Search

Background: Human immunodeficiency virus (HIV) affects nearly 40 million people globally, with roughly 80% of all people living with HIV receiving antiretroviral therapy. Antiretroviral treatment suppresses viral load in peripheral tissues but does not effectively penetrate the blood-brain barrier. Thus, viral reservoirs persist in the central nervous system and continue to produce low levels of inflammatory factors and early viral proteins, including the transactivator of transcription (Tat). HIV Tat is known to contribute to chronic neuroinflammation and synaptodendritic damage, which is associated with the development of cognitive, motor, and/or mood problems, collectively known as HIV-associated neurocognitive disorders (HAND). Cannabinoid anti-inflammatory effects are well documented, but therapeutic utility of cannabis remains limited due to its psychotropic effects, including alterations within brain regions encoding reward processing and motivation, such as the nucleus accumbens. Alternatively, inhibiting monoacylglycerol lipase (MAGL) has demonstrated therapeutic potential through interactions with the endocannabinoid system. Methods: The present study utilized a reward-related operant behavioral task to quantify motivated behavior in female Tat transgenic mice treated with vehicle or MAGL inhibitor MJN110 (1 mg/kg). Brain tissue was collected to assess dendritic injury and neuroinflammatory profiles, including dendritic microtubuleassociated protein (MAP2ab) intensity, microglia density, microglia morphology, astrocyte density, astrocytic interleukin-1ß (IL-1ß) colocalization, and various lipid mediators. Results: No significant behavioral differences were observed; however, MJN110 protected against Tat-induced dendritic injury by significantly upregulating MAP2ab intensity in the nucleus accumbens and in the infralimbic cortex of Tat(+) mice. No or only minor effects were noted for Iba-1+ microglia density and/or microglia morphology. Further, Tat increased GFAP+ astrocyte density in the infralimbic cortex and GFAP+ astrocytic IL-1ß colocalization in the nucleus accumbens, with MJN110 significantly reducing these measures in Tat(+) subjects. Lastly, selected HETErelated inflammatory lipid mediators in the striatum were downregulated by chronic MJN110 treatment. Conclusions: These findings demonstrate anti-inflammatory and neuroprotective properties of MJN110 without cannabimimetic behavioral effects and suggest a promising alternative to cannabis for managing neuroinflammation. [ABSTRACT FROM AUTHOR]

Aims: Activation of the endocannabinoid system by monoacylglycerol lipase (MAGL) blockade may affect the lower urinary tract function. We investigated the effect of an MAGL inhibitor, MJN110, on neurogenic lower urinary tract dysfunction (LUTD) in the mouse model of spinal cord injury (SCI). Methods: Female C57BL/6 mice that underwent spinal cord transection at T8–10 level were divided into three groups consisting of (1) vehicle‐treated SCI mice, (2) 5 mg/kg, or (3) 10 mg/kg of MJN110‐treated SCI mice. MJN110 and vehicle were administered intraperitoneally for 7 days from 4 weeks after spinal cord transection. We then conducted awake cystometrograms and compared urodynamic parameters between three groups. The expression of cannabinoid (CB) receptors, TRP receptors, and inflammatory cytokines in L6‐S1 dorsal root ganglia (DRG) or the bladder mucosa were evaluated and compared among three groups. Changes in the level of serum 2‐arachidonoylglycerol (2‐AG) and bladder MAGL were also evaluated. Results: In the cystometrogram, detrusor overactivity (DO) parameters, such as the number of nonvoiding contraction (NVC), a ratio of time to the 1st NVC to intercontraction interval (ICI), and NVC integrals were improved by MJN110 treatment, and some effects were dose dependent. Although MJN110 did not improve voiding efficiency, it decreased bladder capacity, ICI, and residual urine volume compared to vehicle injection. MJN110 treatment groups had lower CB2, TRPV1, TRPA1, and inflammatory cytokines mRNA levels in DRG and bladder mucosa. Serum 2‐AG was increased, and bladder MAGL was decreased after MAGL inhibitor treatment. Conclusions: MAGL inhibition improved LUTD including attenuation of DO after SCI. Thus, MAGL can be a therapeutic target for neurogenic LUTD after SCI. [ABSTRACT FROM AUTHOR]

BackgroundHuman immunodeficiency virus (HIV) affects nearly 40 million people globally, with roughly 80% of all people living with HIV receiving antiretroviral therapy. Antiretroviral treatment suppresses viral load in peripheral tissues but does not effectively penetrate the blood-brain barrier. Thus, viral reservoirs persist in the central nervous system and continue to produce low levels of inflammatory factors and early viral proteins, including the transactivator of transcription (Tat). HIV Tat is known to contribute to chronic neuroinflammation and synaptodendritic damage, which is associated with the development of cognitive, motor, and/or mood problems, collectively known as HIV-associated neurocognitive disorders (HAND). Cannabinoid anti-inflammatory effects are well documented, but therapeutic utility of cannabis remains limited due to its psychotropic effects, including alterations within brain regions encoding reward processing and motivation, such as the nucleus accumbens. Alternatively, inhibiting monoacylglycerol lipase (MAGL) has demonstrated therapeutic potential through interactions with the endocannabinoid system.MethodsThe present study utilized a reward-related operant behavioral task to quantify motivated behavior in female Tat transgenic mice treated with vehicle or MAGL inhibitor MJN110 (1 mg/kg). Brain tissue was collected to assess dendritic injury and neuroinflammatory profiles, including dendritic microtubule-associated protein (MAP2ab) intensity, microglia density, microglia morphology, astrocyte density, astrocytic interleukin-1ß (IL-1ß) colocalization, and various lipid mediators.ResultsNo significant behavioral differences were observed; however, MJN110 protected against Tat-induced dendritic injury by significantly upregulating MAP2ab intensity in the nucleus accumbens and in the infralimbic cortex of Tat(+) mice. No or only minor effects were noted for Iba-1+ microglia density and/or microglia morphology. Further, Tat increased GFAP+ astrocyte density in the infralimbic cortex and GFAP+ astrocytic IL-1ß colocalization in the nucleus accumbens, with MJN110 significantly reducing these measures in Tat(+) subjects. Lastly, selected HETE-related inflammatory lipid mediators in the striatum were downregulated by chronic MJN110 treatment.ConclusionsThese findings demonstrate anti-inflammatory and neuroprotective properties of MJN110 without cannabimimetic behavioral effects and suggest a promising alternative to cannabis for managing neuroinflammation.

