Tag Archives: CB(1) and CB(2) receptors

CB2 cannabinoid receptors promote mouse neural stem cell proliferation.

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“Neurospheres are clonal cellular aggregates of neural stem/precursor cells that grow in culture as free-floating clusters. Activation of CB1 cannabinoid receptors, which are expressed by these cells, promotes proliferation.

In the present study we investigated the expression of CB2 cannabinoid receptors and the effect of exogenous cannabinoids on neural stem/precursor cell proliferation.

Neurospheres containing nestin-positive and sn-1 diacylglycerol lipase alpha-positive cells expressed both CB1 and CB2 receptors, which were maintained through several passages…

Together, our results suggest that cannabinoids stimulate proliferation of neural stem/precursor cells acting on both CB1 and CB2 cannabinoid receptors through a phosphoinositide-3 kinase/Akt pathway.”

http://www.ncbi.nlm.nih.gov/pubmed/17328768

Cannabinoid receptor 2 and its agonists mediate hematopoiesis and hematopoietic stem and progenitor cell mobilization.

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“Endocannabinoids are arachidonic acid derivatives and part of a novel bioactive lipid signaling system, along with their G-coupled cannabinoid receptors (CB₁ and CB₂) and the enzymes involved in their biosynthesis and degradation.

However, their roles in hematopoiesis and hematopoietic stem and progenitor cell (HSPC) functions are not well characterized. Here, we show that bone marrow stromal cells express endocannabinoids (anandamide and 2-arachidonylglycerol), whereas CB₂ receptors are expressed in human and murine HSPCs.

On ligand stimulation with CB₂ agonists, CB₂ receptors induced chemotaxis, migration, and enhanced colony formation of bone marrow cells, which were mediated via ERK, PI3-kinase, and Gαi-Rac1 pathways.

Taken together, these results demonstrate that the endocannabinoid system is involved in hematopoiesis and that CB₂/CB₂ agonist axis mediates repopulation of hematopoiesis and mobilization of HSPCs.

Thus, CB₂ agonists may be therapeutically applied in clinical conditions, such as bone marrow transplantation.”

http://www.ncbi.nlm.nih.gov/pubmed/21063029

Up-regulation of immunomodulatory effects of mouse bone-marrow derived mesenchymal stem cells by tetrahydrocannabinol pre-treatment involving cannabinoid receptor CB2.

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“Chronic pain is commonly and closely correlated with inflammation.

Both cannabinoid signaling and mesenchymal stem cells (MSCs) have been demonstrated to reduce inflammatory pain.

Although cannabinoid signaling is essential for mesenchymal stem cell survival and differentiation, little is known about its role in modulatory effect of MSCs on inflammation and pain sensitivity. Here we showed that mouse bone-marrow derived MSCs (BM-MSCs) expressed both cannabinoid receptor type 1 and 2 (CB1 and CB2). CB2 expression level in BM-MSCs increased with their maturation.

In addition, we found that tetrahydrocannabinol (THC) activated CB2 receptor and ERK signaling, consequently enhancing the modulation of MSCs on inflammation-associated cytokine release from lipopolysaccharides-stimulated microglia.

Consistent with in vitro data, THC pretreatment enhanced the immunomodulatory effects of BM-MSC on thermal hyperalgesia and mechanical allodynia in chronic constriction injury model, by decreasing the release of pro-inflammation cytokines.

Our study revealed the crucial role of THC in promoting the immunomodulatory effects of MSCs and proposed a new strategy to alleviate pain based on stem cells therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/26824325

Clinical/Therapeutic Approaches for Cannabinoid Ligands in Central and Peripheral Nervous System Diseases: Mini Review.

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“Cannabinoids, the components of Cannabis sativa Linnaeus, interact with CB1 and CB2 receptors, which are located both in the central nervous system and in the periphery and thus may exert a widespread biological activity in the body.

The main medicinal properties of cannabinoids include analgesic, anti-inflammatory, antitumor, appetite stimulation, antiemesis, and muscle relaxation effects.

