Endocannabinoids and immune regulation

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“Cannabinoid pharmacology has made important advances in recent years after the discovery of the cannabinoid receptors.

These discoveries have added to our understanding of exogenous and endogenous cannabinoid signaling along with exploring the various pathways of their biosynthesis, molecular structure, inactivation, and anatomical distribution of their receptors throughout the body.

The endocannabinoid system is involved in immunoregulation and neuroprotection.

The discovery of cannabinoid receptors occurring naturally throughout the vertebrate body and the availability of highly selective and potent canabimimetics led to the identification of a naturally occurring lipid signaling system termed the endocannabinoid system.

Interestingly, the endocannabinoid system dates back very long in the evolution because it exists as an ancient plant signaling system regulating the plant immunity-related genes in response to infection and stress.

The main pharmacological functions of the endocannabinoid system include neuromodulation, controlling motor functions, cognition, emotional responses, homeostasis and motivation. However, in the periphery, this system is an important modulator of autonomic nervous system, the immune system and microcirculation.

There have been a number of recent studies which have demonstrated that the endocannabinoids have both inhibitory effects and stimulatory impact on the immune system and may be actually important in homeostasis or control of the immune reactions.

 The image of endocannabinoid system now appears to be of a modulatory complex which affects the physiological functions in peripheral tissues and can thus be considered as a potential therapeutic target in the future.
Thus, manipulation of endocannabinoids in vivo may constitute a novel treatment modality against inflammatory disorders.”

MAPPING CANNABINOID RECEPTOR 1 ALLOSTERIC SITE(S): CRITICAL MOLECULAR DETERMINANT AND SIGNALING PROFILE OF GAT100 – A NOVEL, POTENT AND IRREVERSIBLY BINDING PROBE.

“One of the most abundant G-protein coupled receptors (GPCRs) in brain, the cannabinoid 1 receptor (CB1R) is a tractable therapeutic target for treating diverse psychobehavioral and somatic disorders.

Adverse on-target effects associated with small-molecule CB1R orthosteric agonists and inverse agonists/antagonists have plagued their translational potential. Allosteric CB1R modulators offer a potentially safer modality through which CB1R signaling may be directed for therapeutic benefit.

Rational design of candidate, drug-like CB1R allosteric modulators requires greater understanding of the architecture of the CB1R allosteric endodomain(s) and the capacity of CB1R allosteric ligands to tune the receptor’s information output.

These data help inform the engineering of newer-generation, druggable CB1R allosteric modulators and demonstrate the utility of GAT100 as a covalent probe for mapping structure-function correlates characteristic of the druggable CB1R allosteric space.”

http://www.ncbi.nlm.nih.gov/pubmed/27046127

Distinctive effects of eicosapentaenoic and docosahexaenoic acids in regulating neural stem cell fate are mediated via endocannabinoid signalling pathways.

“Emerging evidence suggests a complex interplay between the endocannabinoid system, omega-3 fatty acids and the immune system in the promotion of brain self-repair.

However, it is unknown if all omega-3 fatty acids elicit similar effects on adult neurogenesis and if such effects are mediated or regulated by interactions with the endocannabinoid system. This study investigated the effects of DHA and EPA on neural stem cell (NSC) fate and the role of the endocannabinoid signalling pathways in these effects.

EPA, but not DHA, significantly increased proliferation of NSCs compared to controls, an effect associated with enhanced levels of the endocannabinoid 2-arachidonylglycerol (2-AG) and p-p38 MAPK, effects attenuated by pre-treatment with CB1 (AM251) or CB2 (AM630) receptor antagonists.

Furthermore, in NSCs derived from IL-1β deficient mice, EPA significantly decreased proliferation and p-p38 MAPK levels compared to controls, suggesting a key role for IL-1β signalling in the effects observed. Although DHA similarly increased 2-AG levels in wild-type NSCs, there was no concomitant increase in proliferation or p-p38 MAPK activity. In addition, in NSCs from IL-1β deficient mice, DHA significantly increased proliferation without effects on p-P38 MAPK, suggesting effects of DHA are mediated via alternative signalling pathways.

These results provide crucial new insights into the divergent effects of EPA and DHA in regulating NSC proliferation and the pathways involved, and highlight the therapeutic potential of their interplay with endocannabinoid signalling in brain repair.”

http://www.ncbi.nlm.nih.gov/pubmed/27044662

No more pain upon Gq-protein-coupled receptor activation: role of endocannabinoids.

“Marijuana has been used to relieve pain for centuries.

The analgesic mechanism of its constituents, the cannabinoids, was only revealed after the discovery of cannabinoid receptors (CB1 and CB2) two decades ago.”

http://www.ncbi.nlm.nih.gov/pubmed/24494686

Endocannabinoid Signaling Regulates Sleep Stability.

“Since antiquity cannabinoids have been used as a treatment for insomnia, and the first reports in western medical literature regarding the therapeutic utility and physiological effects of cannabis preparations note their hypnogenic properties.

The hypnogenic properties of cannabis have been recognized for centuries, but endogenous cannabinoid (endocannabinoid) regulation of vigilance states is poorly characterized.

We report findings from a series of experiments in mice measuring sleep with polysomnography after various systemic pharmacological manipulations of the endocannabinoid system.

Our findings demonstrate that eCB signaling is necessary and sufficient for the control of sleep stability, but this neurotransmitter system is not necessary for sleep homeostasis.

