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.”
“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

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/

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

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.

“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

Opposite effects of cannabinoid CB1 and CB2 receptors on antipsychotic clozapine-induced cardiotoxicity.

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“Clozapine is an atypical antipsychotic drug that is very efficacious in treating psychosis but the risk of severe cardiotoxicity limits its clinical use.

The present study investigated the myocardial injury effects of clozapine and assessed the involvement of cannabinoid receptors in clozapine cardiotoxicity.

Our data provided evidence that cannabinoid CB1 and CB2 receptors had opposite effects and selective antagonists of CB1R or agonists of CB2R might confer protective effects against clozapine.”

https://www.ncbi.nlm.nih.gov/pubmed/30707759

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14591

Potential Use of Cannabinoids for the Treatment of Pancreatic Cancer.

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Cannabinoid extracts may have anticancer properties, which can improve cancer treatment outcomes.

The aim of this review is to determine the potentially utility of cannabinoids in the treatment of pancreatic cancer.

Results: Cannabinol receptors have been identified in pancreatic cancer with several studies showing in vitroantiproliferative and proapoptotic effects. The main active substances found in cannabis plants are cannabidiol (CBD) and tetrahydrocannabinol (THC). There effects are predominately mediated through, but not limited to cannabinoid receptor-1, cannabinoid receptor-2, and G-protein-coupled receptor 55 pathways. In vitro studies consistently demonstrated tumor growth-inhibiting effects with CBD, THC, and synthetic derivatives. Synergistic treatment effects have been shown in two studies with the combination of CBD/synthetic cannabinoid receptor ligands and chemotherapy in xenograft and genetically modified spontaneous pancreatic cancer models. There are, however, no clinical studies to date showing treatment benefits in patients with pancreatic cancer.

Conclusions: Cannabinoids may be an effective adjunct for the treatment of pancreatic cancer. Data on the anticancer effectiveness of various cannabinoid formulations, treatment dosing, precise mode of action, and clinical studies are lacking.”

“Endogenous cannabinoids, synthetic or cannabis extracted from plants, can reduce tumor invasion and growth, induce tumor cell death, and inhibit tumor angiogenesis via cannabinoid receptor or receptor-independent pathways. Cannabinoid receptors appear to be highly expressed in pancreatic cancer compared with normal pancreatic tissue. CBD and THC appear to have antiproliferative and proapoptotic effects.”

Cannabinoids and Bone Regeneration.

 Publication Cover“Bone is a complex tissue of the with unique properties such as high strength and regeneration capabilities while carrying out multiple functions. Bone regeneration occurs both in physiological situations (bone turnover) and pathological situations (e.g. fractures), being performed by osteoblasts and osteoclasts. If this process is inadequate, fracture nonunion or aseptic loosening of implants occurs and requires a complex treatment.

Exogenous factors are currently used to increase bone regeneration process when needed, such as bisphosphonates and vitamin D, but limitations do exist. Cannabinoid system has been shown to have positive effects on bone metabolism. Cannabinoids at bone level mainly act on two receptors called CB-1 and CB-2, but GPR55, GPR119, TPRV1, TPRV4 receptors may also be involved. The CB-2 receptors are found in bone cells at higher levels compared to other receptors.

Endocannabinods represented by anandamide and 2-arachidonoylglycerol, can stimulate osteoblast formation, bone formation and osteoclast activity. CB-2 agonists including HU-308, HU-433, JWH133 and JWH015 can stimulate osteoblast proliferation and activity, while CB-2 antagonists such as AM630 and SR144528 can inhibit osteoclast differentiation and function. CB-1 antagonist AM251 has been shown to inhibit osteoclast differentiation and activity, while GPR55 antagonist cannabidiol increases osteoblast activity and decreases osteoclast function.

An optimal correlation of dose, duration, moment of action and affinity can lead to an increased bone regeneration capacity, with important benefits in many pathological situations which involve bone tissue. As adverse reactions of cannabinoids haven’t been described in patients under controlled medication, cannabinoids can represent future treatment for bone regeneration.”

https://www.ncbi.nlm.nih.gov/pubmed/30702341

https://www.tandfonline.com/doi/abs/10.1080/03602532.2019.1574303?journalCode=idmr20

Diet-Induced Obesity in Cannabinoid-2 Receptor Knockout Mice and Cannabinoid Receptor 1/2 Double-Knockout Mice.

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“Evidence suggests that cannabinoid-1 receptor (CB1R) activation is associated with increased food intake and body weight gain. Human epidemiological studies, however, show decreased prevalence of obesity in cannabis users.

