Decreased age-related cardiac dysfunction, myocardial nitrative stress, inflammatory gene expression, and apoptosis in mice lacking fatty acid amide hydrolase.

Recent studies have uncovered important cross talk between inflammation, generation of reactive oxygen and nitrogen species, and lipid metabolism in the pathogenesis of cardiovascular aging. Inhibition of the endocannabinoid anandamide metabolizing enzyme, the fatty acid amide hydrolase (FAAH), is emerging as a promising novel approach for the treatment of various inflammatory disorders. In this study, we have investigated the age-associated decline of cardiac function and changes in inflammatory gene expression, nitrative stress, and apoptosis in FAAH knockout (FAAH(-/-)) mice and their wild-type (FAAH(+/+)) littermates. Additionally, we have explored the effects of anandamide on TNF-alpha-induced ICAM-1 and VCAM-1 expression and monocyte-endothelial adhesion in human coronary artery endothelial cells (HCAECs). There was no difference in the cardiac function (measured by the pressure-volume conductance catheter system) between 2- to 3-mo-old (young) FAAH(-/-) and FAAH(+/+) mice. In contrast, the aging-associated decline in cardiac function and increased myocardial gene expression of TNF-alpha, gp91phox, matrix metalloproteinase (MMP)-2, MMP-9, caspase-3 and caspase-9, myocardial inducible nitric oxide synthase protein expression, nitrotyrosine formation, poly (ADP-ribose)polymerase cleavage and caspase-3/9 activity, observed in 28- to 31-mo-old (aging) FAAH(+/+) mice, were largely attenuated in knockouts. There was no difference in the myocardial cannabinoid CB(1) and CB(2) receptor gene expression between young and aging FAAH(-/-) and FAAH(+/+) mice. Anandamide dose dependently attenuated the TNF-alpha-induced ICAM-1 and VCAM-1 expression, NF-kappaB activation in HCAECs, and the adhesion of monocytes to HCAECs in a CB(1)- and CB(2)-dependent manner. These findings suggest that pharmacological inhibition of FAAH may represent a novel protective strategy against chronic inflammation, oxidative/nitrative stress, and apoptosis associated with cardiovascular aging and atherosclerosis

Cannabinoids: Drug or Medication?

This chapter aims at exploring the use and misuse of cannabinoids as it has become a major societal issue. In the first section, we describe the historical use of cannabis as a natural cure in ancient civilizations. We then explore the current use of cannabinoids in medicine, which includes innovative strategies for treating various diseases such as multiple sclerosis or cancer‐induced pain. In the second section, we consider how the discovery and characterization of the endocannabinoid system have increased knowledge of this system\u27s mode of action. Consumption of cannabis for recreational use however is a significant public health issue today. Scientific advances are confronted with the adverse health effects that are demonstrated in preclinical and clinical studies based on the psychotic and addictive properties of this compound. In the third section, we therefore provide an overview of the recent findings on the endocannabinoid system using animal models with proposed molecular mechanisms and potential interactions with other neuromodulatory systems like the opioid system. Finally, through alternative strategies to current treatments with both phyto‐ and synthetic cannabinoids, we try to reconcile the beneficial aspects of the use of cannabinoids for medication and the aspects associated with addictive properties

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years.

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients

A Themed Issue in Honor of Professor Raphael Mechoulam: The Father of Cannabinoid and Endocannabinoid Research

During the last 60 years the relevance of cannabis (Cannabis sativa or Cannabis indica) ingredients, like the psychoactive Δ9-tetrahydrocannabinol (THC), cannabidiol, 120+ additional cannabinoids and 440+ non-cannabinoid compounds, for human health and disease has become apparent. Approximately 30 years after the elucidation of THC structure the molecular reasons for the biological activity of these plant extracts were made clearer by the discovery of endocannabinoids, that are endogenous lipids able to bind to the same receptors activated by THC. Besides endocannabinoids, that include several N-acylethanolamines and acylesters, a complex array of receptors, metabolic enzymes, transporters (transmembrane, intracellular and extracellular carriers) were also discovered, and altogether they form a so-called “endocannabinoid system” that has been shown to finely tune the manifold biological activities of these lipid signals. Both plant-derived cannabinoids and endocannabinoids were first discovered by the group led by Prof. Dr. Raphael Mechoulam, who has just celebrated his 90th birthday and clearly stood out as a giant of modern science. The many implications of his seminal work for chemistry, biochemistry, biology, pharmacology and medicine are described in this special issue by the scientists who reached during the last 20 years the highest recognition in the field of (endo)cannabinoid research, receiving the Mechoulam Award for their major contributions. I thank them for having accepted my invitation to be part of this honorary issue of Molecules, and Raphi for continuing to illuminate our field with his always inspiring investigations and new ideas

An investigation of pain mechanisms in a model of osteoarthritis : modulation by the endocannabinoid receptor system

