Category Archives: Uncategorized

CB1 cannabinoid receptor activity is modulated by the cannabinoid receptor interacting protein CRIP 1a.

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“The CB1 cannabinoid receptor is a G-protein coupled receptor that has important physiological roles in synaptic plasticity, analgesia, appetite, and neuroprotection.

We report the discovery of two structurally related CB1 cannabinoid receptor interacting proteins (CRIP1a and CRIP1b) that bind to the distal C-terminal tail of CB1. CRIP1a and CRIP1b are generated by alternative splicing of a gene located on chromosome 2 in humans, and orthologs of CRIP1a occur throughout the vertebrates, whereas CRIP1b seems to be unique to primates.

CRIP1a coimmunoprecipitates with CB1receptors derived from rat brain homogenates, indicating that CRIP1a and CB1 interact in vivo. Furthermore, in superior cervical ganglion neurons coinjected with CB1 and CRIP1a or CRIP1b cDNA, CRIP1a, but not CRIP1b, suppresses CB1-mediated tonic inhibition of voltage-gated Ca2+ channels.

Discovery of CRIP1a provides the basis for a new avenue of research on mechanisms of CB1 regulation in the nervous system and may lead to development of novel drugs to treat disorders where modulation of CB1 activity has therapeutic potential (e.g., chronic pain, obesity, and epilepsy).”

http://www.ncbi.nlm.nih.gov/pubmed/17895407

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

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“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.

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“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.

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“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

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

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“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

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.

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“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

Marijuana users do not have increased healthcare utilization: A National Health and Nutrition Examination Survey (NHANES) study

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“There is paucity of data on healthcare utilization due to marijuana use on a national scale.

Our study found no significant association exists between marijuana use and healthcare utilization.

The frequency of marijuana use also does not have significant impact on healthcare utilization.”

http://www.ejinme.com/article/S0953-6205(16)30231-X/fulltext

Effective treatment of spasticity using dronabinol in pediatric palliative care.

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“Cannabis extracts have a wide therapeutic potential but in many countries they have not been approved for treatment in children so far.

We conducted an open, uncontrolled, retrospective study on the administration of dronabinol to determine the value, efficacy, and safety of cannabis-based medicines in the treatment of refractory spasticity in pediatric palliative care.

Sixteen children, adolescents and young adults having complex neurological conditions with spasticity (aged 1.3-26.6 years, median 12.7 years) were treated with dronabinol by our specialized pediatric palliative care team between 01.12.2010 and 30.04.2015 in a home-care setting. Therapeutic efficacy and side effects were closely monitored.

RESULTS:

Drops of the 2.5% oily tetrahydrocannabinol solution (dronabinol) were administered. A promising therapeutic effect was seen, mostly due to abolishment or marked improvement of severe, treatment resistant spasticity (n = 12). In two cases the effect could not be determined, two patients did not benefit. The median duration of treatment was 181 days (range 23-1429 days). Dosages to obtain a therapeutic effect varied from 0.08 to 1.0 mg/kg/d with a median of 0.33 mg/kg/d in patients with a documented therapeutic effect. When administered as an escalating dosage scheme, side effects were rare and only consisted in vomiting and restlessness (one patient each).

No serious and enduring side effects occurred even in young children and/or over a longer period of time.

CONCLUSIONS:

In the majority of pediatric palliative patients the treatment with dronabinol showed promising effects in treatment resistant spasticity.”

http://www.ncbi.nlm.nih.gov/pubmed/27506815

Pure Δ9-tetrahydrocannabivarin and a Cannabis sativa extract with high content in Δ9-tetrahydrocannabivarin inhibit nitrite production in murine peritoneal macrophages.

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“Historical and scientific evidence suggests that Cannabis use has immunomodulatory and anti-inflammatory effects.

We have here investigated the effect of the non-psychotropic phytocannabinoid Δ9-tetrahydrocannabivarin (THCV) and of a Cannabis sativa extract with high (64.8%) content in THCV (THCV-BDS) on nitric oxide (NO) production, and on cannabinoid and transient receptor potential (TRP) channel expression in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages.

THCV-BDS and THCV exhibited similar affinity in radioligand binding assays for CB1 and CB2 receptors, and inhibited, via CB2 but not CB1 cannabinoid receptors, nitrite production evoked by LPS in peritoneal macrophages.

THCV down-regulated the over-expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and interleukin 1β (IL-1β) proteins induced by LPS.

Furthermore, THCV counteracted LPS-induced up-regulation of CB1 receptors, without affecting the changes in CB2, TRPV2 or TRPV4 mRNA expression caused by LPS. Other TRP channels, namely, TRPA1, TRPV1, TRPV3 and TRPM8 were poorly expressed or undetectable in both unstimulated and LPS-challenged macrophages.

It is concluded that THCV – via CB2 receptor activation – inhibits nitrite production in macrophages. The effect of this phytocannabinoid was associated with a down-regulation of CB1, but not CB2 or TRP channel mRNA expression.”

http://www.ncbi.nlm.nih.gov/pubmed/27498155