Tag Archives: cannabinoid receptors

Crystal Structure of the Human Cannabinoid Receptor CB2

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“The cannabinoid receptor CB2 is predominately expressed in the immune system, and selective modulation of CB2 without the psychoactivity of CB1 has therapeutic potential in inflammatory, fibrotic, and neurodegenerative diseases. Here, we report the crystal structure of human CB2 in complex with a rationally designed antagonist, AM10257, at 2.8 Å resolution. The CB2-AM10257 structure reveals a distinctly different binding pose compared with CB1. However, the extracellular portion of the antagonist-bound CB2 shares a high degree of conformational similarity with the agonist-bound CB1, which led to the discovery of AM10257’s unexpected opposing functional profile of CB2 antagonism versus CB1 agonism. Further structural analysis using mutagenesis studies and molecular docking revealed the molecular basis of their function and selectivity for CB2 and CB1. Additional analyses of our designed antagonist and agonist pairs provide important insight into the activation mechanism of CB2. The present findings should facilitate rational drug design toward precise modulation of the endocannabinoid system.”
https://www.cell.com/cell/pdf/S0092-8674(18)31625-8.pdf

“Structure of human type 2 cannabinoid receptor revealed” https://www.news-medical.net/news/20190228/Structure-of-human-type-2-cannabinoid-receptor-revealed.aspx

“Study reveals the structure of the 2nd human cannabinoid receptor”   HTTPS://MIPT.RU/ENGLISH/NEWS/STUDY_REVEALS_THE_STRUCTURE_OF_THE_2ND_HUMAN_CANNABINOID_RECEPTOR

“Structure of the Human Cannabinoid Receptor CB2 Solved”  https://www.technologynetworks.com/drug-discovery/news/structure-of-the-human-cannabinoid-receptor-cb2-solved-316091

CBN: The cancer fighting Cannabinoid

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“CBN, cannabinol, is a mildly psychoactive cannabinoid found within the cannabis plant. We examine the very complex mechanisms that give allowance for this cannabinoids entrance into the cell membrane and its effect on cannabinoid receptors and the inhibition of the enzyme adenylate cyclase that is responsible for phosphate production. Prior study bears weight accordingly; we examine this phosphate as a potent energy source, the enzymes responsible for cell replication cycle and inhibition thereof. Moreover, how IL-2, (Interleukin-2), a type of cytokine signaling molecule in the immune system stops being produced when immune T cells are exposed to cannabinoids. How IL-2 stimulates the cell cycle via promotion of the c-Fos protein and is responsible for modulation of the immune response. This is shown by Faubert and Kaminski, that administration of CBN can slow cell replication and endure cell death (apoptosis).”

http://www.imedpub.com/proceedings/cbn-the-cancer-fighting-cannabinoid-5528.html

“Programmed Cell Death (Apoptosis)” http://www.ncbi.nlm.nih.gov/books/NBK26873/

Decreased Expression of Cannabinoid Receptors in the Eutopic and Ectopic Endometrium of Patients with Adenomyosis.

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“Adenomyosis is a common gynecologic benign disease that may have a life-long negative impact on women.

Previous studies have indicated that the endocannabinoid system may participate in the progress of endometriosis.

Our research aims to analyze the expression patterns of the typical cannabinoid receptors (CB1 and CB2), the main constituents of the endocannabinoid system, in endometrial samples derived from patients diagnosed as adenomyosis or not.

RESULTS:

In either the proliferative or the secretory phase, CB1 and CB2 protein and mRNA levels were both significantly lower in the eutopic and ectopic endometrium of adenomyosis when compared with normal endometrium. For women with adenomyosis, CB1 and CB2 protein and mRNA levels were much lower in the ectopic endometrium than the eutopic in both phases of the cycle. Both CB1 and CB2 protein and mRNA levels were increased during the secretory phase in normal endometrium, while CB1 lost its cyclic variation in the eutopic and ectopic endometrium from patients diagnosed as adenomyosis.

CONCLUSION:

The decreased expression of CB1 and CB2 in the eutopic and ectopic endometrium from patients diagnosed as adenomyosis suggests that cannabinoid receptors may participate in the pathogenesis of adenomyosis.”

https://www.ncbi.nlm.nih.gov/pubmed/30800671

“In conclusion, we found a significant decrease in the cannabinoid receptors CB1 and CB2 in the eutopic and ectopic endometrium of patients with adenomyosis, regardless of the menstrual phase, suggesting that CB1 and CB2 participate in the pathogenesis of this condition.”

https://www.hindawi.com/journals/bmri/2019/5468954/

Cannabinoid receptor 2 deficiency exacerbates inflammation and neutrophil recruitment.

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“Cannabinoid receptor (CB)2 is an immune cell-localized GPCR that has been hypothesized to regulate the magnitude of inflammatory responses.

