Cannabinoids, eating behaviour, and energy homeostasis

Soon after the discovery of cannabis by western societies, its psychotropic effects overshadowed its medical benefits. How-ever, investigation into the molecular action of the main constituents of cannabis has led to the discovery of an intercellularsignalling system, called the endocannabinoid system (ECS). The ECS comprises a set of molecular components, including en-zymes, signalling lipids and G-protein coupled receptors, which has an outstanding role in modulating eating behaviour andenergy homeostasis. Interestingly, evidence has shown that the ECS is present at the central and peripheral nervous system,modulating the function of the hypothalamus, the brain reward system and the brainstem, and coordinating the crosstalk be-tween these brain structures and peripheral organs. Indeed, the ECS is present and functional in metabolically relevant periph-eral tissues, directly modulating their physiology. In the context of a global obesity pandemic, these discoveries are highlysuggestive in order to design novel pharmaceutical tools to fight obesity and related morbidities. In fact, a cannabinoid-based first generation of drugs was developed and marketed. Their failure, due to central side-effects, is leading to a secondgeneration of these drugs unable to cross the blood–brain barrier, as well as other ECS-focused strategies that are still in thepipeline. In the next few years we will hopefully know whether such an important player in energy homeostasis can be suc-cessfully targeted without significantly affecting other vital processes related to mood and sense of well-being

The role of the endocannabinoid system in eating disorders: pharmacological implications

The endocannabinoid (eCB) system is a widespread intercellular signalling mechanism that plays a critical role in body homoeostasis. It is located in key points involved in food intake and energy expenditure, coordinating all the players involved in energy balance. As such, it has come to be seen as an interesting target for the management of diseases characterized by an imbalanced energy homoeostasis, such as obesity and eating disorders. The aetiology of eating disorders and the molecular systems involved are still largely a mystery. Research has focused on brain circuits where the eCB system plays an important role, such as those related to feeding behaviour and the rewarding properties of food. Accordingly, recent findings have suggested a deregulation of the eCB system in eating disorders. At present, cannabinoid agonists are safe and effective tools in the management of diseases in which weight gain is needed, for example cachexia in AIDS patients. However, studies on the potential therapeutic validity of cannabinoids in eating disorders are scarce and inconclusive. Taken together, all these considerations warrant more preclinical and clinical investigations in the role of the eCB system in eating disorders. Eventually, they may provide novel pharmacological approaches for the treatment of these diseases

The cannabinoid ligand LH-21 reduces anxiety and improves glucose handling in diet-induced obese pre-diabetic mice

LH-21 is a triazol derivative that has been described as a low-permeant neutral CB1 antagonist, though its pharmacology is still unclear. It has been associated with anti-obesity actions in obese rats. However, its role in preventing type 2 diabetes (T2D) onset have not been studied yet. Given CB1 receptors remain as potential pharmacological targets to fight against obesity and T2D, we wanted to explore the metabolic impact of this compound in an animal model of obesity and pre-diabetes as well as the lack of relevant actions in related central processes such as anxiety. C57BL/6J mice were rendered obese and pre-diabetic by feeding a high-fat diet for 15 weeks and then treated with LH-21 or vehicle for two weeks. Food intake, body weight and glucose handling were assessed, together with other relevant parameters. Behavioural performance was evaluated by the open field test and the elevated plus maze. LH-21 did not affect food intake nor body weight but it improved glucose handling, displaying tissue-specific beneficial actions. Unexpectedly, LH-21 induced anxiolysis and reverted obesity-induced anxiety, apparently through GPR55 receptor. These results suggest that LH-21 can be a new candidate to fight against diabetes onset. Indeed, this compound shows potential in counteracting obesity-related anxiety.España, Ministerio de Sanidad 13/00309 to F.J.B.S. and PI13/00593 to B.R.GConsejería de Salud Junta de Andalucía C-0070-201

Role of Insulin-Growth Factor II on mitochondrial recovery in a cellular model of Parkinson's Disease

