Tag Archives: cannabinoid receptors

The Structure-Function Relationships of Classical Cannabinoids: CB1/CB2 Modulation.

Posted on by
Reply

“The cannabinoids are members of a deceptively simple class of terpenophenolic secondary metabolites isolated from Cannabis sativa highlighted by (-)-Δ(9)-tetrahydrocannabinol (THC), eliciting distinct pharmacological effects mediated largely by cannabinoid receptor (CB1 or CB2) signaling. Since the initial discovery of THC and related cannabinoids, synthetic and semisynthetic classical cannabinoid analogs have been evaluated to help define receptor binding modes and structure-CB1/CB2 functional activity relationships. This perspective will examine the classical cannabinoids, with particular emphasis on the structure-activity relationship of five regions: C3 side chain, phenolic hydroxyl, aromatic A-ring, pyran B-ring, and cyclohexenyl C-ring. Cumulative structure-activity relationship studies to date have helped define the critical structural elements required for potency and selectivity toward CB1 and CB2 and, more importantly, ushered the discovery and development of contemporary nonclassical cannabinoid modulators with enhanced physicochemical and pharmacological profiles.”

http://www.ncbi.nlm.nih.gov/pubmed/27398024

Cannabinoid signalling in glioma cells

Posted on by
Reply

SpringerPlus Cover Image

“Cannabinoids, originally derived from Cannabis sativa, as well as their endogenous and synthetic counterparts, were shown to induce apoptosis of glioma cells in vitro and tumour regression in vivo via their specific receptors, cannabinoid receptors CB1 and/or CB2.

CB2 are abnormally expressed in human gliomas and glioma cell lines. Most of the analysed gliomas expressed significant levels of CB2 receptor and the extent of CB2 expression in the tumour specimens was related to tumour malignancy.

A synthetic cannabinoid, WIN 55,212-2, down-regulated the Akt and Erk signalling pathways in C6 glioma cells that resulted in reduction of phosphorylated Bad levels, mitochondrial depolarization and activation of caspase cascade leading to apoptosis.

We examined whether synthetic cannabinoids with different receptor specificity: WIN55,212-2 (a non-selective CB1/CB2 agonist) and JWH133 (a CB2-selective agonist) affect survival of four human glioma cell lines and three primary human glioma cell lines.

WIN-55,212-2 decreased cell viability in all examined cell lines and induced cell death. Susceptibility of the cells to JWH133 treatment correlated with the CB2 expression. Cannabinoids triggered a decrease of mitochondrial membrane potential, cleavage of caspase-9 and effector caspases.

Induction of cell death by cannabinoid treatment led to the generation of a pro-apoptotic sphingolipid ceramide and disruption of signalling pathways crucial for regulation of proliferation and survival. Increased ceramide levels induced ER-stress and autophagy in drug-treated glioblastoma cells.

We conclude that cannabinoids are efficient inhibitors of human glioma cells growth, once the cells express specific type of cannabinoid receptor.”

http://springerplus.springeropen.com/articles/10.1186/2193-1801-4-S1-L11

The endocannabinoid system – a target for the treatment of LUTS?

Posted on by
Reply

“Lower urinary tract symptoms (LUTS) are common in all age groups and both sexes, resulting in tremendous personal suffering and a substantial burden to society.

Antimuscarinic drugs are the mainstay of symptom management in patients with LUTS, although their clinical utility is limited by the high prevalence of adverse effects, which often limit patients’ long-term adherence to these agents.

Data from controversial studies in the 1990s revealed the positive effects of marijuana-based compounds on LUTS, and sparked an interest in the possibility of treating bladder disorders with cannabis.

Increased understanding of cannabinoid receptor pharmacology and the discovery of endogenous ligands of these receptors has prompted debate and further research into the clinical utility of exogenous cannabinoid receptor agonists relative to the unwanted psychotropic effects of these agents.

Currently, the endocannabinoid system is considered as a potential drug target for pharmacological management of LUTS, with a more favourable adverse event profile than antimuscarinic agents.”

http://www.ncbi.nlm.nih.gov/pubmed/27377161

The cannabinoid 2 receptor agonist β-caryophyllene modulates the inflammatory reaction induced by Mycobacterium bovis BCG by inhibiting neutrophil migration.

