Tag Archives: cannabinoid receptors

Structure of a Signaling Cannabinoid Receptor 1-G Protein Complex.

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“Cannabis elicits its mood-enhancing and analgesic effects through the cannabinoid receptor 1 (CB1), a G protein-coupled receptor (GPCR) that signals primarily through the adenylyl cyclase-inhibiting heterotrimeric G protein Gi. Activation of CB1-Gi signaling pathways holds potential for treating a number of neurological disorders and is thus crucial to understand the mechanism of Giactivation by CB1.

Here, we present the structure of the CB1-Gi signaling complex bound to the highly potent agonist MDMB-Fubinaca (FUB), a recently emerged illicit synthetic cannabinoid infused in street drugs that have been associated with numerous overdoses and fatalities.”

https://www.ncbi.nlm.nih.gov/pubmed/30639101

https://linkinghub.elsevier.com/retrieve/pii/S0092867418315654

“Antidepressant-like effect of delta9-tetrahydrocannabinol and other cannabinoids isolated from Cannabis sativa L. Results of this study show that Delta(9)-THC and other cannabinoids exert antidepressant-like actions, and thus may contribute to the overall mood-elevating properties of cannabis.”   https://www.ncbi.nlm.nih.gov/pubmed/20332000

∆9-Tetrahydrocannabinol, a major marijuana component, enhances the anesthetic effect of pentobarbital through the CB1 receptor.

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 “∆9 –Tetrahydrocannabinol (∆9-THC) and cannabidiol (CBD), major psychoactive constituents of marijuana, induce potentiation of pentobarbital-induced sleep in mice.

We have elucidated the mechanism of enhancement of the anesthetic effect of pentobarbital by cannabinoids.

These results suggest that binding of ∆9-THC to the CB1 receptor is involved in the synergism with pentobarbital, and that potentiating effect of CBD with pentobarbital may differ from that of ∆9-THC. We successfully demonstrated that ∆9-THC enhanced the anesthetic effect of pentobarbital through the CB1 receptor.”

https://www.ncbi.nlm.nih.gov/pubmed/30636988

“The pharmacological results indicate the effect of ∆9-THC co-administered with pentobarbital was a synergistic, but not additive, action in mice. Further evidence suggests the CB1 receptor plays an important role as a trigger in potentiating pentobarbital-induced sleep by ∆9-THC.”

https://link.springer.com/article/10.1007%2Fs11419-018-0457-2

Do Endocannabinoids Regulate Glucose Reabsorption in the Kidney?

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“Diabetic nephropathy (DN), a distinct manifestation of diabetic kidney disease, affects approximately 30% of patients with diabetes. While most attention has been focused on glomerular changes related to DN, there is growing evidence that tubulopathy is a key feature in the pathogenesis of this disease. The renal proximal tubule cells (RPTCs) are particularly sensitive to the deleterious effect of chronic hyperglycemia. However, the cellular changes that control the dysfunction of the RPTCs are not fully understood.

Controlling glucose reabsorption in the proximal tubules via inhibition of glucose transporters (GLUT) has emerged as a promising therapeutic in ameliorating DN.

Overactivation of the renal endocannabinoid (eCB) system via the cannabinoid-1 receptor (CB1R) contributes to the development of DN, and its blockade by globally acting or peripherally restricted CB1R antagonists has been shown to ameliorate renal dysfunction in different murine models for diabetes. Recently, we have utilized various pharmacological and genetic tools to show that the eCB/CB1R system contributes to the development of DN via regulating the expression, translocation, and activity of the facilitative GLUT2 located in the RPTCs.

These findings have the potential to be translated into therapy, and support the rationale for the preclinical development of novel renal-specific CB1R and/or GLUT2 inhibitors for the treatment of DN.”

https://www.ncbi.nlm.nih.gov/pubmed/30636250

https://www.karger.com/Article/FullText/494512

Expression and Preparation of a G-Protein-Coupled Cannabinoid Receptor CB2 for NMR Structural Studies.

