Tag Archives: cannabinoid receptors

Expression of the Endocannabinoid Receptor 1 in Human Stroke: An Autoptic Study.

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“Stroke is one of the leading causes of disability and death in the world.

The endocannabinoid (eCB) system is upregulated in several neurological diseases including stroke. A previous animal study demonstrated an increased expression of the endocannabinoid receptor 1 (CB1R) in the penumbra area surrounding the ischemic core, suggesting a crucial role in inflammation/reperfusion after stroke. Regarding the localization of CB1/CB2 receptors, animal studies showed that cortical neurons, activated microglia, and astroglia are involved. Our aim was to evaluate the cerebral expression of CB1R in the ischemic brain areas of 9 patients who died due to acute cerebral infarction in the middle cerebral artery territory.

METHODS:

The cerebral autoptic tissue was collected within 48 hours since death. Ischemic and contralateral normal-appearing areas were identified. After tissue preprocessing, 4-µm-thick cerebral sections were incubated with the primary CB1R antibodies (Cayman Chemical Company, Ann Arbor, MI). Thereafter, all cerebral sections were hematoxylin treated. In each section, the total cell number and CB1R-positive cells were counted and the CB1R-positive cell count ratio was calculated. For statistical analysis, Student’s t-test was used.

RESULTS:

In normal tissue, CB1R-positive neurons were the majority; a few non-neuronal cells expressed CB1R. In the ischemic areas, a few neurons were detectable. A significant increase in total CB1R staining was found in the ischemic regions compared to contralateral areas.

CONCLUSIONS:

We found an increase in CB1R expression in the ischemic region (neuronal and non-neuronal cell staining), suggesting the inflammatory reaction to the ischemic insult. Whether such response might mediate neuroprotective actions or excitotoxicity-related detrimental effects is still unclear.”

http://www.ncbi.nlm.nih.gov/pubmed/27425766

Cannabinoid receptor agonist WIN55,212-2 and fatty acid amide hydrolase inhibitor URB597 may protect against cognitive impairment in rats of chronic cerebral hypoperfusion via PI3K/AKT signaling.

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“The present study further investigated the protective effects of cannabinoid receptor agonist WIN55,212-2 (WIN) and fatty acid amide hydrolase (FAAH) inhibitor URB597 (URB) on chronic cerebral hypoperfusion (CCH)-induced cognitive impairment in rats.

These findings suggest that WIN and URB are promising agents for therapeutic management of CCH.”

http://www.ncbi.nlm.nih.gov/pubmed/27424778

“Chronic cerebral hypoperfusion (CCH) is one of the causes of vascular dementia (VaD) and is also an etiological factor for Alzheimer’s disease (AD).”  http://journal.frontiersin.org/article/10.3389/fnagi.2014.00010/full

Endocannabinoid system as a regulator of tumor cell malignancy – biological pathways and clinical significance

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“The endocannabinoid system (ECS) comprises cannabinoid receptors (CBs), endogenous cannabinoids, and enzymes responsible for their synthesis, transport, and degradation of (endo)cannabinoids.

To date, two CBs, CB1 and CB2, have been characterized; however, orphan G-protein-coupled receptor GPR55 has been suggested to be the third putative CB.

Several different types of cancer present abnormal expression of CBs, as well as other components of ECS, and this has been shown to correlate with the clinical outcome.

Although most effects of (endo)cannabinoids are mediated through stimulation of classical CBs, they also interact with several molecules, either prosurvival or proapoptotic molecules.

It should be noted that the mode of action of exogenous cannabinoids differs significantly from that of endocannabinoid and results from the studies on their activity both in vivo and in vitro could not be easily compared.

This review highlights the main signaling pathways involved in the antitumor activity of cannabinoids and the influence of their activation on cancer cell biology.

We also discuss changes in the expression pattern of the ECS in various cancer types that have an impact on disease progression and patient survival.

A growing amount of experimental data imply possible exploitation of cannabinoids in cancer therapy.”

https://www.dovepress.com/endocannabinoid-system-as-a-regulator-of-tumor-cell-malignancy-ndash-b-peer-reviewed-article-OTT

Cannabinoids protect cells from oxidative cell death: a receptor-independent mechanism.

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Journal of Pharmacology and Experimental Therapeutics

“Serum is required for the survival and growth of most animal cells. In serum-free medium, B lymphoblastoid cells and fibroblasts die after 2 days.

We report that submicromolar concentrations of Delta(9)-tetrahydrocannabinol (THC), Delta(8)-THC, cannabinol, or cannabidiol, but not WIN 55,212-2, prevented serum-deprived cell death. Delta(9)-THC also synergized with platelet-derived growth factor in activating resting NIH 3T3 fibroblasts.