[Display omitted] Monoacylglycerol lipase (MAGL) is a promising target for cancer therapy due to its involvement in lipid metabolism and its impact on cancer hallmarks like cell proliferation, migration, and tumor progression. A potent reversible MAGL inhibitor, MAGL23, has been recently developed by our group, demonstrating promising anticancer activities. To enhance its pharmacological properties, a nanoformulation using nanocrystals coated with albumin was prepared (MAGL23AF). In a previous work, the formulated inhibitor showed potency in ovarian and colon cancer cell lines in terms of IC 50 , and was tested on mice in order to assess its biocompatibility, organs biodistribution and toxicity. In the present work, we expanded the investigation to assess the potential in vivo application of MAGL23AF. Stability assays in serum and in human derived microsomes showed a good structural stability in physiological conditions of MAGL23AF. The antitumor efficacy tested on mice bearing ovarian cancer tumor xenografts demonstrated that MAGL23AF is more potent than the non-formulated drug, leading to necrosis-driven cancer cell death. In vivo studies revealed that albumin-complexed nanocrystals improved the therapeutic window of MAGL23, exhibiting a favorable biodistribution with slightly increased accumulation in the tumor. In conclusion, the MAGL23AF showed increased in vitro stability in conditions mirroring the bloodstream environment and hepatic metabolism coupled with an optimal antitumor efficacy in vivo. These results not only validates the efficacy of our formulation but also positions it as a promising strategy for addressing challenges related to the solubility of drugs in body fluids. [ABSTRACT FROM AUTHOR]

Cell-free enzymatic assays are highly useful tools in early compound profiling due to their robustness and scalability. However, their inadequacy to reflect the complexity of target engagement in a cellular environment may lead to a significantly divergent pharmacology that is eventually observed in cells. The discrepancy that emerges from properties like permeability and unspecific protein binding may largely mislead lead compound selection to undergo further chemical optimization. We report the development of a new intracellular NanoBRET assay to assess MAGL inhibition in live cells. Based on a reverse design approach, a highly potent, reversible preclinical inhibitor was conjugated to the cell-permeable BODIPY590 acceptor fluorophore while retaining its overall balanced properties. An engineered MAGL-nanoluciferase (Nluc) fusion protein provided a suitable donor counterpart for the facile interrogation of intracellular ligand activity. Validation of assay conditions using a selection of known MAGL inhibitors set the stage for the evaluation of over 1'900 MAGL drug candidates derived from our discovery program. This evaluation enabled us to select compounds for further development based not only on target engagement, but also on favorable physicochemical parameters like permeability and protein binding. This study highlights the advantages of cell-based target engagement assays for accelerating compound profiling and progress at the early stages of drug discovery programs., (© 2024 The Author(s). ChemBioChem published by Wiley-VCH GmbH.)

Endocannabinoids have an important role for the regulation of neuropathic pain. In our previous study, we observed that preventing the degradation of a endocannabinoid, 2-arachidonoylglycerol (2-AG), using an inhibitor of monoacylglycerol lipase (JZL184), attenuated neuropathic orofacial pain (NOP). The present study aimed to investigate mechanisms underlying JZL184-induced attenuation of NOP. We hypothesized that JZL184 may suppress microglial reactivity in the trigeminal spinal subnucleus caudalis (Vc) under NOP. The infraorbital nerve (ION) was hemisected to model NOP in mice, resulting in a significant reduction of mechanical head-withdrawal threshold (MHWT) on day 4 following the ION hemisection. Chronic systemic application of JZL184 at a concentration of 8 or 16 mg/kg/day for 4 days significantly attenuated the reduction of MHWT in mice exposed to NOP. Administering JZL184 at 4 mg/kg/day or its vehicle, however, did not attenuate the MHWT of mice with NOP. The reactivity of microglial cells in the Vc increased in mice with NOP compared to sham-operated controls. The application of JZL184 at 8 or 16 mg/kg/day for 4 days significantly reduced the increased microglial reactivity in the Vc. The changes of microglia under NOP were, by contrast, not reduced by application of the drug at 4 mg/kg/day or its vehicle. The results indicate that preventing 2-AG degradation may increase its accumulation in the Vc and normalize microglial reactivity under NOP, which may contribute to suppressing NOP.

As a serine hydrolase, monoacylglycerol lipase (MAGL) is principally responsible for the metabolism of 2-arachidonoylglycerol (2-AG) in the central nervous system (CNS), leading to the formation of arachidonic acid (AA). Dysfunction of MAGL has been associated with multiple CNS disorders and symptoms, including neuroinflammation, cognitive impairment, epileptogenesis, nociception and neurodegenerative diseases. Inhibition of MAGL provides a promising therapeutic direction for the treatment of these conditions, and a MAGL positron emission tomography (PET) probe would greatly facilitate preclinical and clinical development of MAGL inhibitors. Herein, we design and synthesize a small library of fluoropyridyl-containing MAGL inhibitor candidates. Pharmacological evaluation of these candidates by activity-based protein profiling identified 14 as a lead compound, which was then radiolabeled with fluorine-18 via a facile SNAr reaction to form 2-[18F]fluoropyridine scaffold. Good blood–brain barrier permeability and high in vivo specific binding was demonstrated for radioligand [18F]14 (also named as [18F]MAGL-1902). This work may serve as a roadmap for clinical translation and further design of potent 18F-labeled MAGL PET tracers.

The endocannabinoid system (ECS) is critically involved in the pathophysiology of Multiple Sclerosis (MS), a neuroinflammatory and neurodegenerative disease of the central nervous system (CNS). Over the past decade, researchers have extensively studied the neuroprotective and anti-inflammatory effects of the ECS. Inhibiting the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG) has emerged as a promising strategy to mitigate brain damage in MS. In this study, we investigated the effects of a novel reversible MAGL inhibitor (MAGLi 432) on C57/BL6 female mice with experimental autoimmune encephalomyelitis (EAE), a model of MS. We assessed its implications on motor disability, neuroinflammation, and synaptic dysfunction. Systemic in vivo treatment with MAGLi 432 resulted in a less severe EAE disease, accompanied by increased 2-AG levels and decreased levels of arachidonic acid (AA) and prostaglandins (PGs) in the brain. Additionally, MAGLi 432 reduced both astrogliosis and microgliosis, as evidenced by decreased microglia/macrophage density and a less reactive morphology. Flow cytometry analysis further revealed fewer infiltrating CD45+ and CD3+ cells in the brains of MAGLi 432-treated EAE mice. Finally, MAGLi treatment counteracted the striatal synaptic hyperexcitability promoted by EAE neuroinflammation. In conclusion, MAGL inhibition significantly ameliorated EAE clinical disability and striatal inflammatory synaptopathy through potent anti-inflammatory effects. These findings provide new mechanistic insights into the neuroprotective role of the ECS during neuroinflammation and highlight the therapeutic potential of MAGLi-based drugs in mitigating MS-related inflammatory and neurodegenerative brain damage. [Display omitted] • Intraperitoneal treatment with MAGLi 432 (inhibitor of 2-AG degradation) induces the increase of 2-AG levels into the brain. • In vivo treatment with MAGLi 432 ameliorates the clinical score and the synaptic hyperexcitability typical of EAE. • MAGLi 432 ameliorates striatal inflammation and attenuates the infiltration of CD45+ and CD3+ cells in the brain of EAE mice. [ABSTRACT FROM AUTHOR]

Monoacylglycerol lipase (MAGL) is a cytosolic serine hydrolase that cleaves monoacylglycerols into fatty acids and is a potential target for the novel treatment of CNS disorders related to the endocannabinoid system and neuroinflammation. We have developed [18F]T-401 as a selective Positron emission tomography (PET) imaging agent for MAGL. In this study, we determined an analytical method to quantify MAGL availability and its occupancy by an exogenous inhibitor in rhesus monkey brains using [18F]T-401-PET. In rhesus monkeys, regional time-activity curves were described well when using an extended 2-tissue compartment model that accommodated the formation of a radiometabolite in the brain. This model yielded reliable estimates of the total distribution volume (V T), and the rank order of V T was consistent with known regional activity of MAGL enzyme in primates. The pretreatment of monkeys with JW642 resulted in a dose-dependent reduction of [18F]T-401 retentions in the brain, and V T. Lassen's graphical analysis indicated a V ND of 0.69 mL/cm3 and a plasma JW642 concentration of 126 ng/mL for inhibiting the specific binding by 50%. [18F]T-401 and the method established can be used for quantification of MAGL in healthy brain and in disease conditions, and is suitable for evaluations of target engagement at cerebral MAGL. [ABSTRACT FROM AUTHOR]

