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.ncbi.nlm.nih.gov/pubmed/30639103

https://linkinghub.elsevier.com/retrieve/pii/S0092867418316258

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Cannabis sativa L. and Nonpsychoactive Cannabinoids: Their Chemistry and Role against Oxidative Stress, Inflammation, and Cancer.

 Related image“In the last decades, a lot of attention has been paid to the compounds present in medicinal Cannabis sativa L., such as Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), and their effects on inflammation and cancer-related pain.

The National Cancer Institute (NCI) currently recognizes medicinal C. sativa as an effective treatment for providing relief in a number of symptoms associated with cancer, including pain, loss of appetite, nausea and vomiting, and anxiety.

Several studies have described CBD as a multitarget molecule, acting as an adaptogen, and as a modulator, in different ways, depending on the type and location of disequilibrium both in the brain and in the body, mainly interacting with specific receptor proteins CB1 and CB2.

CBD is present in both medicinal and fibre-type C. sativa plants, but, unlike Δ9-THC, it is completely nonpsychoactive. Fibre-type C. sativa (hemp) differs from medicinal C. sativa, since it contains only few levels of Δ9-THC and high levels of CBD and related nonpsychoactive compounds.

In recent years, a number of preclinical researches have been focused on the role of CBD as an anticancer molecule, suggesting CBD (and CBD-like molecules present in the hemp extract) as a possible candidate for future clinical trials.

CBD has been found to possess antioxidant activity in many studies, thus suggesting a possible role in the prevention of both neurodegenerative and cardiovascular diseases. In animal models, CBD has been shown to inhibit the progression of several cancer types. Moreover, it has been found that coadministration of CBD and Δ9-THC, followed by radiation therapy, causes an increase of autophagy and apoptosis in cancer cells. In addition, CBD is able to inhibit cell proliferation and to increase apoptosis in different types of cancer models.

These activities seem to involve also alternative pathways, such as the interactions with TRPV and GRP55 receptor complexes. Moreover, the finding that the acidic precursor of CBD (cannabidiolic acid, CBDA) is able to inhibit the migration of breast cancer cells and to downregulate the proto-oncogene c-fos and the cyclooxygenase-2 (COX-2) highlights the possibility that CBDA might act on a common pathway of inflammation and cancer mechanisms, which might be responsible for its anticancer activity.

In the light of all these findings, in this review we explore the effects and the molecular mechanisms of CBD on inflammation and cancer processes, highlighting also the role of minor cannabinoids and noncannabinoids constituents of Δ9-THC deprived hemp.”

https://www.ncbi.nlm.nih.gov/pubmed/30627539

https://www.hindawi.com/journals/bmri/2018/1691428/

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The effects of cannabinoids on the endocrine system.

“Cannabinoids are the derivatives of the cannabis plant, the most potent bioactive component of which is tetrahydrocannabinol (THC). The most commonly used drugs containing cannabinoids are marijuana, hashish, and hashish oil.

These compounds exert their effects via interaction with the cannabinoid receptors CB1 and CB2. Type 1 receptors (CB1) are localised mostly in the central nervous system and in the adipose tissue and many visceral organs, including most endocrine organs. Type 2 cannabinoid receptors (CB2) are positioned in the peripheral nervous system (peripheral nerve endings) and on the surface of the immune system cells.

Recently, more and more attention has been paid to the role that endogenous ligands play for these receptors, as well as to the role of the receptors themselves. So far, endogenous cannabinoids have been confirmed to participate in the regulation of food intake and energy homeostasis of the body, and have a significant impact on the endocrine system, including the activity of the pituitary gland, adrenal cortex, thyroid gland, pancreas, and gonads.

Interrelations between the endocannabinoid system and the activity of the endocrine system may be a therapeutic target for a number of drugs that have been proved effective in the treatment of infertility, obesity, diabetes, and even prevention of diseases associated with the cardiovascular system.”

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Cannabinoid receptor expression in estrogen-dependent and estrogen-independent endometrial cancer.

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“The lack of good diagnostic/prognostic biomarkers and the often late presentation of endometrial cancer (EC) hinders the amelioration of the morbidity and mortality rates associated with this primarily estrogen-driven disease, a disease that is becoming more prevalent in the population.

Previous studies on the expression of the classical cannabinoid receptors, CB1 and CB2, suggest these could provide good diagnostic/prognostic biomarkers for EC but those observations have been contradictory. In this study, we sought to resolve the inconsistency of CB1 and CB2 expression levels in different EC studies.

