Identification of novel mouse and rat CB1R isoforms and in silico modeling of human CB1R for peripheral cannabinoid therapeutics.

Image result for aps acta pharmacologica

“Targeting peripheral CB1R is desirable for the treatment of metabolic syndromes without adverse neuropsychiatric effects.

We previously reported a human hCB1b isoform that is selectively enriched in pancreatic beta-cells and hepatocytes, providing a potential peripheral therapeutic hCB1R target. It is unknown whether there are peripherally enriched mouse and rat CB1R (mCB1 and rCB1, respectively) isoforms.

In this study, we found no evidence of peripherally enriched rodent CB1 isoforms; however, some mCB1R isoforms are absent in peripheral tissues. We show that the mouse Cnr1 gene contains six exons that are transcribed from a single promoter. We found that mCB1A is a spliced variant of extended exon 1 and protein-coding exon 6; mCB1B is a novel spliced variant containing unspliced exon 1, intron 1, and exon 2, which is then spliced to exon 6; and mCB1C is a spliced variant including all 6 exons.

Using RNAscope in situ hybridization, we show that the isoforms mCB1A and mCB1B are expressed at a cellular level and colocalized in GABAergic neurons in the hippocampus and cortex. RT-qPCR reveals that mCB1A and mCB1B are enriched in the brain, while mCB1B is not expressed in the pancreas or the liver. Rat rCB1R isoforms are differentially expressed in primary cultured neurons, astrocytes, and microglia.

We also investigated modulation of Cnr1 expression by insulin in vivo and carried out in silico modeling of CB1R with JD5037, a peripherally restricted CB1R inverse agonist, using the published crystal structure of hCB1R.

The results provide models for future CB1R peripheral targeting.”

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Combined deficiency of the Cnr1 and Cnr2 receptors protects against age-related bone loss by osteoclast inhibition.

Aging Cell

“The endocannabinoid system plays a role in regulating bone mass and bone cell activity and inactivation of the type 1 (Cnr1) or type 2 (Cnr2) cannabinoid receptors influences peak bone mass and age-related bone loss. As the Cnr1 and Cnr2 receptors have limited homology and are activated by different ligands, we have evaluated the effects of combined deficiency of Cnr1 and 2 receptors (Cnr1/2-/- ) on bone development from birth to old age and studied ovariectomy induced bone loss in female mice. The Cnr1/2-/- mice had accelerated bone accrual at birth when compared with wild type littermates, and by 3 months of age, they had higher trabecular bone mass. They were also significantly protected against ovariectomy-induced bone loss due to a reduction in osteoclast number. The Cnr1/2-/- mice had reduced age-related bone loss when compared with wild-type due to a reduction in osteoclast number. Although bone formation was reduced and bone marrow adiposity increased in Cnr1/2-/- mice, the osteoclast defect outweighed the reduction in bone formation causing preservation of bone mass with aging. This contrasts with the situation previously reported in mice with inactivation of the Cnr1 or Cnr2 receptors individually where aged-related bone loss was greater than in wild-type. We conclude that the Cnr1 and Cnr2 receptors have overlapping but nonredundant roles in regulating osteoclast and osteoblast activities. These observations indicate that combined inhibition of Cnr1 and Cnr2 receptors may be beneficial in preventing age-related bone loss, whereas blockade of individual receptors may be detrimental.”

https://www.ncbi.nlm.nih.gov/pubmed/28752643

http://onlinelibrary.wiley.com/doi/10.1111/acel.12638/abstract

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Sativex® effects on promoter methylation and on CNR1/CNR2 expression in peripheral blood mononuclear cells of progressive multiple sclerosis patients.

Image result for journal of the neurological sciences

“Multiple sclerosis (MS) is a chronic demyelinating central nervous system (CNS) disease that involve oligodendrocyte loss and failure to remyelinate damaged brain areas causing a progressive neurological disability.

Studies in MS mouse model suggest that cannabinoids ameliorate symptoms as spasticity, tremor and pain reducing inflammation via cannabinoid-mediated system.

