Endocannabinoid biosynthetic enzymes regulate pain response via LKB1-AMPK signaling.

Diacylglycerol lipase-beta (DAGLß) serves as a principal 2-arachidonoylglycerol (2-AG) biosynthetic enzyme regulating endocannabinoid and eicosanoid metabolism in immune cells including macrophages and dendritic cells. Genetic or pharmacological inactivation of DAGLß ameliorates inflammation and hyper-nociception in preclinical models of pathogenic pain. These beneficial effects have been assigned principally to reductions in downstream proinflammatory lipid signaling, leaving alternative mechanisms of regulation largely underexplored. Here, we apply quantitative chemical- and phospho-proteomics to find that disruption of DAGLß in primary macrophages leads to LKB1-AMPK signaling activation, resulting in reprogramming of the phosphoproteome and bioenergetics. Notably, AMPK inhibition reversed the antinociceptive effects of DAGLß blockade, thereby directly supporting DAGLß-AMPK crosstalk in vivo. Our findings uncover signaling between endocannabinoid biosynthetic enzymes and ancient energy-sensing kinases to mediate cell biological and pain responses.

Striatonigral direct pathway 2-arachidonoylglycerol contributes to ethanol effects on synaptic transmission and behavior.

Endocannabinoids (eCB) and cannabinoid receptor 1 (CB1) play important roles in mediating short- and long-term synaptic plasticity in many brain regions involved in learning and memory, as well as the reinforcing effects of misused substances. Ethanol-induced plasticity and neuroadaptations predominantly occur in striatal direct pathway projecting medium spiny neurons (dMSNs). It is hypothesized that alterations in eCB neuromodulation may be involved. Recent work has implicated a role of eCB 2-arachidonoylglycerol (2-AG) in the rewarding effects of ethanol. However, there is insufficient research to answer which cellular subtype is responsible for mediating the 2-AG eCB signal that might be involved in the rewarding properties of ethanol and the mechanisms by which that occurs. To examine the role of dMSN mediated 2-AG signaling in ethanol related synaptic transmission and behaviors, we used conditional knockout mice in which the 2-AG-synthesizing enzyme diacylglycerol lipase α (DGLα) was deleted in dMSNs, DGLαD1-Cre+. Using acute brain slice photometry and a genetically encoded fluorescent eCB sensor, GRABeCB2.0, to assess real-time eCB mediated activity of sensorimotor inputs from primary motor cortices (M1/M2) to the dorsolateral striatum, we showed that DGLαD1-Cre+ mice had blunted evoked eCB-mediated presynaptic eCB signaling compared to littermate controls. Furthermore, ethanol induced eCB inhibition was significantly reduced in DGLαD1-Cre+ deficient mice. Additionally, there was a reduction in the duration of loss of righting reflex (LORR) to a high dose of ethanol in the DGLαD1-Cre+ mice compared to controls. These mice also showed a male-specific decrease in ethanol preference accompanied by an increase in ethanol-induced water consumption in a voluntary drinking paradigm. There were no significant differences observed in sucrose and quinine consumption between the genotypes. These findings reveal a novel role for dMSN mediated 2-AG signaling in modulating ethanol effects on presynaptic function and behavior.

Beneficial effects of Lactobacillus rhamnosus hsryfm 1301 fermented milk on rats with nonalcoholic fatty liver disease.