Osteoarthritis (OA) is expected to become the fourth leading cause of disability worldwide by 2020. There is no cure, and joint replacement surgery becomes a final resort. Chronic pain associated with OA is poorly controlled by current treatments, and often involve chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), which is associated with serious side-effects. OA is associated with alterations in endocannabinoid (EC), an attractive target for the control of pain. ECs are rapidly degraded by a number of enzymes, including cyclooxygenase-2 (COX- 2), the major target of NSAIDs. However, the role of COX-2 in EC-mediated effects on nociceptive transmission is not fully understood. The aims of this thesis were to investigate peripheral and spinal pain responses in a model of OA pain, understand the role of COX-2 inhibition on neuronal responses and the potential role of ECs in mediating these effects, and to establish the functional effects of the EC system in a model of OA pain. Effects of spinal and peripheral administration of the COX-2 inhibitor nimesulide (1-1 OOlJgin 501JL)on mechanically evoked responses of dorsal horn neurones in the naive, anaesthetised rat were measured, and the contribution of the CB1 receptor was determined with the antagonist AM251 (11Jgin 50IJL). Effects of nimesulide on spinal levels of ECs and related compounds were quantified using liquid chromatography-tandem mass spectrometry. Spinal, but not peripheral, injection of nimesulide significantly reduced mechanically evoked responses of dorsal horn neurones. Inhibitory effects of spinal nimesulide were blocked by the CB1 receptor antagonist AM251, but spinal EC levels were not elevated. Indeed, both anandamide and N-oleoylethanolamide were significantly decreased by nimesulide, highlighting a putative role for other oxidative enzymes of ECs in the generation of CB1-active metabolites. The monosodium-iodoacetate (MIA) model of OA pain has recently received much interest, but is not yet fully defined. Work in this thesis sought to further characterise this model. Cytokine levels in synovial fluid, spinal cord and hindpaw skin at early time-points post- intra-articular injection (1mg MIA in 50IJL, P.O. 3-24hr) were measured, and the later (P.O. day 28-31) effects on neuronal responses and pain behaviour were determined. Intra-articular injection of 1mg MIA produced stable and robust changes in two measures of pain relevant to clinical OA, and evidence for the presence of central sensitisation was demonstrated. It was also demonstrated that early-stage painful responses in this model are not associated with changes in cytokines in the joint. Effects of spinal and systemic administration of nimesulide (3-100IJg in 501JL)on mechanically evoked and post-stimulus responses of dorsal horn neurones in MIA-treated rats were also measured, as were the effects of spinal cannabinoid receptor antagonism with AM251 (0.1- 10IJg in 501JL)and the CB2 receptor antagonist SR144528 (0.001-0.1IJg in 50IJL). Spinal and systemic COX-2 inhibition in the MIA model attenuated spinal neuronal responses to both noxious and innocuous stimuli, demonstrating the importance of both spinal and peripheral COX-2 products in mediating neuronal responses in this model. Antagonism of the spinal cannabinoid receptors resulted in elevated spinal neuronal responses in MIA-treated rats, demonstrating a functional role for spinal EC-mediated modulation of nociceptive transmission in the MIA model, expanding on work in this lab which showed elevated spinal ECs in the MIA model of OA pain. This work therefore demonstrates that the central EC system may be an important target for the treatment of OA pain

In silico investigations of the ionotropic cannabinoid receptor TRPV1

Whether caused by inflammation or dysfunctional nerves, chronic pain affects nearly 10% of the world’s population. Since there are few treatments that are effective while being noninvasive and non-addictive, new targets are being explored. Found in the peripheral nervous system, the transient receptor potential subfamily vanilloid type 1 (TRPV1) ion channel can be activated by a plethora of exogenous and endogenous stimuli including the spicy compound found in chili peppers, capsaicin, as well as temperatures above 43oC and acidic conditions. TRPV1, having the ability to be modulated by cannabinoid ligands, acts as an ionotropic cannabinoid receptor (ICR). Chapter II reviews cannabinoid ligands that can modulate ionotropic cannabinoid receptors, including TRPV1. The endocannabinoid anandamide has been shown to have a similar binding affinity to TRPV1 as capsaicin and can rapidly desensitize the channel producing an analgesic effect. Models of the open and closed structures of TRPV1 were constructed for use in molecular dynamics simulations. Chapter III details the construction of the models, as well as observed interactions between the endogenous ligand anandamide and TRPV1 in a novel location across 10+ µs of simulation time. TRPV2, a close cousin of TRPV1 and another ICR, was recently resolved with the phytogenic cannabinoid cannabidiol (CBD). From Chapter II, CBD is shown to modulate some, though not all, ICRs. Chapter IV focuses on the cryo-EM structure of TRPV2 resolved with CBD (PDB: 6U88) and analyzes the putative binding site via sequence alignment and structural analyses, comparing these features to the comparable site among the other ICRs, lending credence to this novel CBD binding site in other ICRs. Chapter V focuses on the results of additional long timescale MD simulations of TRPV1 in the presence of anandamide. In two independent runs, anandamide was observed to activate TRPV1 in a novel location between helices S1-S4. The colocalization of canonical cannabinoid receptor CB2 and TRPV1 presents an interesting dynamic, especially when considering the crosstalk of the two receptors presumed to exist. CB2 and TRPV1 are implicated various disorders, making them prime targets for the identification and development of dual modulators. Chapter VI describes a virtual screening protocol used to screen ChEMBL indexed CB2 and TRPV1 agonists at the opposing receptor, leading to the identification of moieties that may be relevant in dual modulatory ligands

