Tag Archives: CB2

Cannabinoid receptor 2‑selective agonist JWH015 attenuates bone cancer pain through the amelioration of impaired autophagy flux induced by inflammatory mediators in the spinal cord.

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Journal Cover “Bone cancer pain (BCP) is a severe complication of advanced bone cancer.

Although cannabinoid receptor 2 (CB2) agonists may have an analgesic effect, the underlying mechanism remains unclear.

CB2 serves a protective role in various pathological states through the activation of autophagy. Therefore, the present study aimed to determine whether the analgesic effects of the selective CB2 agonist JWH015 was mediated by the activation of autophagy in BCP.

The results of the present study suggested that the impairment of autophagy flux was induced by glia‑derived inflammatory mediators in spinal neurons. Intrathecal administration of the selective CB2 agonist JWH015 ameliorated autophagy flux through the downregulation of IL‑1β and IL‑6 and attenuated BCP.”

https://www.ncbi.nlm.nih.gov/pubmed/31661120

https://www.spandidos-publications.com/10.3892/mmr.2019.10772

Ligands of the CB2 cannabinoid receptors augment activity of the conventional antidepressant drugs in the behavioural tests in mice.

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Behavioural Brain Research“Although a lot of information can be found on the specific dual role of the endocannabinoid system in the emotional-related responses, little is known whether stimulation or inhibition of the CB receptors may affect the activity of the frequently prescribed antidepressant drugs.

Our interests have been particularly focused on the potential influence of the CB2 receptors, as the ones whose central effects are relatively poorly documented when compared to the central effects of the CB1 receptors. Therefore, we evaluated the potential interaction between the CB2 receptor ligands (i.e., JWH133 – CB2 receptor agonist and AM630 – CB2 receptor inverse agonist) and several common antidepressant drugs that influence the monoaminergic system (i.e., imipramine, escitalopram, reboxetine).

Summarizing, the results of the present study revealed that both activation and inhibition of the CB2 receptor function have a potential to strengthen the antidepressant activity of drugs targeting the monoaminergic system. Most probably, the described interaction has a pharmacodynamic background.”

https://www.ncbi.nlm.nih.gov/pubmed/31626848

“Interplay between CB2 receptor ligands and antidepressants is pharmacodynamic in nature.”

https://www.sciencedirect.com/science/article/pii/S0166432819311891?via%3Dihub

Systematic Affinity Purification Coupled to Mass Spectrometry Identified p62 as Part of the Cannabinoid Receptor CB2 Interactome.

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Image result for frontiers in molecular neuroscience“The endocannabinoid system (ECS) consists particularly of cannabinoid receptors 1 and 2 (CB1 and CB2), their endogenous ligands, and enzymes that synthesize and degrade their ligands. It acts in a variety of organs and disease states ranging from cancer progression over neuropathic pain to neurodegeneration. Protein components engaged in the signaling, trafficking, and homeostasis machinery of the G-protein coupled CB2, are however largely unknown. It is therefore important to identify further interaction partners to better understand CB2 receptor functions in physiology and pathophysiology. For this purpose, we used an affinity purification and mass spectrometry-based proteomics approach of Strep-HA-CB2 receptor in HEK293 cells. After subtraction of background interactions and protein frequency library assessment we could identify 83 proteins that were classified by the identification of minimally 2 unique peptides as highly probable interactors. A functional protein association network analysis obtained an interaction network with a significant enrichment of proteins functionally involved in protein metabolic process, in endoplasmic reticulum, response to stress but also in lipid metabolism and membrane organization. The network especially contains proteins involved in biosynthesis and trafficking like calnexin, Sec61A, tubulin chains TUBA1C and TUBB2B, TMED2, and TMED10. Six proteins that were only expressed in stable CB2 expressing cells were DHC24, DHRS7, GGT7, HECD3, KIAA2013, and PLS1. To exemplify the validity of our approach, we chose a candidate having a relatively low number of edges in the network to increase the likelihood of a direct protein interaction with CB2 and focused on the scaffold/phagosomal protein p62/SQSTM1. Indeed, we independently confirmed the interaction by co-immunoprecipitation and immunocytochemical colocalization studies. 3D reconstruction of confocal images furthermore showed CB2 localization in close proximity to p62 positive vesicles at the cell membrane. In summary, we provide a comprehensive repository of the CB2 interactome in HEK293 cells identified by a systematic unbiased approach, which can be used in future experiments to decipher the signaling and trafficking complex of this cannabinoid receptor. Future studies will have to analyze the exact mechanism of the p62-CB2 interaction as well as its putative role in disease pathophysiology.”

https://www.ncbi.nlm.nih.gov/pubmed/31616248

https://www.frontiersin.org/articles/10.3389/fnmol.2019.00224/full

The Endocannabinoid System as a Window Into Microglial Biology and Its Relationship to Autism.

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Image result for frontiers in cellular neuroscience“Microglia are the resident, innate immune cells of the central nervous system (CNS) and are critical in managing CNS injuries and infections. Microglia also maintain CNS homeostasis by influencing neuronal development, viability, and function. However, aberrant microglial activity and phenotypes are associated with CNS pathology, including autism spectrum disorder (ASD). Thus, improving our knowledge of microglial regulation could provide insights into the maintenance of CNS homeostasis as well as the prevention and treatment of ASD.

