Tag Archives: cannabinoid receptors

Alterations in Brain Cannabinoid Receptor Levels Are Associated with HIV-Associated Neurocognitive Disorders in the ART Era: Implications for Therapeutic Strategies Targeting the Endocannabinoid System

Posted on by

viruses-logo“HIV-associated neurocognitive disorders (HAND) persist despite the advent of antiretroviral therapy (ART), suggesting underlying systemic and central nervous system (CNS) inflammatory mechanisms.

The endogenous cannabinoid receptors 1 and 2 (CB1 and CB2) modulate inflammatory gene expression and play an important role in maintaining neuronal homeostasis. Cannabis use is disproportionately high among people with HIV (PWH) and may provide a neuroprotective effect for those on ART due to its anti-inflammatory properties. However, expression profiles of CB1 and CB2 in the brains of PWH on ART with HAND have not been reported.

In this study, biochemical and immunohistochemical analyses were performed to determine CB1 and CB2 expression in the brain specimens of HAND donors.

Immunoblot revealed that CB1 and CB2 were differentially expressed in the frontal cortices of HAND brains compared to neurocognitively unimpaired (NUI) brains of PWH. CB1 expression levels negatively correlated with memory and information processing speed. CB1 was primarily localized to neuronal soma in HAND brains versus a more punctate distribution of neuronal processes in NUI brains. CB1 expression was increased in cells with glial morphology and showed increased colocalization with an astroglial marker.

These results suggest that targeting the endocannabinoid system may be a potential therapeutic strategy for HAND.”

https://pubmed.ncbi.nlm.nih.gov/34578323/

https://www.mdpi.com/1999-4915/13/9/1742

Hepatic Cannabinoid Signaling in the Regulation of Alcohol-Associated Liver Disease

Posted on by

Logo of arcr“Purpose: The endocannabinoid system has emerged as a key regulatory signaling pathway in the pathophysiology of alcohol-associated liver disease (ALD). More than 30 years of research have established different roles of endocannabinoids and their receptors in various aspects of liver diseases, such as steatosis, inflammation, and fibrosis. However, pharmacological applications of the endocannabinoid system for the treatment of ALD have not been successful because of psychoactive side effects, despite some beneficial effects. Thus, a more delicate and detailed elucidation of the mechanism linking the endocannabinoid system and ALD may be of paramount significance in efforts to apply the system to the treatment of ALD.

Search results: According to the inclusion and exclusion criteria, the authors selected 47 eligible full-text articles out of 2,691 searched initially. Studies in the past 3 decades revealed the opposite effects of cannabinoid receptors CB1R and CB2R on steatosis, inflammation, and fibrosis in ALD.

Discussion and conclusions: This review summarizes the endocannabinoid signaling in the general physiology of the liver, the pathogenesis of ALD, and some of the potential therapeutic implications of cannabinoid-based treatments for ALD.”

https://pubmed.ncbi.nlm.nih.gov/34646717/

“Over the past 30 years, it has been found that the endocannabinoid system is involved in a variety of pathways associated with the onset, or the progression, of several diseases, including ALD. The endocannabinoid system has been observed in both the hepatocytes and various nonparenchymal cells in the liver, in which the endocannabinoid production and its receptor activation may contribute to the development of a spectrum of ALD, ranging from simple alcoholic steatosis to more severe forms such as steatohepatitis and fibrosis. Therefore, understanding the precise physiology of the endocannabinoid system in the liver and unveiling the mechanism underlying the association between ALD progression and hepatic endocannabinoid signaling seem to bear a paramount significance for the advancement of ALD treatment, as well as for the treatment of other chronic liver diseases (e.g., NAFLD, viral hepatitis). Moreover, developing efficacious and highly selective cannabinoid receptor–modulating drugs could be a major breakthrough in the treatment of ALD.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8496755/

An external file that holds a picture, illustration, etc. Object name is arcr-41-1-12f1.jpg

The potential of cannabinoids and inhibitors of endocannabinoid degradation in respiratory diseases

Posted on by

European Journal of Pharmacology“The global incidence of respiratory diseases and complications is increasing. Therefore, new methods of treatment, as well as prevention, need to be investigated.

