Endocannabinoids and fatty acid amides in cancer, inflammation and related disorders

Hyphenation of Liquid Chromatography and Trapped Ion Mobility - Mass Spectrometry for Characterization of Isomeric Phosphatidylethanolamines with Focus on N-Acylated Species

In prior research, hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) has demonstrated applicability for characterizing regioisomers in lipidomics studies, including phosphatidylglycerols (PG) and bis(monoacyl)glycerophosphates (BMP). However, there are other lipid regioisomers, such as phosphatidylethanolamines (PE) and lyso-N-acyl-PE (LNAPE), that have not been studied as extensively. Therefore, hyphenated mass spectrometric methods are needed to investigate PE and LNAPE regioisomers individually. The asymmetric structure of LNAPE favors isomeric species, which can result in coelution and chimeric MS/MS spectra. One way to address the challenge of chimeric MS/MS spectra is through mobility-resolved fragmentation using trapped ion mobility spectrometry (TIMS). Therefore, we developed a multidimensional HILIC-TIMS-MS/MS approach for the structural characterization of isomeric phosphatidylethanolamines in both negative and positive ionization modes. The study revealed the complementary fragmentation pattern and ion mobility behavior of LNAPE in both ionization modes, which was confirmed by a self-synthesized LNAPE standard. With this knowledge, a distinction of regioisomeric PE and LNAPE was achieved in human plasma samples. Furthermore, regioisomeric LNAPE species containing at least one unsaturated fatty acid were noted to exhibit a change in collision cross-section in positive ionization mode, leading to a lipid characterization with respect to fatty acyl positional level. Similar mobility behavior was also observed for the biological LNAPE precursor N-acyl-PE (NAPE). Application of this approach to plasma and cereal samples demonstrated its effectiveness in regioisomeric LNAPE and NAPE species' elucidation.

Improving the functionality of virgin and cold-pressed edible vegetable oils: Oxidative stability, sensory acceptability and safety challenges

In recent years, there has been a growing demand for minimally processed foods that offer health benefits and premium sensory characteristics. This trend has led to increased consumption of virgin (VOs) and cold-pressed (CPOs) oils, which are rich sources of bioactive substances. To meet consumer needs for new oil products conferring multi-functional properties over a longer storage period, the scientific community has been revisiting traditional enrichment practices while exploring novel fortification technologies. In the last four years, the interest has been growing faster; an ascending number of annually published studies are about the addition of different plant materials, agri-food by-products, or wastes (intact or extracts) to VOs and CPOs using traditional or innovative fortification processes. Considering this trend, the present review aims to provide an overview and summarize the key findings from relevant papers that were retrieved from extensively searched databases. Our meta-analysis focuses on exposing the most recent trends regarding the exploitation of VOs and CPOs as substrates, the fortification agents and their form of use, as well as the fortification technologies employed. The review critically discusses possible health claim and labeling issues and highlights some chemical and microbial safety concerns along with authenticity issues and gaps in quality specifications that manufacturers have yet to address. All these aspects are examined from the perspective of developing new oil products with well-balanced techno-, senso- and bio-functional characteristics.

Circulating inflammatory markers, cell-free mitochondrial DNA, cortisol, endocannabinoids, and N-acylethanolamines in female depressed outpatients

OBJECTIVES

Major depressive disorder (MDD) involves peripheral low-grade pro-inflammatory activity. This multi-biomarker case-control study characterises the proinflammatory status in MDD beyond C-reactive protein (CRP) and Interleukin (IL)-6 levels through investigating concomitant alterations of immunoregulatory biomolecules.

METHODS

In 20 female MDD patients and 24 non-depressed women, circulating levels of CRP, IL-6, cortisol, selected endocannabinoids (ECs; anandamide [AEA], 2-arachidonylglycerol [2-AG]), and N-acylethanolamines (NAEs), as well as circulating cell-free mitochondrial DNA (ccf-mtDNA) were measured.

RESULTS

We found higher serum CRP and plasma AEA levels in MDD and a positive association of CRP and AEA levels with current depressive symptoms. Blood levels of cortisol, ccf-mtDNA, 2-AG, and NAEs did depend on MDD diagnosis nor correlated with the severity of current depressive symptoms. CRP correlated positively with AEA, and AEA showed positive associations with 2-AG and NAE levels.

CONCLUSIONS

In this study, female MDD outpatients with mild to moderate disorder severity did not substantially differ from non-depressed controls in the resting levels of multiple immunoregulatory markers in peripheral blood. Instead of investigating resting levels, future research on the role of inflammatory activity in MDD should focus on investigating the reactivity of pathways modulating the immune system upon exposure to physical and psychosocial stressors.

MGAT2 inhibitor decreases liver fibrosis and inflammation in murine NASH models and reduces body weight in human adults with obesity

Monoacylglycerol acyltransferase 2 (MGAT2) is an important enzyme highly expressed in the human small intestine and liver for the regulation of triglyceride absorption and homeostasis. We report that treatment with BMS-963272, a potent and selective MGAT2 inhibitor, decreased inflammation and fibrosis in CDAHFD and STAM, two murine nonalcoholic steatohepatitis (NASH) models. In high-fat-diet-treated cynomolgus monkeys, in contrast to a selective diacylglycerol acyltransferase 1 (DGAT1) inhibitor, BMS-963272 did not cause diarrhea. In a Phase 1 multiple-dose trial of healthy human adults with obesity (NCT04116632), BMS-963272 was safe and well tolerated with no treatment discontinuations due to adverse events. Consistent with the findings in rodent models, BMS-963272 elevated plasma long-chain dicarboxylic acid, indicating robust pharmacodynamic biomarker modulation; increased gut hormones GLP-1 and PYY; and decreased body weight in human subjects. These data suggest MGAT2 inhibition is a promising therapeutic opportunity for NASH, a disease with high unmet medical needs.