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Current Protocols in Protein Science banner

“Cannabinoid receptor type II, or CB2 , is an integral membrane protein that belongs to a large class of G-protein-coupled receptors (GPCR)s. CB2 is a part of the endocannabinoid system, which plays an important role in the regulation of immune response, inflammation, and pain.

Information about the structure and function of CB2 is essential for the development of specific ligands targeting this receptor.

We present here a methodology for recombinant expression of CB2 and its stable isotope labeling, purification, and reconstitution into liposomes, in preparation for its characterization by nuclear magnetic resonance (NMR).

Correctly folded, functional CB2 labeled with [13 C,15 N]tryptophan or uniformly labeled with 13 C and 15 N is expressed in a medium of defined composition, under controlled aeration, pH, and temperature conditions.

The receptor is purified by affinity chromatography and reconstituted into lipid bilayers in the form of proteoliposomes suitable for analysis by NMR spectroscopy.”

https://www.ncbi.nlm.nih.gov/pubmed/30624864

https://currentprotocols.onlinelibrary.wiley.com/doi/abs/10.1002/cpps.83

The protective effects of β-caryophyllene on LPS-induced primary microglia M1/M2 imbalance: A mechanistic evaluation.

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Life Sciences

“Neuroinflammation is observed as a routine characterization of neurodegenerative disorders such as dementia, multiple sclerosis (MS) and Alzheimer’s diseases (AD). Scientific evidence propounds both of the neuromodulatory and immunomodulatory effects of CB2 in the immune system. β-Caryophyllene (BCP) is a dietary selective CB2 agonist, which deserves the anti-inflammatory and antioxidant effects at both low and high doses through activation of the CB2 receptor.

METHODS:

In this study, we investigated the protective effects of a broad range concentration of BCP against LPS-induced primary microglia cells inflammation and M1/M2 imbalance and identifying the portion of the involvement of related signaling pathways on BCP effects using pharmacological antagonists of CB2, PPAR-γ, and sphingomyelinase (SMase).

KEY FINDINGS:

The protective effects of BCP on LPS-induced microglia imbalance is provided by the M2 healing phenotype of microglia, releasing the anti-inflammatory (IL-10, Arg-1, and urea) and anti-oxidant (GSH) parameters and reducing the inflammatory (IL-1β, TNF-α, PGE2, iNOS and NO) and oxidative (ROS) biomarkers. Moreover, we showed that BCP exerts its effects through CB2receptors which overproduction of ceramides by SMase at middle to higher concentrations of BCP reduce the protective activity of BCP and results in the activation of the PPAR-γ pathway.

SIGNIFICANCE:

In conclusion, the low concentration of BCP has higher selective anti-inflammatory effects rather than high levels. On this occasion, BCP by modulating the microglia is able to have potential therapeutic effects in neuro-inflammation conditions and microglia cells such as MS and AD.”

https://www.ncbi.nlm.nih.gov/pubmed/30620895

https://www.sciencedirect.com/science/article/abs/pii/S0024320518308610?via%3Dihub

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

“Beta-caryophyllene is a dietary cannabinoid.”  https://www.ncbi.nlm.nih.gov/pubmed/18574142

Changes in Monoaminergic Neurotransmission in an Animal Model of Osteoarthritis: The Role of Endocannabinoid Signaling.

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“Chronic pain is a main symptom of osteoarthritis (OA). Moreover, a high percentage of OA patients suffer from mental health problems.

The endocannabinoid (EC) system has attracted attention as an emerging drug target for pain treatment together with its activity on the mesolimbic reward system.

Understanding the circuits that govern the reward of pain relief is crucial for the search for effective analgesics. Therefore, we investigated the role of the EC system on dopamine (DA) and noradrenaline (NA) in an animal model of OA-related chronic pain.

Our results demonstrated that chronic pain in OA rats was reflected by the inhibition of mesolimbic and mesocortical dopaminergic transmission, and may indicate the pro-pain role of NA in the FCx.

The data provide understanding about changes in neurotransmission in chronic pain states and may explain the clinical improvement in perceived life quality following cannabinoid treatment.