Posted on by
Reply

“β-Caryophyllene (BCP) is a sesquiterpene that binds to the cannabinoid 2 (CB2) receptor and exerts anti-inflammatory effects. In this study, we investigated the anti-inflammatory effect of BCP and another CB2 agonist, GP1a in inflammatory experimental model induced by Mycobacterium bovis (BCG).

These results suggest that the CB2 receptor may represent a new target for modulating the inflammatory reaction induced by mycobacteria.”

http://www.ncbi.nlm.nih.gov/pubmed/27379721

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”  http://www.ncbi.nlm.nih.gov/pubmed/23138934

Microglia activation states and cannabinoid system: Therapeutic implications.

Posted on by
Reply

“Microglial cells are recognized as the brain’s intrinsic immune cells, mediating actions that range from the protection against harmful conditions that modify CNS homeostasis, to the control of proliferation and differentiation of neurons and their synaptic pruning. To perform these functions, microglia adopts different activation states, the so-called phenotypes that depending on the local environment involve them in neuroinflammation, tissue repair and even the resolution of the inflammatory process.

There is accumulating evidence indicating that cannabinoids (CBs) might serve as a promising tool to modify the outcome of inflammation, especially by influencing microglial activity.

Microglia has a functional endocannabinoid (eCB) signaling system, composed of cannabinoid receptors and the complete machinery for the synthesis and degradation of eCBs.

The expression of cannabinoid receptors – mainly CB2 – and the production of eCBs have been related to the activation profile of these cells and therefore, the microglial phenotype, emerging as one of the mechanisms by which microglia becomes alternatively activated.

Here, we will discuss recent studies that provide new insights into the role of CBs and their endogenous counterparts in defining the profile of microglia activation.

These actions make CBs a promising therapeutic tool to avoid the detrimental effects of inflammation and possibly paving the way to target microglia in order to generate a reparative milieu in neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27373505

Cannabinoid receptors in the kidney.

Posted on by
Reply

“The endocannabinoid system modulates cell signaling targets that are essential for energy homeostasis. Endocannabinoids bind to G protein-coupled receptors in the central nervous system and periphery, including the kidney. Modulation of cannabinoid receptor 1 (CB1) and CB2 activity in the kidney in diabetes and obesity has been identified as potential therapeutic target to reduce albuminuria and renal fibrosis.

CB1 and CB2 have been reported to play key roles in renal function and dysfunction. Recent studies have determined that antagonism of CB1 and agonism of CB2 in diabetic nephropathy and obesity associated kidney disease can reduce albuminuria, potentially by acting on both the glomeruli and tubules. Emerging studies have also identified a role for CB1 in renal diseases associated with fibrosis, with CB1 upregulated in multiple models of human nephropathies.

Emerging studies using isolated cells, rodent models, and human studies have identified a critical role for the endocannabinoid system in renal function and disease. Thus, therapeutics that modulate the activity of CB1 and CB2 in renal disease could become clinically relevant.”

http://www.ncbi.nlm.nih.gov/pubmed/27367912

 

Endocannabionoid System in Neurological Disorders.

Posted on by
Reply

“Several studies support the evidence that the endocannabinoid system and cannabimimetic drugs might have therapeutic potential in numerous pathologies. These pathologies range from neurological disorders, atherosclerosis, stroke, cancer to obesity/metabolic syndrome and others.

In this paper we review the endocannabinoid system signaling and its alteration in neurodegenerative disorders like multiple sclerosis, Alzheimer’s disease, Parkinson’s disease and Huntington’s disease and discuss the main findings about the use of cannabinoids in the therapy of these pathologies.

Despite different etiologies, neurodegenerative disorders exhibit similar mechanisms like neuro-inflammation, excitotoxicity, deregulation of intercellular communication, mitochondrial dysfunction and disruption of brain tissue homeostasis.

Current treatments ameliorate the symptoms but are not curative.

Interfering with the endocannabinoid signaling might be a valid therapeutic option in neuro-degeneration.

