The endocannabinoid system – a target for the treatment of LUTS?

“Lower urinary tract symptoms (LUTS) are common in all age groups and both sexes, resulting in tremendous personal suffering and a substantial burden to society.

Antimuscarinic drugs are the mainstay of symptom management in patients with LUTS, although their clinical utility is limited by the high prevalence of adverse effects, which often limit patients’ long-term adherence to these agents.

Data from controversial studies in the 1990s revealed the positive effects of marijuana-based compounds on LUTS, and sparked an interest in the possibility of treating bladder disorders with cannabis.

Increased understanding of cannabinoid receptor pharmacology and the discovery of endogenous ligands of these receptors has prompted debate and further research into the clinical utility of exogenous cannabinoid receptor agonists relative to the unwanted psychotropic effects of these agents.

Currently, the endocannabinoid system is considered as a potential drug target for pharmacological management of LUTS, with a more favourable adverse event profile than antimuscarinic agents.”

http://www.ncbi.nlm.nih.gov/pubmed/27377161

The cannabinoid 2 receptor agonist β-caryophyllene modulates the inflammatory reaction induced by Mycobacterium bovis BCG by inhibiting neutrophil migration.

“β-Caryophyllene (BCP) is a sesquiterpene that binds to the cannabinoid 2 (CB2) receptor and exerts anti-inflammatory effects. In this study, we investigated the anti-inflammatory effect of BCP and another CB2 agonist, GP1a in inflammatory experimental model induced by Mycobacterium bovis (BCG).

These results suggest that the CB2 receptor may represent a new target for modulating the inflammatory reaction induced by mycobacteria.”

http://www.ncbi.nlm.nih.gov/pubmed/27379721

“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

Microglia activation states and cannabinoid system: Therapeutic implications.

“Microglial cells are recognized as the brain’s intrinsic immune cells, mediating actions that range from the protection against harmful conditions that modify CNS homeostasis, to the control of proliferation and differentiation of neurons and their synaptic pruning. To perform these functions, microglia adopts different activation states, the so-called phenotypes that depending on the local environment involve them in neuroinflammation, tissue repair and even the resolution of the inflammatory process.

There is accumulating evidence indicating that cannabinoids (CBs) might serve as a promising tool to modify the outcome of inflammation, especially by influencing microglial activity.

Microglia has a functional endocannabinoid (eCB) signaling system, composed of cannabinoid receptors and the complete machinery for the synthesis and degradation of eCBs.

The expression of cannabinoid receptors – mainly CB2 – and the production of eCBs have been related to the activation profile of these cells and therefore, the microglial phenotype, emerging as one of the mechanisms by which microglia becomes alternatively activated.

Here, we will discuss recent studies that provide new insights into the role of CBs and their endogenous counterparts in defining the profile of microglia activation.

These actions make CBs a promising therapeutic tool to avoid the detrimental effects of inflammation and possibly paving the way to target microglia in order to generate a reparative milieu in neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27373505

Fatty Acid Amide Hydrolase Binding in Brain of Cannabis Users: Imaging With the Novel Radiotracer [11C]CURB.

“One of the major mechanisms for terminating the actions of the endocannabinoid anandamide is hydrolysis by fatty acid amide hydrolase (FAAH), and inhibitors of the enzyme were suggested as potential treatment for human cannabis dependence.

In cannabis users, FAAH binding was significantly lower by 14%-20% across the brain regions examined than in matched control subjects.

Lower FAAH binding levels in the brain may be a consequence of chronic and recent cannabis exposure and could contribute to cannabis withdrawal. This effect should be considered in the development of novel treatment strategies for cannabis use disorder that target FAAH and endocannabinoids.”

http://www.ncbi.nlm.nih.gov/pubmed/27345297

Dissecting the signaling pathways involved in the crosstalk between mGlu5 and CB1 receptors.