Modulation du système endocannabinoïde dans des modèles de douleur inflammatoire et neuropathique

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

An investigation of pain mechanisms in a model of osteoarthritis : modulation by the endocannabinoid receptor system

Osteoarthritis (OA) is expected to become the fourth leading cause of disability worldwide by 2020. There is no cure, and joint replacement surgery becomes a final resort. Chronic pain associated with OA is poorly controlled by current treatments, and often involve chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), which is associated with serious side-effects. OA is associated with alterations in endocannabinoid (EC), an attractive target for the control of pain. ECs are rapidly degraded by a number of enzymes, including cyclooxygenase-2 (COX- 2), the major target of NSAIDs. However, the role of COX-2 in EC-mediated effects on nociceptive transmission is not fully understood. The aims of this thesis were to investigate peripheral and spinal pain responses in a model of OA pain, understand the role of COX-2 inhibition on neuronal responses and the potential role of ECs in mediating these effects, and to establish the functional effects of the EC system in a model of OA pain. Effects of spinal and peripheral administration of the COX-2 inhibitor nimesulide (1-1 OOlJgin 501JL)on mechanically evoked responses of dorsal horn neurones in the naive, anaesthetised rat were measured, and the contribution of the CB1 receptor was determined with the antagonist AM251 (11Jgin 50IJL). Effects of nimesulide on spinal levels of ECs and related compounds were quantified using liquid chromatography-tandem mass spectrometry. Spinal, but not peripheral, injection of nimesulide significantly reduced mechanically evoked responses of dorsal horn neurones. Inhibitory effects of spinal nimesulide were blocked by the CB1 receptor antagonist AM251, but spinal EC levels were not elevated. Indeed, both anandamide and N-oleoylethanolamide were significantly decreased by nimesulide, highlighting a putative role for other oxidative enzymes of ECs in the generation of CB1-active metabolites. The monosodium-iodoacetate (MIA) model of OA pain has recently received much interest, but is not yet fully defined. Work in this thesis sought to further characterise this model. Cytokine levels in synovial fluid, spinal cord and hindpaw skin at early time-points post- intra-articular injection (1mg MIA in 50IJL, P.O. 3-24hr) were measured, and the later (P.O. day 28-31) effects on neuronal responses and pain behaviour were determined. Intra-articular injection of 1mg MIA produced stable and robust changes in two measures of pain relevant to clinical OA, and evidence for the presence of central sensitisation was demonstrated. It was also demonstrated that early-stage painful responses in this model are not associated with changes in cytokines in the joint. Effects of spinal and systemic administration of nimesulide (3-100IJg in 501JL)on mechanically evoked and post-stimulus responses of dorsal horn neurones in MIA-treated rats were also measured, as were the effects of spinal cannabinoid receptor antagonism with AM251 (0.1- 10IJg in 501JL)and the CB2 receptor antagonist SR144528 (0.001-0.1IJg in 50IJL). Spinal and systemic COX-2 inhibition in the MIA model attenuated spinal neuronal responses to both noxious and innocuous stimuli, demonstrating the importance of both spinal and peripheral COX-2 products in mediating neuronal responses in this model. Antagonism of the spinal cannabinoid receptors resulted in elevated spinal neuronal responses in MIA-treated rats, demonstrating a functional role for spinal EC-mediated modulation of nociceptive transmission in the MIA model, expanding on work in this lab which showed elevated spinal ECs in the MIA model of OA pain. This work therefore demonstrates that the central EC system may be an important target for the treatment of OA pain

Palmitoylethanolamide modulates high-fat diet-shaped gut function and microbiota composition in obese mice

Introduction/Background & aims: Emerging data indicate a pivotal role for gut microbiota in the progression of obesity. Indeed, in the gut, high-fat diet (HFD) intake induces the loss of barrier integrity, causing the transfer of detrimental factors (i.e. lipopolysaccharide, LPS) into the systemic circulation, leading to metabolic dysfunctions and an overall state of low-grade inflammation, called “met- ainflammation” [1]. The metabolic and anti-inflammatory activities of palmitoylethanolamide (PEA), an endogenous lipid mediator, prompt us to evaluate its capability to improve intestinal homeostasis and shape gut microbiota composition altered in HFD-fed obese mice. Method/Summary of work: Male C57Bl/6 J mice received standard diet (STD) or HFD (n = 10 each group). After 12 weeks, a subgroup of HFD mice was treated with PEA (30 μg/kg/die per os) for 7 weeks. Body weight was monitored during the treatment and fat mass was evaluated at the end of experimental time. Systemic parameters and intestinal function were examined using ELISA assay, and Real-Time PCR analysis, respectively. Faecal microbiota was studied by per- forming 16S rDNA amplicon sequencing and linear discriminant analy- sis in order to obtain the operational taxonomic units (OTUs) defining the bacterial communities