To this aim, pharmacological intervention to modulate the endocannabinoid system and the use of natural and synthetic cannabimimetic drugs have been assessed. CB1 and CB2 receptor signaling contributes to the control of Ca2+ homeostasis, trophic support, mitochondrial activity, and inflammatory conditions.

Several studies and patents suggest that the endocannabinoid system has neuro-protective properties and might be a target in neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27364363

Amyloid proteotoxicity initiates an inflammatory response blocked by cannabinoids

Posted on by
Reply

“The beta amyloid (Aβ) and other aggregating proteins in the brain increase with age and are frequently found within neurons. The mechanistic relationship between intracellular amyloid, aging and neurodegeneration is not, however, well understood.

We use a proteotoxicity model based upon the inducible expression of Aβ in a human central nervous system nerve cell line to characterize a distinct form of nerve cell death caused by intracellular Aβ.

It is shown that intracellular Aβ initiates a toxic inflammatory response leading to the cell’s demise. Aβ induces the expression of multiple proinflammatory genes and an increase in both arachidonic acid and eicosanoids, including prostaglandins that are neuroprotective and leukotrienes that potentiate death.

Cannabinoids such as tetrahydrocannabinol stimulate the removal of intraneuronal Aβ, block the inflammatory response, and are protective.

Altogether these data show that there is a complex and likely autocatalytic inflammatory response within nerve cells caused by the accumulation of intracellular Aβ, and that this early form of proteotoxicity can be blocked by the activation of cannabinoid receptors.”

http://www.nature.com/articles/npjamd201612

“Cannabinoids remove plaque-forming Alzheimer’s proteins from brain cells. Preliminary lab studies at the Salk Institute find THC reduces beta amyloid proteins in human neurons.” http://www.salk.edu/news-release/cannabinoids-remove-plaque-forming-alzheimers-proteins-from-brain-cells/

Expression of the endocannabinoid receptors in human fascial tissue.

Posted on by
Reply

“Cannabinoid receptors have been localized in the central and peripheral nervous system as well as on cells of the immune system, but recent studies on animal tissue gave evidence for the presence of cannabinoid receptors in different types of tissues.

Their presence was supposed also in myofascial tissue, suggesting that the endocannabinoid system may help resolve myofascial trigger points and relieve symptoms of fibromyalgia.

However, until now the expression of CB1 (cannabinoid receptor 1) and CB2 (cannabinoid receptor 2) in fasciae has not yet been established.

Small samples of fascia were collected from volunteers patients during orthopedic surgery. For each sample were done a cell isolation, immunohistochemical investigation (CB1 and CB2 antibodies) and real time RT-PCR to detect the expression of CB1 and CB2.

Both cannabinoid receptors are expressed in human fascia and in human fascial fibroblasts culture cells, although to a lesser extent than the control gene. We can assume that the expression of mRNA and protein of CB1 and CB2 receptors in fascial tissue are concentrated into the fibroblasts.

This is the first demonstration that the fibroblasts of the muscular fasciae express CB1 and CB2. The presence of these receptors could help to provide a description of cannabinoid receptors distribution and to better explain the role of fasciae as pain generator and the efficacy of some fascial treatments.

Indeed the endocannabinoid receptors of fascial fibroblasts can contribute to modulate the fascial fibrosis and inflammation.”

http://www.ncbi.nlm.nih.gov/pubmed/27349320

The Cannabinoid Receptor 2 Protects Against Alcoholic Liver Disease Via a Macrophage Autophagy-Dependent Pathway.

Posted on by
Reply

“Kupffer cells, the resident macrophages of the liver, play a major role in the pathogenesis of alcoholic liver disease. We have previously demonstrated that CB2 receptor protects against alcoholic liver disease by inhibiting alcohol-induced inflammation and steatosis via the regulation of Kupffer cell activation.

Here, we explored the mechanism underlying these effects and hypothesized that the anti-inflammatory properties of CB2 receptor in Kupffer cells rely on activation of autophagy.

Altogether these results demonstrate that CB2 receptor activation in macrophages protects from alcohol-induced steatosis by inhibiting hepatic inflammation through an autophagy-dependent pathway.”

http://www.ncbi.nlm.nih.gov/pubmed/27346657