Exploration of Multiverse Activities of Endocannabinoids in Biological Systems

Over the last 25 years, the human endocannabinoid system (ECS) has come into the limelight as an imperative neuro-modulatory system. It is mainly comprised of endogenous cannabinoid (endocannabinoid), cannabinoid receptors and the associated enzymes accountable for its synthesis and deterioration. The ECS plays a proven role in the management of several neurological, cardiovascular, immunological, and other relevant chronic conditions. Endocannabinoid or endogenous cannabinoid are endogenous lipid molecules which connect with cannabinoid receptors and impose a fashionable impact on the behavior and physiological processes of the individual. Arachidonoyl ethanolamide or Anandamide and 2-arachidonoyl glycerol or 2-AG were the endocannabinoid molecules that were first characterized and discovered. The presence of lipid membranes in the precursor molecules is the characteristic feature of endocannabinoids. The endocannabinoids are released upon rapid enzymatic reactions into the extracellular space via activation through G-protein coupled receptors, which is contradictory to other neurotransmitter that are synthesized beforehand, and stock up into the synaptic vesicles. The current review highlights the functioning, synthesis, and degradation of endocannabinoid, and explains its functioning in biological systems.

The role of endocannabinoid pathway in the neuropathology of Alzheimer's disease: Can the inhibitors of MAGL and FAAH prove to be potential therapeutic targets against the cognitive impairment associated with Alzheimer's disease?

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.

A comprehensive analysis of metabolomics and transcriptomics in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer death globally. More accurate and reliable diagnostic methods/biomarkers are urgently needed. Joint application of metabolomics and transcriptomics technologies possesses the high efficiency of identifying key metabolic pathways and functional genes in lung cancer patients. In this study, we performed an untargeted metabolomics analysis of 142 NSCLC patients and 159 healthy controls; 35 identified metabolites were significantly different between NSCLC patients and healthy controls, of which 6 metabolites (hypoxanthine, inosine, L-tryptophan, indoleacrylic acid, acyl-carnitine C10:1, and lysoPC(18:2)) were chosen as combinational potential biomarkers for NSCLC. The area under the curve (AUC) value, sensitivity (SE), and specificity (SP) of these six biomarkers were 0.99, 0.98, and 0.99, respectively. Potential diagnostic implications of the metabolic characteristics in NSCLC was studied. The metabolomics results were further verified by transcriptomics analysis of 1027 NSCLC patients and 108 adjacent peritumoral tissues from TCGA database. This analysis identified 2202 genes with significantly different expressions in cancer cells compared to normal controls, which in turn defined pathways implicated in the metabolism of the compounds revealed by metabolomics analysis. We built a fully connected network of metabolites and genes, which shows a good correspondence between the transcriptome analysis and the metabolites selected for diagnosis. In conclusion, this work provides evidence that the metabolic biomarkers identified may be used for NSCLC diagnosis and screening. Comprehensive analysis of metabolomics and transcriptomics data offered a validated and comprehensive understanding of metabolism in NSCLC.

Role of the kynurenine pathway and the endocannabinoid system as modulators of inflammation and personality traits

BACKGROUND

Kynurenine pathway metabolites and endocannabinoids both exert potent regulatory effects on the immune system, but the relationship between these molecules is unknown. The role of these immunobiological mediators in emotionality and personality traits is not previously characterized.

METHODS

Interleukin-6 (IL-6), 2-arachidonoylglycerol (2-AG) and picolinic acid (PIC) were measured in the plasma of physically healthy individuals who had history of mood, anxiety, and personality disorders (n = 96) or who had no history of any psychiatric disorder (n = 56) by DSM-5 Criteria. Dimensional assessments of personality were performed using the Eysenck Personality Questionnaire (EPQ) and the Tridimensional Personality Questionnaire (TPQ).

RESULTS

Plasma IL-6 levels were significantly associated with plasma 2-AG levels and plasma PIC levels across all subjects. PIC levels were also negatively associated with 2-AG levels across all subjects, independent of IL-6 levels. In our analysis of the biological determinants of personality factors, we identified significant associations between IL-6 and novelty seeking assessment, and between PIC and neuroticism assessment.

CONCLUSIONS

These data provide evidence of a biological link between metabolites of the kynurenine pathway, the endocannabinoid system and IL-6 and suggest that these factors may influence personality traits.