However, there is currently no consensus as to the mechanism by which CB2 mediates its anti-inflammatory effects in vivo. To address this question, we employed a murine dorsal air pouch model with wild-type and CB2-/- 8-12-wk-old female and male C57BL/6 mice and found that acute neutrophil and lymphocyte antigen 6 complex, locus Chi monocyte recruitment in response to Zymosan was significantly enhanced in CB2-/- mice.

Additionally, levels of matrix metalloproteinase 9 and the chemokines C-C motif chemokine ligand (CCL)2, CCL4, and C-X-C motif chemokine ligand 10 in CB2-/- pouch exudates were elevated at earlier time points. Importantly, using mixed bone marrow chimeras, we revealed that the proinflammatory phenotype in CB2-/- mice is neutrophil-intrinsic rather than stromal cell-dependent. Indeed, neutrophils isolated from CB2-/- mice exhibited an enhanced migration-related transcriptional profile and increased adhesive phenotype, and treatment of human neutrophils with a CB2 agonist blocked their endothelial transmigration.

Overall, we have demonstrated that CB2 plays a nonredundant role during acute neutrophil mobilization to sites of inflammation and, as such, it could represent a therapeutic target for the development of novel anti-inflammatory compounds to treat inflammatory human diseases.”

https://www.ncbi.nlm.nih.gov/pubmed/30799631

https://www.fasebj.org/doi/10.1096/fj.201802524R

Activation of cannabinoid 2 receptor relieves colonic hypermotility in a rat model of irritable bowel syndrome.

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“Irritable bowel syndrome (IBS) is a common disease with intestinal dysmotility, whose mechanism remains elusive.

The endocannabinoid system is emerging as an important modulator of gastrointestinal (GI) motility in multiple diseases, but its involvement in IBS is unknown.

We aimed to determine whether cannabinoid 2 (CB2) receptor modulates intestinal motility associated with stress-induced IBS.

CONCLUSION:

CB2 receptor may exert an important inhibitory effect in stress-induced colonic hypermotility by modulating NO synthesis through p38 mitogen-activated protein kinase signaling. AM1241 could be used as a potential drug to treat disorders with colonic hypermotility.”

https://www.ncbi.nlm.nih.gov/pubmed/30793435

https://onlinelibrary.wiley.com/doi/abs/10.1111/nmo.13555

The Endocannabinoid System, Our Universal Regulator

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“The endocannabinoid system (ECS) plays a very important role in the human body for our survival. This is due to its ability to play a critical role in maintaining the homeostasis of the human body, which encompasses the brain, endocrine, and immune system, to name a few. ECS is a unique system in multiple dimensions.

To begin with, it is a retrograde system functioning post- to pre-synapse, allowing it to be a “master regulator” in the body. Secondly, it has a very wide scope of influence due to an abundance of cannabinoid receptors located anywhere from immune cells to neurons. Finally, cannabinoids are rapidly synthesized and degraded, so they do not stay in the body for very long in high amounts, possibly enabling cannabinoid therapy to be a safer alternative to opioids or benzodiazepines. This paper will discuss how ECS functions through the regulation of neurotransmitter function, apoptosis, mitochondrial function, and ion-gated channels. The practical applications of the ECS, as well as the avenues for diseases such as epilepsy, cancer, amyotrophic lateral sclerosis (ALS), and autism, which have no known cure as of now, will be explored.

The ECS is one of the, if not the most, important systems in our body. Its role in the homeostatic function of our body is undeniable, and its sphere of influence is incredible. Additionally, it also plays a major role in apoptotic diseases, mitochondrial function, and brain function.

Its contribution is more than maintaining homeostasis; it also has a profound ability in regulation. Working in a retrograde fashion and with a generally inhibitory nature, ECS can act as a “kill switch.” However, it has been shown to play an inhibitory or stimulatory role based on the size of the influx of cannabinoids, resulting in a bimodal regulation. Furthermore, due to the nature of the rate of degradation of cannabinoids, it does not have as many long-term side effects as most of the current drugs on the market.

The ECS may not only provide answers for diseases with no known cures, but it could change the way we approach medicine. This system would allow us to change our focus from invasive pharmacological interventions (i.e. SSRIs for depression, benzodiazepines for anxiety, chemotherapies for cancer) to uncovering the mystery of why the body is failing to maintain homeostasis. Understanding the roles of ECS in these diseases confers a new direction for medicine which may eradicate the use of some of the less tolerable therapeutics.”

https://www.jyi.org/2018-june/2018/6/1/the-endocannabinoid-system-our-universal-regulator

Activation of ATP-sensitive K-channel promotes the anticonvulsant properties of cannabinoid receptor agonist through mitochondrial ATP level reduction.

