Category Archives: Endocannabinoid System

GPR55 in the tumor microenvironment of pancreatic cancer controls tumorigenesis

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“Background: The G protein-coupled receptor 55 (GPR55) is part of an expanded endocannabinoid system (ECS), and plays a pro-tumorigenic role in different cancer models, including pancreatic cancer. Next to cancer cells, various cells of the immune tumor microenvironment (TME) express receptors of the ECS that critically determine tumor growth. The role of GPR55 in cancer cells has been widely described, but its role in the immune TME is not well understood.

Methods: We intended to uncover the role of GPR55 in tumor immunity in a model of pancreatic ductal adenocarcinoma (PDAC). To this end, a KPCY tumor cell line or a GPR55-overexpressing KPCY cell line (KPCY55) from murine PDAC were subcutaneously injected into wildtype (WT) and GPR55 knockout (KO) mice, and immune cell populations were evaluated by flow cytometry.

Results: Deficiency of GPR55 in the TME led to reduced tumor weight and volume, and altered the immune cell composition of tumors, favoring an anti-tumorigenic environment by increasing the number of CD3+ T cells, particularly CD8+ T cells, and the expression of PDL1 on macrophages. RNA-seq pathway analysis revealed higher T cell activity in KPCY55 tumors of GPR55 KO vs. WT mice. In addition, tumors from GPR55 KO mice displayed increased levels of T cell chemokines Cxcl9 and Cxcl10. Migration of T cells from GPR55 KO mice towards CXCL9 was increased in comparison to T cells from WT mice, suggesting that a CXCR3/CXCL9 axis was involved in T cell influx into tumors of GPR55 KO mice. Notably, anti-PD-1 immunotherapy increased tumor burden in WT mice, while this effect was absent in the GPR55 KO mice.

Conclusion: Our study indicates that GPR55 in TME cells may drive tumor growth by suppressing T cell functions, such as migration, in a model of PDAC, making it an interesting target for immunotherapies.”

https://pubmed.ncbi.nlm.nih.gov/39885986/

“Our study indicates that GPR55 in TME cells may drive tumor growth by suppressing T cell functions, such as migration, in a model of PDAC, making it an interesting target for immunotherapies.”

https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1513547/full

“GPR55 – a putative “type 3″ cannabinoid receptor in inflammation”

https://pubmed.ncbi.nlm.nih.gov/26669245/

“Therapeutic targeting of the tumor microenvironments with cannabinoids and their analogs: Update on clinical trials”

https://pubmed.ncbi.nlm.nih.gov/37146933/

“Anti-proliferative and apoptotic effect of cannabinoids on human pancreatic ductal adenocarcinoma xenograft in BALB/c nude mice model”

https://pubmed.ncbi.nlm.nih.gov/38499634/

“Antitumor Effects of Cannabinoids in Human Pancreatic Ductal Adenocarcinoma Cell Line (Capan-2)-Derived Xenograft Mouse Model”

https://pubmed.ncbi.nlm.nih.gov/35937289/

“Cannabinoid improves survival rates of mice with pancreatic cancer”

https://medicalxpress.com/news/2018-07-cannabinoid-survival-mice-pancreatic-cancer.html

Bridging the gap: The endocannabinoid system as a functional fulcrum for benzodiazepines in a novel frontier of anxiety pharmacotherapy

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“While benzodiazepines have been a mainstay of the pharmacotherapy of anxiety disorders, their short-term efficacy and risk of abuse have driven the exploration of alternative treatment approaches.

The endocannabinoid (eCB) system has emerged as a key modulator of anxiety-related processes, with evidence suggesting dynamic interactions between the eCB system and the GABAergic system, the primary target of benzodiazepines.

According to the existing literature, the activation of the cannabinoid receptors has been shown to exert anxiolytic effects, while their blockade or genetic deletion results in heightened anxiety-like responses. Moreover, studies have provided evidence of interactions between the eCB system and benzodiazepines in anxiety modulation. For instance, the attenuation of benzodiazepine-induced anxiolysis by cannabinoid receptor antagonism or genetic variations in the eCB system components in animal studies, have been associated with variations in benzodiazepine response and susceptibility to anxiety disorders.

The combined use of cannabinoid-based medications, such as cannabinoid receptor agonists and benzodiazepine co-administration, has shown promise in augmenting anxiolytic effects and reducing benzodiazepine dosage requirements.

