Les MICI (maladies inflammatoires chroniques de l'intestin) invalident 200 000 personnes en France. La région Nord-Pas-de-Calais est particulièrement touchée par ces affections et les traitements disponibles pour ces pathologies demeurent coûteux et peu nombreux. Des études récentes ont suggéré que le système endocannabinoïde, exprimé au seing du tractus gastro-intestinal, est une cible thérapeutique prometteuse pour le traitement des MICI. Ce système se compose des récepteurs aux cannabinoïdes CB1 et CB2, des ligands endogènes de ces récepteurs, notamment l'anandamide et le 2-arachidonoylglycérol et des protéines impliquées dans l'anabolisme et le catabolisme des ligands. L'anandamide a présenté des capacités à prévenir la colite induite par le TNBS à des rongeurs. Toutefois, in vivo ce composé possède un temps de demi-vie court et est rapidement dégradé par une amidase à sérine, la FAAH (Fatty Acid Amide Hydrolase). Nous avons ainsi envisagé la conception, la synthèse et l'évaluation pharmacologique de nouveau inhibiteurs de la FAAH. L'une de nos molécules, le composé 95, présentant une CI50 sur l'enzyme de 88 nM a ensuite été injectée par voie intrapéritonéale à des souris dont la colite a été induite trois jours plus tard par l'injection intrarectale de TNBS. L'évaluation des scores macroscopiques et microscopiques des dommages causés sur le côlon par l'agent irritant a ensuite été effectuée. L'inflammation du côlon a été significativement réduite chez le groupe de souris ayant été traité par le composé 95, montrant que l'inhibition de la FAAH est une stratégie thérapeutique efficace dans le traitement des MICI. / IBD (Inflammatory Bowel Diseases) invalidate 200 000 persons in France. Nord-Pas-de-Calais region is particularly touched by these diseases and the available treatments for these pathologies are few and expensive. Recent studies have suggested that endocannabinoid system expressed in the gastrointestinal tract, was a promising therapeutic target for the IBD treatment. This system is made up of cannabinoids receptors CB1 and CB2, endogenous ligands of these receptors, notably anandamide and 2-arachidonoylglycerol, and proteins involved in ligands metabolism. Anandamide has shown properties to prevent TNBS-induced colitis in mice. However, in vivo, anandamide possesses a short life time and is rapidly hydrolyzed by a serine amidase, the FAAH (Fatty Acid Amide Hydrolase). In this context, we have considered the design, the synthesis and the pharmacological evaluation of new FAAH inhibitors. One of our molecules, compound 95, inhibiting the enzyme with an IC50 value of 88 nM has been injected intraperitonally to mice which the colitis was induced three days later by intrarectal TNBS-administration. The assessment of macroscopic and microscopic scores of colonic damages was undergone. Colonic inflammation was significatively reduced in the group of mice which has been treated by 95, showing evidence that FAAH inhibition was an effective therapeutic target for the treatment of IBD.