To that end, we used qRT-PCR and immunohistochemistry (IHC) for CB1 and CB2 in endometrial biopsies from women with or without EC and found that transcript levels for both CB1 and CB2 were significantly decreased by 90 and 80%, respectively in EC. These observations were supported by histomorphometric studies where CB1 and CB2 staining intensity was decreased in all types of EC.

These data suggest that the loss of both types of CB receptors is potentially involved in the development of or progression of EC and that CB1 and CB2 receptor expression could serve as useful histological markers and therapeutic targets in the treatment of or prevention of EC.”

https://www.ncbi.nlm.nih.gov/pubmed/30569804

https://www.tandfonline.com/doi/abs/10.1080/10799893.2018.1531890?journalCode=irst20

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Δ9-Tetrahydrocannabinol and Cannabidiol Differentially Regulate Intraocular Pressure.

“It has been known for nearly 50 years that cannabis and the psychoactive constituent Δ9-tetrahydrocannabinol (THC) reduce intraocular pressure (IOP).

Elevated IOP remains the chief hallmark and therapeutic target for glaucoma, a major cause of blindness.

THC likely acts via one of the known cannabinoid-related receptors (CB1, CB2, GPR18, GPR119, GPR55) but this has never been determined explicitly.

Cannabidiol (CBD) is a second major constituent of cannabis that has been found to be without effect on IOP in most studies.

RESULTS:

We now report that a single topical application of THC lowered IOP substantially (∼28%) for 8 hours in male mice. This effect is due to combined activation of CB1 and GPR18 receptors each of which has been shown to lower ocular pressure when activated. We also found that the effect was sex-dependent, being stronger in male mice, and that mRNA levels of CB1 and GPR18 were higher in males. Far from inactive, CBD was found to have two opposing effects on ocular pressure, one of which involved antagonism of tonic signaling.

CBD prevents THC from lowering ocular pressure.

CONCLUSIONS:

We conclude that THC lowers IOP by activating two receptors-CB1 and GPR18-but in a sex-dependent manner. CBD, contrary to expectation, has two opposing effects on IOP and can interfere with the effects of THC.”

https://www.ncbi.nlm.nih.gov/pubmed/30550613

https://iovs.arvojournals.org/article.aspx?articleid=2718702

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Effects of cannabinoids in Amyotrophic Lateral Sclerosis (ALS) murine models: A systematic review and meta-analysis.

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“Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder that results from motor neuron damage.

Cannabinoids have been proposed as treatments for ALS due to their anti-excitotoxicity, anti-oxidant, and anti-inflammatory effects.

This review provides some evidence for the efficacy of cannabinoids in prolonging survival time in an ALS mouse model. A delay in disease progression is also suggested following cannabinoid treatment”

https://www.ncbi.nlm.nih.gov/pubmed/30520038

https://onlinelibrary.wiley.com/doi/abs/10.1111/jnc.14639

“The endocannabinoid system in amyotrophic lateral sclerosis. There is increasing evidence that cannabinoids and manipulation of the endocannabinoid system may have therapeutic value in ALS, in addition to other neurodegenerative conditions. Cannabinoids exert anti-glutamatergic and anti-inflammatory actions through activation of the CB(1) and CB(2) receptors, respectively. Cannabinoid agents may also exert anti-oxidant actions by a receptor-independent mechanism. Therefore the ability of cannabinoids to target multiple neurotoxic pathways in different cell populations may increase their therapeutic potential in the treatment of ALS.”  https://www.ncbi.nlm.nih.gov/pubmed/18781981

http://www.thctotalhealthcare.com/category/amyotrophic-lateral-sclerosis-als-lou-gehrigs-disease/

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Disordered Peptides Looking for Their Native Environment: Structural Basis of CB1 Endocannabinoid Receptor Binding to Pepcans.

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“Endocannabinoid peptides, or “pepcans,” are endogenous ligands of the CB1 cannabinoid receptor. Depending on their length, they display diverse activity: For instance, the nona-peptide Pepcan-9, also known as hemopressin, is a powerful inhibitor of CB1, whereas the longer variant Pepcan-12, which extends by only three amino acid residues at the N-terminus, acts on both CB1 and CB2 as an allosteric modulator. These findings open the way to structure-driven design of selective peptide modulators of CB1.”

https://www.ncbi.nlm.nih.gov/pubmed/30505835

https://www.frontiersin.org/articles/10.3389/fmolb.2018.00100/full

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The Role of CB2 Receptor in the Recovery of Mice after Traumatic Brain Injury.