A growing stream of research suggests that probiotic fermented milk has a good effect on nonalcoholic fatty liver disease. This work aimed to study the beneficial effects of Lactobacillus rhamnosus hsryfm 1301 fermented milk (fermented milk) on rats with nonalcoholic fatty liver disease induced by a high-fat diet. The results showed that the body weight and the serum levels of total cholesterol, total glyceride, low-density lipoprotein, alanine transaminase, aspartate aminotransferase, free fatty acid, and reactive oxygen species were significantly increased in rats fed a high-fat diet (M) for 8 wk, whereas high-density lipoprotein cholesterol and superoxide dismutase were significantly decreased. However, the body weight and the serum levels of total cholesterol, total glyceride, alanine transaminase, aspartate aminotransferase, free fatty acid, reactive oxygen species, interleukin-8, tumor necrosis factor-α, and interleukin-6 were significantly decreased with fermented milk (T) for 8 wk, and the number of fat vacuoles in hepatocytes was lower than that in the M group. There were significant differences in 19 metabolites in serum between the M group and the C group (administration of nonfermented milk) and in 17 metabolites between the T group and the M group. The contents of 7 different metabolites, glycine, glycerophosphocholine, 1,2-dioleoyl-sn-glycero-3-phosphocholine, thioetheramide-PC, d-aspartic acid, oleic acid, and l-glutamate, were significantly increased in the M group rat serum, and l-palmitoyl carnitine, N6-methyl-l-lysine, thymine, and 2-oxadipic acid were significantly decreased. In the T group rat serum, the contents of 8 different metabolites-1-O-(cis-9-octadecenyl)-2-O-acetyl-sn-glycero-3-phosphocholine, acetylcarnitine, glycine, glycerophosphocholine, 1,2-dioleoyl-sn-glycero-3-phosphocholine, d-aspartic acid, oleic acid, and l-glutamate were significantly decreased, whereas creatinine and thymine were significantly increased. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that 50 metabolic pathways were enriched in the M/C group and T/M group rat serum, of which 12 metabolic pathways were significantly different, mainly distributed in lipid metabolism, amino acid, and endocrine system metabolic pathways. Fermented milk ameliorated inflammation, oxygenation, and hepatocyte injury by regulating lipid metabolism, amino acid metabolic pathways, and related metabolites in the serum of rats with nonalcoholic fatty liver disease.

Radiometric Assay of ABHD2 Activity.

The α,ß-hydrolase fold-containing protein 2 (ABHD2) is a serine hydrolase, responsible for the cleavage of endogenous 2-arachidonoylglycerol (2-AG). ABHD2 is activated by progesterone, thus, it is considered a nonnuclear receptor of this steroid hormone that terminates its biological effects. The products of ABHD2-catalyzed cleavage by the natural substrate 2-AG are glycerol and arachidonic acid; here, instead of 2-AG, the radioactive substrate 2-oleoyl-[3H]glycerol has been used as already done in various acylglycerol lipase activity assays. The amount of [3H]glycerol released allows to measure ABHD2 enzymatic activity.

Small Intestine-specific Knockout of CIDEC Improves Obesity and Hepatic Steatosis by Inhibiting Synthesis of Phosphatidic Acid.

The small intestine is main site of exogenous lipid digestion and absorption, and it is important for lipid metabolic homeostasis. Cell death-inducing DNA fragmentation-factor like effector C (CIDEC) is active in lipid metabolism in tissues other than those in the intestine. We developed small intestine-specific CIDEC (SI-CIDEC-/-) knockout C57BL/6J mice by Cre/LoxP recombination to investigate the in vivo effects of intestinal CIDEC on lipid metabolism. Eight-week-old SI-CIDEC-/- mice fed a high-fat diet for 14 weeks had 15% lower body weight, 30% less body fat mass, and 79% lower liver triglycerides (TG) than wild-type (WT) mice. In addition, hepatic steatosis and fatty liver inflammation were less severe in knockout mice fed a high-fat diet (HFD) compared with wild-type mice fed an HFD. SI-CIDEC-/- mice fed an HFD diet had lower serum TG and higher fecal TG and intestinal lipase activity than wild-type mice. Mechanistic studies showed that CIDEC accelerated phosphatidic acid synthesis by interacting with 1-acylglycerol-3-phosphate-O-acyltransferase to promote TG accumulation. This study identified a new interacting protein and previously unreported CIDEC mechanisms that revealed its activity in lipid metabolism of the small intestine.

Inhibitory Effect of Bacterial Lysates Extracted from Pediococcus acidilactici on the Differentiation of 3T3-L1 Pre-Adipocytes.