HU-671, a Novel Oleoyl Serine Derivative, Exhibits Enhanced Efficacy in Reversing Ovariectomy-Induced Osteoporosis and Bone Marrow Adiposity

Oleoyl serine (OS), an endogenous fatty acyl amide (FAA) found in bone, has been shown to have an anti-osteoporotic effect. OS, being an amide, can be hydrolyzed in the body by amidases. Hindering its amide bond by introducing adjacent substituents has been demonstrated as a successful method for prolonging its skeletal activity. Here, we tested the therapeutic efficacy of two methylated OS derivatives, oleoyl α-methyl serine (HU-671) and 2-methyl-oleoyl serine (HU-681), in an ovariectomized mouse model for osteoporosis by utilizing combined micro-computed tomography, histomorphometry, and cell culture analyses. Our findings indicate that daily treatment for 6 weeks with OS or HU-671 completely rescues bone loss, whereas HU-681 has only a partial effect. The increased bone density was primarily due to enhanced trabecular thickness and number. Moreover, the most effective dose of HU-671 was 0.5 mg/kg/day, an order of magnitude lower than with OS. The reversal of bone loss resulted from increased bone formation and decreased bone resorption, as well as reversal of bone marrow adiposity. These results were further confirmed by determining the serum levels of osteocalcin and type 1 collagen C-terminal crosslinks, as well as demonstrating the enhanced antiadipogenic effect of HU-671. Taken together, these data suggest that methylation interferes with OS’s metabolism, thus enhancing its effects by extending its availability to its target cells.

Distribution of cannabinoid synthase genes in non-Cannabis organisms

The discovery of phytocannabinoid synthesizing enzymes, tetrahydrocannabinolic acid synthase (THCAs) and cannabidiolic acid synthase (CBDAs) was a breakthrough in Cannabis research. However, their evolutionary aspects and distribution across organisms has not been adequately studied. We searched for THCAs and CBDAs genes in organisms other than Cannabis plants using the database available in NCBI. Both cannabinoid synthases seem to be widely distributed in the plant kingdom. Of several complete or partial sequences of cannabinoid synthases-likes, CBDAs-like from Morus notabilis matched closely to CsCBDAs and CsTHCAs. When amino acid sequences of CsTHCAs, CsCBDAs and MnCBDAs-like were compared to each other, and to the motif database stored in Expasy, all three proteins contained the FAD_PCMH (PCMH-type FAD-binding) domain indicating the conservation of this domain in cannabinoid synthases. Apart from FAD binding, Berberine Bridge Enzyme (BBE-likes), which catalyzes the synthesis of isoquinoline alkaloids in many plants such as mulberry, poplas and citrus, were the other most closely related enzymes to CsTHCAs and CsCBDAs. We also searched for THCAs and CBDAs in fungal and bacterial kingdom but could not find any notably similar sequence. However, partial mRNA from FAD binding enzyme from Trametes versicolor and 6-hydroxy D nicotine oxidase from Aspergillus saccharolyticus matched the CsTHCA sequence and a partial mRNA from a hypothetical protein in Pneumocystis carinii was the most closely matched fungal enzyme to the CsCBDA. Our database search showed that Morus notabilis from mulberry family could be the candidate plant for further studies. Comparative transcriptomic and metabolomic studies for mulberry and Cannabis plants could provide a much clear concepts on the co-evolution of these syanthases. Moreover, the understanding of cannabinoid synthesis pathway is still evolving, in-depth bioinformatics and functional analysis of the enzymes involved are required for pharmaceutical research and industrial advancement.

Lipidome Evolution in Mammalian Tissues

Lipids are essential structural and functional components of cells. Little is known, however, about the evolution of lipid composition in different tissues. Here, we report a large-scale analysis of the lipidome evolution in six tissues of 32 species representing primates, rodents, and bats. While changes in genes’ sequence and expression accumulate proportionally to the phylogenetic distances, <2% of the lipidome evolves this way. Yet, lipids constituting this 2% cluster in specific functions shared among all tissues. Among species, human show the largest amount of species-specific lipidome differences. Many of the uniquely human lipidome features localize in the brain cortex and cluster in specific pathways implicated in cognitive disorders.

Magel2 Modulates Bone Remodeling and Mass in Prader-Willi Syndrome by Affecting Oleoyl Serine Levels and Activity

Among a multitude of hormonal and metabolic complications, individuals with Prader-Willi syndrome (PWS) exhibit significant bone abnormalities, including decreased BMD, osteoporosis, and subsequent increased fracture risk. Here we show in mice that loss of Magel2, a maternally imprinted gene in the PWS critical region, results in reduced bone mass, density, and strength, corresponding to that observed in humans with PWS, as well as in individuals suffering from Schaaf-Yang syndrome (SYS), a genetic disorder caused by a disruption of the MAGEL2 gene. The low bone mass phenotype in Magel2^-/- mice was attributed to reduced bone formation rate, increased osteoclastogenesis and osteoclast activity, and enhanced trans-differentiation of osteoblasts to adipocytes. The absence of Magel2 in humans and mice resulted in reduction in the fatty acid amide bone homeostasis regulator, N-oleoyl serine (OS), whose levels were positively linked with BMD in humans and mice as well as osteoblast activity. Attenuating the skeletal abnormalities in Magel2^-/- mice was achieved with chronic administration of a novel synthetic derivative of OS. Taken together, Magel2 plays a key role in modulating bone remodeling and mass in PWS by affecting OS levels and activity. The use of potent synthetic analogs of OS should be further tested clinically as bone therapeutics for treating bone loss. © 2018 American Society for Bone and Mineral Research.