A group of compounds that should be considered for use in respiratory diseases is cannabinoids. There are three groups of cannabinoids – plant-derived phytocannabinoids, synthetic cannabinoids, and endogenous endocannabinoids including the enzymes responsible for their synthesis and degradation.

All cannabinoids exert their biological effects through either type 1 cannabinoid receptors (CB1) and/or type 2 cannabinoid receptors (CB2). In numerous studies (in vitro and in vivo), cannabinoids and inhibitors of endocannabinoid degradation have shown beneficial anti-inflammatory, antioxidant, anti-cancer, and anti-fibrotic properties.

Although in the respiratory system, most of the studies have focused on the positive properties of cannabinoids and inhibitors of endocannabinoid degradation. There are few research reports discussing the negative impact of these compounds. This review summarizes the properties and mechanisms of action of cannabinoids and inhibitors of endocannabinoid degradation in various models of respiratory diseases.

A short description of the effects selected cannabinoids have on the human respiratory system and their possible use in the fight against COVID-19 is also presented. Additionally, a brief summary is provided of cannabinoid receptors properties and their expression in the respiratory system and cells of the immune system.”

https://pubmed.ncbi.nlm.nih.gov/34648805/

“Phytocannabinoids are terpenophenolic compounds produced by specialized parts of the Cannabis sativa plant and are found in high concentrations in marijuana and hashish. In most of models, these compounds have shown positive biological properties. Anti-inflammatory, anti-oxidant, anti-cancer and anti-fibrotic actions are especially emphasized.”

https://www.sciencedirect.com/science/article/pii/S0014299921007160?via%3Dihub

Characterization of cannabinoid receptors expressed in Ewing sarcoma TC-71 and A-673 cells as potential targets for anti-cancer drug development

Posted on by

Life Sciences“Aims: Characterizing cannabinoid receptors (CBRs) expressed in Ewing sarcoma (EWS) cell lines as potential targets for anti-cancer drug development.

Main methods: CBR affinity and function were examined by competitive binding and G-protein activation, respectively. Cannabinoid-mediated cytotoxicity and cell viability were evaluated by LDH, and trypan blue assays, respectively.

Key findings: qRT-PCR detected CB1 (CB1R) and CB2 receptor (CB2R) mRNA in TC-71 cells. However, binding screens revealed that CBRs expressed exhibit atypical properties relative to canonical receptors, because specific binding in TC-71 could only be demonstrated by the established non-selective CB1/CB2R radioligand [3H]WIN-55,212-2, but not CB1/CB2R radioligand [3H]CP-55,940. Homologous receptor binding demonstrated that [3H]WIN-55,212-2 binds to a single site with nanomolar affinity, expressed at high density. Further support for non-canonical CBRs expression is provided by subsequent binding screens, revealing that only 9 out of 28 well-characterized cannabinoids with high affinity for canonical CB1 and/or CB2Rs were able to displace [3H]WIN-55,212-2, whereas two ligands enhanced [3H]WIN-55,212-2 binding. Five cannabinoids producing the greatest [3H]WIN-55,212-2 displacement exhibited high nanomolar affinity (Ki) for expressed receptors. G-protein modulation and adenylyl cyclase assays further indicate that these CBRs exhibit distinct signaling/functional profiles compared to canonical CBRs. Importantly, cannabinoids with the highest affinity for non-canonical CBRs reduced TC-71 viability and induced cytotoxicity in a time-dependent manner. Studies in a second EWS cell line (A-673) showed similar atypical binding properties of expressed CBRs, and cannabinoid treatment produced cytotoxicity.

Significance: Cannabinoids induce cytotoxicity in EWS cell lines via non-canonical CBRs, which might be a potential therapeutic target to treat EWS.”

https://pubmed.ncbi.nlm.nih.gov/34592231/

“Cannabinoid receptors (CBRs) were detected in EWS TC-71 and A-673 cells. CBRs expressed in EWS cell lines exhibit atypical binding and signaling characteristics. Ligands with highest affinity for these non-canonical CBRs induce EWS cell death.”

https://www.sciencedirect.com/science/article/abs/pii/S0024320521009802?via%3Dihub

 

The strengths and limits of cannabinoids and their receptors in cancer: Insights into the role of tumorigenesis-underlying mechanisms and therapeutic aspects