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“Cannabinoid receptor (CBR) agonist could act as a protective agent against seizure susceptibility in animal models of epilepsy.

Studies have shown that potassium channels could play a key role in ameliorating neuronal excitability.

In this study, we attempted to evaluate how CBRs and Adenosine Tri-Phosphate (ATP)-sensitive potassium channels collaborate to affect seizure susceptibility by changing the clonic seizure threshold (CST).

In conclusion, CB1 agonist accomplishes at least a part of its anticonvulsant actions through ATP-sensitive potassium channels, probably by decreasing the mitochondrial ATP level to open the potassium channel to induce its anticonvulsant effect.”

https://www.ncbi.nlm.nih.gov/pubmed/30776677

https://linkinghub.elsevier.com/retrieve/pii/S1525505018308503

WIN55,212-2 induces caspase-independent apoptosis on human glioblastoma cells by regulating HSP70, p53 and Cathepsin D.

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Toxicology in Vitro

“Despite the standard approaches to treat the highly aggressive and invasive glioblastoma (GBM), it remains incurable.

In this sense, cannabinoids highlight as a promising tool, because this tumor overexpresses CB1 and/or CB2 receptors and being, therefore, can be susceptible to cannabinoids treatment.

Thus, this work investigated the action of the cannabinoid agonist WIN55-212-2 on GBM cell lines and non-malignant cell lines, in vitro and in vivo. WIN was selectively cytotoxic to GBM cells. These presented blebbing and nuclear alterations in addition to cell shrinkage and chromatin condensation. WIN also significantly inhibited the migration of GAMG and U251 cells.

Finally, the data also showed that the antitumor effects of WIN are exerted, at least to some extent, by the expression of p53 and increased cathepsin D in addition to the decreased expression of HSP70.This data can indicate caspase-independent cell death mechanism. In addition, WIN decreased tumoral perimeter as well as caused a reduction the blood vessels in this area, without causing lysis, hemorrhage or blood clotting.

So, the findings herein presented reinforce the usefulness of cannabinoids as a candidate for further evaluation in treatment in glioblastoma treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/30776504

https://www.sciencedirect.com/science/article/pii/S0887233318307537?via%3Dihub

New Insights in Cannabinoid Receptor Structure and Signaling.

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“Cannabinoid has long been used for medicinal purposes. Cannabinoid signaling has been considered the therapeutic targets for treating pain, addiction, obesity, inflammation, and other diseases. Recent studies have suggested that in addition to CB1 and CB2, there are non-CB1 and non-CB2 cannabinoid-related orphan GPCRs including GPR18, GPR55, and GPR119. In addition, CB1 and CB2 display allosteric binding and biased signaling, revealing correlations between biased signaling and functional outcomes. Interestingly, new investigations have indicated that CB1 is functionally present within mitochondria of striated and heart muscles directly regulating intramitochondrial signaling and respiration.

CONCLUSION:

In this review, we summarize the recent progress in cannabinoid-related orphan GPCRs, CB1/CB2 structure, Gi/Gs coupling, allosteric ligands and biased signaling, and mitochondria-localized CB1, and discuss the future promise of this research.”

https://www.ncbi.nlm.nih.gov/pubmed/30767756

http://www.eurekaselect.com/170011/article

On the influence of cannabinoids on cell morphology and motility of glioblastoma cells.

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“The mechanisms behind the anti-tumoral effects of cannabinoids by impacting the migratory activity of tumor cells are only partially understood. Previous studies demonstrated that cannabinoids altered the organization of the actin cytoskeleton in various cell types.

As actin is one of the main contributors to cell motility and is postulated to be linked to tumor invasion, we tested the following hypothesizes: 1) Can cannabinoids alter cell motility in a cannabinoid receptor dependent manner? 2) Are these alterations associated with reorganizations in the actin cytoskeleton? 3) If so, what are the underlying molecular mechanisms?

Three different glioblastoma cell lines were treated with specific cannabinoid receptor 1 and 2 agonists and antagonists. Afterwards, we measured changes in cell motility using live cell imaging and alterations of the actin structure in fixed cells. Additionally, the protein amount of phosphorylated p44/42 mitogen-activated protein kinase (MAPK), focal adhesion kinases (FAK) and phosphorylated FAK (pFAK) over time were measured.

Cannabinoids induced changes in cell motility, morphology and actin organization in a receptor and cell line dependent manner. No significant changes were observed in the analyzed signaling molecules. Cannabinoids can principally induce changes in the actin cytoskeleton and motility of glioblastoma cell lines. Additionally, single cell motility of glioblastoma is independent of their morphology. Furthermore, the observed effects seem to be independent of p44/42 MAPK and pFAK pathways.”

https://www.ncbi.nlm.nih.gov/pubmed/30753211

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212037