Endocannabinoids and the Immune System in Health and Disease.

“Endocannabinoids are bioactive lipids that have the potential to signal through cannabinoid receptors to modulate the functional activities of a variety of immune cells.

Their activation of these seven-transmembranal, G protein-coupled receptors sets in motion a series of signal transductional events that converge at the transcriptional level to regulate cell migration and the production of cytokines and chemokines.

There is a large body of data that supports a functional relevance for 2-arachidonoylglycerol (2-AG) as acting through the cannabinoid receptor type 2 (CB2R) to inhibit migratory activities for a diverse array of immune cell types.

However, unequivocal data that supports a functional linkage of anandamide (AEA) to a cannabinoid receptor in immune modulation remains to be obtained.

Endocannabinoids, as typical bioactive lipids, have a short half-life and appear to act in an autocrine and paracrine fashion.

Their immediate effective action on immune function may be at localized sites in the periphery and within the central nervous system.

It is speculated that endocannabinoids play an important role in maintaining the overall “fine-tuning” of the immune homeostatic balance within the host.”

http://www.ncbi.nlm.nih.gov/pubmed/26408161

Genetic Manipulation of the Endocannabinoid System.

“The physiological and pathophysiological functions of the endocannabinoid system have been studied extensively using transgenic and targeted knockout mouse models.

The first gene deletions of the cannabinoid CB1 receptor were described in the late 1990s, soon followed by CB2 and FAAH mutations in early 2000.

These mouse models helped to elucidate the fundamental role of endocannabinoids as retrograde transmitters in the CNS and in the discovery of many unexpected endocannabinoid functions, for example, in the skin, bone and liver.

We now have knockout mouse models for almost every receptor and enzyme of the endocannabinoid system.

Conditional mutant mice were mostly developed for the CB1 receptor, which is widely expressed on many different neurons, astrocytes and microglia, as well as on many cells outside the CNS.

These mouse strains include “floxed” CB1 alleles and mice with a conditional re-expression of CB1. The availability of these mice made it possible to decipher the function of CB1 in specific neuronal circuits and cell populations or to discriminate between central and peripheral effects.

Many of the genetic mouse models were also used in combination with viral expression systems.

The purpose of this review is to provide a comprehensive overview of the existing genetic models and to summarize some of the most important discoveries that were made with these animals.”

http://www.ncbi.nlm.nih.gov/pubmed/26408160

A Cannabinoid Receptor 2 Agonist Prevents Thrombin-Induced Blood-Brain Barrier Damage via the Inhibition of Microglial Activation and Matrix Metalloproteinase Expression in Rats.

“Thrombin mediates the life-threatening cerebral edema and blood-brain barrier (BBB) damage that occurs after intracerebral hemorrhage (ICH).

We previously found that the selective cannabinoid receptor 2 (CB2R) agonist JWH-133 reduced brain edema and neurological deficits following germinal matrix hemorrhage (GMH).

We explored whether CB2R stimulation ameliorated thrombin-induced brain edema and BBB permeability as well as the possible molecular mechanism involved.

The results demonstrated that JWH-133 administration significantly decreased thrombin-induced brain edema and reduced the number of Iba-1-positive microglia…

We demonstrated that CB2R stimulation reduced thrombin-induced brain edema and alleviated BBB damage.”

http://www.ncbi.nlm.nih.gov/pubmed/26376816

Pro-inflammatory obesity in aged cannabinoid-2 receptor deficient mice.

“Cannabinoid-1 receptor signaling increases the rewarding effects of food intake and promotes the growth of adipocytes, whereas CB2 possibly opposes these pro-obesity effects by silencing the activated immune cells that are key drivers of the metabolic syndrome.

Pro- and anti-orexigenic cannabimimetic signaling may become unbalanced with age because of alterations of the immune and endocannabinoid system…

CB2 agonists may fortify CB2-mediated anti-obesity signaling without the risk of anti-CB1 mediated depression that caused the failure of rimonabant.”

http://www.ncbi.nlm.nih.gov/pubmed/26303348

Synthesis and biological evaluation of (3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-aryl/alkyl-methanone selective CB2 inverse agonist.