Cannabinoid pharmacology and therapy in gut disorders

Cannabis sp. and their products (marijuana, hashish…), in addition to their recreational, industrial and other uses, have a long history for their use as a remedy for symptoms related with gastrointestinal diseases. After many reports suggesting these beneficial effects, it was not surprising to discover that the gastrointestinal tract expresses endogenous cannabinoids, their receptors, and enzymes for their synthesis and degradation, comprising the so-called endocannabinoid system. This system participates in the control of tissue homeostasis and important intestinal functions like motor and sensory activity, nausea, emesis, the maintenance of the epithelial barrier integrity, and the correct cellular microenvironment. Thus, different cannabinoid-related pharmacological agents may be useful to treat the main digestive pathologies. To name a few examples, in irritable bowel syndrome they may normalize dysmotility and reduce pain, in inflammatory bowel disease they may decrease inflammation, and in colorectal cancer, apart from alleviating some symptoms, they may play a role in the regulation of the cell niche. This review summarizes the main recent findings on the role of cannabinoid receptors, their synthetic or natural ligands and their metabolizing enzymes in normal gastrointestinal function and in disorders including irritable bowel syndrome, inflammatory bowel disease, colon cancer and gastrointestinal chemotherapy-induced adverse effects (nausea/vomiting, constipation, diarrhea).

Study of sample preparation for determination of endocannabinoids and analogous compounds in human serum by LC-MS/MS in MRM mode

Endocannabinoids are lipids with a key role in physiological processes such as the immune response or the metabolism. This involvement explains their association to pathologies such as cancer, obesity or multiple sclerosis. The determination of endocannabinoids constitutes a challenge for clinical laboratories due to the variety of biological matrices and the wide range of concentrations at which they can be found. This research deals with the comparison of three sample preparation strategies (viz., on-line SPE, off-line SPE for interferents removal, and protein precipitation) for subsequent LC-MS/MS analysis of 14 endocannabinoids and analogous compounds in serum. As a result, the on-line coupling between SPE and LC-MS/MS is proposed as the best approach for this determination. The proposed method allows full automation of the overall process, shortening of the analysis time, and avoidance of errors associated with sample preparation steps. The improvement in sensitivity and selectivity thus achieved allows obtaining quantification limits at the pg mL^-1 level, which makes possible the application of the method for clinical studies.

Δ9-Tetrahydrocannabinol induces endocannabinoid accumulation in mouse hepatocytes: antagonism by Fabp1 gene ablation

Phytocannabinoids, such as Δ9-tetrahydrocannabinol (THC), bind and activate cannabinoid (CB) receptors, thereby "piggy-backing" on the same pathway's endogenous endocannabinoids (ECs). The recent discovery that liver fatty acid binding protein-1 (FABP1) is the major cytosolic "chaperone" protein with high affinity for both Δ9-THC and ECs suggests that Δ9-THC may alter hepatic EC levels. Therefore, the impact of Δ9-THC or EC treatment on the levels of endogenous ECs, such as N-arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), was examined in cultured primary mouse hepatocytes from WT and Fabp1 gene-ablated (LKO) mice. Δ9-THC alone or 2-AG alone significantly increased AEA and especially 2-AG levels in WT hepatocytes. LKO alone markedly increased AEA and 2-AG levels. However, LKO blocked/diminished the ability of Δ9-THC to further increase both AEA and 2-AG. In contrast, LKO potentiated the ability of exogenous 2-AG to increase the hepatocyte level of AEA and 2-AG. These and other data suggest that Δ9-THC increases hepatocyte EC levels, at least in part, by upregulating endogenous AEA and 2-AG levels. This may arise from Δ9-THC competing with AEA and 2-AG binding to FABP1, thereby decreasing targeting of bound AEA and 2-AG to the degradative enzymes, fatty acid amide hydrolase and monoacylglyceride lipase, to decrease hydrolysis within hepatocytes.

AM404, paracetamol metabolite, prevents prostaglandin synthesis in activated microglia by inhibiting COX activity

Background

N-arachidonoylphenolamine (AM404), a paracetamol metabolite, is a potent agonist of the transient receptor potential vanilloid type 1 (TRPV1) and low-affinity ligand of the cannabinoid receptor type 1 (CB1). There is evidence that AM404 exerts its pharmacological effects in immune cells. However, the effect of AM404 on the production of inflammatory mediators of the arachidonic acid pathway in activated microglia is still not fully elucidated.

Method

In the present study, we investigated the effects of AM404 on the eicosanoid production induced by lipopolysaccharide (LPS) in organotypic hippocampal slices culture (OHSC) and primary microglia cultures using Western blot, immunohistochemistry, and ELISA.

Results

Our results show that AM404 inhibited LPS-mediated prostaglandin E₂ (PGE₂) production in OHSC, and LPS-stimulated PGE₂ release was totally abolished in OHSC if microglial cells were removed. In primary microglia cultures, AM404 led to a significant dose-dependent decrease in the release of PGE₂, independent of TRPV1 or CB1 receptors. Moreover, AM404 also inhibited the production of PGD₂ and the formation of reactive oxygen species (8-iso-PGF₂ alpha) with a reversible reduction of COX-1- and COX-2 activity. Also, it slightly decreased the levels of LPS-induced COX-2 protein, although no effect was observed on LPS-induced mPGES-1 protein synthesis.

Conclusions

This study provides new significant insights about the potential anti-inflammatory role of AM404 and new mechanisms of action of paracetamol on the modulation of prostaglandin production by activated microglia.

Electronic supplementary material

The online version of this article (10.1186/s12974-017-1014-3) contains supplementary material, which is available to authorized users.

