Emerging strategies targeting cb2 cannabinoid receptor: biased agonism and allosterism.

Biochemical Pharmacology

“During these last years, the CB2 cannabinoid receptor has emerged as a potential anti-inflammatory target in diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Huntington’s disease, ischemic stroke, autoimmune diseases, osteoporosis, and cancer. However, the development of clinically useful CB2 agonists reveals to be very challenging. Allosterism and biased-signaling mechanisms at CB2 receptor may offer new avenues for the development of improved CB2 receptor-targeted therapies. Although there has been some exploration of CB1 receptor activation by new CB1 allosteric or biased-signaling ligands, the CB2 receptor is still at initial stages in this domain. In an effort to understand the molecular basis behind these pharmacological approaches, we have analyzed and summarized the structural data reported so far at CB2 receptor.”

Decisive role of P42/44 mitogen-activated protein kinase in Δ9-tetrahydrocannabinol-induced migration of human mesenchymal stem cells.

Related image “In past years, medical interest in Δ9-tetrahydrocannabinol (THC), the major psychoactive ingredient of the Cannabis plant, has been renewed due to the elucidation of the endocannabinoid system and diverse other receptor targets involved in biological cannabinoid effects.

The present study therefore investigates the impact of THC on the migration of mesenchymal stem cells (MSCs) which are known to be involved in various regenerative processes such as bone healing.

Collectively, this study demonstrates THC to exert a promigratory effect on MSCs via a CB1 receptor-dependent activation of p42/44 MAPK phosphorylation. This pathway may be involved in regenerative effects of THC and could be a target of pharmacological intervention.”   https://www.ncbi.nlm.nih.gov/pubmed/29285308

“Collectively and to the best of our knowledge, this is the first study reporting a promigratory impact of THC on MSCs, which may be an additional mechanism in the complex network of regenerative action of cannabinoids.”   http://www.oncotarget.com/index.php?journal=oncotarget&page=article&op=view&path[]=22517&path[]=71182

Restoration of osteogenic differentiation by overexpression of cannabinoid receptor 2 in bone marrow mesenchymal stem cells isolated from osteoporotic patients.

 Journal Cover

“Cannabinoid receptor 2 (CNR2) has a critical role in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). CNR2 expression was found to be downregulated in osteoporotic patients.

The present study aimed to investigate the functionality of CNR2 in restoring osteogenic differentiation and mineralization of BMSCs isolated from osteoporotic patients.

The results demonstrated that overexpression of CNR2 in osteoporotic BMSCs increased ALP activity, promoted expression of osteogenic genes and enhanced deposition of mineralized extracellular matrix. In addition, phosphorylation of p38 MAPK was found to be increased by overexpression of CNR2.

In conclusion, the present study indicated that restoration of CNR2 recovered the osteogenic differentiation of BMSCs isolated from osteoporotic patients. This finding may provide a novel strategy for a treatment approach for osteoporosis.”

https://www.ncbi.nlm.nih.gov/pubmed/29250156

https://www.spandidos-publications.com/10.3892/etm.2017.5369

G protein-coupled receptors as anabolic drug targets in osteoporosis.

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“Osteoporosis is a progressive bone disorder characterised by imbalance between bone building (anabolism) and resorption (catabolism). Most therapeutics target inhibition of osteoclast-mediated bone resorption, but more recent attention in early drug discovery has focussed on anabolic targets in osteoblasts or their precursors. Two marketed agents that display anabolic properties, strontium ranelate and teriparatide, mediate their actions via the G protein-coupled calcium-sensing and parathyroid hormone-1 receptors, respectively. This review explores their activity, the potential for improved therapeutics targeting these receptors and other putative anabolic GPCR targets, including Smoothened, Wnt/Frizzled, relaxin family peptide, adenosine, cannabinoid, prostaglandin and sphingosine-1-phosphate receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/29080701

“The action of THC is mediated by two major G-protein coupled receptors, cannabinoid receptor type 1 (CB1) and CB2″  https://www.ncbi.nlm.nih.gov/pubmed/28967368

“Cannabis may prevent osteoporosis”  http://news.bbc.co.uk/2/hi/uk_news/scotland/edinburgh_and_east/8199007.stm

Is cannabis an effective treatment for joint pain?

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“Cannabis has been used to treat pain for thousands of years.

However, since the early part of the 20th century, laws restricting cannabis use have limited its evaluation using modern scientific criteria. Over the last decade, the situation has started to change because of the increased availability of cannabis in the United States for either medical or recreational purposes, making it important to provide the public with accurate information as to the effectiveness of the drug for joint pain among other indications.

The major psychotropic component of cannabis is Δ9-tetrahydrocannabinol (THC), one of some 120 naturally occurring phytocannabinoids. Cannabidiol (CBD) is another molecule found in herbal cannabis in large amounts. Although CBD does not produce psychotropic effects, it has been shown to produce a variety of pharmacological effects. Hence, the overall effects of herbal cannabis represent the collective activity of THC, CBD and a number of minor components.