• eCB modify inflammatory, degenerative, cognitive aspects of Alzheimer's pathology. • MAGL FAAH inhibitors modulate eCB and inhibit Alzheimer's progression. • Effects of MAGL FAAH inhibitors on experimental behavioural paradigm is presented. • Also included are potencies of different classes of MAGL and FAAH inhibitors. Alzheimer's disease is a neurodegenerative disease characterized by progressive decline of cognitive function in combination with neuronal death. Current approved treatment target single dysregulated pathway instead of multiple mechanism, resulting in lack of efficacy in slowing down disease progression. The proclivity of endocannabinoid system to exert neuroprotective action and mitigate symptoms of neurodegeneration condition has received substantial interest. Growing evidence suggest the endocannabinoids (eCB) system, viz. anadamide (AEA) and arachidonoyl glycerol (2-AG), as potential therapeutic targets with the ability to modify Alzheimer's pathology by targeting the inflammatory, neurodegenerative and cognitive aspects of the disease. In order to modulate endocannabinoid system, number of agents have been reported amongst which are inhibitors of the monoacylglycerol (MAGL) and fatty acid amide hydrolase (FAAH), the enzymes that hydrolyses 2-AG and AEA respectively. However, little is known regarding the exact mechanistic signalling and their effects on pathophysiology and cognitive decline associated with Alzheimer's disease. Both MAGL and FAAH inhibitors possess fascinating properties that may offer a multi-faceted approach for the treatment of Alzheimer's disease such as potential to protect neurons from deleterious effect of amyloid-β, reducing phosphorylation of tau, reducing amyloid-β induced oxidative stress, stimulating neurotrophin to support brain intrinsic repair mechanism etc. Based on empirical evidence, MAGL and FAAH inhibitors might have potential for therapeutic efficacy against cognitive impairment associated with Alzheimer's disease. The aim of this review is to summarize the experimental studies demonstrating the polyvalent properties of MAGL or FAAH inhibitor compounds for the treatment of Alzheimer's disease, and also effect of these on learning and types of memories, which together encourage to study these compounds over other therapeutics targets. Further research in this direction would enhance the molecular mechanisms and development of applicable interventions for the treatment of Alzheimer's disease, which nevertheless stay as the primary unmet need. [ABSTRACT FROM AUTHOR]

As a serine hydrolase, monoacylglycerol lipase (MAGL) is principally responsible for the metabolism of 2-arachidonoylglycerol (2-AG) in the central nervous system (CNS), leading to the formation of arachidonic acid (AA). Dysfunction of MAGL has been associated with multiple CNS disorders and symptoms, including neuroinflammation, cognitive impairment, epileptogenesis, nociception and neurodegenerative diseases. Inhibition of MAGL provides a promising therapeutic direction for the treatment of these conditions, and a MAGL positron emission tomography (PET) probe would greatly facilitate preclinical and clinical development of MAGL inhibitors. Herein, we design and synthesize a small library of fluoropyridyl-containing MAGL inhibitor candidates. Pharmacological evaluation of these candidates by activity-based protein profiling identified 14 as a lead compound, which was then radiolabeled with fluorine-18 via a facile S N Ar reaction to form 2-[18F]fluoropyridine scaffold. Good blood–brain barrier permeability and high in vivo specific binding was demonstrated for radioligand [18F] 14 (also named as [18F]MAGL-1902). This work may serve as a roadmap for clinical translation and further design of potent 18F-labeled MAGL PET tracers. A highly potent irreversible MAGL PET tracer [18F] 14 was described, which exhibited favorable in vitro and in vivo characteristics, including excellent affinity, high brain uptake, and good binding specificity. [Display omitted] [ABSTRACT FROM AUTHOR]

The endocannabinoid system (ECS) has been shown to play a critical role in the regulation of alcohol intake and alcohol-related behaviors. However, there are discrepancies between studies examining the interaction of the ECS and alcohol administration due to different experimental procedures. The present study aims at clarifying the time course effects of acute alcohol consumption on the ECS in the peripheral circulatory systems and central nervous systems of the same cohort of subjects. We have closely monitored the critical indicators reflecting changes of the ECS during the entire process from alcohol absorption to its metabolization, after acute alcohol (4.5 g/kg) intake by intragastric administration, including two key endocannabinoids (arachidonoylethanolamide and 2-arachidonoylglycerol) and their hydrolytic enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) in blood and three brain regions, as well as a crucial and abundant receptor (cannabinoid 1 receptor) of the ECS in the three brain regions. Our results indicate that acute alcohol consumption inhibits endocannabinoid (eCB) production in the blood and in the prefrontal cortex of the brain, whereas the reverse was observed in the brain regions of the hippocampus and striatum. The variation between levels of two hydrolytic enzymes in the blood and in the three brain regions failed to reach statistical significance. After acute alcohol consumption, CB1R levels in striatum, hippocampus, and prefrontal cortex showed a similar trend of increasing, while the significant changes occurred at different time points. The present findings reveal different ligand-receptor changing patterns in the blood and in different brain regions, supporting the notion that the ECS plays a vital role in acute alcohol intoxication. Additionally, the temporal effects of alcohol on key elements of the ECS of blood and different brain nuclei were different. Our investigation may lead to a deeper understanding of the effect of acute alcohol consumption on the ECS. [ABSTRACT FROM AUTHOR]

A set of chiral polyhydrochromenes was synthesized by clay-catalyzed reactions of monoterpenoids (−)-isopulegol, (+)-neoisopulegol and (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 5 with aromatic and heteroaromatic aldehydes. These compounds resemble in structure phytocannabinoids, some of them demonstrated analgesic activity in vivo. Polyhydrochromenes containing amino groups were obtained through the interaction of (−)-isopulegol with 5-hydroxymethylfurfural, followed by substitution of hydroxy-group with bromine and further reaction with amines. The ability of all synthesized compounds to influence the endocannabinoid system was studied for the first time. Although the polyhydrochromenes did not significantly bind to CB1 and CB2 cannabinoid receptors and did not inhibit MAGL activity at the concentration of 10 µM, isopulegol derivative 2i containing 3-bromothiophene substituent inhibited FAAH activity with an IC50 value of 7.6 µM. Thus, this compound may increase endocannabinoid system activity. [ABSTRACT FROM AUTHOR]

The endocannabinoid system is a key modulator of memory consolidation for aversive experiences. We recently found that the fatty acid amide hydrolase (FAAH) inhibitor URB597, which increases anandamide levels by inhibiting its hydrolysis, facilitates memory consolidation through a concurrent activation of both cannabinoid receptor type 1 (CB1) and 2 (CB2). Here, we investigated the role played on memory consolidation by the other major endocannabinoid, 2-arachidonoylglycerol (2-AG). To this aim, we tested the effects of pharmacological inhibition of monoacylglycerol lipase (MAGL) through systemic administration of the MAGL inhibitor JZL184 to rats immediately after training of the inhibitory avoidance task. Pharmacological enhancement of 2-AG tone facilitated memory consolidation through activation of CB2 receptor signaling. Moreover, we found that increased 2-AG signaling prevented the activation of the mammalian target of rapamycin (mTOR) signaling pathway in the hippocampus through a CB2-dependent mechanism. Our results identify a fundamental role for 2-AG and CB2 receptors in the modulation of memory consolidation for aversive experiences. [ABSTRACT FROM AUTHOR]