Lipid and Carbohydrate Metabolism in Caenorhabditis elegans

Lipid and carbohydrate metabolism are highly conserved processes that affect nearly all aspects of organismal biology. Caenorhabditis elegans eat bacteria, which consist of lipids, carbohydrates, and proteins that are broken down during digestion into fatty acids, simple sugars, and amino acid precursors. With these nutrients, C. elegans synthesizes a wide range of metabolites that are required for development and behavior. In this review, we outline lipid and carbohydrate structures as well as biosynthesis and breakdown pathways that have been characterized in C. elegans We bring attention to functional studies using mutant strains that reveal physiological roles for specific lipids and carbohydrates during development, aging, and adaptation to changing environmental conditions.

FABP-1 gene ablation impacts brain endocannabinoid system in male mice

Liver fatty acid-binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid-binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as oleoyl ethanolamide (OEA), PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* as a result of compensatory up-regulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid-binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids. Fatty acid-binding protein-1 (FABP-1) is not detectable in brain but instead is highly expressed in liver. The possibility that FABP1 outside the central nervous system may regulate brain endocannabinoids arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG) was examined in wild-type (WT) and FABP-1 null (LKO) male mice. LKO increased brain levels of arachidonic acid-containing endocannabinoids (AEA, 2-AG), correlating with increased free and total arachidonic acid in brain and serum. Read the Editorial Highlight for this article on page 371.

Acute Toxicity Associated with Use of 5F-Derivations of Synthetic Cannabinoid Receptor Agonists with Analytical Confirmation

INTRODUCTION

Synthetic Cannabinoid Receptor Agonists (SCRAs) are the largest group of new psychoactive substances reported to the European Warning System and the United Nations Office on Drugs and Crime to date. The heterogeneous nature and speed of diversification of these compounds make it challenging to accurately characterise and predict harms of these compounds in pre-clinical studies, ahead of their appearance.

CASE REPORT

We report the case of a 19-year-old female who purchased three products from a headshop: two new psychoactive substances (sachets of "cannabis tea" and "mushroom tea") as well as two LSD blotters. After the "cannabis tea" was smoked and the two LSD blotters and "mushroom tea" were ingested, the patient became tachycardic (HR 128), developed seizures, agitation, visual hallucinations as well as suspected serotonergic toxicity (sustained ankle clonus 20-30 beats) 1-2 hours after use. She was treated with 1 mg of intravenous midazolam. Symptoms/signs resolved within 13 hours. No further supportive care was required. Plasma, blood, and urine samples confirmed the presence of two SCRAs: 5FAKB-48 and 5F-PB-22. The patient also reported therapeutic use of both fluoxetine and citalopram for depression.

DISCUSSION

To the best of our knowledge, this is the first case report of non-fatal intoxication with 5F-AKB-48 with analytical confirmation and exposure times. It also highlights the difficulties in understanding the pattern of toxicity of certain SCRAs in the context of psychotropic medications/co-morbid mental illness.

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

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

Metabolic Profile Changes of CCl₄-Liver Fibrosis and Inhibitory Effects of Jiaqi Ganxian Granule

Jiaqi Ganxian Granule (JGG) is a famous traditional Chinese medicine, which has been long used in clinical practice for treating liver fibrosis. However, the mechanism underlying its anti-hepatic fibrosis is still not clear. In this study, an Ultra-Performance Liquid Chromatography-Time-Of-Flight Mass Spectrometry (UPLC-TOF-MS)-based metabolomics strategy was used to profile the metabolic characteristic of serum obtained from a carbon tetrachloride (CCl₄)-induced hepatic fibrosis model in Sprague-Dawley (SD) rats with JGG treatment. Through Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA), it was shown that metabolic perturbations induced by CCl₄ were inhibited after treatment of JGG, for 17 different metabolites related to CCl₄. Among these compounds, the change tendency of eight potential drug targets was restored after the intervention with JGG. The current study indicates that JGG has a significant anti-fibrosis effect on CCl₄-induced liver fibrosis in rats, which might be by regulating the dysfunction of sphingolipid metabolism, glycerophospholipid metabolism, N-acylethanolamine biosynthesis, fat digestion and absorption, while glycerophospholipid metabolism played vital roles in the inhibitory effects of JGG on hepatic fibrosis according to Metabolic Pathway Analysis (MetPA). Our findings indicated that the metabolomics approach may provide a useful tool for exploring potential biomarkers involved in hepatic fibrosis and elucidate the mechanisms underlying the action of therapies used in traditional Chinese medicine.

The Endocannabinoid System in the Postimplantation Period: A Role during Decidualization and Placentation

Although the detrimental effects of cannabis consumption during gestation are known for years, the vast majority of studies established a link between cannabis consumption and foetal development. The complex maternal-foetal interrelationships within the placental bed are essential for normal pregnancy, and decidua definitively contributes to the success of this process. Nevertheless, the molecular signalling network that coordinates strategies for successful decidualization and placentation are not well understood. The discovery of the endocannabinoid system highlighted new signalling mediators in various physiological processes, including reproduction. It is known that endocannabinoids present regulatory functions during blastocyst development, oviductal transport, and implantation. In addition, all the endocannabinoid machinery was found to be expressed in decidual and placental tissues. Additionally, endocannabinoid's plasmatic levels were found to fluctuate during normal gestation and to induce decidual cell death and disturb normal placental development. Moreover, aberrant endocannabinoid signalling during the period of placental development has been associated with pregnancy disorders. It indicates the existence of a possible regulatory role for these molecules during decidualization and placentation processes, which are known to be particularly vulnerable. In this review, the influence of the endocannabinoid system in these critical processes is explored and discussed.