Insulin-growth factor II (IGF-II) has shown antioxidant and neuroprotective effects in some neurodegenerative disorders. ROS causes damage to cellular macromolecules affecting several cellular processes and resulting in cell death. Mitochondrial ROS damage has a critical role in the pathobiology of PD. The objective was to assess the IGF-II role in the recovery of the oxidative damage produced on mitochondrial in a cellular model of PD. SN4741 cell line was treated as follows: MPP+ alone, in presence of IGF-II and/or co-incubated BMS (Ins/IGF-I receptors antagonist) or AB (anti-IGF-II-receptor). To assess the effect of IGF-II in the recovery of MPP+ damage, this treatment was removed after 2 h and replaced during another 2 h by medium, IGF-II or IGF-II + BMS or IGF-II + AB. Cell death was analysed through annexin-V Mitochondrial structure, localization and morphology was studied by western blot/ immunochemistry of Mitofilin (Mtf) and electron microscopy; function by Mitotracker and oxygen consumption rate. IGF-II prevented MPP+ cell death. In morphological/structural studies, MPP+ treated cells showed swollen mitochondria with loss of cristae, and electron-lucent matrix, inducing a mitochondrial number reduction. IGF-II retrieved normal-shaped mitochondria with intact cristae and outer/inner membranes. Moreover, MPP+ incubation significantly reduced the expression levels of Mtf compared to the CO. This expression was found in areas that had a very weak mark, indicating mitochondrial destruction or dysfunction. IGF-II coincubation, recovered the expression of Mtf, remaining associated with healthy mitochondrial function. Additionally, the decrease in OCR levels after MPP+ administration was recovered in presence of IGF-II. The BMS-receptor blockage did not modify the IGF-II responses, and AB limited its effect. In conclusion, IGF-II recovers mitochondrial structure and function due to MPP+ damage. This improvement is carried out through the specific IGF-II receptor.Supported by M.G-F.&L.J.S. Proyectos I+D+I-Programa Operativo-FEDER Andalucía 2014-2020 (UMA18-FEDERJA-004) Junta de Andalucía. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Ulcerative Colitis Impairs the Acylethanolamide-Based Anti-Inflammatory System Reversal by 5-Aminosalicylic Acid and Glucocorticoids

Studies in animal models and humans suggest anti-inflammatory roles on the N-acylethanolamide (NAE)-peroxisome proliferators activated receptor alpha (PPARα) system in inflammatory bowel diseases. However, the presence and function of NAE-PPARα signaling system in the ulcerative colitis (UC) of humans remain unknown as well as its response to active anti-inflammatory therapies such as 5-aminosalicylic acid (5-ASA) and glucocorticoids. Expression of PPARα receptor and PPARα ligands-biosynthetic (NAPE-PLD) and -degrading (FAAH and NAAA) enzymes were analyzed in untreated active and 5-ASA/glucocorticoids/immunomodulators-treated quiescent UC patients compared to healthy human colonic tissue by RT-PCR and immunohistochemical analyses. PPARα, NAAA, NAPE-PLD and FAAH showed differential distributions in the colonic epithelium, lamina propria, smooth muscle and enteric plexus. Gene expression analysis indicated a decrease of PPARα, PPARγ and NAAA, and an increase of FAAH and iNOS in the active colitis mucosa. Immunohistochemical expression in active colitis epithelium confirmed a PPARα decrease, but showed a sharp NAAA increase and a NAPE-PLD decrease, which were partially restored to control levels after treatment. We also characterized the immune cells of the UC mucosa infiltrate. We detected a decreased number of NAAA-positive and an increased number of FAAH-positive immune cells in active UC, which were partially restored to control levels after treatment. NAE-PPARα signaling system is impaired during active UC and 5-ASA/glucocorticoids treatment restored its normal expression. Since 5-ASA actions may work through PPARα and glucocorticoids through NAE-producing/degrading enzymes, the use of PPARα agonists or FAAH/NAAA blockers that increases endogenous PPARα ligands may yield similar therapeutics advantages