Current therapeutics are not effective for orofacial neuropathic pain, and better options are needed. The present study used inferior orbital nerve (ION)-injured mice to investigate the effect of inhibiting monoacylglycerol lipase (MAGL), an enzyme that degrades the major endocannabinoid 2-arachydonoylgycerol (2-AG) in orofacial neuropathic pain. The head-withdrawal threshold to mechanical stimulation of the whisker pad was reduced on days 3, 5, and 7 after ION injury. Injection of JZL184, a selective inhibitor of MAGL, on day 7 after ION injury attenuated the reduction in head-withdrawal threshold at 2 h after administration. Moreover, the numbers of MAGL-immunoreactive neurons in the trigeminal subnucleus caudalis (Vc) and upper cervical spinal cord (C1-C2) were significantly greater in ION-injured mice than in sham-operated mice but were reduced after administration of JZL184. The increase in MAGL immunoreactivity suggests that increased 2-AG production is followed by rapid enzymatic degradation of 2-AG. JZL184 inhibited this degradation and thus increased 2-AG concentration in the brain, particularly in the Vc and C1-C2 regions, thus attenuating pain. Our findings suggest that inhibition of 2-AG degradation by MAGL inhibitors is a promising therapeutic option for treatment of orofacial neuropathic pain. [ABSTRACT FROM AUTHOR]

Substantial challenges exist for investigating the cannabinoid receptor type 1 (CB 1 )-mediated discriminative stimulus effects of the endocannabinoids, 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (anandamide; AEA), compared with exogenous CB 1 receptor agonists, such as Δ 9 -tetrahydrocannabinol (THC) and the synthetic cannabinoid CP55,940. Specifically, each endocannabinoid is rapidly degraded by the respective hydrolytic enzymes, monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH). Whereas MAGL inhibitors partially substitute for THC and fully substitute for CP55,940, FAAH inhibitors do not substitute for either drug. Interestingly, combined FAAH-MAGL inhibition results in full THC substitution, and the dual FAAH-MAGL inhibitor SA-57 serves as its own discriminative training stimulus. Because MAGL inhibitors fully substitute for SA-57, we tested whether the selective MAGL inhibitor MJN110 would serve as a training stimulus. Twelve of 13 C57BL/6J mice learned to discriminate MJN110 from vehicle, and the CB 1 receptor antagonist rimonabant dose-dependently blocked its discriminative stimulus. CP55,940, SA-57, and another MAGL inhibitor JZL184, fully substituted for MJN110. In contrast, the FAAH inhibitor PF-3845 failed to substitute for the MJN110 discriminative stimulus, but produced a 1.6 (1.1–2.2; 95% confidence interval) leftward shift in the MJN110 dose-response curve. Inhibitors of other relevant enzymes (i.e., ABHD6, COX-2) and nicotine did not engender substitution. Diazepam partially substituted for MJN110, but rimonabant failed to block this partial effect. These findings suggest that MAGL normally throttles 2-AG stimulation of CB 1 receptors to a magnitude insufficient to produce cannabimimetic subjective effects. Accordingly, inhibitors of this enzyme may release this endogenous brake producing effects akin to those produced by exogenously administered cannabinoids. [ABSTRACT FROM AUTHOR]

Although opioids are highly efficacious analgesics, their abuse potential and other untoward side effects diminish their therapeutic utility. The addition of non-opioid analgesics offers a promising strategy to reduce required antinociceptive opioid doses that concomitantly reduce opioid-related side effects. Inhibitors of the primary endocannabinoid catabolic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) show opioid-sparing effects in preclinical models of pain. As simultaneous inhibition of these enzymes elicits enhanced antinociceptive effects compared with single enzyme inhibition, the present study tested whether the dual FAAH-MAGL inhibitor SA-57 [4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester] produces morphine-sparing antinociceptive effects, without major side effects associated with either drug class. SA-57 dose-dependently reversed mechanical allodynia in the constriction injury (CCI) of the sciatic nerve model of neuropathic pain and carrageenan inflammatory pain model. As previously reported, SA-57 was considerably more potent in elevating anandamide (AEA) than 2-arachidonyl glycerol (2-AG) in brain. Its anti-allodynic effects required cannabinoid (CB) 1 and CB 2 receptors; however, only CB 2 receptors were necessary for the anti-edematous effects in the carrageenan assay. Although high doses of SA-57 alone were required to produce antinociception, low doses of this compound, which elevated AEA and did not affect 2-AG brain levels, augmented the antinociceptive effects of morphine, but lacked cannabimimetic side effects. Because of the high abuse liability of opioids and implication of the endocannabinoid system in the reinforcing effects of opioids, the final experiment tested whether SA-57 would alter heroin seeking behavior. Strikingly, SA-57 reduced heroin-reinforced nose poke behavior and the progressive ratio break point for heroin. In conclusion, the results of the present study suggest that inhibition of endocannabinoid degradative enzymes represents a promising therapeutic approach to decrease effective doses of opioids needed for clinical pain control, and may also possess therapeutic potential to reduce opioid abuse. [ABSTRACT FROM AUTHOR]

From the Aristotelian ancient Greece, pain has been associated with appetites or emotions and is opposite to pleasure. Reward and addiction is also linked to pleasure and compulsive drug seeking reinstates pleasure. Alleviation of chronic pain can induce a euphoric phase similar to what is found in addiction. Both chronic pain and addiction are recognized as a disease of the central nervous system. They share many characteristics and brain regions/mechanisms. Evidence points to the usefulness of cannabinoids as a new class of agents to add to the pharmaceutical toolbox in the management of chronic pain. Wilkerson and colleagues, in this issue, examine SA-57, an inhibitor of two different endocannabinoid catabolic enzymes FAAH and MAGL, demonstrating its analgesic effectiveness and morphine-sparing properties in a chronic pain model, as well as its ability to reduce heroin seeking behavior in a self-administration paradigm in mice. This timely study emphasizes the need for development of more efficacious chronic pain therapeutics with minimized abuse potential and/or reinforcing properties. It also highlights the need for better understanding of the overlapping circuitry of chronic pain, reward, and addiction. [ABSTRACT FROM AUTHOR]

Endocannabinoids [2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)], endogenously produced arachidonate-based lipids, are anti-inflammatory physiological ligands for two known cannabinoid receptors, CB1 and CB2, yet the molecular and cellular mechanisms underlying their effects after brain injury are poorly defined. In the present study, we hypothesize that traumatic brain injury (TBI)-induced loss of endocannabinoids exaggerates neurovascular injury, compromises brain-cerebrospinal fluid (CSF) barriers (BCB) and causes behavioral dysfunction. Preliminary analysis in human CSF and plasma indicates changes in endocannabinoid levels. This encouraged us to investigate the levels of endocannabinoid-metabolizing enzymes in a mouse model of controlled cortical impact (CCI). Reductions in endocannabinoid (2-AG and AEA) levels in plasma were supported by higher expression of their respective metabolizing enzymes, monoacylglycerol lipase (MAGL), fatty acid amide hydrolase (FAAH), and cyclooxygenase 2 (Cox-2) in the post-TBI mouse brain. Following increased metabolism of endocannabinoids post-TBI, we observed increased expression of CB2, non-cannabinoid receptor Transient receptor potential vanilloid-1 (TRPV1), aquaporin 4 (AQP4), ionized calcium binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and acute reduction in cerebral blood flow (CBF). The BCB and pericontusional cortex showed altered endocannabinoid expressions and reduction in ventricular volume. Finally, loss of motor functions and induced anxiety behaviors were observed in these TBI mice. Taken together, our findings suggest endocannabinoids and their metabolizing enzymes play an important role in the brain and BCB integrity and highlight the need for more extensive studies on these mechanisms. • TBI leads to chronic vascular, ventricular, and neurological deficits. • Brain barriers are compromised after traumatic brain injury. • Compromised brain-CSF barrier (BCB) shows altered cannabinoid regulation. • Altered endocannabinoid system (ECS) reduces endocannabinoids (2-AG and AEA). • Restoring cannabinoid homeostasis may promote neurological recovery after TBI. [ABSTRACT FROM AUTHOR]