The cannabinoids‘ growth supportive effect did not correlate with their ability to bind to known cannabinoid receptors and showed no stereoselectivity, suggesting a nonreceptor-mediated pathway.

Direct measurement of oxidative stress revealed that cannabinoids prevented serum-deprived cell death by antioxidation.

The antioxidative property of cannabinoids was confirmed by their ability to antagonize oxidative stress and consequent cell death induced by the retinoid anhydroretinol.

Therefore, cannabinoids act as antioxidants to modulate cell survival and growth of B lymphocytes and fibroblasts.”

http://www.ncbi.nlm.nih.gov/pubmed/10869379/

“Marijuana has been known for centuries to be a psychoactive medicinal plant. Cannabinoids, especially the nonpsychoactive cannabinoids, may become clinically useful antioxidants in preventing and treating the oxidative stress-related diseases.” http://jpet.aspetjournals.org/content/293/3/807.long

Cannabidiol attenuates high glucose-induced endothelial cell inflammatory response and barrier disruption.

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“Cannabinoids, components of the Cannabis sativa (marijuana) plant, are known to exert potent anti-inflammatory, immunomodulatory and analgesic effects through activation of cannabinoid-1 and -2 (CB1 and CB2) receptors located in the central nervous system and immune cells.

The limitation of the therapeutic utility of the major cannabinoid, Δ9-tetrahydrocannabinol, is the development of psychoactive effects through central nervous system CB1 receptor. In contrast, cannabidiol (CBD), one of the most abundant cannabinoids of Cannabis sativa with reported antioxidant, anti-inflammatory, and immunomodulatory effects is well tolerated without side effects when chronically administered to humans and is devoid of psychoactive properties due to a low affinity for the CB1 and CB2 receptors.

A nonpsychoactive cannabinoid cannabidiol (CBD) has been shown to exert potent anti-inflammatory and antioxidant effects and has recently been reported to lower the incidence of diabetes in nonobese diabetic mice and to preserve the blood-retinal barrier in experimental diabetes.

In this study we have investigated the effects of CBD on high glucose (HG)-induced, mitochondrial superoxide generation, NF-κB activation, nitrotyrosine formation, inducible nitric oxide synthase (iNOS) and adhesion molecules ICAM-1 and VCAM-1 expression, monocyte-endothelial adhesion, transendothelial migration of monocytes, and disruption of endothelial barrier function in human coronary artery endothelial cells (HCAECs).

HG markedly increased mitochondrial superoxide generation (measured by flow cytometry using MitoSOX), NF-κB activation, nitrotyrosine formation, upregulation of iNOS and adhesion molecules ICAM-1 and VCAM-1, transendothelial migration of monocytes, and monocyte-endothelial adhesion in HCAECs. HG also decreased endothelial barrier function measured by increased permeability and diminished expression of vascular endothelial cadherin in HCAECs.

Remarkably, all the above mentioned effects of HG were attenuated by CBD pretreatment.

Since a disruption of the endothelial function and integrity by HG is a crucial early event underlying the development of various diabetic complications, our results suggest that CBD, which has recently been approved for the treatment of inflammation, pain, and spasticity associated with multiple sclerosis in humans, may have significant therapeutic benefits against diabetic complications and atherosclerosis.

Collectively, our results suggest that the nonpsychoactive cannabinoid CBD have significant therapeutic benefits against diabetic complications and atherosclerosis by attenuating HG-induced mitochondrial superoxide generation, increased NF-κB activation, upregulation of iNOS and adhesion molecules, 3-NT formation, monocyte-endothelial adhesion, TEM of monocytes, and disruption of the endothelial barrier function.

This is particularly encouraging in light of the excellent safety and tolerability profile of CBD in humans.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2228254/

Fluorinated Cannabidiol Derivatives: Enhancement of Activity in Mice Models Predictive of Anxiolytic, Antidepressant and Antipsychotic Effects.

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“Cannabidiol (CBD) is a major Cannabis sativa constituent, which does not cause the typical marijuana psychoactivity. However, it has been shown to be active in a numerous pharmacological assays, including mice tests for anxiety, obsessive-compulsive disorder, depression and schizophrenia. In human trials the doses of CBD needed to achieve effects in anxiety and schizophrenia are high. We report now the synthesis of 3 fluorinated CBD derivatives, one of which, 4′-F-CBD (HUF-101) (1), is considerably more potent than CBD in behavioral assays in mice predictive of anxiolytic, antidepressant, antipsychotic and anti-compulsive activity. Similar to CBD, the anti-compulsive effects of HUF-101 depend on cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27416026

5-lipoxygenase mediates docosahexaenoyl ethanolamide and N-arachidonoyl-L-alanine-induced reactive oxygen species production and inhibition of proliferation of head and neck squamous cell carcinoma cells.

