Tag Archives: G-Protein coupled receptors

The role of cannabinoid receptors and the endocannabinoid system in mantle cell lymphoma and other non-Hodgkin lymphomas.

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“The initiating oncogenic event in mantle cell lymphoma (MCL) is the translocation of cyclin D1, t(11;14)(q13;q32). However, other genetic aberrations are necessary for an overt lymphoma to arise. Like other B cell lymphomas, MCL at some points during the oncogenesis is dependent on interactions with other cells and factors in the microenvironment.

The G protein coupled receptors cannabinoid receptors 1 and 2 (CB1 and CB2) are expressed at low levels on non-malignant lymphocytes and at higher levels in MCL and other lymphoma subtypes.

In this review we give an overview of what is known on the role of the cannabinoid receptors and their ligands in lymphoma as compared to non-malignant T and B lymphocytes.

In MCL cannabinoids mainly reduce cell proliferation and induce cell death.

Importantly, our recent findings demonstrate that cannabinoids may induce either apoptosis or another type of programmed cell death, cytoplasmic vacuolation/paraptosis in MCL.”

http://www.ncbi.nlm.nih.gov/pubmed/22024769

Stimulated CB1 Cannabinoid Receptor Inducing Ischemic Tolerance and Protecting Neuron from Cerebral Ischemia.

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“Anandamide system is mainly made up of cannabinoid receptors, their endogenous ligands and some related enzymes. Activation of the system mediates various molecular events, thereafter leading to vasodilation, bradycardia and anti-inflammation.

The stimulated cannabinoid receptors may take part in protection of endothelial cells from injury and therefore can be potential targets in therapy for some diseases, especially cardio or cerebral vascular disturbances.

Cerebral ischemia is a deadly disease that modern people have to face and will probably face for a long period of time. Ischemic tolerance has the protective effect of brain as an endogenous event in cerebral ischemia, in which variety of inducers such as transient cerebral ischemia, hypoxia, hypothermia and drug agents are involved.

Most of cannabinoid 1 receptors (CB1Rs), a member in G protein-coupled receptor family, exist in central nervous systems.

Mechanism of neuroprotection mediated by the receptor is considered through facilitating neurotransmitter release and regulating other molecular events. In this review, advance of the neuroprotection against cerebral ischemia and the mechanism of the action are overviewed.”

http://www.ncbi.nlm.nih.gov/pubmed/27142423

“Cerebral ischemia or brain ischemia, is a condition that occurs when there isn’t enough blood flow to the brain to meet metabolic demand. This leads to limited oxygen supply or cerebral hypoxia and leads to the death of brain tissue, cerebral infarction, or ischemic stroke. It is a sub-type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage. There are two kinds of ischemia: focal ischemia: confined to a specific region of the brain; global ischemia: encompasses wide areas of brain tissue.”  http://www.columbianeurosurgery.org/conditions/cerebral-ischemia/

Modulation of breast cancer cell viability by a cannabinoid receptor 2 agonist, JWH-015, is calcium dependent

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“Cannabinoid compounds, both nonspecific as well as agonists selective for either cannabinoid receptor 1 (CB1) or cannabinoid receptor 2 (CB2), have been shown to modulate the tumor microenvironment by inducing apoptosis in tumor cells in several model systems.

The mechanism of this modulation remains only partially delineated, and activity induced via the CB1 and CB2 receptors may be distinct despite significant sequence homology and structural similarity of ligands.

The results of this work characterize the actions of a CB2-selective agonist on breast cancer cells in a syngeneic murine model representing how a clinical presentation of cancer progression and metastasis may be significantly modulated by a G-protein-coupled receptor.”

https://www.dovepress.com/modulation-of-breast-cancer-cell-viability-by-a-cannabinoid-receptor-2-peer-reviewed-article-BCTT

The multiplicity of action of cannabinoids: implications for treating neurodegeneration.

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“The cannabinoid (CB) system is widespread in the central nervous system and is crucial for controlling a range of neurophysiological processes such as pain, appetite, and cognition. The endogenous CB molecules, anandamide, and 2-arachidonoyl glycerol, interact with the G-protein coupled CB receptors, CB(1) and CB(2).

These receptors are also targets for the phytocannabinoids isolated from the cannabis plant and synthetic CB receptor ligands.

The CB system is emerging as a key regulator of neuronal cell fate and is capable of conferring neuroprotection by the direct engagement of prosurvival pathways and the control of neurogenesis.