Inflammation plays a pivotal role in the pathogenesis of many diseases in the central nervous system. Caudate nucleus (CN), the largest nucleus in the brain, is also implicated in many neurological disorders. 2-Arachidonoylglycerol (2-AG), the most abundant endogenous cannabinoid, has been shown to exhibit neuroprotective effects through its anti-inflammatory action from some proinflammatory stimuli. However, the neuroprotective mechanism of 2-AG is complex and has not been fully understood. A-type K channels critically regulate neuronal excitability and have been demonstrated to be associated with some nervous system diseases. The aim of this study was to explore whether A-type K channels were involved in neurotoxicity of lipopolysaccharides (LPS) and the neuroprotective mechanism of 2-AG in CN neurons. Whole cell patch clamp recording was used to investigate the influence of LPS on the function of A-type K channels and its modulation by 2-AG in primary cultured rat CN neurons. Our findings showed that in cultured CN neurons, LPS significantly decreased the A-type potassium currents ( I ) in a voltage-insensitive way. The further data demonstrated that an elevation of 2-AG levels by directly applying exogenous 2-AG or inhibiting monoacylglycerol lipase (MAGL) to prevent 2-AG hydrolysis was capable of suppressing the LPS-induced inhibition of I and the action of 2-AG is mediated through CB1 receptor-dependant way. The study provides a better understanding of inflammation-related neurological disorders and suggests the therapeutic potential for 2-AG for the treatment of these diseases. [ABSTRACT FROM AUTHOR]

Cannabinoid (CB) agonists suppress nausea in humans and animal models; yet, their underlying neural substrates remain largely unknown. Evidence suggests that the visceral insular cortex (VIC) plays a critical role in nausea. Given the expression of CB 1 receptors and the presence of endocannabinoids in this brain region, we hypothesized that the VIC endocannabinoid system regulates nausea. In the present study, we assessed whether inhibiting the primary endocannabinoid hydrolytic enzymes in the VIC reduces acute lithium chloride (LiCl)-induced conditioned gaping, a rat model of nausea. We also quantified endocannabinoid levels during an episode of nausea, and assessed VIC neuronal activation using the marker, c-Fos. Local inhibition of monoacylglycerol lipase (MAGL), the main hydrolytic enzyme of 2-arachidonylglycerol (2-AG), reduced acute nausea through a CB 1 receptor mechanism, whereas inhibition of fatty acid amide hydrolase (FAAH), the primary catabolic enzyme of anandamide (AEA), was without effect. Levels of 2-AG were also selectively elevated in the VIC during an episode of nausea. Inhibition of MAGL robustly increased 2-AG in the VIC, while FAAH inhibition had no effect on AEA. Finally, we demonstrated that inhibition of MAGL reduced VIC Fos immunoreactivity in response to LiCl treatment. Taken together, these findings provide compelling evidence that acute nausea selectively increases 2-AG in the VIC, and suggests that 2-AG signaling within the VIC regulates nausea by reducing neuronal activity in this forebrain region. [ABSTRACT FROM AUTHOR]

Aims Pro-inflammatory cytokines, growth and angiogenic factors released by leukocytes are involved in carcinogenesis and cancer progression, but they are also crucial for fighting tumour growth and spreading. We have previously demonstrated that endocannabinoids modulate cell-to-cell crosstalk during inflammation. Here, we investigated the inflammatory and tumourigenic properties of endocannabinoids in a human urinary bladder carcinoma cell line. Main methods Endocannabinoid-treated ECV304 cells were checked for tumour necrosis factor (TNF)-α secretion (by ELISA assay) and surface exposure of selectins (by in situ ELISA and FACS analysis). ECV304/Jurkat T cell interaction was assessed by adhesion and live imaging experiments. Proliferation rate, cell death and cell cycle were determined by FACS analysis. Key findings By binding to type-1 (CB 1 ) and type-2 (CB 2 ) cannabinoid receptors, the endocannabinoid 2-arachidonoylglycerol (2-AG) exacerbates the pro-inflammatory status surrounding bladder carcinoma ECV304 cells, by: (i) enhancing TNF-α release, (ii) increasing surface exposure of P- and E-selectins, and (iii) allowing Jurkat T lymphocytes to adhere to treated cancer cells. We also found that the CB 1 inverse agonist AM281, unlike 2-AG, decreases cancer proliferation by delaying cell cycle progression. Significance Our data suggest that 2-AG modulates the inflammatory milieu of cancer cells in vitro, while AM281 plays a more specific role in proliferation. Collectively, these findings suggest that CB receptors may play distinct roles in cancer biology, depending on the specific ligand employed. Conclusions The in vivo assessment of the role of CB receptors in inflammation and cancer might be instrumental in broadening the understanding about bladder cancer biology. [ABSTRACT FROM AUTHOR]

Monoacylglycerol lipase (MAGL) is important for neuroinflammation. However, the regulatory mechanisms underlying its expression and function remain unknown. Lipopolysaccharide (LPS) treatment post-translationally upregulated MAGL expression, whereas it downregulated MAGL transcription through a Stat6-mediated mechanism in microglia. Neither MAGL knockdown nor JZL-184, a selective MAGL inhibitor, suppressed LPS-induced upregulation of inflammatory cytokines in microglia. Moreover, exogenous expression of MAGL in BV-2 microglial cell line, which lacks endogenous MAGL, did not promote the induction of inflammatory cytokines by LPS treatment. Interestingly, MAGL knockdown reduced Fcγ receptor-mediated phagocytosis in primary microglia, and introduction of MAGL into the BV-2 cells increased Fcγ receptor-mediated phagocytosis. Collectively, these results suggest that MAGL regulates phagocytosis, but not LPS-mediated cytokine induction in microglia. [ABSTRACT FROM AUTHOR]

The key hydrolytic enzymes of the endocannabinoid system, fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), are potential targets for various therapeutic applications. In this paper, we present more extensively the results of our previous work on piperazine and piperidine carboxamides and carbamates as FAAH and MAGL inhibitors. The best compounds of these series function as potent and selective MAGL/FAAH inhibitors or as dual FAAH/MAGL inhibitors at nanomolar concentrations. This study revealed that MAGL inhibitors should comprise leaving-groups with a conjugate acid p K a of 8–10, while diverse leaving groups are tolerated for FAAH inhibitors. [ABSTRACT FROM AUTHOR]