Posted on by

Biomedicine & Pharmacotherapy“Cancer, as a mysterious and complex disease, has a multi-stage molecular process that uses the cellular molecular machine and multiple signaling pathways to its advantage. Cannabinoids, as terpenophenolic compounds and their derivatives, showed influences on immune system responses, inflammation, and cell growth that have sparked a growing interest in exploring their effects on cancer cell fate, as well. A large body of evidence in experimental models indicating the involvement of cannabinoids and their related receptors in cancer cell growth, development, and fate. In accordance, the present study provided insights regarding the strengths and limits of cannabinoids and their receptors in critical steps of tumorigenesis and its underlying molecular pathways such as; cancer cell proliferation, type of cell death pathway, angiogenesis, invasion, metastasis and, immune system response. Based on the results of the present study and due to the contribution of cannabinoids in various cancer cell growth control processes, these compounds cancer can be considered worthwhile in finding new alternatives for cancer therapy.”

https://pubmed.ncbi.nlm.nih.gov/34624678/

“Cannabinoids execute critical roles in multiple steps of tumorigenesis. Cannabinoids trigger apoptosis, autophagy and mitophagy in cancer cells. Cannabinoids attenuate angiogenesis; thus regulate tumor invasion. Cannabinoids and their receptors can be effective therapeutic targets in cancer pathogenesis.”

https://www.sciencedirect.com/science/article/pii/S0753332221010635?via%3Dihub

 

Cannabinoids induce functional Tregs by promoting tolerogenic DCs via autophagy and metabolic reprograming

Posted on by

Mucosal Immunology“The generation of functional regulatory T cells (Tregs) is essential to keep tissue homeostasis and restore healthy immune responses in many biological and inflammatory contexts.

Cannabinoids have been pointed out as potential therapeutic tools for several diseases.

Dendritic cells (DCs) express the endocannabinoid system, including the cannabinoid receptors CB1 and CB2. However, how cannabinoids might regulate functional properties of DCs is not completely understood.

We uncover that the triggering of cannabinoid receptors promote human tolerogenic DCs that are able to prime functional FOXP3+ Tregs in the context of different inflammatory diseases. Mechanistically, cannabinoids imprint tolerogenicity in human DCs by inhibiting NF-κB, MAPK and mTOR signalling pathways while inducing AMPK and functional autophagy flux via CB1- and PPARα-mediated activation, which drives metabolic rewiring towards increased mitochondrial activity and oxidative phosphorylation.

Cannabinoids exhibit in vivo protective and anti-inflammatory effects in LPS-induced sepsis and also promote the generation of FOXP3+ Tregs. In addition, immediate anaphylactic reactions are decreased in peanut allergic mice and the generation of allergen-specific FOXP3+ Tregs are promoted, demonstrating that these immunomodulatory effects take place in both type 1- and type 2-mediated inflammatory diseases.

Our findings might open new avenues for novel cannabinoid-based interventions in different inflammatory and immune-mediated diseases.”

https://pubmed.ncbi.nlm.nih.gov/34548620/

“Cannabinoids have been pointed out as potential therapeutic tools for several diseases. Our results might well contribute to pave the way for the future development of novel cannabinoid-based strategies for different inflammatory and immune-mediated diseases.”

https://www.nature.com/articles/s41385-021-00455-x

Cannabinoid Receptor Type 2 is Upregulated in Synovium following Joint Injury and Mediates Anti-Inflammatory Effects in Synovial Fibroblasts and Macrophages

Posted on by

The effect of protease inhibitors on the indcution of osteoarthritis-related biomarkers in bovine full-depth cartilage explants - Osteoarthritis and Cartilage“Objective: Joint injury-induced perturbations to the endocannabinoid system (ECS), a regulator of both inflammation and nociception, remain largely uncharacterized. We employed a mouse model of ACL rupture to assess alterations to nociception, inflammation, and the ECS while using in vitro models to determine whether CB2 agonism can mitigate inflammatory signaling in macrophages and fibroblast-like synoviocytes (FLS).