“The metabotropic glutamate (mGlu) receptor 5 and the cannabinoid type 1 (CB1) receptor are G-protein-coupled receptors (GPCR) that are widely expressed in the central nervous system (CNS). mGlu5 receptors, present at the postsynaptic site, are coupled to Gαq/11 proteins and display an excitatory response upon activation, while the CB1 receptor, mainly present at presynaptic terminals, is coupled to the Gi/o protein and triggers an inhibitory response. Recent studies suggest that the glutamatergic and endocannabinoid systems exhibit a functional interaction to modulate several neural processes. In this review we discuss possible mechanisms involved in this crosstalk and its relationship with physiological and pathological conditions, including nociception, addiction and fragil X syndrome.”

http://www.ncbi.nlm.nih.gov/pubmed/27338080

Anatomical characterization of the cannabinoid cb1 receptor in cell type-specific mutant mouse rescue models.

“Type-1 cannabinoid (CB1 ) receptors are widely distributed in the brain. Their physiological roles depend on their distribution pattern that differs remarkably among cell types. Hence, subcellular compartments with little but functional relevant CB1 receptors can be overlooked, fostering an incomplete mapping. To overcome this, knock-in mice with cell-type specific rescue of CB1 receptors have emerged as excellent tools to investigate its cell type-specific localization and sufficient functional role with no bias.

However, to know whether these rescue mice maintain endogenous CB1 receptor expression level, detailed anatomical studies are called for. The subcellular distribution of hippocampal CB1 receptors of rescue mice that express the gene exclusively in dorsal telencephalic glutamatergic neurons (Glu-CB1 -RS) or GABAergic neurons (GABA-CB1 -RS) was studied by immunoelectron microscopy. Results were compared with conditional CB1 receptor knock-out lines.

As expected, CB1immunoparticles appeared at presynaptic plasmalemma making asymmetric and symmetric synapses. In the hippocampal CA1 stratum radiatum, the values of the CB1 receptor immunopositive excitatory and inhibitory synapses were: Glu-CB1 -RS: 21.89% (glutamatergic terminals); 2.38% (GABAergic terminals); GABA-CB1 -RS: 1.92% (glutamatergic terminals); 77.92% (GABAergic terminals). The proportion of CB1 receptor immunopositive excitatory and inhibitory synapses in the inner third of the dentate molecular layer was: Glu-CB1 -RS: 53.19% (glutamatergic terminals); 2.30% (GABAergic terminals); GABA-CB1 -RS: 3.19% (glutamatergic terminals); 85.07% (GABAergic terminals).

Taken together, Glu-CB1 -RS and GABA-CB1 -RS mice show the usual CB1 receptor distribution and expression in hippocampal cell types with specific rescue of the receptor, being therefore ideal for in-depth anatomical and functional investigations of the endocannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/27339436

The multiple waves of cannabinoid 1 receptor signaling.

“The cannabinoid 1 receptor (CB1R) is one of the most abundant G protein-coupled receptor (GPCR) in the CNS with key roles during neurotransmitter release and synaptic plasticity. Upon ligand activation, CB1Rs may signal in three different spatiotemporal waves.

The first wave is transient (<10 minutes) and is initiated by heterotrimeric G proteins followed by a second wave (>10 minutes) mediated by beta-arrestins. A final third wave occurs at intracellular compartments and could be elicited by G proteins or beta-arrestins.

This functional complexity presents multiple challenges, from the correct classification of receptor ligands to the identification of the signaling pathways regulated by each wave and their underlying molecular mechanisms and physiological impact.

Simultaneously, it provides new opportunities to harness the therapeutic potential of the cannabinoid system.

Over the last several years, we have significantly expanded our understanding of the mechanisms and pathways downstream from CB1R. The identification of mutations in the receptor that can bias signaling to specific pathways and the use of siRNA technology in combination with toxins have been key tools to identify which signaling cascades are controlled by G proteins or beta-arrestins.

Here, we review our current knowledge of the multiple waves of CB1R signaling with particular emphasis on the mechanisms and cascades mediated by beta-arrestins downstream from the CB1R.”

http://www.ncbi.nlm.nih.gov/pubmed/27338082

Cannabinoids and Neuro-Inflammation: Regulation of Brain Immune Response.

“Cannabinoid receptors are involved in neurophatogenic mechanisms of inflammatory disorders of the central nervous system and their expression can be modulated during the disease.