Additional mechanistic studies in preclinical models examining the intersection between chronic pain and reward circuits may offer new approaches for improving pain therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/30618615

https://www.frontiersin.org/articles/10.3389/fnmol.2018.00466/full

The effects of cannabinoids on the endocrine system.

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“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.”

 https://www.ncbi.nlm.nih.gov/pubmed/30618031
https://journals.viamedica.pl/endokrynologia_polska/article/view/58487

Cannabinoids-induced peripheral analgesia depends on activation of BK channels.

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 Brain Research“The endogenous cannabinoid system is involved in the physiological inhibitory control of pain and is of particular interest for the development of therapeutic approaches for pain management.

Selective activation of the peripheral CB1 cannabinoid receptor has been shown to suppress the heightened firing of primary afferents, which is the peripheral mechanism underlying neuropathic pain after nerve injury. However, the mechanism underlying this effect of CB1 receptor remains unclear.

The large-conductance calcium-activated potassium (BK) channels have been reported to participate in anticonvulsant and vasorelaxant effects of cannabinoids. We asked whether BK channels participate in cannabinoids-induced analgesia and firing-suppressing effects in primary afferents after nerve injury.

Here, using mice with chronic constriction injury(CCI)-induced neuropathic pain, antinociception action and firing-suppressing effect of HU210 were measured before and after BK channel blocker application. We found that local peripheral application of HU210 alleviated CCI-induced pain behavior and suppressed the heightened firing of injured fibers. Co-administration of IBTX with HU210 significantly reversed the analgesia and the firing-suppressing effect of HU210.

This result indicated that the peripheral analgesic effects of cannabinoids depends on activation of BK channels.”

https://www.ncbi.nlm.nih.gov/pubmed/30615887

https://www.sciencedirect.com/science/article/pii/S0006899319300071?via%3Dihub

Progress in Brain Cannabinoid CB2 Receptor Research: From Genes to Behavior.

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Neuroscience & Biobehavioral Reviews

“The type 2 cannabinoid receptor (CB2R) was initially regarded as a peripheral cannabinoid receptor. However, recent technological advances in gene detection, alongside the availability of transgenic mouse lines, indicate that CB2Rs are expressed in both neurons and glial cells in the brain under physiological and pathological conditions, and are involved in multiple functions at cellular and behavioral levels. Brain CB2Rs are inducible and neuroprotective via up-regulation in response to various insults, but display species differences in gene and receptor structures, CB2R expression, and receptor responses to various CB2R ligands. CB2R transcripts also differ between the brain and spleen. In the brain, CB2A is the major transcript isoform, while CB2A and CB2B transcripts are present at higher levels in the spleen. These new findings regarding brain versus spleen CB2R isoforms may in part explain why early studies failed to detect brain CB2R gene expression. Here, we review evidence supporting the expression and function of brain CB2R from gene and receptor levels to cellular functioning, neural circuitry, and animal behavior.”

https://www.ncbi.nlm.nih.gov/pubmed/30611802

https://www.sciencedirect.com/science/article/pii/S0149763418308297?via%3Dihub

Adenosine A2A-Cannabinoid CB1 Receptor Heteromers in the Hippocampus: Cannabidiol Blunts Δ9-Tetrahydrocannabinol-Induced Cognitive Impairment

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“At present, clinical interest in the plant-derived cannabinoid compound cannabidiol (CBD) is rising exponentially, since it displays multiple therapeutic properties. In addition, CBD can counteract the undesirable effects of the psychoactive cannabinoid Δ9-tetrahydrocannabinol (Δ9-THC) that hinder clinical development of cannabis-based therapies. Here, by combining in vivo and complementary molecular techniques, we demonstrate for the first time that CBD blunts the Δ9-THC-induced cognitive impairment in an adenosine A2A receptor (A2AR)-dependent manner. Overall, these data provide new evidence regarding the mechanisms of action of CBD and the nature of A2AR-CB1R interactions in the brain.”

https://www.ncbi.nlm.nih.gov/pubmed/30610611

https://link.springer.com/article/10.1007%2Fs12035-018-1456-3