Fish oil and inflammatory status alter the n-3 to n-6 balance of the endocannabinoid and oxylipin metabolomes in mouse plasma and tissues

It is well established that dietary intake of n-3 fatty acids is associated with anti-inflammatory effects, and this has been linked to modulation of the oxylipin and endocannabinoid metabolomes. However, the amount of data on specific tissue effects is limited, and it is not known how inflammation affects this relation. In the present study we systematically explored the combined effects of n-3 fatty acid diets and inflammation on the in vivo endocannabinoid and oxylipin metabolomes using a multicompartment, detailed targeted lipidomics approach. Male C57BL/6 mice received diets containing 0, 1, or 3 % w/w fish oil (FO) for 6 weeks, after which 2 mg/kg LPS or saline was administered i.p. Levels of endocannabinoids/N-acylethanolamines (NAEs) and oxylipins, covering n-3 and n-6 fatty acid derived compounds, were determined in plasma, liver, ileum and adipose tissue using LC-MS/MS. FO generally increased 'n-3' NAEs and oxylipins at the expense of compounds derived from other fatty acids, affecting all branches of the oxylipin metabolome. LPS generally increased levels of endocannabinoids/NAEs and oxylipins, with opposing effects across plasma and tissues. Multivariate data analysis revealed that separation between diet groups in the saline treated groups was primarily explained by decreases in other than n-3 derived compounds. In the LPS treated groups, the separation was primarily explained by increases in n-3 derived compounds. In conclusion, FO caused marked changes in the n-3 to n-6 balance of the endocannabinoid and oxylipin metabolomes, with specific effects depending on inflammatory status. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-012-0421-9) contains supplementary material, which is available to authorized users.

Marine cyanobacterial fatty acid amides acting on cannabinoid receptors

Striking cAMP: certain fatty acid amides from marine cyanobacteria can mimic the endocannabinoids. Serinolamide B, a new analogue identified from a Guamanian sample, and malyngamide B, a representative member of a large class of cyanobacterial metabolites, can decrease forskolin-induced cAMP accumulation through the cannabinoid receptors.

Dual inhibition of MAGL and type II topoisomerase by N-phenylmaleimides as a potential strategy to reduce neuroblastoma cell growth

The endocannabinoid system is implicated in numerous physiopathological processes while more and more pieces of evidence wave the link between this complex machinery and cancer related phenomenon. In these lines, we confirmed the effects of 2-arachidonoylglycerol (2-AG), the main endocannabinoid, on neuroblastoma cells proliferation in vitro, and proved that some N-phenylmaleimide compounds that were previously shown as MAGL inhibitors can also inhibit type 2 topoisomerase. We also shed light on their antiproliferative effects on a neuroblastoma cell line. In order to establish a link between MAGL inhibition, topoisomerase inhibition and the effects on N1E-115 cells, we tested combinations of maleimides or known endocannabinoid metabolism inhibitors and 2-AG, the major MAGL substrate, on N1E-115 cells. However, none of the inhibitors tested, except the carbamate CAY10499, managed to increase 2-AG's effects. Even the MAGL reference inhibitor JZL184 failed to induce a stronger inhibition of proliferation.

The role of cannabinoid receptors and the endocannabinoid system in mantle cell lymphoma and other non-Hodgkin lymphomas

The initiating oncogenic event in mantle cell lymphoma (MCL) is the translocation of cyclin D1, t(11;14)(q13;q32). However, other genetic aberrations are necessary for an overt lymphoma to arise. Like other B cell lymphomas, MCL at some points during the oncogenesis is dependent on interactions with other cells and factors in the microenvironment. The G protein coupled receptors cannabinoid receptors 1 and 2 (CB1 and CB2) are expressed at low levels on non-malignant lymphocytes and at higher levels in MCL and other lymphoma subtypes. In this review we give an overview of what is known on the role of the cannabinoid receptors and their ligands in lymphoma as compared to non-malignant T and B lymphocytes. In MCL cannabinoids mainly reduce cell proliferation and induce cell death. Importantly, our recent findings demonstrate that cannabinoids may induce either apoptosis or another type of programmed cell death, cytoplasmic vacuolation/paraptosis in MCL. The signalling to death has been partly characterized. Even though cannabinoid receptors seem to be expressed in many other types of B cell lymphoma, the functional role of cannabinoid receptor targeting is yet largely unknown. In non-malignant B and T lymphocytes, cannabinoid receptors are up-regulated in response to antigen receptor signalling or CD40. For T lymphocytes IL-4 has also a crucial role in transcriptional regulation of CB1. In lymphocytes, cannabinoid act in several ways - by affecting cell migration, cytokine response, at high doses inhibit cell proliferation and inducing cell death. The possible role for the endocannabinoid system in the immune microenvironment of lymphoma is discussed.

Decoding functional metabolomics with docosahexaenoyl ethanolamide (DHEA) identifies novel bioactive signals

Neuroinflammation and traumatic brain injury involve activation of inflammatory cells and production of local pro-inflammatory mediators that can amplify tissue damage. Using LC-UV-MS-MS-based lipidomics in tandem with functional screening at the single-cell level in microfluidic chambers, we identified a series of novel bioactive oxygenated docosahexaenoyl ethanolamide- (DHEA) derived products that regulated leukocyte motility. These included 10,17-dihydroxydocosahexaenoyl ethanolamide (10,17-diHDHEA) and 15-hydroxy-16(17)-epoxy-docosapentaenoyl ethanolamide (15-HEDPEA), each of which was an agonist of recombinant CB2 receptors with EC(50) 3.9 × 10(-10) and 1.0 × 10(-10) M. In human whole blood, 10,17-diHDHEA and 15-HEDPEA at concentrations as low as 10 pM each prevented formation of platelet-leukocyte aggregates involving either platelet-monocyte or platelet-polymorphonuclear leukocyte. In vivo, 15-HEDPEA was organ-protective in mouse reperfusion second organ injury. Together these results indicate that DHEA oxidative metabolism produces potent novel molecules with anti-inflammatory and organ-protective properties.