Control of microglial activity is in part overseen by small, lipid-derived molecules known as endogenous cannabinoids (endocannabinoids). Endocannabinoids are one component of the endocannabinoid system (ECS), which also includes the enzymes that metabolize these ligands, in addition to cannabinoid receptor 1 (CB1) and 2 (CB2).

Interestingly, increased ECS signaling leads to an anti-inflammatory, neuroprotective phenotype in microglia. Here, we review the literature and propose that ECS signaling represents a largely untapped area for understanding microglial biology and its relationship to ASD, with special attention paid to issues surrounding the use of recreational cannabis (marijuana). We also discuss major questions within the field and suggest directions for future research.”

https://www.ncbi.nlm.nih.gov/pubmed/31619967

“Microglial activity can be modulated by eCB signaling, which makes the ECS a potentially forceful tool in the prevention and management of CNS dysfunction.”

https://www.frontiersin.org/articles/10.3389/fncel.2019.00424/full

Endocannabinoid system and the expression of endogenous ceramides in human hepatocellular carcinoma.

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 Journal Cover“The endogenous lipid metabolism network is associated with the occurrence and progression of malignancies.

Endocannabinoids and ceramides have demonstrated their anti-proliferative and pro-apoptotic properties in a series of cancer studies.

The aim of the present study was to evaluate the expression patterns of endocannabinoids and endogenous ceramides in 67 pairs of human hepatocellular carcinoma (HCC) tissues and non-cancerous counterpart controls.

Anandamide (AEA), the major endocannabinoid, was reduced in tumor tissues, probably due to the high expression and activity of fatty acid amide hydrolase. Another important endocannabinoid, 2-arachidonylglycerol (2-AG), was elevated in tumor tissues compared with non-tumor controls, indicating that the biosynthesis of 2-AG is faster than the degradation of 2-AG in tumor cells.

Furthermore, western blot analysis demonstrated that cannabinoid receptor 1 was downregulated, while cannabinoid receptor 2 was elevated in HCC tissues, in accordance with the alterations in the levels of AEA and 2-AG, respectively. For HCC tissues, the expression levels of C18:0, 20:0 and 24:0-ceramides decreased significantly, whereas C12:0, 16:0, 18:1 and 24:1-ceramides were upregulated, which may be associated with cannabinoid receptor activation and stearoyl-CoA desaturase protein downregulation.

The exact role of endocannabinoids and ceramides in regulating the fate of HCC cells requires further investigation.”

https://www.ncbi.nlm.nih.gov/pubmed/31423220

https://www.spandidos-publications.com/10.3892/ol.2019.10399

A Novel Highly Selective Cannabinoid CB2 Agonist Reduces in Vitro Growth and TGF-beta Release of Human Glial Cell Tumors.

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“Cannabinoid receptors have been detected in human gliomas and cannabinoids have been proposed as novel drug candidates in the treatment of brain tumors.

Aim of this study was to test the in vitro antitumor activity of COR167, a novel cannabinoid CB2-selective agonist displaying high binding affinity for human CB2 receptors, on tumor cells isolated from human glioblastoma multiforme and anaplastic astrocytoma.

RESULTS:

COR167 was found to significantly reduce the proliferation of both glioblastoma and anaplastic astrocytoma in a dose-dependent manner at lower doses than other known, less specific CB2 agonists. This activity is independent of apoptosis and is associated with significant reduction of TGF-beta 1 and 2 levels in supernatants of glioma cell cultures.

CONCLUSIONS:

These findings add to the role of cannabinoid CB2 receptor as a possible pharmacological target to counteract glial tumor growth and encourage further work to explore any other pharmacological effect of this novel CB2 agonist useful in the treatment of human gliomas.”

https://www.ncbi.nlm.nih.gov/pubmed/31549596

http://www.eurekaselect.com/175066/article

Potential of Cannabinoid Receptor Ligands as Treatment for Substance Use Disorders.

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 “Substance use disorder (SUD) is a major public health crisis worldwide, and effective treatment options are limited.

During the past 2 decades, researchers have investigated the impact of a variety of pharmacological approaches to treat SUD, one of which is the use of medical cannabis or cannabinoids.

Significant progress was made with the discovery of rimonabant, a selective CB1 receptor (CB1R) antagonist (also an inverse agonist), as a promising therapeutic for SUDs and obesity. However, serious adverse effects such as depression and suicidality led to the withdrawal of rimonabant (and almost all other CB1R antagonists/inverse agonists) from clinical trials worldwide in 2008.

Since then, much research interest has shifted to other cannabinoid-based strategies, such as peripheral CB1R antagonists/inverse agonists, neutral CB1R antagonists, allosteric CB1R modulators, CB2R agonists, fatty acid amide hydrolase (FAAH) inhibitors, monoacylglycerol lipase (MAGL) inhibitors, fatty acid binding protein (FABP) inhibitors, or nonaddictive phytocannabinoids with CB1R or CB2R-binding profiles, as new therapeutics for SUDs.