In recent years, metabolism is talked highly important in cancer research, especially the lipid metabolism. Researchers believe that the de novo fatty acid synthesis plays an important role in tumor development, while many studies illustrated that Endocannabinoids have anti-tumorigenic actions, including anti-proliferation, apoptosis induction, and anti-metastatic effects, MAGL as an important decomposing enzyme of both lipid metabolism and endocannabinoids system, additionally as a part of a gene expression signature contributes to different aspects of tumourigenesis. [ABSTRACT FROM AUTHOR]

Abstract: The Lewis (LEW) and Fischer 344 (F344) rat strains have been proposed as a model to study certain genetic influences on drug use. These strains differ in terms of the self-administration of several drugs, and in their expression of various components of the dopaminergic, glutamatergic, GABAergic and endogenous opioid neurotransmitter systems. As the endocannabinoid system is linked to these systems, we investigated whether these two strains exhibit differences in cannabinoid receptor binding and in the expression of cannabinoid-related genes. Quantitative autoradiography of [3 H]-CP 55,940 binding levels and real-time PCR assays were used. F344 rats displayed higher levels of cannabinoid receptor binding in the lateral globus pallidus and weaker CNR1 gene expression in the prefrontal cortex (PFc) than LEW rats. Moreover, the N-acyl phosphatidylethanolamine-specific phospholipase D/fatty acid amide hydrolase ratio was greater in the PFc and NAcc of F344 rats. Our results suggest that the endocannabinoid system may be a mediator of the individual differences that exist in the susceptibility to the rewarding effects of drugs of abuse. [Copyright &y& Elsevier]

Abstract: 2-Arachidonoylglycerol (2-AG) is one of the principal endocannabinoids involved in the protection against neurodegenerative processes. Cannabinoids primarily interact with the seven-segment transmembrane cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2), both of which are expressed in the central nervous system (CNS). The level of 2-AG is controlled through key enzymes responsible for its synthesis or degradation. We have previously observed a deregulation of 2-AG metabolism in physiological aging. The aim of this study was to analyze how 2-AG metabolism is modulated by CB1/CB2 receptors during aging. To this end, both CB1 and CB2 receptor expression and the enzymatic activities (diacylglycerol lipase (DAGL), lysophosphatidate phosphohydrolase (LPAase) and monoacylglycerol lipase (MAGL)) involved in 2-AG metabolism were analyzed in the presence of cannabinoid receptor (CBR) agonists (WIN and JWH) and/or antagonists (SR1 and SR2) in synaptosomes from adult and aged rat cerebral cortex (CC). Our results demonstrate that: (a) aging decreases the expression of both CBRs; (b) LPAase inhibition, due to the individual action of SR1 or SR2, is reverted in the presence of both antagonists together; (c) LPAase activity is regulated mainly by the CB1 receptor in adult and in aged synaptosomes while the CB2 receptor acquires importance when CB1 is blocked; (d) modulation via CBRs of DAGL and MAGL by both antagonists occurs only in aged synaptosomes, stimulating DAGL and inhibiting MAGL activities; (e) only DAGL stimulation is reverted by WIN. Taken together, the results of the present study show that CB1 and/or CB2 receptor antagonists trigger a significant modulation of 2-AG metabolism, underlining their relevance as therapeutic strategy for controlling endocannabinoid levels in physiological aging. [Copyright &y& Elsevier]

Abstract: Endogenous cannabinoids play important roles in a variety of functions in the mammalian brain, including the regulation reward-related information processing. The primary mechanism through which this is achieved is the presynaptic modulation of synaptic transmission. During reward- and reinforcement-related behavior dopamine levels increase in forebrain areas and this has recently been shown to be modulated by the endocannabinoid system. Therefore, understanding how endocannabinoids are mobilized to modulate synaptic inputs impinging on midbrain dopamine neurons is crucial to a complete understanding of the roles that these molecules play in reward behavior, drug abuse and addiction. Here we summarize the literature describing short-term and long-term regulation of afferent connections on dopamine neurons in the ventral tegmental area via endocannabinoid activation of cannabinoid CB1 receptors, and describe the mechanisms through which these molecules are released during reward-based behavior and exposure to abused drugs. [Copyright &y& Elsevier]

Abstract: Accumulated evidence points to a key role for endocannabinoids in cell migration, and here we sought to characterize the role of these substances in early events that modulate communication between endothelial cells and leukocytes. We found that 2-arachidonoylglycerol (2-AG) was able to initiate and complete the leukocyte adhesion cascade, by modulating the expression of selectins. A short exposure of primary human umbilical vein endothelial cells (HUVECs) to 2-AG was sufficient to prime them towards an activated state: within 1h of treatment, endothelial cells showed time-dependent plasma membrane expression of P- and E-selectins, which both trigger the initial steps (i.e., capture and rolling) of leukocyte adhesion. The effect of 2-AG was mediated by CB1 and CB2 receptors and was long lasting, because endothelial cells incubated with 2-AG for 1h released the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α) for up to 24h. Consistently, TNF-α-containing medium was able to promote leukocyte recruitment: human Jurkat T cells grown in conditioned medium derived from 2-AG-treated HUVECs showed enhanced L-selectin and P-selectin glycoprotein ligand-1 (PSGL1) expression, as well as increased efficiency of adhesion and trans-migration. In conclusion, our in vitro data indicate that 2-AG, by acting on endothelial cells, might indirectly promote leukocyte recruitment, thus representing a potential therapeutic target for treatment of diseases where impaired endothelium/leukocyte interactions take place. [Copyright &y& Elsevier]

Abstract: Low-dose dexamethasone has been widely used for the prevention of nausea and vomiting after chemotherapy and surgical procedures and to treat motion sickness due to its minimal adverse effects, but the mechanisms underlying its anti-motion sickness effects are poorly understood. Previous studies have demonstrated that the endocannabinoid system is suppressed by motion sickness but stimulated by dexamethasone. The aim of the present study was to determine whether dexamethasone has an anti-motion sickness effect in rats and to elucidate the mechanism of this action. We used HPLC–MS/MS to measure the plasma concentrations of anandamide and 2-arachidonoylglycerol+1-arachidonoylglycerol, and we employed real-time quantitative PCR (qRT-PCR) and/or Western blot analysis to assay the expression of N-acylphosphatidyl-ethanolamine hydrolyzing phospholipase D, sn-1-selective diacylglycerol lipase, fatty acid hydrolase, monoacylglycerol lipase and endocannabinoid CB1 receptor in the dorsal vagal complex and stomach of rats exposed to a motion sickness protocol. The results showed that dexamethasone lowered the motion sickness index and restored the levels of endogenous cannabinoids and the expression of the endocannabinoid CB1 receptor, which declined after the induction of motion sickness, in the dorsal vagal complex and stomach. [Copyright &y& Elsevier]

