Author Archives: David Worrell

Cannabinoid receptor activation inhibits cell cycle progression by modulating 14-3-3β.

Posted on by

“Cannabinoids display various pharmacological activities, including tumor regression, anti-inflammatory and neuroprotective effects.

To investigate the molecular mechanisms underlying the pharmacological effects of cannabinoids, we used a yeast two-hybrid system to screen a mouse brain cDNA library for proteins interacting with type 1 cannabinoid receptor (CB1R). Using the intracellular loop 3 of CB1R as bait, we identified 14-3-3β as an interacting partner of CB1R and confirmed their interaction using affinity-binding assays. 14-3-3β has been reported to induce a cell cycle delay at the G2/M phase.

We tested the effects of cannabinoids on cell cycle progression in HeLa cells synchronized using a double-thymidine block-and-release protocol and found an increase in the population of G2/M phase cells. We further found that CB1R activation augmented the interaction of 14-3-3β with Wee1 and Cdc25B, and promoted phosphorylation of Cdc2 at Tyr-15.

These results suggest that cannabinoids induce cell cycle delay at the G2/M phase by activating 14-3-3β.”

http://www.ncbi.nlm.nih.gov/pubmed/25002257

Cannabinoid receptor interacting protein (CRIP1a) attenuates CB1R signaling in neuronal cells.

Posted on by

“CB1 cannabinoid receptors (CB1R) are one of the most abundantly expressed G protein coupled receptors (GPCR) in the CNS and regulate diverse neuronal functions.

The identification of GPCR interacting proteins has provided additional insight into the fine-tuning and regulation of numerous GPCRs.

The cannabinoid receptor interacting protein 1a (CRIP1a) binds to the distal carboxy terminus of CB1R, and has been shown to alter CB1R-mediated neuronal function.

The mechanisms by which CRIP1a regulates CB1R activity have not yet been identified; therefore the focus of this investigation is to examine the cellular effects of CRIP1a on CB1R signaling using neuronal N18TG2 cells stably transfected with CRIP1a over-expressing and CRIP1a knockdown constructs.

These studies suggest a mechanism by which endogenous levels of CRIP1a modulate CB1R-mediated signal transduction by facilitating a Gi/o protein subtype preference for Gi1 and Gi2, accompanied by an overall suppression of G-protein-mediated signaling in neuronal cells.”

http://www.ncbi.nlm.nih.gov/pubmed/25446256

Cannabinoid Receptor Interacting Protein (CRIP1a) suppresses agonist-driven CB1 receptor internalization, and regulates receptor replenishment in an agonist-biased manner.

Posted on by

“Cannabinoid Receptor Interacting Protein1a (CRIP1a) is a CB1 receptor (CB1 R) distal C-terminus-associated protein that modulates CB1 R signaling via G proteins, and CB1 R down-regulation but not desensitization.

In the present study, we determined the involvement of CRIP1a in CB1 R plasma membrane trafficking.

These studies demonstrate a novel role for CRIP1a in agonist-driven CB1 R cell surface regulation postulated to occur by two mechanisms: attenuating agonist-mediated but not internalization in the absence of exogenous agonists, and biased agonist-dependent trafficking of de novo synthesized receptor to the cell surface.”

http://www.ncbi.nlm.nih.gov/pubmed/27513693

Cannabidiol-2′,6′-dimethyl ether as an effective protector of 15-lipoxygenase-mediated low-density lipoprotein oxidation in vitro.

Posted on by

“15-Lipoxygenase (15-LOX) is one of the key enzymes responsible for the formation of oxidized low-density lipoprotein (ox-LDL), a major causal factor for atherosclerosis.

We have recently reported that cannabidiol-2′,6′-dimethyl ether (CBDD) is a selective and potent inhibitor of 15-LOX-catalyzed linoleic acid oxygenation.

The results obtained demonstrate that CBDD is a potent and selective inhibitor of ox-LDL formation generated by the 15-LOX pathway.

These studies establish CBDD as both an important experimental tool for characterizing 15-LOX-mediated ox-LDL formation, and as a potentially useful therapeutic agent for treatment of atherosclerosis.

In sum, these findings suggest that CBDD may be a useful adjuvant in the treatment of atherosclerosis as well as an experimental tool for analyzing the mechanistic details of PUFAs oxygenation by 15-LOX.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4012644/

“Cannabidiol-2′,6′-dimethyl ether, a cannabidiol derivative, is a highly potent and selective 15-lipoxygenase inhibitor. Thus, 15-LOX is suggested to be involved in development of atherosclerosis, and CBDD may be a useful prototype for producing medicines for atherosclerosis.”  http://www.ncbi.nlm.nih.gov/pubmed/19406952

[Cannabinoids in multiple sclerosis — therapeutically reasonable?].

