Is the Cannabinoid CB2 Receptor a Major Regulator of the Neuroinflammatory Axis of the Neurovascular Unit in Humans?

“The central nervous system (CNS) is an immune privileged site where the neurovascular unit (NVU) and the blood-brain barrier (BBB) act as a selectively permeable interface to control the passage of nutrients and inflammatory cells into the brain parenchyma. However, in response to injury, infection, or disease, CNS cells become activated, and release inflammatory mediators to recruit immune cells to the site of inflammation. Increasing evidence suggests that cannabinoids may have a neuroprotective role in CNS inflammatory conditions. For many years, it was widely accepted that cannabinoid receptor type 1 (CB1) modulates neurological function centrally, while peripheral cannabinoid receptor type 2 (CB2) modulates immune function. As knowledge about the physiology and pharmacology of the endocannabinoid system advances, there is increasing interest in targeting CB2 as a potential treatment for inflammation-dependent CNS diseases (Ashton & Glass, 2007), where recent rodent and human studies have implicated intervention at the level of the NVU and BBB. These are incredibly important in brain health and disease. Therefore, this review begins by explaining the cellular and molecular components of these systems, highlighting important molecules potentially regulated by cannabinoid ligands and then takes an unbiased look at the evidence in support (or otherwise) of cannabinoid receptor expression and control of the NVU and BBB function in humans.” https://www.ncbi.nlm.nih.gov/pubmed/28826541 http://www.sciencedirect.com/science/article/pii/S1054358917300376?via%3Dihub]]>

Functional Selectivity at Cannabinoid Receptors.

“It is now clear that, in contrast to traditional descriptions of G protein-coupled receptor signaling, agonists can activate or inhibit characteristic patterns of downstream effector pathways depending on their structures and the conformational changes induced in the receptor. This is referred to as functional selectivity (also known as agonist-directed trafficking, ligand-induced differential signaling, or biased agonism). It is important because even small structural differences can result in significant variations in overall agonist effects (wanted and unwanted) depending on which postreceptor signaling systems are engaged by each agonist/receptor pairing. In addition to the canonical signaling pathways mediated by Gi/o proteins, CB1 and CB2 receptor agonists can have effects via differential activation not only of Gi subtypes but also of Gs and Gq/11 proteins. For example, the classical cannabinoid HU-210 produces maximal activation of both Gi and Go proteins, while the endocannabinoid anandamide and aminoalkylindole WIN 55,212 both produce maximal activation of Gi, but submaximal activation of Go. Cannabinoid agonists can also signal differentially via β-arrestins coupled to mitogen-activated protein kinases, subsequently promoting varying degrees of receptor internalization and agonist desensitization. A recent extensive characterization of the molecular pharmacology of CB2 agonists (Soethoudt et al., 2017) identified marked differences (bias) in the ability of certain agonists to activate distinct signaling pathways (cAMP accumulation, ERK phosphorylation, GIRK activation, GTPγS binding, and β-arrestin recruitment) and to cause off-target effects, exemplifying the need to evaluate functional selectivity in agonist drug development.” https://www.ncbi.nlm.nih.gov/pubmed/28826535 http://www.sciencedirect.com/science/article/pii/S1054358917300285?via%3Dihub]]>

CB1 and CB2 Receptor Pharmacology.

“The CB1 and CB2 cannabinoid receptors (CB1R, CB2R) are members of the G protein-coupled receptor (GPCR) family that were identified over 20 years ago. CB1Rs and CB2Rs mediate the effects of Δ9-tetrahydrocannabinol (Δ9-THC), the principal psychoactive constituent of marijuana, and subsequently identified endogenous cannabinoids (endocannabinoids) anandamide and 2-arachidonoyl glycerol. CB1Rs and CB2Rs have both similarities and differences in their pharmacology. Both receptors recognize multiple classes of agonist and antagonist compounds and produce an array of distinct downstream effects. Natural polymorphisms and alternative splice variants may also contribute to their pharmacological diversity. As our knowledge of the distinct differences grows, we may be able to target select receptor conformations and their corresponding pharmacological responses. This chapter will discuss their pharmacological characterization, distribution, phylogeny, and signaling pathways. In addition, the effects of extended agonist exposure and how that affects signaling and expression patterns of the receptors are considered.” https://www.ncbi.nlm.nih.gov/pubmed/28826534 http://www.sciencedirect.com/science/article/pii/S1054358917300340?via%3Dihub]]>

Endocannabinoid Analytical Methodologies: Techniques That Drive Discoveries That Drive Techniques.