This article aims to comprehensively review and discuss the current evidence on the involvement of the eCB system as a key modulator of benzodiazepine-related anxiolytic effects, and further, the possible mechanisms by which the region-specific eCB system-GABAergic connectivity modulates the neuro-endocrine/behavioral stress response, providing an inclusive understanding of the complex interplay between the eCB system and benzodiazepines in the context of anxiety regulation, to inform future research and clinical practice.”

https://pubmed.ncbi.nlm.nih.gov/39862927/

https://www.sciencedirect.com/science/article/abs/pii/S0163725825000117?via%3Dihub

Exploring the diversity of cannabis cannabinoid and non-cannabinoid compounds and their roles in Alzheimer’s disease: A review

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“Cannabis sativa is recognized for its chemical diversity and therapeutic potential, particularly in addressing neurodegenerative diseases such as Alzheimer’s disease (AD). Given the complexity of AD, where single-target therapies often prove inadequate, a multi-target approach utilizing cannabis-derived compounds may offer promising alternatives.

This review first highlights the chemical diversity of cannabis by categorizing its compounds into cannabinoids and non-cannabinoids. It then examines studies investigating the effects of these compounds on AD-related pathological features.

By synthesizing existing knowledge, identifying research gaps, and facilitating comparative analysis, this review aims to advance future research and understanding. It underscores cannabis’s potential as a multi-target therapeutic strategy for AD, contributing valuable insights to ongoing scientific discussions.”

https://pubmed.ncbi.nlm.nih.gov/39866750/

“Cannabis sativa exhibits rich chemical diversity, categorized into cannabinoid and non-cannabinoid compounds.”

“The plant’s therapeutic potential is particularly relevant for treating neurodegenerative diseases like AD.”

“The discovery of the endocannabinoid system underscores the importance of cannabis-derived compounds in AD research.”

“A multi-target approach with cannabis compounds may overcome the limitations of single-target therapies in AD.”

“The review synthesizes existing research, identifies gaps, and aims to improve future studies on cannabis and AD.”

https://www.ibroneuroreports.org/article/S2667-2421(24)00119-2/fulltext


Cannabinoid receptor 1 ligands: Biased signaling mechanisms driving functionally selective drug discovery

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“G protein-coupled receptors (GPCRs) adopt conformational states that activate or inhibit distinct signaling pathways, including those mediated by G proteins or β-arrestins. Biased signaling through GPCRs may offer a promising strategy to enhance therapeutic efficacy while reducing adverse effects.

Cannabinoid receptor 1 (CB1), a key GPCR in the endocannabinoid system, presents therapeutic potential for conditions such as pain, anxiety, cognitive impairment, psychiatric disorders, and metabolic diseases.

This review examines the structural conformations of CB1 coupling to different signaling pathways and explores the mechanisms underlying biased signaling, which are critical for the design of functionally selective ligands. We discuss the structure-function relationships of endogenous cannabinoids (eCBs), phytocannabinoids, and synthetic cannabinoid ligands with biased properties. Challenges such as the complexity of ligand bias screening, the limited availability of distinctly biased ligands, and the variability in receptor signaling profiles in vivo have hindered clinical progress.

Although the therapeutic potential of biased ligands in various clinical conditions remains in its infancy, retrospective identification of such molecules provides a strong foundation for further development. Recent advances in CB1 crystallography, particularly insights into its conformations with G proteins and β-arrestins, now offer a framework for structure-based drug design. While there is still a long way to go before biased CB1 ligands can be widely used in clinical practice, ongoing multidisciplinary research shows promise for achieving functional selectivity in targeting specific pathways.

These progresses could lead to the development of safer and more effective cannabinoid-based therapies in the future.”

https://pubmed.ncbi.nlm.nih.gov/39828030/

https://www.sciencedirect.com/science/article/abs/pii/S0163725825000075?via%3Dihub

∆9-Tetrahydrocannabinol Increases Growth Factor Release by Cultured Adipose Stem Cells and Adipose Tissue in vivo

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“Background: Because of its biocompatibility and its soft and dynamic nature, the grafting of adipose tissue is regarded an ideal technique for soft-tissue repair. The adipose stem cells (ASCs) contribute significantly to the regenerative potential of adipose tissue, because they can differentiate into adipocytes and release growth factors for tissue repair and neovascularization to facilitate tissue survival. The present study tested the effect of administering a chronic low dose of ∆9-tetrahydrocannabinol (THC) on these regenerative properties, in vitro and in vivo.

Methods: Human ASCs were exposed to increasing concentrations of THC. Resazurin conversion was applied to investigate the effect on metabolic activity, cell number was assessed by crystal violet staining, tri-linear differentiation was evaluated by specific colorimetric approaches, and the release of growth factors was analyzed by ELISA. Two groups of mice were treated daily either with a low dose of THC (3 mg/kg) or a vehicle solution. After 3 weeks, adipose tissue was obtained from excised fat deposits, homogenized and tested for growth factor contents.