 These results support the hypothesis that endocannabinoid signaling through CB1 is necessary for NREM stability but it is not necessary for sleep homeostasis.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816426/

http://www.thctotalhealthcare.com/category/insomnia/

Beyond the CB1 Receptor: Is Cannabidiol the Answer for Disorders of Motivation?

“The Cannabis sativa plant has been used to treat various physiological and psychiatric conditions for millennia.

Current research is focused on isolating potentially therapeutic chemical constituents from the plant for use in the treatment of many central nervous system disorders.

Of particular interest is the primary nonpsychoactive constituent cannabidiol (CBD).

Unlike Δ9-tetrahydrocannabinol (THC), CBD does not act through the cannabinoid type 1 (CB1) receptor but has many other receptor targets that may play a role in psychiatric disorders.

Here we review preclinical and clinical data outlining the therapeutic efficacy of CBD for the treatment of motivational disorders such as drug addiction, anxiety, and depression.

Across studies, findings suggest promising treatment effects and potentially overlapping mechanisms of action for CBD in these disorders and indicate the need for further systematic investigation of the viability of CBD as a psychiatric pharmacotherapy.”

http://www.ncbi.nlm.nih.gov/pubmed/27023732

The role of carbon monoxide on the anti-nociceptive effects and expression of cannabinoid 2 receptors during painful diabetic neuropathy in mice.

“The activation of cannabinoid 2 receptors (CB2R) attenuates chronic pain, but the role played by carbon monoxide synthesized by the inducible heme oxygenase 1 (HO-1) on the anti-nociceptive effects produced by a selective CB2R agonist, JWH-015, during painful diabetic neuropathy remains unknown.

The activation of HO-1 enhanced the anti-nociceptive effects of JWH-015 in diabetic mice, suggesting that coadministration of JWH-015 with CORM-2 or CoPP might be an interesting approach for the treatment of painful diabetic neuropathy in mice.”

http://www.ncbi.nlm.nih.gov/pubmed/27020787

Experimental cannabinoid 2 receptor inhibition in CNS injury-induced immunodeficiency syndrome.

“Severe central nervous system (CNS) injury, such as stroke, traumatic brain injury or spinal cord injury, is known to increase susceptibility to infections. The increased susceptibility to infection is due to an impaired immune response and is referred to as CNS injury-induced immune deficiency syndrome (CIDS).

The cannabinoid 2 receptor (CB2 R) on immune cells presents a potential therapeutic target in CIDS as activation of this receptor has been shown to be involved in immunosuppression.

Our findings suggest that inhibition of CB2 R signaling in animals with CIDS challenged with endotoxin restored peripheral leukocyte recruitment without detrimental impact on infarct size.

We conclude that the endocannabinoid system is involved in the impaired immune response following CNS injury and future studies should further explore the CB2 R pathway in order to develop novel therapies for CIDS.”

http://www.ncbi.nlm.nih.gov/pubmed/26999797

Cannabinoids Occlude the HIV-1 Tat-Induced Decrease in GABAergic Neurotransmission in Prefrontal Cortex Slices.

“In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is now considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND).

Endocannabinoids exhibit neuroprotective and anti-inflammatory properties in several central nervous system (CNS) disease models, but their effects in HAND are poorly understood.

Results indicated a Tat-induced decrease in GABAergic neurotransmission, which was occluded by cannabinoids via a CB1R-related mechanism.

Understanding the relationship between Tat toxicity and endocannabinoid signaling has the potential to identify novel therapeutic interventions to benefit individuals suffering from HAND and other cognitive impairments.”

http://www.ncbi.nlm.nih.gov/pubmed/26993829

http://www.thctotalhealthcare.com/category/hivaids/

The cannabinoid receptor type 2 Q63R variant increases the risk of celiac disease: implication for a novel molecular biomarker and future therapeutic intervention.

“Celiac disease (CD) is a chronic inflammatory disease of the small bowel that occurs with the ingestion of gluten, found in several grains products. Although HLA-DQ2 variant is required for the gluten-derived peptide gliadin presentation by antigen-presenting cells to T-cells, non-HLA genetic factors account for the majority of heritable risk. Several genome-wide association studies have identified susceptibility loci for CD on chromosome 1. Cells of the immune system express the cannabinoid receptor type 2 (CB2), a plasma-membrane receptor activated by both endogenous and exogenouscannabinoids. Consistent data evidence that CB2 is linked to a variety of immune functional events and that, in the course of an inflammatory process, an increased number of receptors becomes available for activation. The cannabinoid receptor type 2 gene (CNR2; GeneID1269) maps on 1p36.11. In order to investigate the possible involvement of CB2 in CD establishment, immunohistochemistry toward CB2 receptor and CD4+ cells in small bowel biopsies from celiac children and association analysis, through TaqMan assay, of a CNR2 common missense variant, rs35761398 (CAA/CGG), resulting in the aminoacidic substitution of Glutamine at codon 63 with Arginine (Q63R), in a cohort of 327 South Italian children have been performed. We observed in this study that CB2 is up-regulated in CD small bowel biopsies and CNR2 rs35761398 is significantly associated with CD (χ(2) = 37.064; d.f. 1; p = 1.14 × 10(-9)). Our findings suggest a role of CB2 in CD. The Q63R variant, increasing more than six-fold the risk for CD susceptibility, might eventually represent a novel molecular biomarker for CD risk stratification. Indeed, we provide here further evidence that CB2 receptor plays a critical role in autoimmunity susceptibility and indicates that it represents a molecular target to pharmacologically modulate the immune components in CD.”

http://www.ncbi.nlm.nih.gov/pubmed/22465144