“Identification of the two major endogenous cannabinoid ligands, known as endocannabinoids, N-arachidonoyl-ethanolamine (anandamide, AEA) and 2-arachidonoyl-glycerol (2-AG), opened the way for the identification and isolation of other lipid congeners, all derivatives of fatty acids and related to the Endocannabinoid System. The nomenclature of this anandamide-type class of lipids is evolving as new species are discovered all the time. However, they each fall under the larger umbrella of lipids that are a conjugation of a fatty acid with an amine through and amide bond, which we will refer to as lipoamines. Specific subspecies of lipoamines that have been discovered are the N-acyl-ethanolamides (including AEA), N-acyl-dopamines, N-acyl-serotonins, N-acyl-GABA, N-acyl-taurines, and a growing number of N-acyl amino acids. Emerging data from multiple labs also show that monoacylglycerols (including 2-AG), COX-2 metabolites, and fatty acid esters of hydroxyl fatty acids are interconnected with these lipoamines at both the biosynthetic and metabolic levels. Understanding the molecular relatedness of these lipids is important for studying how they act as signaling molecules; however, a first step in this process hinges on advances in being able to accurately measure them.” https://www.ncbi.nlm.nih.gov/pubmed/28826532]]>

Topical Medical Cannabis (TMC): A new treatment for wound pain-Three cases of Pyoderma Gangrenosum.

“Pain associated with integumentary wounds is highly prevalent yet it remains an area of significant unmet need within healthcare. Currently, systemically administered opioids are the mainstay of treatment. However, recent publications are casting opioids in a negative light given their high side effect profile, inhibition of wound healing, and association with accidental overdose, incidents that are frequently fatal. Thus, novel analgesic strategies for wound-related pain need to be investigated. The ideal methods of pain relief for wound patients are modalities that are topical, lack systemic side effects, non-invasive, self-administered, and display rapid onset of analgesia. Extracts derived from the cannabis plant have been applied to wounds for thousands of years. The discovery of the human endocannabinoid system and its dominant presence throughout the integumentary system provides a valid and logical scientific platform to consider the use of topical cannabinoids for wounds. We are reporting a prospective case series of 3 patients with Pyoderma Gangrenosum (PG) that were treated with Topical Medical Cannabis (TMC) compounded in non-genetically modified organic sunflower oil. Clinically significant analgesia that was associated with reduced opioid utilization was noted in all 3 cases. TMC has the potential to improve pain management in patients suffering from wounds of all classes.” https://www.ncbi.nlm.nih.gov/pubmed/28818631 http://www.jpsmjournal.com/article/S0885-3924(17)30351-2/fulltext]]>

Smoking Marijuana Can Reduce Risk Of Stroke, Study Finds.

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“Smoking marijuana can reduce the risk of a stroke to a large extent, a new study has found. In the states where marijuana use is legal, strains of the drug are prescribed to cure chronic pain, anxiety, and epilepsy. A new study conducted by the University of Texas at Dallas has found cannabis can improve a person’s health by enhancing the blood and oxygen flow, thus reducing the risk of blood clots and the possibility of a stroke.” http://www.ibtimes.com/smoking-marijuana-can-reduce-risk-stroke-study-finds-2579489
“Residual Effects of THC via Novel Measures of Brain Perfusion and Metabolism in a Large Group of Chronic Cannabis Users” https://www.nature.com/npp/journal/vaop/ncurrent/full/npp201744a.html
“Could cannabis PROTECT you from a stroke? People who smoke marijuana every day have better blood flow and oxygen to the brain, controversial study claims. A study by the University of Texas at Dallas has found the drug can improve oxygen and blood flow to the brain, reducing the risk of clots that cause a brain attack. In fact, the research team found chronic cannabis users have the most efficient brain blood flow of all, suggesting their stroke risk is lowest.” http://www.dailymail.co.uk/health/article-4797444/Cannabis-PROTECTS-stroke-study-claims.html
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