 Journal of Neurotrauma cover image“Cannabis is one of the most widely used plant drugs in the world today. In spite of the large number of scientific reports on medical marijuana there still exists much controversy surrounding its use and the potential for abuse due to the undesirable psychotropic effects. However, recent developments in medicinal chemistry of novel non-psychoactive synthetic cannabinoids have indicated that it is possible to separate some of the therapeutic effects from the psychoactivity. We have previously shown that treatment with the endocannabinoid 2-AG that binds to both CB1 and CB2 receptors 1 hr after traumatic brain injury in mice attenuates neurological deficits, edema formation, infarct volume, blood-brain barrier permeability, neuronal cell loss at the CA3 hippocampal region and neuroinflammation. Recently, we synthesized a set of camphor-resorcinol derivatives, which represent a novel series of CB2 receptor selective ligands. Most of the novel compounds exhibited potent binding and agonistic properties at the CB2 receptors, with very low affinity for the CB1 receptor, and some were highly anti-inflammatory. This selective binding correlated with their intrinsic activities. HU-910 and HU-914 were selected in the present study to evaluate their potential effect in the pathophysiology of traumatic brain injury (TBI). In mice and rats, subjected to closed head injury and treated with these novel compounds, we showed enhanced neurobehavioral recovery, inhibition of TNF-alpha production, increased synaptogenesis and partial recovery of the cortical spinal tract. We propose these CB2 agonists as potential drugs for development of novel therapeutic modality to TBI.”

https://www.ncbi.nlm.nih.gov/pubmed/30489198

https://www.liebertpub.com/doi/10.1089/neu.2018.6063

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Cannabidiol reduces airway inflammation and fibrosis in experimental allergic asthma.

European Journal of Pharmacology

“Asthma is characterized by chronic lung inflammation and airway hyperresponsiveness. Asthma remains a major public health problem and, at present, there are no effective interventions capable of reversing airway remodelling.

Cannabidiol (CBD) is known to exert immunomodulatory effects through the activation of cannabinoid-1 and -2 (CB1 and CB2) receptors located in the central nervous system and immune cells, respectively. However, as the role of CBD on airway remodelling and the mechanisms of CB1 and CB2 aren’t fully elucidated, this study was designed to evaluate the effects of cannabidiol in this scenario.

Allergic asthma was induced in Balb/c mice exposed to ovalbumin, and respiratory mechanics, collagen fibre content in airway and alveolar septa, cytokine levels, and CB1 and CB2 expression were determined. Moreover, expressions of CB1 and CB2 in induced sputum of asthmatic individuals and their correlation with airway inflammation and lung function were also evaluated.

CBD treatment, regardless of dosage, decreased airway hyperresponsiveness, whereas static lung elastance only reduced with high dose. These outcomes were accompanied by decreases in collagen fibre content in both airway and alveolar septa and the expression of markers associated with inflammation in the bronchoalveolar lavage fluid and lung homogenate. There was a significant and inverse correlation between CB1levels and lung function in asthmatic patients.

CBD treatment decreased the inflammatory and remodelling processes in the model of allergic asthma. The mechanisms of action appear to be mediated by CB1/CB2 signalling, but these receptors may act differently on lung inflammation and remodelling.”

https://www.ncbi.nlm.nih.gov/pubmed/30481497

https://www.sciencedirect.com/science/article/pii/S0014299918306836?via%3Dihub

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Novel inverse agonists for the orphan G protein-coupled receptor 6.

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“The orphan G protein-coupled receptor 6 (GPR6) displays unique promise as a therapeutic target for the treatment of neuropsychiatric disorders due to its high expression in the striatopallidal neurons of the basal ganglia.

GPR6, along with closely related orphan receptors GPR3 and GPR12, are phylogenetically related to CB1 and CB2 cannabinoid receptors.

In the current study, we performed concentration-response studies on the effects of three different classes of cannabinoids: endogenous, phyto-, and synthetic, on both GPR6-mediated cAMP accumulation and β-arrestin2 recruitment. In addition, structure-activity relationship studies were conducted on cannabidiol (CBD), a recently discovered inverse agonist for GPR6.

We have identified four additional cannabinoids, cannabidavarin (CBDV), WIN55212-2, SR141716A and SR144528, that exert inverse agonism on GPR6. Furthermore, we have discovered that these cannabinoids exhibit functional selectivity toward the β-arrestin2 recruitment pathway.

These novel, functionally selective inverse agonists for GPR6 can be used as research tools and potentially developed into therapeutic agents.”

https://www.ncbi.nlm.nih.gov/pubmed/30480157

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