Cancer cachexia: traditional therapies and novel molecular mechanism-based approaches to treatment

The complex syndrome of cancer cachexia (CC) that occurs in 50% to 80% cancer patients has been identified as an independent predictor of shorter survival and increased risk of treatment failure and toxicity, contributing to the mortality and morbidity in this population. CC is a pathological state including a symptom cluster of loss of muscle (skeletal and visceral) and fat, manifested in the cardinal feature of emaciation, weakness affecting functional status, impaired immune system, and metabolic dysfunction. The most prominent feature of CC is its non-responsiveness to traditional treatment approaches; randomized clinical trials with appetite stimulants, 5-HT3 antagonists, nutrient supplementation, and Cox-2 inhibitors all have failed to demonstrate success in reversing the metabolic abnormalities seen in CC. Interventions based on a clear understanding of the mechanism of CC, using validated markers relevant to the underlying metabolic abnormalities implicated in CC are much needed. Although the etiopathogenesis of CC is poorly understood, studies have proposed that NFkB is upregulated in CC, modulating immune and inflammatory responses induce the cellular breakdown of muscle, resulting in sarcopenia. Several recent laboratory studies have shown that n-3 fatty acid may attenuate protein degradation, potentially by preventing NFkB accumulation in the nucleus, preventing the degradation of muscle proteins. However, clinical trials to date have produced mixed results potentially attributed to timing of interventions (end stage) and utilizing outcome markers such as weight which is confounded by hydration, cytotoxic therapies, and serum cytokines. We propose that selective targeting of proteasome activity with a standardized dose of omega-3-acid ethyl esters, administered to cancer patients diagnosed with early stage CC, in addition to a standard intervention with nutritionally adequate diet and appetite stimulants, will alter metabolic abnormalities by downregulating NFkB, preventing the breakdown of myofibrillar proteins and resulting in increasing serum protein markers, lean body mass, and functional status.

Endocannabinoids and Human Sperm Cells

N-acylethanolamides (NAEs) are naturally occurring signaling lipids consisting of amides and esters of long-chain polyunsaturated fatty acids. Usually they are present in a very small amounts in many mammalian tissues and cells, including human reproductive tracts and fluids. Recently, the presence of N-arachidonoylethanolamide (anandamide, AEA), the most characterised member of endocannabinoids, and its congeners palmitoylethanolamide (PEA) and oleylethanolamide (OEA) in seminal plasma, oviductal fluid, and follicular fluids was demonstrated. AEA has been shown to bind not only type-1 (CB1) and type-2 (CB2) cannabinoid receptors, but also type-1 vanilloid receptor (TRPV1), while PEA and OEA are inactive with respect to classical cannabinoid CB1 and CB2 but activate TRPV1 or peroxisome proliferator activate receptors (PPARs). This review concerns the most recent experimental data on PEA and OEA, endocannabinoid-like molecules which appear to exert their action exclusively on sperm cells with altered features, such as membrane characteristics and kinematic parameters. Their beneficial effects on these cells could suggest a possible pharmacological use of PEA and OEA on patients affected by some forms of idiopathic infertility.

N-acylethanolamine levels and expression of their metabolizing enzymes during pregnancy

Decidualization is essential for a successful pregnancy and is a tightly regulated process influenced by the local microenvironment. Lipid-based mediators, such as the endocannabinoid anandamide, and other compounds that have cannabimimetic actions may act on the decidua during early pregnancy. In this study, the levels of N-arachidonoylethanolamine (anandamide) and two other N-acylethanolamines, N-oleoylethanolamine and N-palmitoylethanolamine, were measured in rat plasma and maternal tissues between d 8 and 19 of pregnancy by ultraperformance liquid chromatography tandem mass spectrometry. The spatiotemporal expression of N-acylethanolamine metabolizing enzymes in implantation units were also determined by quantitative PCR, Western blot, and immunohistochemistry and shown to vary with gestation being mainly localized in decidual cells. The data also indicated that plasma and tissues levels of all three N-acylethanolamines fluctuate throughout pregnancy. Tissue levels of endocannabinoids did not correlate with plasma, suggesting that during pregnancy, maternal tissue levels of endocannabinoids are primarily regulated by in situ production and degradation to create endocannabinoid gradients conducive to successful pregnancy.