This mini review aims to explore existing clinical trials that investigated the use of cannabinoids in diseases affecting the nervous system.

There is evidence that cannabinoid-based drugs may effectively control some symptoms associated with nervous system dysfunction, especially various types of pain and neurologic disorders, although studies are limited.

The efficacy of cannabinoid drugs in the treatment of nervous system diseases should be verified in future large-scale randomized clinical trials.”

http://www.ncbi.nlm.nih.gov/pubmed/26818043

Opposite regulation of cannabinoid CB1 and CB2 receptors in the prefrontal cortex of rats treated with cocaine during adolescence.

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“The endocannabinoid system is implicated in the neurobiology of cocaine addiction, although it is not clear how cocaine regulates brain CB1 and CB2receptors, especially during adolescence, a critical moment for shaping adult response to drug use.

This study evaluated CB1 and CB2 protein levels in prefrontal cortex (PFC) and hippocampus (HC) by western blot analysis with specific and validated antibodies: (1) basally during adolescence (post-natal day PND 40, PND 47, PND 54), (2) by a sensitizing regimen of cocaine (15mg/kg, 7 d, i.p.) during different windows of adolescence vulnerability (PND 33-39, PND 40-46, PND 47-53), and (3) following repeated cocaine administration during adolescence (PND 33-39) in adulthood (PND 64).

The results demonstrated a dynamic and opposite basal modulation of CB1 and CB2 receptors in PFC and HC during adolescence. CB1 receptor levels were increased while CB2 receptors were decreased as compared to adulthood with asymptotes values around mid adolescence (PND 47) both in PFC (CB1: +45±22, p<0.05; CB2: -24±6%, p<0.05) and HC (CB1: +53±23, p<0.05; CB2: -20±8%, p<0.05).

Interestingly, cocaine only altered CB1(+55±10%, p<0.05) and CB2 (-25±10%, p<0.05) receptors when administered during early adolescence and only in PFC. However, the changes observed in PFC by repeated cocaine administration in adolescence were transient and did not endure into adulthood.

These results identified a period of vulnerability during adolescence at which cocaine dysregulated the content of CB receptors in PFC, suggesting an opposite role for these receptors in the effects mediated by cocaine.“

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

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“One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated.

Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats.

Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26778127

Ligands for cannabinoid receptors, promising anticancer agents.

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“Cannabinoid compounds are unique to cannabis and provide some interesting biological properties.

These compounds along with endocannabinoids, a group of neuromodulator compounds in the body especially in brain, express their effects by activation of G-protein-coupled cannabinoid receptors, CB1 and CB2.

There are several physiological properties attributed to the endocannabinoids including pain relief, enhancement of appetite, blood pressure lowering during shock, embryonic development, and blocking of working memory.

On the other hand, activation of endocannabinoid system may be suppresses evolution and progression of several types of cancer.

According to the results of recent studies, CB receptors are over-expressed in cancer cell lines and application of multiple cannabinoid or cannabis-derived compounds reduce tumor size through decrease of cell proliferation or induction of cell cycle arrest and apoptosis along with desirable effect on decrease of tumor-evoked pain.

Therefore, modulation of endocannabinoid system by inhibition of fatty acid amide hydrolase (FAAH), the enzyme, which metabolized endocannabinoids, or application of multiple cannabinoid or cannabis-derived compounds, may be appropriate for the treatment of several cancer subtypes. This review focuses on how cannabinoid affect different types of cancers.”

http://www.ncbi.nlm.nih.gov/pubmed/26764235

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

Cannabinoid receptor-specific mechanisms to ameliorate pain in sickle cell anemia via inhibition of mast cell activation and neurogenic inflammation.

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“Sickle cell anaemia is a manifestation of a single point mutation in haemoglobin, but inflammation and pain are the insignia of this disease which can start in infancy and continue throughout life.

Earlier studies showed that mast cell activation contributes to neurogenic inflammation and pain in sickle mice.