Given the overlapping and complementary functions of the cannabinoid receptors (CB1R and CB2R), mice lacking CB2R and mice lacking both CB1R and CB2R were studied.

These results indicate that lacking both CB1R and CB2R protected mice from diet-induced obesity, possibly through the prominent role of CB1R in obesity or through an interactive effect of both receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/30699233

https://onlinelibrary.wiley.com/doi/abs/10.1002/oby.22403

Cannabinoids (Marijuana) A Stem Cell Stimulator!!

Institute of Regenerative Medicine®“Some time ago a wrote a blog about the use of certain components of the marijuana plant. It was a fairly short blog which I will include here. More and more states are proposing the legalization of marijuana. There are numerous health claims about hemp oil which is a derivative of Cannabis. There may be merit to these claims possibly by the action of the Cannabis on stem cells. Below is the blog and I will expand more on it:

“We use to think that marijuana was bad for one’s health. Now we are not so sure about it. We need to clarify things a bit.
Cannabinoids, the active components of cannabis (Cannabis sativa) extracts, have attracted the attention of human civilizations for centuries for a variety of uses. The use of Cannabis or Marijuana (scientific name is Cannabis sativa) came before we were able to discover the active portion or substrate. This substrate is called endocannabinoid system. The endocannabbinoid system has a number of components. The system consists of lipids, the receptors for the lipids and certain metabolic enzymes. The Cannabinoid signaling regulates cell proliferation, differentiation and it reduces cell aptosis or death. These receptors are found in the very early stages of life. The results of the Cannabinoid receptors depend upon molecular targets and cellular context involved. There are two main receptors which are called CB1 and CB2 receptors. These receptors seem to be involved in neural degeneration. They seem to be involved in all three germ layer formations. . CB1 and CB2 show opposite patterns of expression, the former increasing and the latter decreasing along neuronal differentiation. It is thought that the CB2 receptors may be most important. Recently, endocannabinoid (eCB) signaling has also been shown to regulate proliferation and differentiation of hematopoietic and mesenchymal stem cells, with a key role in determining the formation of several cell types in peripheral tissues, including blood cells, adipocytes, osteoblasts/osteoclasts and epithelial cells. The developmental regulation of cannabinoid receptor expression and cellular/sub-cellular localization, together with their role in progenitor/stem cell biology, may have important implications in human health and disease. Bone marrow and stem cells make endocannabinoids, these endocannabinoids interact with the cannabinoid receptors (Cannabinoid receptors have been found in nearly every cell in the human body). If cannabinoids can enhance stem cell migration and proliferation, this could be a powerful therapy. For instance, if you can increase the numbers and movement of stem cells to an injured tissue, you could vastly enhance the healing process. Lastly, the synthetic cannabinoid HU-210 is about 100-1000x times more potent than THC from Cannabis and this synthetic agent has been found to be neurogenic. Meaning that HU-210 can cause new neurons (brain cells) in the brain to form. However this study was done in rats…and humans are different from rats. Will I prescribe medical marijuana for my stem cell patients? At present I do not think I have enough information to make an intelligent decision about this. I suspect if some day I do prescribe this it will be some derivative of Cannabis. There are certainly some intriguing aspects of Cannabis but I feel the jury is still out. I suspect we will certainly hear more about this. Thanks Dr. P”

That was the blog I wrote some time ago. At this juncture I am getting closer to utilizing some component of Cannabis. I have further looked at the literature and there seems to be some very good science on the effect of Cannabis on stem cell workings. One of the intriguing aspects of the CB2 receptor is that it is found mostly in the immune system. At the University of South Carolina, a team discovered that THC could reduce the inflammation associated with autoimmune diseases by suppressing the activity of certain genes involved in the immune response. Its presence there interests scientists because the immune system triggers inflammation, and studies show marijuana can have an anti-inflammatory effect. When we start talking about the immune system we have a host of implications. We are aware that many diseases of aging may have some basis as an auto-immune disease. One of these that interests me is Osteoporosis. There may be both receptors at work. CB-2 works on the immune system while CB-1 is induced during osteogenic differentiation. As I have written in another blog, Very Small Embryonic Like Stem Cells may have a profound effect on the course of Osteoporosis. The next question is can we prime these cells additionally with Cannabis and take things to the next level. More to come I am sure. Dr. P.”

https://stcell.com/blogs/128/cannabinoids-marijuana-a-stem