In this article, we first review recent progress in research regarding the endocannabinoid systems, cannabis reward versus aversion, and the underlying receptor mechanisms. We then review recent progress in cannabinoid-based medication development for the treatment of SUDs.

As evidence continues to accumulate, neutral CB1R antagonists (such as AM4113), CB2R agonists (JWH133, Xie2-64), and nonselective phytocannabinoids (cannabidiol, β-caryophyllene, ∆9-tetrahydrocannabivarin) have shown great therapeutic potential for SUDs, as shown in experimental animals.

Several cannabinoid-based medications (e.g., dronabinol, nabilone, PF-04457845) that entered clinical trials have shown promising results in reducing withdrawal symptoms in cannabis and opioid users.”

https://www.ncbi.nlm.nih.gov/pubmed/31549358

https://link.springer.com/article/10.1007%2Fs40263-019-00664-w

Selective Cannabinoid 2 Receptor Agonists as Potential Therapeutic Drugs for the Treatment of Endotoxin-Induced Uveitis.

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molecules-logo“The cannabinoid 2 receptor (CB2R) is a promising anti-inflammatory drug target and development of selective CB2R ligands may be useful for treating sight-threatening ocular inflammation. This study examined the pharmacology of three novel chemically-diverse selective CB2R ligands. These unique ligands are potent and selective for CB2R and have good immunomodulating actions in the eye. The data generated with these three structurally-diverse and highly-selective CB2R agonists support selective targeting of CB2R for treating ocular inflammatory diseases.”
https://www.ncbi.nlm.nih.gov/pubmed/31540271
https://www.mdpi.com/1420-3049/24/18/3338

The Impact of Cannabinoid Receptor 2 Deficiency on Neutrophil Recruitment and Inflammation.

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View details for DNA and Cell Biology cover image“Neutrophil trafficking into damaged or infected tissues is essential for the initiation of inflammation, clearance of pathogens and damaged cells, and ultimately tissue repair. Neutrophil recruitment is highly dependent on the stepwise induction of adhesion molecules and promigratory chemokines and cytokines.

A number of studies in animal models have shown the efficacy of cannabinoid receptor 2 (CB2) agonists in limiting inflammation in a range of preclinical models of inflammation, including colitis, atherosclerosis, multiple sclerosis, and ischemia-reperfusion injury.

Recent work in preclinical models of inflammation raises two questions: by what mechanisms do CB2 agonists provide anti-inflammatory effects during acute inflammation and what challenges exist in the translation of CB2 modulating therapeutics into the clinic.”

 https://www.ncbi.nlm.nih.gov/pubmed/31532239
https://www.liebertpub.com/doi/10.1089/dna.2019.5024

Interplay of liver-heart inflammatory axis and cannabinoid 2 receptor signalling in an experimental model of hepatic cardiomyopathy.

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Publication cover image“Hepatic cardiomyopathy, a special type of heart failure develops in up to 50% of patients with cirrhosis and is a major determinant of survival. However, there is no reliable model of hepatic cardiomyopathy in mice. Herein we aimed to characterize the detailed hemodynamics of mice with bile-duct ligation (BDL)-induced liver fibrosis, by monitoring echocardiography and intracardiac pressure-volume (PV) relationships and myocardial structural alterations. Treatment of mice with a selective cannabinoid-2 receptor (CB2 -R) agonist, known to attenuate inflammation and fibrosis, was used to explore the impact of liver inflammation, fibrosis on cardiac function.

MAIN RESULTS:

BDL induced massive inflammation (increased leukocyte infiltration, inflammatory cytokines and chemokines), oxidative stress, microvascular dysfunction, and fibrosis in the liver. These pathological changes were accompanied by impaired diastolic, systolic and macrovascular functions, cardiac inflammation (increased MIP1, interleukin-1, P-selectin, CD45+ cells) and oxidative stress (increased malondialdehyde, 3-nitrotyrosine and NADPH-oxidases). CB2 -R up-regulation was observed both in livers and hearts of mice exposed to BDL. CB2 -R activation markedly improved hepatic inflammation, impaired microcirculation, fibrosis. CB2 -R activation also decreased serum TNF-alpha levels, and improved cardiac dysfunction, myocardial inflammation and oxidative stress underlining the importance of inflammatory mediators in the pathology of hepatic cardiomyopathy.

CONCLUSION:

We propose BDL-induced cardiomyopathy in mice as a model for hepatic/cirrhotic cardiomyopathy. This cardiomyopathy, similarly to cirrhotic cardiomyopathy in humans, is characterized by systemic hypotension, impaired macro- and microvascular function accompanied by both systolic and diastolic dysfunction. Our results indicate that the liver-heart inflammatory axis has a pivotal pathophysiological role in the development of hepatic cardiomyopathy. Thus, controlling liver and/or myocardial inflammation (e.g. with selective CB2-R agonists) may delay/prevent the development of cardiomyopathy in severe liver disease. ”

https://www.ncbi.nlm.nih.gov/pubmed/31469200

https://aasldpubs.onlinelibrary.wiley.com/doi/abs/10.1002/hep.30916