Morphine is the common analgesic treatment but also remains a major challenge due to the side effects and ability to activate mast cells. Therefore, we examined the cannabinoid receptor-specific mechanisms to ameliorate mast cell activation, neurogenic inflammation and hyperalgesia, using HbSS-BERK sickle and cannabinoid receptor 2 deleted sickle mice.

We show that cannabinoids ameliorate mast cell activation, inflammation and neurogenic inflammation in sickle mice via both cannabinoid receptors 1 and 2.

Thus, cannabinoids influence systemic and neural mechanisms, ameliorating the disease pathobiology and hyperalgesia in sickle mice.

This study provides a “proof of principle” for the potential of cannabinoid/cannabinoid receptor-based therapeutics to treat several manifestations of sickle cell anaemia.”

Oxyradical Stress, Endocannabinoids, and Atherosclerosis.

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“Atherosclerosis is responsible for most cardiovascular disease (CVD) and is caused by several factors including hypertension, hypercholesterolemia, and chronic inflammation.

Oxidants and electrophiles have roles in the pathophysiology of atherosclerosis and the concentrations of these reactive molecules are an important factor in disease initiation and progression.

Overactive NADPH oxidase (Nox) produces excess superoxide resulting in oxidized macromolecules, which is an important factor in atherogenesis. Although superoxide and reactive oxygen species (ROS) have obvious toxic properties, they also have fundamental roles in signaling pathways that enable cells to adapt to stress.

In addition to inflammation and ROS, the endocannabinoid system (eCB) is also important in atherogenesis.

Linkages have been postulated between the eCB system, Nox, oxidative stress, and atherosclerosis.

For instance, CB2 receptor-evoked signaling has been shown to upregulate anti-inflammatory and anti-oxidative pathways, whereas CB1 signaling appears to induce opposite effects.

The second messenger lipid molecule diacylglycerol is implicated in the regulation of Nox activity and diacylglycerol lipase β (DAGLβ) is a key biosynthetic enzyme in the biosynthesis eCB ligand 2-arachidonylglycerol (2-AG).

Furthermore, Nrf2 is a vital transcription factor that protects against the cytotoxic effects of both oxidant and electrophile stress.

This review will highlight the role of reactive oxygen species (ROS) in intracellular signaling and the impact of deregulated ROS-mediated signaling in atherogenesis.

In addition, there is also emerging knowledge that the eCB system has an important role in atherogenesis.

We will attempt to integrate oxidative stress and the eCB system into a conceptual framework that provides insights into this pathology.”

http://www.ncbi.nlm.nih.gov/pubmed/26702404

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

An Introduction to the Endogenous Cannabinoid System.

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“The endocannabinoid system (ECS) is a widespread neuromodulatory system that plays important roles in central nervous system development, synaptic plasticity, and the response to endogenous and environmental insults.

The ECS comprises cannabinoid receptors, endogenouscannabinoids (endocannabinoids), and the enzymes responsible for the synthesis and degradation of the endocannabinoids.

The most abundant cannabinoid receptors are the CB1 cannabinoid receptors; however, CB2 cannabinoid receptors, transient receptor potential channels, and peroxisome proliferator activated receptors are also engaged by some cannabinoids.

Exogenous cannabinoids, such as tetrahydrocannabinol, produce their biological effects through their interactions with cannabinoid receptors.

The best-studied endogenous cannabinoids are 2-arachidonoyl glycerol and arachidonoyl ethanolamide (anandamide). Despite similarities in chemical structure, 2-arachidonoyl glycerol and anandamide are synthesized and degraded by distinct enzymatic pathways, which impart fundamentally different physiologic and pathophysiologic roles to these two endocannabinoids.

As a result of the pervasive social use of cannabis and the involvement of endocannabinoids in a multitude of biological processes, much has been learned about the physiologic and pathophysiologic roles of the ECS.

This review provides an introduction to the ECS with an emphasis on its role in synaptic plasticity and how the ECS is perturbed in schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/26698193