without the typical central side effects of cannabino-mimetics has paved the way for emerging peripherally acting drugs. This review summarizes the possible mechanisms linking the ECS to GI disorders and describes the most recent advances in the manipulation of the ECS in the treatment of GI diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/28990365

http://onlinelibrary.wiley.com/doi/10.1111/jcmm.13359/abstract

Involvement of cannabinoid system in the nucleus accumbens on delay-based decision making in the rat.

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“The nucleus accumbens (NAc) plays a fundamental role in decision making and anticipation of reward. In addition, exogenous cannabinoids affect the behavior of humans and animals including disruption of short-term memory and cognitive impairments. Therefore, in this study, cannabinoid agonist and antagonist were administrated into the NAc to determine the effect of cannabinoid activation in the entire NAc on delay-based decision making. Rats were trained on a cost-benefit T-maze decision making task in which the animals were well-trained to choose between a small/immediate reward and a large/delay reward. After training, the animals were implanted with guide cannulae in the NAc. On test day, they received cannabinoid agonist (Win 55,212-2; 10, 50 and 100μM) and/or antagonist (AM251; 45μM) into the NAc. Percentage of high reward choice and latency of reward achievement were evaluated. Results showed that cannabinoid agonist administration caused a decrease in high reward choice such that rats selected small/immediate reward instead of large/delay reward. Moreover, in agonist-treated animals latency of reward achievement increased. Effects of cannabinoid activation on delay-based decision making with equivalent delays demonstrated that if the delay was equated on both arm goals, animals still had a preference for the high/delay reward, showing the results was not caused by an impairment of spatial preference or memory. These finding clarified that cannabinoid system activation in the entire NAc plays a critical role in the regulation of delay-based decision making.”

https://www.ncbi.nlm.nih.gov/pubmed/28987618

Cannabinoid Receptor-2 Ameliorates Inflammation in Murine Model of Crohn’s Disease.

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“Cannabinoid receptor stimulation may have positive symptomatic effects on inflammatory bowel disease [IBD] patients through analgesic and anti-inflammatory effects.

The cannabinoid 2 receptor [CB2R] is expressed primarily on immune cells, including CD4+ T cells, and is induced by active inflammation in both humans and mice. We therefore investigated the effect of targeting CB2R in a preclinical IBD model.

 In summary, the endocannabinoid system is induced in murine ileitis but is downregulated in chronic murine and human intestinal inflammation, and CB2R activation attenuates murine ileitis, establishing an anti-inflammatory role of the endocannabinoid system.”

https://www.ncbi.nlm.nih.gov/pubmed/28981653

https://academic.oup.com/ecco-jcc/article-abstract/doi/10.1093/ecco-jcc/jjx096/3977952/Cannabinoid-Receptor-2-Ameliorates-Inflammation-in?redirectedFrom=fulltext

Photobiomodulation Therapy Improves Acute Inflammatory Response in Mice: the Role of Cannabinoid Receptors/ATP-Sensitive K+ Channel/p38-MAPK Signalling Pathway.

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Molecular Neurobiology

“Although photobiomodulation therapy (PBM) has been applied clinically for the treatment of pain and inflammation, wound healing, sports and soft tissue injuries, as well as to repair injured spinal cords and peripheral nerves, it remains unclear which molecular substrates (receptor) are implicated in the cellular mechanisms of PBM.

Here, we reported that PBM (660 nm, 30 mW, 0.06 cm2, 50 J/cm2, plantar irradiation) significantly inhibited carrageenan-induced paw oedema, but not noxious thermal response, through positive modulation to both CB1 and CB2 cannabinoid receptors. The use of CB1 antagonist AM281 or CB2 antagonist AM630 significantly reversed the anti-inflammatory effect of PBM. Analysis of signalling pathway downstream of cannabinoid receptors activation reveals that anti-inflammatory effects of PBM depend, in great extent, on its ability to activate ATP-dependent K+ channels and p38 mitogen-activated protein kinase. Moreover, PBM therapy significantly reduced the levels of pro-inflammatory cytokine IL-6 in both paw and spinal cord, and restored the reduction of the level of anti-inflammatory cytokine IL-10 in spinal cord after carrageenan injection. Unlike the potent cannabinoid receptor agonist (WIN 55212-2), PBM did not exert any CNS-mediated effects in the tetrad assay. Finally, PBM does not reduce inflammation and noxious thermal response induced by LPS and zymosan, a TLR4 and TLR2/dectin-1 ligand, respectively.

Thus, cannabinoid receptors and, possibly, the endocannabinoid system, represent an important site of action of PBM that opens the possibility of complementary and nonpsychotropic therapeutic interventions in clinical practice.”

https://www.ncbi.nlm.nih.gov/pubmed/28980210

https://link.springer.com/article/10.1007%2Fs12035-017-0792-z