The action of THC is mediated by two major G-protein coupled receptors, cannabinoid receptor type 1 (CB1) and CB2, and recent work has suggested that other targets may also exist. Arachidonic acid derived endocannabinoids are the normal physiological activators of the two cannabinoid receptors.

Natural phytocannabinoids and synthetic derivatives have produced clear activity in a variety of models of joint pain in animals. These effects are the result of both inhibition of pain pathway signalling (mostly CB1) and anti-inflammatory effects (mostly CB2). There are also numerous anecdotal reports of the effectiveness of smoking cannabis for joint pain.

Indeed, it is the largest medical request for the use of the drug. However, these reports generally do not extend to regulated clinical trials for rheumatic diseases. Nevertheless, the preclinical and human data that do exist indicate that the use of cannabis should be taken seriously as a potential treatment of joint pain.”

https://www.ncbi.nlm.nih.gov/pubmed/28967368

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

Cannabidiol administration reduces sublesional cancellous bone loss in rats with severe spinal cord injury.

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“Patients with spinal cord injury (SCI) undergo severe loss of bone mineral below the level of lesion, and data on available treatment options after SCI is scarce.

The aim of this work was to investigate the therapeutic effect of cannabidiol (CBD), a non-psychoactive cannabis, on sublesional bone loss in a rat model of SCI.

In conclusion, CBD administration attenuated SCI-induced sublesional cancellous bone loss.”

https://www.ncbi.nlm.nih.gov/pubmed/28479140

http://www.sciencedirect.com/science/article/pii/S0014299917303230

Cannabis use and bone mineral density: NHANES 2007-2010.

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“Cannabis use is rising in the USA. Its relationship to cannabinoid signaling in bone cells implies its use could affect bone mineral density (BMD) in the population. In a national survey of people ages 20-59, we found no association between self-reported cannabis use and BMD of the hip or spine.

No association between cannabis and BMD was observed for any level of use.

A history of cannabis use, although highly prevalent and related to other risk factors for low BMD, was not independently associated with BMD in this cross-sectional study of American men and women.”

https://www.ncbi.nlm.nih.gov/pubmed/28286929

β-Caryophyllene promotes osteoblastic mineralization, and suppresses osteoclastogenesis and adipogenesis in mouse bone marrow cultures in vitro.

 

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“Osteoporosis is induced by the reduction in bone mass through decreased osteoblastic osteogenesis and increased osteoclastic bone resorption, and it is associated with obesity and diabetes. Osteoblasts and adipocytes are derived from bone marrow mesenchymal stem cells. The prevention of osteoporosis is an important public health concern in aging populations. β-caryophyllene, a component of various essential oils, is a selective agonist of the cannabinoid receptor type 2 and exerts cannabimimetic anti-inflammatory effects in animals. The present study aimed to identify the effect of β-caryophyllene on adipogenesis, osteoblastic mineralization and osteoclastogenesis in mouse bone marrow cell cultures in vitro. Bone marrow cells obtained from mouse femoral tissues were cultured in the presence of β-caryophyllene (0.1-100 µM) in vitro. The results revealed that β-caryophyllene stimulated osteoblastic mineralization, and suppressed adipogenesis and osteoclastogenesis. Thus, β-caryophyllene may be used as a therapeutic agent for the prevention and treatment of osteoporosis.”

https://www.ncbi.nlm.nih.gov/pubmed/28105093

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”  http://www.ncbi.nlm.nih.gov/pubmed/23138934

Overlapping molecular pathways between cannabinoid receptors type 1 and 2 and estrogens/androgens on the periphery and their involvement in the pathogenesis of common diseases (Review).

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“The physiological and pathophysiological roles of sex hormones have been well documented and the modulation of their effects is applicable in many current treatments.

On the other hand, the physiological role of endocannabinoids is not yet clearly understood and the endocannabinoid system is considered a relatively new therapeutic target.

The physiological association between sex hormones and cannabinoids has been investigated in several studies; however, its involvement in the pathophysiology of common human diseases has been studied separately.

Herein, we present the first systematic review of molecular pathways that are influenced by both the cannabinoids and sex hormones, including adenylate cyclase and protein kinase A, epidermal growth factor receptor, cyclic adenosine monophosphate response element-binding protein, vascular endothelial growth factor, proto-oncogene serine/threonine-protein kinase, mitogen-activated protein kinase, phosphatidylinositol-4,5-bisphosphate 3-kinase, C-Jun N-terminal kinase and extracellular-signal-regulated kinases 1/2.

Most of these influence cell proliferative activity.

Better insight into this association may prove to be beneficial for the development of novel pharmacological treatment strategies for many common diseases, including breast cancer, endometrial cancer, prostate cancer, osteoporosis and atherosclerosis.

The associations between cannabinoids, estrogens and androgens under these conditions are also presented and the molecular interactions are highlighted.”