Results: THC decreased ASC proliferation but increased metabolic activity as well as adipogenic and chondrogenic differentiation. A low concentration of THC (1 µM) enhanced the growth factor release by ASCs. The concentration of these cytokines was also increased in adipose tissue of mice treated with THC.

Conlusion: Our results indicate that chronic activation of the endocannabinoid system promoted differentiation and growth factor release of ASCs, which could be of specific value for enhancing the regenerative potential of adipose tissue.”

https://pubmed.ncbi.nlm.nih.gov/39825991/

“Our findings may offer a new approach for improved application of adipose tissue in regenerative medicine.”

https://link.springer.com/article/10.1007/s13770-024-00692-8

Cannabinoid-based Pharmacology for the Management of Substance Use Disorders

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“In the last two decades, the endocannabinoid system has emerged as a crucial modulator of motivation and emotional processing. Due to its widespread neuroanatomical distribution and characteristic retrograde signaling nature, cannabinoid type I receptors and their endogenous ligands finely orchestrate somatic and axon terminal activity of dopamine neurons.

Owing to these unique features, this signaling system is a promising pharmacological target to ameliorate dopamine-mediated drug-seeking behaviors while circumventing the adverse side effects of, for instance, dopaminergic antagonists.

Despite considerable preclinical efforts, an agreement on the efficacy of endocannabinoid-targeting compounds for treating drug substance use disorders in humans has not been reached. In the following chapter, we will summarize preclinical and clinical evidence addressing the therapeutic potential of cannabinoids and endocannabinoid-targeting compounds in substance use disorders.

To bridge the gap between animal and clinical research, we capitalize on studies evaluating the impact of endocannabinoid-targeting compounds in relevant settings, such as the management of drug relapse.

Finally, we discuss the therapeutic potential of novel cannabinoid compounds that hold promise for treating substance use disorders.”

https://pubmed.ncbi.nlm.nih.gov/39813001/

https://link.springer.com/chapter/10.1007/7854_2024_551

Determination of the Negative Allosteric Binding Site of Cannabidiol at the CB1 Receptor: A Combined Computational and Site-Directed Mutagenesis Study

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“Cannabinoid receptor 1 (CB1R) has been extensively studied as a potential therapeutic target for various conditions, including pain management, obesity, emesis, and metabolic syndrome. Unlike orthosteric agonists such as Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD) has been identified as a negative allosteric modulator (NAM) of CB1R, among its other pharmacological targets. Previous computational and structural studies have proposed various binding sites for CB1R NAMs. An X-ray crystal structure revealed a binding site for the NAM, ORG27569, at an extrahelical location within the inner leaflet of the membrane. In contrast, multiple computational studies have previously proposed several potential allosteric binding sites for CBD within the CB1R structure. Given that a prior structural study suggested CBD might occupy the same site as ORG27569, we conducted a comprehensive investigation of potential CBD binding sites using molecular docking, molecular dynamics (MD) simulations, metadynamics (MTD) simulations, binding free-energy calculations, and in vitro mutagenesis experiments. Molecular docking, MD, and MTD simulations results, along with binding free-energy calculations, suggest that CBD may potentially bind to either the same extrahelical site as ORG27569 or a previously unidentified intracellular site located near TMHs 2, 6, and 7 and helix 8. This intracellular site is consistent with allosteric binding sites observed in other G protein-coupled receptors (GPCRs). To establish the most favorable allosteric site for CBD, we conducted site-directed mutagenesis of key residues at each site. Mutations at S4018.47ΔA and D4038.49ΔA augmented the binding of [3H]-SR141716A, suggesting these residues play critical roles in CBD binding. As a result, the combined computational and mutagenesis results identified a binding site for CBD between TMHs 2, 6, and 7 and helix 8, involving residues Y1532.40, I1562.43, M3376.29, L3416.33, S4018.47, and D4038.49. These findings provide valuable insights into how CBD binds to CB1R, thereby informing the rational design of new, selective, and potent NAMs. Moreover, the elucidation of this previously unexplored allosteric site might explain the polypharmacology of CBD due to structural conservation among Class A GPCRs.”

https://pubmed.ncbi.nlm.nih.gov/39812521/

https://pubs.acs.org/doi/10.1021/acschemneuro.4c00343

Cannabinoids: Role in Neurological Diseases and Psychiatric Disorders

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“An impact of legalization and decriminalization of marijuana is the gradual increase in the use of cannabis for recreational purposes, which poses a potential threat to society and healthcare systems worldwide. However, the discovery of receptor subtypes, endogenous endocannabinoids, and enzymes involved in synthesis and degradation, as well as pharmacological characterization of receptors, has led to exploration of the use of cannabis in multiple peripheral and central pathological conditions.