Stimulation of cardiac β-adrenoceptors is the primary mechanism by which cardiac output is increased to meet metabolic demands of the body. Recently, nicotinic acid adenine dinucleotide phosphate (NAADP), has been implicated as a novel component of the β-adrenoceptor signalling pathway. NAADP is thought to mobilise Ca²⁺ from acidic endolysosomal stores which then supplements sarcoplasmic reticulum Ca²⁺ load, leading to a positive inotropic effect. Recent progress in the field has been made with the identification of two-pore channel 2 (TPC2) as a candidate NAADP receptor. Isolated ventricular myocytes from mice lacking TPC2 proteins (Tpcn2^-/-) displayed blunted maximal responses to the β-adrenoceptor agonist isoprenaline. This blunted response was also evident in Langendorff-perfused Tpcn2^-/- hearts. Furthermore, a blunted response was observed in guinea pig ventricular myocytes which had been treated with bafilomycin A1, which disrupts the integrity of acidic endolysosomal stores. These data add to the body of evidence that NAADP signalling forms an important additional component of the β-adrenoceptor signalling pathway. Chronic activation of the β-adrenoceptor pathway is associated with certain disease states including heart failure and arrhythmias. Anandamide is an endogenous cannabinoid, ('endocannabinoid'), with similar properties to δ⁹-tetrahydrocannabinol (δ⁹-THC), the primary active constituent of Cannabis sativa. These compounds have widespread physiological effects through actions at cannabinoid CB₁ and CB₂ receptors, which are negatively coupled to adenylyl cyclases and are expressed in cardiac muscle. Exposure of guinea pig ventricular myocytes to anandamide resulted in a reduction in the amplitude of contractions and Ca²⁺ transients. This was associated with a reduction in action potential duration and amplitude of I_CaL. These effects of anandamide could not be prevented by cannabinoid receptor antagonists, and could not be mimicked by cannabinoid receptor agonists. An inhibition of IKs was also observed. Given the reported Gi-protein coupling of cannabinoid receptors, it may be expected that additional negative inotropic actions of anandamide might be observed when adenylyl cyclases are stimulated. However, the effects of anandamide to reduce amplitude of contraction and I_CaL were no greater in the presence of isoprenaline. Furthermore, the effects of anandamide were not prevented by pre-treatment of myocytes with pertussis toxin (PTX). This is in contrast to the actions of adenosine, which displayed clear PTX sensitive actions in the presence of isoprenaline. These data suggest that cannabinoid receptors are not involved in mediating the negative inotropic actions of anandamide. Another endocannabinoid, 2-arachidonoylglycerol, was without significant effect on action potentials or contractions in the absence or presence of isoprenaline. δ⁹-THC shared many of the actions of anandamide. It appears that anandamide and δ⁹-THC exert significant effects on cardiac muscle through direct modulation of ion channel function, although additional actions, for example, on the sarcoplasmic reticulum or myofilaments, cannot be ruled out.

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In this study, the effects of antagonists to the cannabinoid receptors in MCL cell lines were studied. Results presented in this study show that signalling through cannabinoid receptor with antagonists such as SR141716, SR144528 decreases cell viability but hemopressin when analyzing with XTT. The decrease in cell viability by SR141716 is caused by apoptosis triggered after 5 hours of treatment. The CB1 expression was confirmed in all MCL cell lines tested via western blotting but the expression of CB2 and GPR55 – another receptor to which SR141716 has affinity - was not confirmed due to lack of reliable antibodies. Specific agonist to GPR55 – LPI (l-α-lysophosphatidylinositol) showed different response compared to SR141716 which suggests that the effect seen by SR141716 was not induced through GPR55. The effect induced by CB1/CB2 agonist AEA is shown to be neither through CB1 or CB2 alone but possibly on another receptor yet to be described.

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Mosses are bryophytes with a simple cellular organization and distinctive growth stages. With their unique lipid profile, most mosses are also tolerant to various stressors. A ubiquitous class of bioactive fatty acid ethanolamides in eukaryotes called N-acylethanolamines (NAEs) also occurs in the moss Physcomitrella patens. Unlike in higher plants, where saturated and unsaturated NAE types are limited to those with acyl chains 12C to 18C, P. patens also contains anandamide, NAE 20:4. In higher plants, NAEs are most abundant in desiccated seeds and mediate plant growth, development, cellular organization and response to stress, in an abscisic acid (ABA)-dependent or independent manner. In mammals, NAE 20:4 acts as an endocannabinoid ligand and mediates a multitude of physiological responses. This unique NAE type, NAE 20:4 is hypothesized to effect development, growth and cellular organization of P. patens. To determine the role of NAEs in moss development, NAE content and composition in protonema, early and late gametophyte stages, and sporophytes, will be quantified from their total lipid extracts, using selective lipidomics. The effects of anandamide on growth will be studied by culturing moss in the presence of exogenous NAE 20:4 in a dose-dependent manner. Temporal changes in growth patterns will be determined by the evaluation of digital images using Image tool. The effect of anandamide on cytoskeletal organization will be visualized by immunostaining the phyllodes exposed to NAE 20:4 and observing them under confocal microscope. Preliminary results indicate that the endogenous NAE content and composition is variable, depending on the developmental stage and that NAE 20:4 is a potent negative regulator of moss growth. More detailed studies are expected to provide novel insights into the role NAEs, specifically NAE 20:4 might play in mediating growth and development of seedless plants.