Conclusions: Joint injury perturbs the intra-articular ECS, characterized by an increase in synovial F4/80(+) cells, which express CB2, but not CB1. Targeting CB2 in murine macrophages and human FLS induced potent anti-inflammatory and anti-catabolic effects, which indicates that the CB2 receptor plays a key role in regulating inflammatory signaling in the two primary effector cells in the synovium. The intraarticular ECS is therefore a potential therapeutic target for blocking pathological inflammation in future disease-modifying PTOA treatments.”

https://pubmed.ncbi.nlm.nih.gov/34537380/

https://www.oarsijournal.com/article/S1063-4584(21)00888-8/fulltext

Cannabinoid receptor 1 expression is higher in muscle of old vs. young males, and increases upon resistance exercise in older adults

Posted on by

Scientific Reports“Aged skeletal muscle undergoes metabolic and structural alterations eventually resulting in a loss of muscle strength and mass, i.e. age-related sarcopenia. Therefore, novel targets for muscle growth purposes in elderly are needed.

Here, we explored the role of the cannabinoid system in muscle plasticity through the expression of muscle cannabinoid receptors (CBs) in young and old humans.

The CB1 expression was higher (+ 25%; p = 0.04) in muscle of old (≥ 65 years) vs. young adults (20-27 years), whereas CB2 was not differently expressed. Furthermore, resistance exercise tended to increase the CB1 (+ 11%; p = 0.055) and CB2 (+ 37%; p = 0.066) expression in muscle of older adults. Interestingly, increases in the expression of CB2 following resistance exercise positively correlated with changes in key mechanisms of muscle homeostasis, such as catabolism (FOXO3a) and regenerative capacity (Pax7, MyoD).

This study for the first time shows that CB1 is differentially expressed with aging and that changes in CB2 expression upon resistance exercise training correlate with changes in mediators that play a central role in muscle plasticity.

These data confirm earlier work in cells and mice showing that the cannabinoid system might orchestrate muscle growth, which is an incentive to further explore CB-based strategies that might counteract sarcopenia.”

https://pubmed.ncbi.nlm.nih.gov/34526596/

“In conclusion, cell culture and murine experiments suggested that CBs can be a promising target to treat cachexia and sarcopenia through modulation of the metabolism and muscle regenerative capacity. These data imply that CB modulation might be a promising tool to combat muscle degeneration. ”

https://www.nature.com/articles/s41598-021-97859-3

Endocannabinoid Levels in Ulcerative Colitis Patients Correlate With Clinical Parameters and Are Affected by Cannabis Consumption

Posted on by

Logo of frontendo“Inflammatory bowel diseases (IBDs) are chronic, idiopathic, inflammatory, gastrointestinal disorders.

The endocannabinoid system may have a role in the pathogenesis of IBD.

We aimed to assess whether cannabis treatment influences endocannabinoids (eCBs) level and clinical symptoms of IBD patients.

Conclusion

Our study supports the notion that cannabis use affects eCB “tone” in UC patients and may have beneficial effects on disease symptoms in UC patients.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8438407/

“In conclusion, our study suggests that cannabis use may affect eCBs tone in UC patients. This affect has a beneficial effect on UC symptoms.”

https://www.frontiersin.org/articles/10.3389/fendo.2021.685289/full

Cannabinoids and Cancer

Posted on by

cancers-logo“Cannabinoids, active components of the plant Cannabis sativa, had been used for centuries in ancient medicine as therapeutic remedies for a variety of conditions, before becoming stigmatized due to their psychoactive effects.

In the second half of the 19th century, phyto-cannabinoids have been re-evaluated after the discovery of the chemical structure and isolation of different substances, and the subsequent development of cannabinoid-based drugs that have been FDA approved mainly to treat chemotherapy-induced nausea, insomnia and appetite, epilepsy, spasticity, and pain management.

Then, the elucidation of the endocannabinoid system, from the initial type 1 and type 2 (CB1 and CB2) cannabinoid receptors and their endogenous ligands (especially N-arachidonoylethanolamine, or anandamide, and 2-arachidonoylglycerol) to the emerging complexity of a wider system made up of additional putative receptors, ligands and enzymes, altogether termed endocannabinoidome, has further boosted research into the therapeutic potential of phyto-, endo- and even syntho-(synthetic) cannabinoids, cancer treatment included.”

https://pubmed.ncbi.nlm.nih.gov/34503268/

https://www.mdpi.com/2072-6694/13/17/4458/htm