Brain inflammatory processes are characterized by infiltration of numerous types of cells, peripheral immune cells, brain resident immune cells, the microglial cells and numerous other neuronal cells. The disruption of the blood brain barrier favours cell infiltration in the central nervous system with consequent neuronal damage, common event in many neuro-inflammatory diseases.

In this review we evidence the role of cannabinoid receptor, their expression at peripheral and central levels in order to better understand their implication in neuro-inflammation.

Cannabinoids affect brain adaptive and immune response, have regulatory action on inflammatory mediators and can exert a role in blood brain barrier damage prevention.

Furthermore, in numerous neurodegenerative diseases with inflammatory component the beneficial effects of cannabinoids have been widely reported, so current knowledge of cannabinoid involvement in these central nervous system disorders are also reviewed.”

http://www.ncbi.nlm.nih.gov/pubmed/27334610

Cannabimimetic Drugs: Recent Patents in Central Nervous System Disorders.

“Agents acting via cannabinoid receptors have been widely developed; starting from the chemical structure of phytocannabinoids isolated from cannabis sativa plant, specific and selective compounds of these receptors have been produced ranging from partial to full agonists and /or antagonists endowed with different potency.

The enhanced interest on developing such classes of drugs is due to the beneficial properties widely reported by both anecdotal reports and scientific studies describing the potential medicinal use of cannabinoids and their derivatives in numerous pathological conditions in both in vitro and in vivo models.

The use of these drugs has been found to be of benefit in a wide number of neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases, just to mention some.

In particular, being the cannabinoid CB1 receptor a central receptor expressed by neurons of the central nervous system, the attention for the treatment of neurological diseases has been mainly focused on compounds acting via this receptor, however some of these compounds has been showed to act by alternative pathways in some cases unrelated to CB1 receptors.

Nonetheless, endocannabinoids are potent regulators of the synaptic function in the central nervous system and their levels are modulated in neurological diseases.

In this study, we focused on endocannabinoid mechanism of action in neuronal signaling and on cannabimimetic drug potential application in neurological disorders.

Finally, novel patents on cannabis-based drugs with applicability in central nervous system disorders are highlighted, to suggest future potential therapeutic utility of derivatives of this ancient plant.”

http://www.ncbi.nlm.nih.gov/pubmed/27334611

Fatty Acid Binding Protein-1 (FABP1) and the Human FABP1 T94A Variant: Roles in the Endocannabinoid System and Dyslipidemias.

“The first discovered member of the mammalian FABP family, liver fatty acid binding protein (FABP1, L-FABP), occurs at high cytosolic concentration in liver, intestine, and in the case of humans also in kidney. While the rat FABP1 is well studied, the extent these findings translate to human FABP1 is not clear-especially in view of recent studies showing that endocannabinoids and cannabinoids represent novel rat FABP1 ligands and FABP1 gene ablation impacts the hepatic endocannabinoid system, known to be involved in non-alcoholic fatty liver (NAFLD) development. Although not detectable in brain, FABP1 ablation nevertheless also impacts brain endocannabinoids. Despite overall tertiary structure similarity, human FABP1 differs significantly from rat FABP1 in secondary structure, much larger ligand binding cavity, and affinities/specificities for some ligands. Moreover, while both mouse and human FABP1 mediate ligand induction of peroxisome proliferator activated receptor-α (PPARα), they differ markedly in pattern of genes induced. This is critically important because a highly prevalent human single nucleotide polymorphism (SNP) (26-38 % minor allele frequency and 8.3 ± 1.9 % homozygous) results in a FABP1 T94A substitution that further accentuates these species differences. The human FABP1 T94A variant is associated with altered body mass index (BMI), clinical dyslipidemias (elevated plasma triglycerides and LDL cholesterol), atherothrombotic cerebral infarction, and non-alcoholic fatty liver disease (NAFLD). Resolving human FABP1 and the T94A variant’s impact on the endocannabinoid and cannabinoid system is an exciting challenge due to the importance of this system in hepatic lipid accumulation as well as behavior, pain, inflammation, and satiety.”

http://www.ncbi.nlm.nih.gov/pubmed/27117865