The role of cannabis in the modulation of crucial events involving perturbed physiological functions and disease progression, including apoptosis, inflammation, oxidative stress, perturbed mitochondrial function, and the impaired immune system, indicates medicinal values.

These events are involved in most neurological diseases and prompt the gradual progression of the disease. At present, several synthetic agonists and antagonists, in addition to more than 70 phytocannabinoids, are available with distinct efficacy as a therapeutic alternative in different pathological conditions. The present review aims to describe the use of cannabis in neurological diseases and psychiatric disorders.”

https://pubmed.ncbi.nlm.nih.gov/39796008/

“Cannabis sativa L. (marijuana), an ancient plant with medicinal values, has been used for medicinal, recreational, and spiritual purposes for a long time worldwide.”

“The discovery of the ECS has sparked the interest of many researchers worldwide due to its potential therapeutic contribution to some of the incurable neurodegenerative diseases such as AD, PD, HD, and psychological abnormalities. To date, studies have uncovered the expression, location, structures, and mechanism of cannabinoid receptors.

When the endocannabinoid system’s associations with other biochemical pathways are fully elucidated, many medical and political changes will be seen, such as the legalization of marijuana and new therapeutic approaches to neurodegenerative diseases.

Recent developments regarding crystal structure and cryoEM open the door to understanding the structural complexity and future therapeutic implication of cannabinoids in neurological and psychiatric disorders. Most genes associated with neurological diseases have been defined; however, the molecular details of other changes are largely elusive and are of immense interest to be explored. At this stage, it will be interesting to elucidate the role of CB2R as a neuroprotective strategy in addition to other proteins that are modulated following cannabis administration.

Neuroinflammation, oxidative stress, and disrupted cell organelles, specifically mitochondria, are intimately associated with compelling causative factors for disease progression and are potential therapeutic avenues to explore in neurodegeneration, along with psychological disturbances; therefore, they should be the prime objective for future studies on cannabinoids to develop novel therapeutic chimeric molecules with minimum side effects and maximum benefits.”

https://www.mdpi.com/1422-0067/26/1/152

Medicinal Cannabis and the Intestinal Microbiome

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“Historically, the multiple uses of cannabis as a medicine, food, and for recreational purposes as a psychoactive drug span several centuries.

The various components of the plant (i.e., seeds, roots, leaves and flowers) have been utilized to alleviate symptoms of inflammation and pain (e.g., osteoarthritis, rheumatoid arthritis), mood disorders such as anxiety, and intestinal problems such as nausea, vomiting, abdominal pain and diarrhea.

It has been established that the intestinal microbiota progresses neurological, endocrine, and immunological network effects through the gut-microbiota-brain axis, serving as a bilateral communication pathway between the central and enteric nervous systems.

An expanding body of clinical evidence emphasizes that the endocannabinoid system has a fundamental connection in regulating immune responses. This is exemplified by its pivotal role in intestinal metabolic and immunity equilibrium and intestinal barrier integrity.

This neuromodulator system responds to internal and external environmental signals while also serving as a homeostatic effector system, participating in a reciprocal association with the intestinal microbiota.

We advance an exogenous cannabinoid-intestinal microbiota-endocannabinoid system axis potentiated by the intestinal microbiome and medicinal cannabinoids supporting the mechanism of action of the endocannabinoid system. An integrative medicine model of patient care is advanced that may provide patients with beneficial health outcomes when prescribed medicinal cannabis.”

https://pubmed.ncbi.nlm.nih.gov/39770543/

“Furthermore, other modes of delivery of medicinal cannabis, such as oro-buccal, sublingual and inhaled/smoked alternatives, provide cannabinoids that have rapid access to the systemic circulation, bypassing the intestinal tract.”

https://www.mdpi.com/1424-8247/17/12/1702

The Role of Cannabinoids and the Endocannabinoid System in the Treatment and Regulation of Nausea and Vomiting

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“Despite using the recommended anti-emetic treatments, control of nausea and vomiting is still an unmet need for cancer patients undergoing chemotherapy treatment. Few properly controlled clinical trials have evaluated the potential of exogenously administered cannabinoids or manipulations of the endogenous cannabinoid (eCB) system to treat nausea and vomiting. In this chapter, we explore the pre-clinical and human clinical trial evidence for the potential of exogenous cannabinoids and manipulations of the eCB system to reduce nausea and vomiting. Although there are limited high-quality human clinical trials, pre-clinical evidence suggests that cannabinoids and manipulations of the eCB system have anti-nausea/anti-emetic potential. The pre-clinical anti-nausea/anti-emetic evidence highlights the need for further evaluation of cannabinoids and manipulations of eCBs and other fatty acid amides in clinical trials.”

https://pubmed.ncbi.nlm.nih.gov/39739175/

https://link.springer.com/chapter/10.1007/7854_2024_554