The aim of our study is to investigate the changes in cannabinoid type 1 (CNR1) and 2 (CNR2) receptors mRNA expression levels and promoter methylation in peripheral blood mononuclear cells (PBMCs) of MS secondary progressive (MSS-SP) patients treated with Sativex®.

These results suggest that the different expression of cannabinoid receptors by Sativex® treatment in leukocytes might be regulated through a molecular mechanism that involve interferon modulation.”

https://www.ncbi.nlm.nih.gov/pubmed/28716266

http://www.jns-journal.com/article/S0022-510X(17)30392-1/fulltext

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

The cannabinoid receptor 1 gene (CNR1) and multiple sclerosis: an association study in two case-control groups from Spain.

Image result for multiple sclerosis journal

“Different studies point to the implication of the endocannabinoid system in multiple sclerosis (MS) and animal models of MS.

The purpose of this study was to evaluate a possible association of MS with polymorphic markers at the CNR1 gene, encoding the cannabinoid 1 (CB(1)) receptor.

We have performed a genetic analysis of an AAT repeat microsatellite localized in the downstream region of the CNR1 gene, in two case-control groups of MS patients and healthy controls (HC) from Spain (Madrid and Bilbao).

MSpatients with primary progressive MS (PPMS) had more commonly long ((AAT) > or = (13)) alleles and genotypes with a significant difference for genotype 7/8 in Madrid (p = 0.043) and in the sum of both groups (p = 0.016); short alleles were less frequently found in PPMS with a significant difference for allele 5 in the analysis of both groups together (p = 0.039).

In patients with relapsing MS, no consistent differences in allele and genotype distribution were found. Disease severity and progression was unrelated to AAT repeat variations.

In conclusion, long (AAT) > or = (13) CNR1 genotypes could behave as risk factors for PPMS.”

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Role of cannabinoid receptor 1 in human adipose tissue for lipolysis regulation and insulin resistance.

Image result for endocrine journal

“We recently showed that the peripheral cannabinoid receptor type 1 (CNR1) gene is upregulated by the synthetic glucocorticoid dexamethasone.

CNR1 is highly expressed in the central nervous system and has been a drug target for the treatment of obesity.

Here we explore the role of peripheral CNR1 in states of insulin resistance in human adipose tissue.

CNR1 is upregulated in states of type 2 diabetes and insulin resistance.

Furthermore, CNR1 is involved in glucocorticoid-regulated lipolysis.

Peripheral CNR1 could be an interesting drug target in type 2 diabetes and dyslipidemia.”

https://www.ncbi.nlm.nih.gov/pubmed/27858284

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Spontaneous involution of pediatric low-grade gliomas: high expression of cannabinoid receptor 1 (CNR1) at the time of diagnosis may indicate involvement of the endocannabinoid system.

Image result for Childs Nerv Syst

“Pediatric low-grade gliomas (P-LGG) consist of a mixed group of brain tumors that correspond to the majority of CNS tumors in children.

Notably, they may exhibit spontaneous involution after subtotal surgical removal (STR). In this study, we investigated molecular indicators of spontaneous involution in P-LGG.

CONCLUSIONS:

The P-LGG, which remained stable or that presented spontaneous involution after STR, showed significantly higher CNR1 expression at the time of diagnosis.

We hypothesize that high expression levels of CNR1 provide tumor susceptibility to the antitumor effects of circulating endocannabinoids like anandamide, resulting in tumor involution.

This corroborates with reports suggesting that CNR1 agonists and activators of the endocannabinoid system may represent therapeutic opportunities for children with LGG.

We also suggest that CNR1 may be a prognostic marker for P-LGG.

This is the first time spontaneous involution of P-LGG has been suggested to be induced by endocannabinoids.”

http://www.ncbi.nlm.nih.gov/pubmed/27613640

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

A frequent polymorphism in the coding exon of the human cannabinoid receptor (CNR1) gene.

“The central cannabinoid receptor (CB1) mediates the pharmacological activities of cannabis, the endogenous agonist anandamide and several synthetic agonists.

The cloning of the human cannabinoid receptor (CNR1) gene facilitates molecular genetic studies in disorders like Gilles de la Tourette syndrome (GTS), obsessive compulsive disorder (OCD), Parkinsons disease, Alzheimers disease or other neuro psychiatric or neurological diseases, which may be predisposed or influenced by mutations or variants in the CNR1 gene.