Alpha-tocopherol protects against oxidative stress in the fragile X knockout mouse: an experimental therapeutic approach for the Fmr1 deficiency.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/4027Fragile X syndrome is the most common genetic cause of mental disability. The mechanisms underlying the pathogenesis remain unclear and specific treatments are still under development. Previous studies have proposed an abnormal hypothalamic–pituitary–adrenal axis and high cortisol levels are demonstrated in the fragile X patients. Additionally, we have previously described that NADPH-oxidase activation leads to oxidative stress in the brain, representing a pathological mechanism in the fragile X mouse model. Fmr1-knockout mice develop an altered free radical production, abnormal glutathione homeostasis, high lipid and protein oxidation, accompanied by stress-dependent behavioral abnormalities and pathological changes in the first months of postnatal life. Chronic pharmacological treatment with α-tocopherol reversed pathophysiological hallmarks including free radical overproduction, oxidative stress, Rac1 and α-PKC activation, macroorchidism, and also behavior and learning deficits. The restoration of the oxidative status in the fragile X mouse emerges as a new and promising approach for further therapeutic research in fragile X syndrome

Enhanced markers of oxidative stress, altered antioxidants and NADPH-oxidase activation in brains from Fragile X mental retardation 1-deficient mice, a pathological model for Fragile X syndrome.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/6992Fragile X syndrome is the most common form of inherited mental retardation in humans. It originates from the loss of expression ofthe Fragile X mental retardation 1 (FMR1) gene, which results in the absence of the Fragile X mental retardation protein. However,the biochemical mechanisms involved in the pathological phenotype are mostly unknown. The availability of the FMR1-knockoutmouse model offers an excellent model system in which to study the biochemical alterations related to brain abnormalities in thesyndrome. We show for the first time that brains from Fmr1-knockout mice, a validated model for the syndrome, display higher levelsof reactive oxygen species, nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase activation, lipid peroxidation and proteinoxidation than brains from wild-type mice. Furthermore, the antioxidant system is deficient in Fmr1-knockout mice, as shown byaltered levels of components of the glutathione system. FMR1-knockout mice lacking Fragile X mental retardation protein werecompared with congenic FVB129 wild-type controls. Our results support the hypothesis that the lack of Fragile X mental retardationprotein function leads to a moderate increase of the oxidative stress status in the brain that may contribute to the pathophysiology ofthe Fragile X syndrome

Neuronal Metabolism and Neuroprotection: Neuroprotective Effect of Fingolimod on Menadione-Induced Mitochondrial Damage

Imbalance in the oxidative status in neurons, along with mitochondrial damage, are common characteristics in some neurodegenerative diseases. The maintenance in energy production is crucial to face and recover from oxidative damage, and the preservation of different sources of energy production is essential to preserve neuronal function. Fingolimod phosphate is a drug with neuroprotective and antioxidant actions, used in the treatment of multiple sclerosis. This work was performed in a model of oxidative damage on neuronal cell cultures exposed to menadione in the presence or absence of fingolimod phosphate. We studied the mitochondrial function, antioxidant enzymes, protein nitrosylation, and several pathways related with glucose metabolism and glycolytic and pentose phosphate in neuronal cells cultures. Our results showed that menadione produces a decrease in mitochondrial function, an imbalance in antioxidant enzymes, and an increase in nitrosylated proteins with a decrease in glycolysis and glucose-6-phosphate dehydrogenase. All these effects were counteracted when fingolimod phosphate was present in the incubation media. These effects were mediated, at least in part, by the interaction of this drug with its specific S1P receptors. These actions would make this drug a potential tool in the treatment of neurodegenerative processes, either to slow progression or alleviate symptoms