Abstract: Objective: The vasorelaxant effect of 2-arachidonoylglycerol (2-AG) has been well characterised in animals. 2-AG is present in human vascular cells and is up-regulated in cardiovascular pathophysiology. However, the acute vascular actions of 2-AG have not been explored in humans. Approach: Mesenteric arteries were obtained from patients receiving colorectal surgery and mounted on a myograph. Arteries were contracted and 2-AG concentration–response curves were carried out. Mechanisms of action were characterised pharmacologically. Post hoc analysis was carried out to assess the effects of cardiovascular disease/risk factors on 2-AG responses. Results: 2-AG caused vasorelaxation of human mesenteric arteries, independent of cannabinoid receptor or transient receptor potential vanilloid-1 activation, the endothelium, nitric oxide or metabolism via monoacyglycerol lipase or fatty acid amide hydrolase. 2-AG-induced vasorelaxation was reduced in the presence of indomethacin and flurbiprofen, suggesting a role for cyclooxygenase metabolism 2-AG. Responses to 2-AG were also reduced in the presence of Cay10441, L-161982 and potentiated in the presence of AH6809, suggesting that metabolism of 2-AG produces both vasorelaxant and vasoconstrictor prostanoids. Finally, 2-AG-induced vasorelaxation was dependent on potassium efflux and the presence of extracellular calcium. Conclusions: We have shown for the first time that 2-AG causes vasorelaxation of human mesenteric arteries. Vasorelaxation is dependent on COX metabolism, activation of prostanoid receptors (EP4 & IP) and ion channel modulation. 2-AG responses are blunted in patients with cardiovascular risk factors. [Copyright &y& Elsevier]

Rationale: Enhancement of the endocannabinoid (EC) system may reduce anticipatory nausea (AN). Objectives: The experiments evaluated the potential of the dual fatty acid amide hydrolase (FAAH)/monoacylglycerol lipase (MAGL) inhibitor, JZL195, on its own and combined with anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) to reduce contextually elicited gaping, a measure of AN in rats. Methods: Following four context lithium chloride (LiCl) pairings, rats were injected with vehicle (VEH) or JZL195 (10 mg kg, intraperitoneally) 105 min before an injection of VEH, 2-AG (1.25 mg kg), or AEA (5.0 mg kg). Fifteen minutes later, all rats were placed in the LiCl-paired context for 5 min and in a different context for a 15-min locomotor test. Whole brains were extracted for EC analysis. The potential of the CB antagonist, SR141716, to reverse the suppression of AN by both JZL195 and AEA and of the CB antagonist, AM630, to reverse the suppression of AN by JZL195 was then evaluated. Results: JZL195 suppressed gaping and elevated AEA, palmitoylethanolamine, and oleoylethanolamide. As the suppression of gaping was reversed by SR141716, but not by AM630, the effect was CB mediated. The suppressive effect of JZL195 on gaping, as well as elevation of AEA and 2-AG, was amplified by pretreatment with either AEA or 2-AG. On its own, AEA, but not 2-AG, also suppressed gaping-an effect that was also prevented by CB antagonism. Conclusions: JZL195 reduces AN primarily by acting as a FAAH inhibitor, but MAGL inhibition is also indicated. [ABSTRACT FROM AUTHOR]

Abstract: Studies in male rodents have shown that stress-induced increases in circulating corticosterone are increased by both CB1 receptor (CB1R) antagonist treatment and genetic deletion. The purposes of the current study were to determine whether female mice respond in the same manner as males, and whether indirect CB1R agonists accelerate the return of corticosterone to baseline. In agreement with earlier studies, CB1R null and rimonabant-treated male mice had significantly increased circulating corticosterone 30min following the end of a restraint episode compared to wild type and vehicle-treated, respectively. Females treated with rimonabant had significantly higher circulating corticosterone compared to vehicle. However, corticosterone concentrations were not different between CB1R null and wild type females at 30min recovery, although CB1R null mice had higher corticosterone concentrations at 90min of recovery. Female CB1R null mice exhibited greater serum binding capacity for corticosterone than wild type. The monoacylglycerol lipase inhibitor, JZL184, attenuated corticosterone concentrations at restraint offset in male, and at 30min recovery in female mice compared to vehicle. Male mice treated with JZL184 exhibited greater concentrations of circulating corticosterone at 120min recovery, even in the absence of restraint. JZL184 had no effect on corticosterone concentrations in CB1R null mice. The fatty acid amide hydrolase inhibitor, URB597, did not affect corticosterone responses to restraint in male or female, wild type or CB1R null mice. These data suggest that 2-arachidonoylglycerol is the primary endocannabinoid involved in CB1R regulation of the recovery of the HPA axis from restraint stress. These data support a role for endocannabinoid-CB1R signaling in the regulation of the corticosterone response to restraint stress and suggest that female mice with life-long loss of the CB1R undergo compensatory changes that minimize the impact of loss of endocannabinoid signaling on circulating corticosterone. [Copyright &y& Elsevier]

Abstract: Endocannabinoids are the endogenous ligands of the G protein-coupled cannabinoid receptors. The principal brain endocannabinoid, 2-arachidonoylglycerol (2-AG), is enzymatically produced by postsynaptic neurons and then activates presynaptic CB1 receptors in a retrograde manner. The primary pathway for 2-AG generation is believed to be conversion from the diacylglycerols (DAGs) by two sn-1-specific lipases, DAGLα and DAGLβ. Previous studies with DAGL-deficient mice indicated that DAGLα is the major enzyme needed for retrograde synaptic 2-AG signalling. The current study investigated whether the CB1 receptor-mediated Gi/o protein activity is altered in brain cryosections of DAGL-deficient mice when compared to wild-type mice and whether the sn-1-specific DAGLs are able to generate 2-AG in brain cryosections. Functional autoradiography indicated that brain regional CB1 receptor-Gi/o-activity largely remained unaltered in DAGLα-knockout and DAGLβ-knockout mice when compared to wild-type littermates. Following comprehensive pharmacological blockade of 2-AG hydrolysis, brain sections generated sufficient amounts of 2-AG to activate CB1 receptors throughout the regions endowed with these receptors. As demonstrated by LC/MS/MS, this pool of 2-AG was generated via tetrahydrolipstatin-sensitive enzymatic pathways distinct from DAGLα or DAGLβ. We conclude that in addition to the sn-1-specific DAGLs, additional 2-AG generating enzymatic pathways are active in brain sections. [Copyright &y& Elsevier]

Highlights: [•] Endocannabinoid system is involved in the antihyperalgesic effect of AJM. [•] Blocking centrally cannabinoid receptors 1 abolished antihyperalgesic effect of AJM. [•] Blocking peripherally cannabinoid receptors 2 reversed antihyperalgesic effect of AJM. [•] Endocannabinoid catabolic enzyme inhibitors produce antihyperalgesic effect. [Copyright &y& Elsevier]

Highlights: [•] LPS decreases FAAH activity in peripheral blood mononuclear cells (PBMC). [•] Progesterone reverses the effects of LPS through classical progesterone receptors (PR). [•] The expression of PR-A and PR-B in PBMC is modulated by LPS and progesterone. [•] Murine T-lymphocytes express classical progesterone receptors. [Copyright &y& Elsevier]

Abstract: De novo lipogenesis is considered the primary source of fatty acids for lipid synthesis in cancer cells, even in the presence of exogenous fatty acids. Here, we have used an isotopic fatty acid labeling strategy coupled with metabolomic profiling platforms to comprehensively map palmitic acid incorporation into complex lipids in cancer cells. We show that cancer cells and tumors robustly incorporate and remodel exogenous palmitate into structural and oncogenic glycerophospholipids, sphingolipids, and ether lipids. We also find that fatty acid incorporation into oxidative pathways is reduced in aggressive human cancer cells, and instead shunted into pathways for generating structural and signaling lipids. Our results demonstrate that cancer cells do not solely rely on de novo lipogenesis, but also utilize exogenous fatty acids for generating lipids required for proliferation and protumorigenic lipid signaling. This article is part of a special issue entitled Lipid Metabolism in Cancer. [Copyright &y& Elsevier]

