“GPR3 and GPR6 are members of a family of constitutively active, Gs protein-coupled receptors. Previously, it has been reported that GPR3 is involved in Alzheimer’s disease whereas GPR6 plays potential roles in Parkinson’s disease. GPR3 and GPR6 are considered orphan receptors because there are no confirmed endogenous agonists for them. However, GPR3 and GPR6 are phylogenetically related to the cannabinoid receptors. In this study, the activities of endocannabinoids and phytocannabinoids were tested on GPR3 and GPR6 using a β-arrestin2 recruitment assay. Among the variety of cannabinoids tested, cannabidiol (CBD), the major non-psychoactive component of marijuana, significantly reduced β-arrestin2 recruitment to both GPR3 and GPR6. In addition, the inhibitory effects of CBD on β-arrestin2 recruitment were concentration-dependent for both GPR3 and GPR6, with a higher potency for GPR6. These data show that CBD acts as an inverse agonist at both GPR3 and GPR6 receptors. These results demonstrate for the first time that both GPR3 and GPR6 are novel molecular targets for CBD. Our discovery that CBD acts as a novel inverse agonist on both GPR3 and GPR6 indicates that some of the potential therapeutic effects of CBD (e.g. treatment of Alzheimer’s disease and Parkinson’s disease) may be mediated through these important receptors.” https://www.ncbi.nlm.nih.gov/pubmed/28571738 http://www.sciencedirect.com/science/article/pii/S0006291X17310744]]>
Category Archives: Endocannabinoid System
The endocannabinoid system as a target for addiction treatment: Trials and tribulations.
“Addiction remains a major public health concern, and while pharmacotherapies can be effective, clinicians are limited by the paucity of existing interventions. Endocannabinoid signaling is involved in reward and addiction, which raises the possibility that drugs targeting this system could be used to treat substance use disorders. This review discusses findings from randomized controlled trials evaluating cannabinergic medications for addiction. Current evidence suggests that pharmacotherapies containing delta-9-tetrahydrocannabinol, such as dronabinol and nabiximols, are effective for cannabis withdrawal. Dronabinol may also reduce symptoms of opioid withdrawal. The cannabinoid receptor 1 (CB1) inverse agonist rimonabant showed promising effects for smoking cessation but also caused psychiatric side effects and currently lacks regulatory approval. Few trials have investigated cannabinergic medications for alcohol use disorder. Overall, the endocannabinoid system remains a promising target for addiction treatment. Development of novel medications such as fatty acid amide hydrolase inhibitors and neutral CB1 antagonists promises to extend the range of available interventions.” https://www.ncbi.nlm.nih.gov/pubmed/28564576 http://www.sciencedirect.com/science/article/pii/S0028390817302563]]>
Cannabinoid CB1/CB2 receptor agonists attenuate hyperactivity and body weight loss in a rat model of activity-based anorexia.
“Anorexia nervosa (AN) is a serious psychiatric condition characterized by excessive body weight loss and disturbed perceptions of body shape and size, often associated with excessive physical activity. There is currently no effective drug-related therapy of this disease and this leads to high relapse rate. Clinical data suggest that a promising therapy to treat and reduce reoccurrence of AN may be based on the use of drugs that target the endocannabinoid (EC) system, which appears dysregulated in AN patients.
Our data show that subchronic treatment with both the CB1/CB2 receptor natural agonist Δ9-tetrahydrocannabinol and the synthetic CB1/CB2 receptor agonist CP-55,940 significantly reduced body weight loss and running wheel activity in ABA rats. These behavioral effects were accompanied by an increase in leptin signaling and a decrease in plasma levels of corticosterone.
Taken together, our results further demonstrate EC system involvement in AN pathophysiology and that strategies which modulate EC signaling are useful to treat this disorder, specifically in patients where physical hyperactivity plays a central role in its progression and maintenance.” https://www.ncbi.nlm.nih.gov/pubmed/28561272 http://onlinelibrary.wiley.com/doi/10.1111/bph.13892/abstract]]>Nonopioid placebo analgesia is mediated by CB1 cannabinoid receptors.
“Placebo analgesia is mediated by both opioid and nonopioid mechanisms, but so far nothing is known about the nonopioid component. Here we show that the specific CB1 cannabinoid receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (rimonabant or SR141716) blocks nonopioid placebo analgesic responses but has no effect on opioid placebo responses. These findings suggest that the endocannabinoid system has a pivotal role in placebo analgesia in some circumstances when the opioid system is not involved.”
Activation of CB2 receptor system restores cognitive capacity and hippocampal Sox2 expression in a transgenic mouse model of Alzheimer's disease.
“Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by neuroinflammation, extensive deposits of amyloid-β aggregates, and loss of memory and cognitive abilities. The brains of patients with AD show increased expression of cannabinoid receptor type 2 (CB2) receptors and glial markers. CB2 receptors act as a negative feedback regulator; when activated by a CB2agonist, they can help limit the extent of the neuroinflammatory response and the subsequent development of neuronal damage in the central nervous system. In a double transgenic APP/PS1 mice model of AD, we evaluated the effect of MDA7, a CB2 agonist, on several neuropathological conditions of AD including amyloid deposition, inflammatory reaction, Sox2 (sex-determining region Y-box 2) expression, and spatial memory. Activation of microglia CB2 receptors by MDA7 suppressed neuroinflammation, demonstrated by decreased immunosignal of Iba1 in the hippocampal CA1 and dentate gyrus (DG) areas, promoted clearance of amyloid plaques in the DG area, restored Sox2 expression, and promoted recovery of the neuronal synaptic plasticity in hippocampal CA1. In addition, treatment with MDA7 improved the behavioral performance in the Morris water maze in APP/PS1mice. Collectively, these findings suggest that MDA7 has a potential therapeutic effect in the setting of AD.” https://www.ncbi.nlm.nih.gov/pubmed/28551012 http://www.sciencedirect.com/science/article/pii/S0014299917303758]]>
Activation of CB2 receptor system restores cognitive capacity and hippocampal Sox2 expression in a transgenic mouse model of Alzheimer’s disease.
“Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by neuroinflammation, extensive deposits of amyloid-β aggregates, and loss of memory and cognitive abilities. The brains of patients with AD show increased expression of cannabinoid receptor type 2 (CB2) receptors and glial markers. CB2 receptors act as a negative feedback regulator; when activated by a CB2agonist, they can help limit the extent of the neuroinflammatory response and the subsequent development of neuronal damage in the central nervous system. In a double transgenic APP/PS1 mice model of AD, we evaluated the effect of MDA7, a CB2 agonist, on several neuropathological conditions of AD including amyloid deposition, inflammatory reaction, Sox2 (sex-determining region Y-box 2) expression, and spatial memory. Activation of microglia CB2 receptors by MDA7 suppressed neuroinflammation, demonstrated by decreased immunosignal of Iba1 in the hippocampal CA1 and dentate gyrus (DG) areas, promoted clearance of amyloid plaques in the DG area, restored Sox2 expression, and promoted recovery of the neuronal synaptic plasticity in hippocampal CA1. In addition, treatment with MDA7 improved the behavioral performance in the Morris water maze in APP/PS1mice. Collectively, these findings suggest that MDA7 has a potential therapeutic effect in the setting of AD.”
https://www.ncbi.nlm.nih.gov/pubmed/28551012
http://www.sciencedirect.com/science/article/pii/S0014299917303758
Endocannabinoids modulate apoptosis in endometriosis and adenomyosis.
“Adenomyosis that is a form of endometriosis is the growth of ectopic endometrial tissue within the muscular wall of the uterus (myometrium), which may cause dysmenorrhea and infertility. Endocannabinoid mediated apoptotic mechanisms of endometriosis and adenomyosis are not known. We hypothesized that the down regulation of endocannabinoid receptors and/or alteration in their regulatory enzymes may have a direct role in the pathogenesis of endometriosis and adenomyosis through apoptosis. Endocannabinoid receptors CB1 and CB2, their synthesizing and catabolizing enzymes (FAAH, NAPE-PLD, DAGL, MAGL) and the apoptotic indexes were immunohistochemically assessed in endometriotic and adenomyotic tissues. Findings were compared to normal endometrium and myometrium. Endometrial adenocarcinoma (Ishikawa) and ovarian endometriosis cyst wall stromal (CRL-7566) cell lines were furthermore cultured with or without cannabinoid receptor agonists. The IC50 value for CB1 and CB2 receptor agonists was quantified. Cannabinoid agonists on cell death were investigated by Annexin-V/Propidium iodide labeling with flow cytometry. CB1 and CB2 receptor levels decreased in endometriotic and adenomyotic tissues compared to the control group (p=0,001 and p=0,001). FAAH, NAPE-PLD, MAGL and DAGL enzyme levels decreased in endometriotic and adenomyotic tissues compared to control (p=0,001, p=0,001, p=0,001 and p=0,002 respectively). Apoptotic cell indexes both in endometriotic and adenomyotic tissues also decreased significantly, compared to the control group (p=0,001 and p=0,001). CB1 and CB2 receptor agonist mediated dose dependent fast anti-proliferative and pro-apoptotic effects were detected in Ishikawa and ovarian endometriosis cyst wall stromal cell lines (CRL-7566). Endocannabinoids are suggested to increase apoptosis mechanisms in endometriosis and adenomyosis. CB1 and CB2 antagonists can be considered as potential medical therapeutic agents for endometriosis and adenomyosis.” https://www.ncbi.nlm.nih.gov/pubmed/28549792 http://www.sciencedirect.com/science/article/pii/S0065128116303154]]>
Activation of cannabinoid receptor type II by AM1241 protects adipose-derived mesenchymal stem cells from oxidative damage and enhances their therapeutic efficacy in myocardial infarction mice via Stat3 activation.
“The cannabis plant and its active ingredients (i.e., cannabinoids and terpenoids) have been socially stigmatized for half a century. Luckily, with more than 430,000 published scientific papers and about 600 ongoing and completed clinical trials, nowadays cannabis is employed for the treatment of many different medical conditions. Nevertheless, even if a large amount of high-throughput functional genomic data exists, most researchers feature a strong background in molecular biology but lack advanced bioinformatics skills. In this work, publicly available gene expression datasets have been analyzed giving rise to a total of 40,224 gene expression profiles taken from cannabis plant tissue at different developmental stages. The resource presented here will provide researchers with a starting point for future investigations with Cannabis sativa.”