Early maternal deprivation induces gender-dependent changes on the expression of hippocampal CB(1) and CB(2) cannabinoid receptors of neonatal rats.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/13858Early maternal deprivation (MD) in rats (24 h, postnatal day 9–10) is a model for neurodevelopmental stress. There are some data proving that MD affects the endocannabinoid system (ECS) in a gender-dependent manner, and that these changes may account for the proposed schizophrenia-like phenotype of MD rats. The impact of MD on cannabinoid receptor distribution in the hippocampus is unknown. The aim of this study is to evaluate the expression of CB1 and CB2 receptors in diverse relevant subregions (DG, CA1, and CA3) of the hippocampus in 13-day-old rats by immunohistochemistry and densitometry. MD induced a significant decrease in CB1 immunoreactivity (more marked in males than in females), which was mainly associated with fibers in the strata pyramidale and radiatum of CA1 and in the strata oriens, pyramidale, and radiatum of CA3. In contrast, MD males and females showed a significant increase in CB2 immunoreactivity in the three hippocampal areas analyzed that was detected in neuropil and puncta in the stratum oriens of CA1 and CA3, and in the polymorphic cell layer of the dentate gyrus. A marked sex dimorphism was observed in CA3, with females exhibiting higher CB1 immunoreactivity than males, and in dentate gyrus, with females exhibiting lower CB2 immunoreactivity than males. These results point to a clear association between developmental stress and dysregulation of the ECS. The present MD procedure may provide an interesting experimental model to further address the role of the ECS in neurodevelopmental mental illnesses such as schizophrenia. © 2008 Wiley-Liss, Inc.Consejería de Salud. Grant Number: PI-0220 Consejería de Innovación, Ciencia y Empresa. Grant Number: P05-CV1-1038 (Junta de Andalucía) Ministerio de Sanidad y Consumo. Grant Numbers: 2006/142, FIS 07/1226 Ministerio de Educación y Ciencia. Grant Number: SAF2006-07523 Red de trastornos adictivos. Grant Number: RD06/0001 Plan Nacional sobre Droga

High fat-fed GPR55 null mice display impaired glucose tolerance without concomitant changes in energy balance or insulin sensitivity but are less responsive to the effects of the cannabinoids rimonabant or Δ(9)-tetrahydrocannabivarin on weight gain

Background The insulin-sensitizing phytocannabinoid, Δ(9)-tetrahydrocannabivarin (THCV) can signal partly via G protein coupled receptor-55 (GPR55 behaving as either an agonist or an antagonist depending on the assay). The cannabinoid receptor type 1 (CB1R) inverse agonist rimonabant is also a GPR55 agonist under some conditions. Previous studies have shown varied effects of deletion of GPR55 on energy balance and glucose homeostasis in mice. The contribution of signalling via GPR55 to the metabolic effects of THCV and rimonabant has been little studied. Methods In a preliminary experiment, energy balance and glucose homeostasis were studied in GPR55 knockout and wild-type mice fed on both standard chow (to 20 weeks of age) and high fat diets (from 6 to 15 weeks of age). In the main experiment, all mice were fed on the high fat diet (from 6 to 14 weeks of age). In addition to replicating the preliminary experiment, the effects of once daily administration of THCV (15 mg.kg-1 po) and rimonabant (10 mg.kg-1 po) were compared in the two genotypes. Results There was no effect of genotype on absolute body weight or weight gain, body composition measured by either dual-energy X-ray absorptiometry or Nuclear Magnetic Resonance (NMR), fat pad weights, food intake, energy expenditure, locomotor activity, glucose tolerance or insulin tolerance in mice fed on chow. When the mice were fed a high fat diet, there was again no effect of genotype on these various aspects of energy balance. However, in both experiments, glucose tolerance was worse in the knockout than the wild-type mice. Genotype did not affect insulin tolerance in either experiment. Weight loss in rimonabant- and THCV-treated mice was lower in knockout than in wild-type mice, but surprisingly there was no detectable effect of genotype on the effects of the drugs on any aspect of glucose homeostasis after taking into account the effect of genotype in vehicle-treated mice. Conclusions Our two experiments differ from those reported by others in finding impaired glucose tolerance in GPR55 knockout mice in the absence of any effect on body weight, body composition, locomotor activity or energy expenditure. Nor could we detect any effect of genotype on insulin tolerance, so the possibility that GPR55 regulates glucose-stimulated insulin secretion merits further investigation. By contrast with the genotype effect in untreated mice, we found that THCV and rimonabant reduced weight gain, and this effect was in part mediated by GPR55