Many neurological conditions feature a neurodegenerative component that is associated with excitotoxicity, oxidative stress, and neuroinflammation, and certain CB molecules have been demonstrated to inhibit these events to halt the progression of neurodegeneration.

Such properties are attractive in the development of new strategies to treat neurodegenerative conditions of diverse etiology, such as Alzheimer’s disease, multiple sclerosis, and cerebral ischemia.

This article will discuss the experimental and clinical evidence supporting a potential role for CB-based therapies in the treatment of certain neurological diseases that feature a neurodegenerative component.”

http://www.ncbi.nlm.nih.gov/pubmed/20875047

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

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“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

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

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“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

Endocannabinoids and Endocannabinoid-Related Mediators: Targets, Metabolism and Role In Neurological Disorders.

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“The endocannabinoid system (ECS) is composed of two G protein-coupled receptors (GPCRs), the cannabinoid CB1 and CB2 receptors, and the two main endogenous lipid ligands of such receptors (also known as the “endocannabinoids”), anandamide and 2-arachidonoyl-glycerol. The ECS is a pleiotropic signalling systems involved in all aspects of mammalian physiology and pathology, and for this reason it represents a potential target for the design and development of new therapeutic drugs. However, the endocannabinoids as well as some of their congeners also interact with a much wider range of receptors, including members of the Transient Receptor Potential (TRP) channels, Peroxisome Proliferator-Activated Receptors (PPARs), and other GPCRs. Indeed, following the discovery of the endocannabinoids, endocannabinoid-related lipid mediators, which often share the same metabolic pathways of the endocannabinoids, have also been identified or rediscovered. In this review article, we discuss the role of endocannabinoids and related lipids during physiological functions, as well as their involvement is some of the most common neurological disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26965148

A Single Intrathecal or Intraperitoneal Injection of CB2 Receptor Agonist Attenuates Bone Cancer Pain and Induces a Time-Dependent Modification of GRK2.

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“The objective of this study was to explore the potential role of G-protein-coupled receptor kinase 2 (GRK2) in the progression of cannabinoid 2 receptor (CB2) agonist-induced analgesic effects of bone cancer pain.

The results affirmed CB2 receptor agonists might serve as new treatment targets for bone cancer pain.

Moreover, spinal GRK2 was an important regulator of CB2 receptor agonist-analgesia pathway.”

http://www.ncbi.nlm.nih.gov/pubmed/26935064

The endocannabinoid system: a new approach to control cardiovascular disease.

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“The endocannabinoid (EC) system consists of 2 types of G-protein-coupled cannabinoid receptors–cannabinoid type 1 (CB1) and cannabinoid type 2 (CB2)–and their natural ligands.

The EC system plays a key role in the regulation of food intake and fat accumulation, as well as glucose and lipid metabolism.

When overactivated, the EC system triggers dyslipidemia, thrombotic and inflammatory states, and insulin resistance.

Blocking CB1 receptors centrally and peripherally in adipose tissue can help normalize an overactivated EC system. CB1 blockade helps regulate food intake and adipose tissue metabolism, contributing to improved insulin sensitivity and other features of the metabolic syndrome.

Visceral adipose tissue is most closely associated with the metabolic syndrome, which is a constellation of conditions that place people at high risk for coronary artery disease.

Targeting the EC system represents a new approach to treating visceral obesity and reducing cardiovascular risk factors.”

 http://www.ncbi.nlm.nih.gov/pubmed/16473257
http://www.thctotalhealthcare.com/category/cardiovascular-disease/

Simultaneous Activation of Induced Heterodimerization between CXCR4 Chemokine Receptor and Cannabinoid Receptor 2 (CB2) Reveal a Mechanism for Regulation of Tumor Progression.

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“The G-protein-coupled chemokine receptor, CXCR4, generates signals that lead to cell migration, cell proliferation, and other survival mechanisms which result in the metastatic spread of primary tumor cells to distal organs.

Numerous studies have demonstrated that CXCR4 can form homodimers, or can heterodimerize with other GPCRs to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor.

Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 (CB2) in human breast and prostate cancer cells.

Simultaneous, agonist-dependent activation of CXCR4 and CB2 resulted in reduced CXCR4-mediated expression of phosphorylated ERK1/2, and ultimately, reduced cancer cell functions such as calcium mobilization and cellular chemotaxis.

Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells, as well as CXCR4-mediated migration of immune cells, it is therefore plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4.

Taken together, the data illustrates a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function, and perhaps, tumor progression.”

http://www.ncbi.nlm.nih.gov/pubmed/26841863