Endogenous N-acyl-dopamines induce COX-2 expression in brain endothelial cells by stabilizing mRNA through a p38 dependent pathway

Cerebral microvascular endothelial cells play an active role in maintaining cerebral blood flow, microvascular tone and blood brain barrier (BBB) functions. Endogenous N-acyl-dopamines like N-arachidonoyl-dopamine (NADA) and N-oleoyl-dopamine (OLDA) have been recently identified as a new class of brain neurotransmitters sharing endocannabinoid and endovanilloid biological activities. Endocannabinoids are released in response to pathogenic insults and may play an important role in neuroprotection. In this study we demonstrate that NADA differentially regulates the release of PGE(2) and PGD(2) in the microvascular brain endothelial cell line, b.end5. We found that NADA activates a redox-sensitive p38 MAPK pathway that stabilizes COX-2 mRNA resulting in the accumulation of the COX-2 protein, which depends on the dopamine moiety of the molecule and that is independent of CB(1) and TRPV1 activation. In addition, NADA inhibits the expression of mPGES-1 and the release of PGE(2) and upregulates the expression of L-PGD synthase enhancing PGD(2) release. Hence, NADA and other molecules of the same family might be included in the group of lipid mediators that could prevent the BBB injury under inflammatory conditions and our findings provide new mechanistic insights into the anti-inflammatory activities of NADA in the central nervous system and its potential to design novel therapeutic strategies to manage neuroinflammatory diseases.

Discovery and characterization of an Arabidopsis thaliana N-acylphosphatidylethanolamine synthase

N-Acylethanolamines (NAEs) are lipids involved in several physiological processes in animal and plant cells. In brain, NAEs are ligands of endocannabinoid receptors, which modulate various signaling pathways. In plant, NAEs regulate seed germination and root development, and they are involved in plant defense against pathogen attack. This signaling activity is started by an enzyme called N-acylphosphatidylethanolamine (NAPE) synthase. This catalyzes the N-acylation of phosphatidylethanolamine to form NAPE, which is most likely hydrolyzed by phospholipase D beta/gamma isoforms to generate NAE. This compound is further catabolized by fatty amide hydrolase. The genes encoding the enzymes involved in NAE metabolism are well characterized except for the NAPE synthase gene(s). By heterologous expression in Escherichia coli and overexpression in plants, we characterized an acyltransferase from Arabidopsis thaliana (At1g78690p) catalyzing the synthesis of lipids identified as NAPEs (two-dimensional TLC, phospholipase D hydrolysis assay, and electrospray ionization-tandem mass spectrometry analyses). The ability of free fatty acid and acyl-CoA to be used as acyl donor was compared in vitro with E. coli membranes and purified enzyme (obtained by immobilized metal ion affinity chromatography). In both cases, NAPE was synthesized only in the presence of acyl-CoA. beta-Glucuronidase promoter experiments revealed a strong expression in roots and young tissues of plants. Using yellow fluorescent protein fusion, we showed that the NAPE synthase is located in the plasmalemma of plant cells.

Development and validation of a quantitative method for the determination of 12 endocannabinoids and related compounds in human plasma using liquid chromatography-tandem mass spectrometry

A sensitive and specific LC-MS/MS method for the quantification of the endocannabinoids and related structures anandamide, 2-arachidonoyl glycerol, 2-arachidonyl glycerol ether, O-arachidonoyl ethanolamide, dihomo-gamma-linolenoyl ethanolamide, docosatetraenoyl ethanolamide, N-arachidonoyl dopamine, N-arachidonyl glycine, N-oleoyl dopamine, oleoyl ethanolamide, palmitoyl ethanolamide, and stearoyl ethanolamide in human plasma was developed and validated. Compounds were extracted using acetonitrile followed by solid-phase extraction. Separation was performed on a Xterra C8 column using gradient elution coupled to a triple-quadrupole MS. LLOQ levels ranged from 0.02 to 1.75 microg/mL, LODs ranged from 0.0002 to 0.1266 ng/mL, and accuracies were >80% (except stearoyl ethanolamide at lowest spike level) at all spike levels.

Cannabinoids, endocannabinoids, and related analogs in inflammation

This review covers reports published in the last 5 years on the anti-inflammatory activities of all classes of cannabinoids, including phytocannabinoids such as tetrahydrocannabinol and cannabidiol, synthetic analogs such as ajulemic acid and nabilone, the endogenous cannabinoids anandamide and related compounds, namely, the elmiric acids, and finally, noncannabinoid components of Cannabis that show anti-inflammatory action. It is intended to be an update on the topic of the involvement of cannabinoids in the process of inflammation. A possible mechanism for these actions is suggested involving increased production of eicosanoids that promote the resolution of inflammation. This differentiates these cannabinoids from cyclooxygenase-2 inhibitors that suppress the synthesis of eicosanoids that promote the induction of the inflammatory process.

Mass-spectrometric identification of anandamide and 2-arachidonoylglycerol in nematodes

The purpose of the study was to see if nematodes (Caenorhabditis elegans, Caenorhabditis briggsae, and Pelodera strongyloides) produce endocannabinoids; i.e., anandamide (AEA) and 2-arachidonoylglycerol (2-AG). In this study, AEA and 2-AG were identified as endogenous products from nematodes by using electrospray-ionization ion-trap MS/MS (ESI-IT-MS) experiments operated in the positive-ionization mode. Endocannabinoids were identified by product ion scan and concentrations were measured by triple quadrupole mass spectrometry in the multiple reaction monitoring mode (MRM). Both AEA and 2-AG were identified in all of the nematode samples, even though these species lack known cannabinoid receptors. Neither AEA nor 2-AG were detected in the fat-3 mutant of C. elegans, which lacks the necessary enzyme to produce arachidonic acid, the fatty acid precursor of these endocannabinoids.

Roles of Eicosanoids in Prostate Cancer

Eicosanoids, the metabolites of arachidonic acid, have diverse functions in the regulation of cancer including prostate cancer. This review will provide an overview of the roles of eicosanoids and endocannabinoids and their potential as therapeutic targets for prostate cancer treatment.