“Cannabinoid receptor 2 (CB2) selective agonists and inverse agonists possess significant potential as therapeutic agents for regulating inflammation and immune function.

Although CB2 agonists have received the greatest attention, it is emerging that inverse agonists also manifest anti-inflammatory activity.

In process of designing new cannabinoid ligands we discovered that the 2,6-dihydroxy-biphenyl-aryl methanone scaffold imparts inverse agonist activity at CB2 receptor without functional activity at CB1. To further explore the scaffold we synthesized a series of (3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-aryl/alkyl-methanone analogs and evaluated the CB1 and CB2 affinity, potency, and efficacy.

The studies reveal that an aromatic C ring is required for inverse agonist activity and that substitution at the 4 position is optimum. The resorcinol moiety is required for optimum CB2 inverse agonist activity and selectivity. Antagonist studies against CP 55,940 demonstrate that the compounds 41 and 45 are noncompetitive antagonists at CB2.”

http://www.ncbi.nlm.nih.gov/pubmed/26275680

Novel Triazolopyrimidine-Derived Cannabinoid Receptor 2 Agonists As Potential Treatment for Inflammatory Kidney Diseases.

“The cannabinoid receptor 2 (CB2) system is described to modulate various pathological conditions, including inflammation and fibrosis.

A series of new heterocyclic small-molecule CB2 receptor agonists were identified from a high-throughput screen…

A significant depletion of the three measured kidney markers indicated a protective role of CB2 receptor activation toward inflammatory kidney damage. Compound 39 was also protective in a model of renal fibrosis.

Oral treatment with 39 at 3 mg kg-1 per day significantly decreased the amount of fibrosis by ∼40 % which was induced by unilateral ureter obstruction.”

http://www.ncbi.nlm.nih.gov/pubmed/26228928

Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

“Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease.

Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury.

We have previously reported the receptor affinity of 3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury.

Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940.

The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined.

Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.”

http://www.ncbi.nlm.nih.gov/pubmed/26196013

Bone cell-autonomous contribution of type 2 cannabinoid receptor to breast cancer induced osteolysis.

“The cannabinoid type 2 receptor (CB2) has previously been implicated as a regulator of tumour growth, bone remodelling and bone pain.

However, very little is known about the role of the skeletal CB2 receptor in the regulation of osteoblasts and osteoclasts changes associated with breast cancer. Here, we found that the CB2 selective agonists HU308 and JWH133 reduced the viability of a variety of parental and bone-tropic human and mouse breast cancer cells at high micro-molar concentrations…

When combined with published work, these findings suggest that breast cancer and bone cells exhibit differential responses to treatment with CB2 ligands, depending upon cell type and concentration used.

We therefore conclude that both, CB2 selective activation and antagonism have potential efficacy in cancer associated bone disease but further studies are warranted and ongoing.”

Activation of CB2 receptor is required for the therapeutic effect of ABHD6 inhibition in experimental autoimmune encephalomyelitis.

“Alpha/beta-hydrolase domain 6 (ABHD6) is a novel 2-arachidonoylglycerol (2-AG) hydrolytic enzyme, that can fine-tune the endocannabinoid signaling in the central nervous system.

Recently we and others have demonstrated the protective effect of ABHD6 inhibition in the animal models of traumatic brain injury and epileptic seizures. In this study, we investigated the role of targeting ABHD6 in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS)…

These results suggest that inhibition of ABHD6 might be used as an ideal strategy for the treatment of MS and other neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/26189763

Time-Dependent Protection of CB2 Receptor Agonist in Stroke.

“Recent studies have indicated that type 2 cannabinoid receptor (CB2R) agonists reduce neurodegeneration after brain injury through anti-inflammatory activity.

The purpose of this study was to examine the time-dependent interaction of CB2R and inflammation in stroke brain.

In conclusion, our data support a time-dependent neuroprotection of CB2 agonist in an animal model of stroke.

Delayed post- treatment with PPAR-γ agonist induced behavioral recovery and microglial suppression; early treatment with CB2R agonist suppressed neurodegeneration in stroke animals.”

http://www.ncbi.nlm.nih.gov/pubmed/26186541

http://www.thctotalhealthcare.com/category/stroke-2/