Abstract: Cannabinoids, the active components of cannabis (Cannabis sativa) extracts, have attracted the attention of human civilizations for centuries, much earlier than the discovery and characterization of their substrate of action, the endocannabinoid system (ECS). The latter is an ensemble of endogenous lipids, their receptors [in particular type-1 (CB1) and type-2 (CB2) cannabinoid receptors] and metabolic enzymes. Cannabinoid signaling regulates cell proliferation, differentiation and survival, with different outcomes depending on the molecular targets and cellular context involved. Cannabinoid receptors are expressed and functional from the very early developmental stages, when they regulate embryonic and trophoblast stem cell survival and differentiation, and thus may affect the formation of manifold adult specialized tissues derived from the three different germ layers (ectoderm, mesoderm and endoderm). In the ectoderm-derived nervous system, both CB1 and CB2 receptors are present in neural progenitor/stem cells and control their self-renewal, proliferation and differentiation. CB1 and CB2 show opposite patterns of expression, the former increasing and the latter decreasing along neuronal differentiation. Recently, endocannabinoid (eCB) signaling has also been shown to regulate proliferation and differentiation of mesoderm-derived hematopoietic and mesenchymal stem cells, with a key role in determining the formation of several cell types in peripheral tissues, including blood cells, adipocytes, osteoblasts/osteoclasts and epithelial cells. Here, we will review these new findings, which unveil the involvement of eCB signaling in the regulation of progenitor/stem cell fate in the nervous system and in the periphery. The developmental regulation of cannabinoid receptor expression and cellular/subcellular localization, together with their role in progenitor/stem cell biology, may have important implications in human health and disease. [Copyright &y& Elsevier]

Abstract: In human platelets the endocannabinoid 2-arachidonoylglycerol (2-AG) stimulates some important pathways leading to thromboxane B2 formation, calcium intracellular elevation, ATP secretion and actin polymerisation. The aim of the present study was to examine the 2-AG effect on myosin light chain (MLC) phosphorylation and to investigate the mechanisms involved. We demonstrated that 2-AG induced a rapid MLC phosphorylation, stimulating both the RhoA kinase (ROCK) and MLC kinase (MLCK) in a dose and time-dependent manner. In addition MLC phosphorylation was strengthened through the MLC phosphatase inhibition. MLC phosphatase inhibition was accomplished through the RhoA/ROCK and protein kinase C mediated phosphorylation of MLC phosphatase inhibiting subunits MYPT1 and CPI-17. The presence of CB1 receptor in human platelets and the involvement of CB1 receptor in MLC phosphorylation and MLC phosphatase inhibition was shown. [Copyright &y& Elsevier]

Abstract: Objective: The G protein-coupled receptor 55 (GPR55) is a novel cannabinoid (CB) receptor, whose role in the gastrointestinal (GI) tract remains unknown. Here we studied the significance of GPR55 in the regulation of GI motility. Design: GPR55 mRNA and protein expression were measured by RT-PCR and immunohistochemistry. The effects of the GPR55 agonist O-1602 and a selective antagonist cannabidiol (CBD) were studied in vitro and in vivo and compared to a non-selective cannabinoid receptor agonist WIN55,212-2. CB1/2 −/− and GPR55−/− mice were employed to identify the receptors involved. Results: GPR55 was localized on myenteric neurons in mouse and human colon. O-1602 concentration-dependently reduced evoked contractions in muscle strips from the colon (∼60%) and weakly (∼25%) from the ileum. These effects were reversed by CBD, but not by CB1 or CB2 receptor antagonists. I.p. and i.c.v. injections of O-1602 slowed whole gut transit and colonic bead expulsion; these effects were absent in GPR55−/− mice. WIN55,212-2 slowed whole gut transit effects, which were counteracted in the presence of a CB1 antagonist AM251. WIN55,212-2, but not O-1602 delayed gastric emptying and small intestinal transit. Locomotion, as a marker for central sedation, was reduced following WIN55,212-2, but not O-1602 treatment. Conclusion: GPR55 is strongly expressed on myenteric neurons of the colon and it is selectively involved in the regulation of colonic motility. Since activation of GPR55 receptors is not associated with central sedation, the GPR55 receptor may serve as a future target for the treatment of colonic motility disorders. [Copyright &y& Elsevier]

Highlights: [•] A compensatory mechanism for endocannabinoid regulation is proposed. [•] The endocannabinoid 2-AG is hydrolyzed by BChE to AA with a k cat/K m of 1.3×103 Ms−1. [•] AEA does not influence 2-AG uptake but does influence AA production. [•] 2-AG hydrolysis by BChE suggests MAGL inhibition may only slow 2-AG turnover. [•] General esterase activity should be considered when monitoring endocannabinoids. [ABSTRACT FROM AUTHOR]

Highlights: [•] Prenatal VPA exposure elicits autistic-like behaviour during adolescence. [•] Social exposure increases hippocampal anandamide levels in VPA exposed rats. [•] DAGLα and MAGL expression is reduced in the cerebellum and hippocampus of VPA exposed rats. [•] PPARα and GPR55 mRNA expression in the cortex is reduced in VPA exposed rats. [•] VPA exposed rats exhibit reduced PPARγ and GPR55 mRNA expression in the hippocampus. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, we have further extended the structure–activity relationships for the tetrazolyl ureas class of compounds as potential FAAH and/or MAGL inhibitors, by replacing the dimethylamino group of the parent compounds 1 and 2 with bulkier groups or by introducing on the distal phenyl ring of 1 and 2 a selected set of substituents. Some of the new compounds (16, 20, 21, 25, and 28) inhibited FAAH potently (IC50 = 3.0–9.7 nM) and selectively (39- to more than 141-fold) over MAGL, while tetrazole 27 turned out to be a promising dual FAAH–MAGL inhibitor of potential therapeutic use. Covalent docking studies on FAAH indicated that the binding modes of tetrazoles 1–32 did not display a unique pattern. The ability of tetrazoles 1–32 to act as TRPV1 and TRPA1 modulators was also investigated. [Copyright &y& Elsevier]

Abstract: Aim: The present study tested whether the selective monoacylglycerol lipase (MAGL) inhibitor JZL184 would reduce allodynia and paw edema in the carrageenan test. Main methods: The anti-edematous and anti-allodynic effects of JZL184 were compared to those of PF-3845, an inhibitor of fatty acid amide hydrolase (FAAH), and diclofenac, a non-selective cyclooxygenase inhibitor. Cannabinoid receptor involvement in the anti-edematous and anti-allodynic effects of JZL184 was evaluated by administration of the respective CB1 and CB2 receptor antagonists rimonabant and SR144528 as well as with CB1(−/−) and CB2(−/−) mice. JZL184 (1.6, 4, 16, or 40mg/kg) was administered for six days to assess tolerance. Key findings: JZL184 administered before or after carrageenan significantly attenuated carrageenan-induced paw edema and mechanical allodynia. Complementary genetic and pharmacological approaches revealed that the anti-allodynic effects of JZL184 required both CB1 and CB2 receptors, but only CB2 receptors mediated its anti-edematous actions. Importantly, both the anti-edematous and anti-allodynic effects underwent tolerance following repeated injections of high dose JZL184 (16 or 40mg/kg), but repeated administration of low dose JZL184 (4mg/kg) retained efficacy. Significance: These results suggest that the MAGL inhibitor JZL184 reduces inflammatory nociception through the activation of both CB1 and CB2 receptors, with no evidence of tolerance following repeated administration of low doses. [Copyright &y& Elsevier]