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“Endocannabinoids have recently drawn attention as promising anti-cancer agents. We previously observed that anandamide (AEA), one of the representative endocannabinoids, effectively inhibited the proliferation of head and neck squamous cell carcinoma (HNSCC) cell lines in a receptor-independent manner. In this study, using HNSCC cell lines, we examined the anti-cancer effects and the mechanisms of action of docosahexaenoyl ethanolamide (DHEA) and N-arachidonoyl-L-alanine (NALA), which are polyunsaturated fatty acid (PUFA)-based ethanolamides like AEA. From these findings, we suggest that ROS production induced by the 5-LO pathway mediates the anti-cancer effects of DHEA and NALA on HNSCC cells. Finally, our findings suggest the possibility of a new cancer-specific therapeutic strategy, which utilizes 5-LO activity rather than inhibiting it.”  http://www.ncbi.nlm.nih.gov/pubmed/27411387

https://bmccancer.biomedcentral.com/articles/10.1186/s12885-016-2499-3

Expression and function of cannabinoid receptors CB1 and CB2 and their cognate cannabinoid ligands in murine embryonic stem cells.

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“Characterization of intrinsic and extrinsic factors regulating the self-renewal/division and differentiation of stem cells is crucial in determining embryonic stem (ES) cell fate.

ES cells differentiate into multiple hematopoietic lineages during embryoid body (EB) formation in vitro, which provides an experimental platform to define the molecular mechanisms controlling germ layer fate determination and tissue formation.

This work has not been addressed previously and yields new information on the function of cannabinoid receptors, CB1 and CB2, as components of a novel pathway regulating murine ES cell differentiation.

This study provides insights into cannabinoid system involvement in ES cell survival and hematopoietic differentiation.

Thus, these observations together with our results strongly suggest that both CB1 and CB2 activation are involved in the maintenance of mES cells and that the endocannabinoid system is essential in stem cell survival and stem cell hematopoietic differentiation.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1919431/

 

Regulation of hematopoietic stem cell trafficking and mobilization by the endocannabinoid system.

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“The cannabinoid receptors CB(1) and CB(2) are seven-transmembrane Gαi protein-coupled receptors and are expressed in certain mature hematopoietic cells.

We recently showed that these receptors are expressed in murine and human hematopoietic stem cells (HSCs) and that CB(2) agonists induced chemotaxis, enhanced colony formation of marrow cells, as well as caused in vivo mobilization of murine HSCs with short- and long-term repopulating abilities. Based on these observations, we have further explored the role of CB(2) and its agonist AM1241 on hematopoietic recovery following sublethal irradiation in mice.

Cannabinoid receptor 2 knockout mice (Cnr2(-/-) deficient mice) exhibited impaired recovery following sublethal irradiation as compared with irradiated wild-type (WT) mice, as determined by low colony-forming units and low peripheral blood counts. WT mice treated with CB(2) agonist AM1241 following sublethal irradiation demonstrated accelerated marrow recovery and increased total marrow cells (approximately twofold) and total lineage- c-kit(+) cells (approximately sevenfold) as well as enhanced HSC survival as compared with vehicle control-treated mice.

When the CB(2) agonist AM1241 was administered to WT mice 12 days before their sublethal irradiation, analysis of hematopoiesis in these mice showed decreased apoptosis of HSCs, enhanced survival of HSCs, as well as increase in total marrow cells and c-kit+ cells in the marrow.

Thus, CB(2) agonist AM1241 promoted recovery after sublethal irradiation by inhibiting apoptosis of HSCs and promoting survival, as well as enhancing the number of HSCs entering the cell cycle.”

http://www.ncbi.nlm.nih.gov/pubmed/22074629

Cannabinoid Receptor-2 Regulates Embryonic Hematopoietic Stem Cell Development via Prostaglandin E2 and P-Selectin Activity

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Cannabinoids (CB) modulate adult hematopoietic stem and progenitor cell (HSPCs) function, however, impact on the production, expansion, or migration of embryonic HSCs is currently uncharacterized.

Here, using chemical and genetic approaches targeting CB-signaling in zebrafish, we show that CB receptor (CNR) 2, but not CNR1, regulates embryonic HSC development.

Together, these data suggest CNR2-signaling optimizes the production, expansion, and migration of embryonic HSCs by modulating multiple downstream signaling pathways.

Our work indicates that CB/CNR2 activity acts as a modifier of embryonic HSC formation by fine-tuning signaling pathways essential for HSC emergence and colonization of secondary niches.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4781665/