Posted on by

“For centuries extracts from the Cannabis sativa plant have been used for recreational use and as remedies.

Anecdotal reports from patients with multiple sclerosis (MS) experiencing relief of their spasticity and pain after smoking marihuana have prompted discussions about a potential therapeutic application of cannabis preparations in MS.

Only recently the first large, multicenter, double-blind, placebo controlled study was conducted evaluating the use of cannabinoids for treatment of spasticity and other symptoms related to MS.

Based on this trial and previous uncontrolled observations together with insights from basic research and animal experiments there is reasonable evidence for the therapeutical employment of cannabinoids in the treatment of MS related symptoms.

Furthermore, data are arising that cannabinoids have immunomodulatory and neuroprotective properties.

This article summarizes the present knowledge of clinical and experimental research regarding the therapeutic potential of cannabinoids for the treatment of MS.”

http://www.ncbi.nlm.nih.gov/pubmed/16052440

Decreased depression in marijuana users.

Posted on by

“Over 4400 adult internet users completed The Center for Epidemiologic Studies Depression scale and measures of marijuana use.

We employed an internet survey in an effort to recruit the most depressed and marijuana-involved participants, including those who might prove unwilling to travel to the laboratory or discuss drug use on the phone or in person.

We compared those who consumed marijuana daily, once a week or less, or never in their lives.

Despite comparable ranges of scores on all depression subscales, those who used once per week or less had less depressed mood, more positive affect, and fewer somatic complaints than non-users.

Daily users reported less depressed mood and more positive affect than non-users.

These data suggest that adults apparently do not increase their risk for depression by using marijuana.”

http://www.ncbi.nlm.nih.gov/pubmed/15964704

Opposite Cannabis-Cognition Associations in Psychotic Patients Depending on Family History.

Posted on by

“The objective of this study is to investigate cognitive performance in a first-episode psychosis sample, when stratifying the interaction by cannabis use and familial or non-familial psychosis.

We found that cannabis use was associated with worse working memory, regardless of family history. However, cannabis use was clearly associated with worse cognitive performance in patients with no family history of psychosis, in cognitive domains including verbal memory, executive function and global cognitive index, whereas cannabis users with a family history of psychosis performed better in these domains.

The main finding of the study is that there is an interaction between cannabis use and a family history of psychosis in the areas of verbal memory, executive function and global cognition: that is, cannabis use is associated with a better performance in patients with a family history of psychosis and a worse performance in those with no family history of psychosis.

In order to confirm this hypothesis, future research should explore the actual expression of the endocannabinoid system in patients with and without a family history of psychosis.”

http://www.ncbi.nlm.nih.gov/pubmed/27513670

Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging.

Posted on by

“Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well-characterized. The cannabinoid receptor type 1 (CB1) is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2) in the brain and spinal cord of healthy individuals are relatively low.”

http://www.ncbi.nlm.nih.gov/pubmed/27512365

The inhibitory effect of combination treatment with leptin and cannabinoid CB1 receptor agonist on food intake and body weight gain is mediated by serotonin 1B and 2C receptors.

Posted on by

“Previous studies reported that the co-injection of leptin and cannabinoid CB1 receptor antagonists reduces food intake and body weight in rats, and this effect is more profound than that induced by these compounds individually. Additionally, serotonin mediates the effects of numerous anorectic drugs.

To investigate whether serotonin interacts with leptin and endocannabinoids to affect food intake and body weight, we administered 5-hydroxytryptamine(HT)1B and 5-hydroxytryptamine(HT)2C serotonin receptor antagonists (3 mg/kg GR 127935 and 0.5 mg/kg SB 242084, respectively) to male Wistar rats treated simultaneously with leptin (100 μg/kg) and the CB1 receptor inverse agonist AM 251 (1 mg/kg) for 3 days.

In accordance with previous findings, the co-injection of leptin and AM 251, but not the individual injection of each drug, resulted in a significant decrease in food intake and body weight gain. Blockade of the 5-HT1B and 5-HT2C receptors completely abolished the leptin- and AM 251-induced anorectic and body-weight-reducing effects.

These results suggest that serotonin mediates the leptin- and AM 251-dependent regulation of feeding behavior in rats via the 5-HT1B and 5-HT2C receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27512006

Cross-validated stable-isotope dilution GC-MS and LC-MS/MS assays for monoacylglycerol lipase (MAGL) activity by measuring arachidonic acid released from the endocannabinoid 2-arachidonoyl glycerol.

Posted on by

“2-Arachidonoyl glycerol (2AG) is an endocannabinoid that activates cannabinoid (CB) receptors CB1 and CB2. Monoacylglycerol lipase (MAGL) inactivates 2AG through hydrolysis to arachidonic acid (AA) and glycerol, thus modulating the activity at CB receptors.” http://www.ncbi.nlm.nih.gov/pubmed/27511795