We detected a frequent silent mutation (1359G–>A) in codon 453 (Thr) of the CNR1 gene that turned out to be a common polymorphism in the German population. Allele frequencies of this polymorphism are 0.76 and 0.24, respectively.

We developed a simple and rapid polymerase chain reaction (PCR)-based assay by artificial creation of a Msp I restriction site in amplified wild-type DNA (G-allele), which is destroyed by the silent mutation (A-allele).

The intragenic CNR1 polymorphism 1359(G/A) should be useful for association studies in neuro psychiatric disorders which may be related to anandamide metabolism disturbances.”

http://www.ncbi.nlm.nih.gov/pubmed/10441206

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Cannabinoid Receptor 1 (CNR1) Gene Variant Moderates Neural Index of Cognitive Disruption during Nicotine Withdrawal.

 

“Nicotine withdrawal-related disruption of cognitive control may contribute to the reinforcement of tobacco use.

Identification of gene variants that predict this withdrawal phenotype may lead to tailored pharmacotherapy for smoking cessation.

Variation on the cannabinoid receptor 1 gene (CNR1) has been related to nicotine dependence, and CNR1 antagonists may increase attention and memory functioning.

The current findings suggest potential efficacy of cannabinoid RECEPTOR antagonism as a pharmacotherapy approach for smoking cessation among individuals who exhibit greater nicotine withdrawal-related cognitive disruption.”

http://www.ncbi.nlm.nih.gov/pubmed/27453054

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Mechanical and material properties of cortical and trabecular bone from cannabinoid receptor-1-null (Cnr1-/-) mice.

“The endocannabinoid system is known for its regulatory effects on bone metabolism through the cannabinoid receptors, Cnr1 and Cnr2. In this study we analysed the mechanical and material properties of long bones from Cnr1-/- mice on a C57BL/6 background. Tibiae and femora from 5- and 12-week-old mice were subjected to three-point bending to measure bending stiffness and yield strength. Elastic modulus, density and mineral content were measured in the diaphysis. Second moment of area (MOA2), inner and outer perimeters of the cortical shaft and trabecular fractional bone volume (BV/TV) were measured using micro-CT. In Cnr1-/- males and females at both ages the bending stiffness was reduced due to a smaller MOA2. Bone from Cnr1-/- females had a greater modulus than wild-type controls, although no differences were observed in males. BV/TV of 12-week-old Cnr1-/- females was greater than controls, although no difference was seen at 5-weeks. On the contrary, Cnr1-/- males had the same BV/TV as controls at 12-weeks while they had significantly lower values at 5-weeks. This study shows that deleting Cnr1 decreases the amount of cortical bone in both males and females at 12-weeks, but increases the amount of trabecular bone only in females.”

http://www.ncbi.nlm.nih.gov/pubmed/27401043

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous

Autophagy activation by novel inducers prevents BECN2-mediated drug tolerance to cannabinoids.

“Cannabinoids and related drugs generate profound behavioral effects (such as analgesic effects) through activating CNR1 (cannabinoid receptor 1 [brain]). However, repeated cannabinoid administration triggers lysosomal degradation of the receptor and rapid development of drug tolerance, limiting the medical use of marijuana in chronic diseases.

Here we show that a protein involved in macroautophagy/autophagy (a conserved lysosomal degradation pathway), BECN2 (beclin 2), mediates cannabinoid tolerance by preventing CNR1 recycling and resensitization after prolonged agonist exposure, and deletion of Becn2 rescues CNR1 activity in mouse brain and conveys resistance to analgesic tolerance to chronic cannabinoids.

Overall, our findings demonstrate the functional link among autophagy, receptor signaling and animal behavior regulated by psychoactive drugs, and develop a new strategy to prevent tolerance and improve medical efficacy of cannabinoids by modulating the BECN2 interactome and autophagy activity.”

http://www.ncbi.nlm.nih.gov/pubmed/27305347

Facebook Twitter Pinterest Stumbleupon Tumblr Posterous