Postbiotics, including bacterial lysates, are considered alternatives to probiotics. The aim of the current study was to investigate the effect of bacterial lysates (BLs) extracted from Pediococcus acidilactici K10 (K10 BL) and P. acidilactici HW01 (HW01 BL) on the differentiation of 3T3-L1 pre-adipocytes. Both K10 and HW01 BLs significantly reduced the accumulation of lipid droplets and the amounts of cellular glycerides in 3T3-L1 cells (p < 0.05). However, another postbiotic molecule, peptidoglycan of P. acidilactici K10 and P. acidilactici HW01, moderately inhibited the accumulation of lipid droplets, whereas heat-killed P. acidilactici did not effectively inhibit the lipid accumulation. The mRNA and protein levels of the transcription factors, peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α, responsible for the differentiation of 3T3-L1 cells, were significantly inhibited by K10 BL and HW01 BL (p < 0.05). Both K10 and HW01 BLs decreased adipocyte-related molecules, adipocyte fatty acid-binding protein and lipoprotein lipase, at the mRNA and protein levels. Furthermore, both K10 and HW01 BLs also downregulated the mRNA expression of leptin, but not resistin. Taken together, these results suggest that P. acidilactici BLs mediate anti-adipogenic effects by inhibiting adipogenic-related transcription factors and their target molecules.

Biosynthesis and metabolism of endocannabinoids and their congeners from the monoacylglycerol and N-acyl-ethanolamine families.

The endocannabinoids 2-arachidonoyl-glycerol (2-AG) and N-arachidonoyl-ethanolamine (AEA) are eicosanoids implicated in numerous physiological processes like appetite, adipogenesis, inflammatory pain and inflammation. They mediate most of their physiological effects by activating the cannabinoid (CB) receptors 1 and 2. Other than directly binding to the CB receptors, 2-AG and AEA are also metabolized by most eicosanoid biosynthetic enzymes, yielding many metabolites that are part of the oxyendocannabinoidome. Some of these metabolites have been found in vivo, have the ability to modulate specific receptors and thus potentially influence physiological processes. In this review, we discuss the biosynthesis and metabolism of 2-AG and AEA, as well as their congeners from the monoacyl-glycerol and N-acyl-ethanolamine families, with a special focus on the metabolism by oxygenases involved in arachidonic acid metabolism. We highlight the knowledge gaps in our understanding of the regulation and roles the oxyendocannabinoidome mediators.

Angiotensin II induces podocyte metabolic reprogramming from glycolysis to glycerol-3-phosphate biosynthesis.

Recent studies have reported that Angiotensin II (Ang II) contributes to podocyte injury by interfering with metabolism. Glycolysis is essential for podocytes and glycolysis abnormality is associated with glomerular injury in chronic kidney disease (CKD). Glycerol-3-phosphate (G-3-P) biosynthesis is a shunt pathway of glycolysis, in which cytosolic glycerol-3-phosphate dehydrogenase 1 (GPD1) catalyzes dihydroxyacetone phosphate (DHAP) to generate G-3-P in the presence of the NADH. G-3-P is not only a substrate in glycerophospholipids and glyceride synthesis but also can be oxidated by mitochondrial glycerol-3-phosphate dehydrogenase (GPD2) to regenerate DHAP in mitochondria. Since G-3-P biosynthesis links to glycolysis, mitochondrial metabolism and lipid synthesis, we speculate G-3-P biosynthesis abnormality is probably involved in podocyte injury. In this study, we demonstrated that Ang II upregulated GPD1 expression and increased G-3-P and glycerophospholipid syntheses in podocytes. GPD1 knockdown protected podocytes from Ang II-induced lipid accumulation and mitochondrial dysfunction. GPD1 overexpression exacerbated Ang II-induced podocyte injury. In addition, we proved that lipid accumulation and mitochondrial dysfunction were correlated with G-3-P content in podocytes. These results suggest that Ang II upregulates GPD1 and promotes G-3-P biosynthesis in podocytes, which promote lipid accumulation and mitochondrial dysfunction in podocytes.

Human and Mouse Eosinophils Differ in Their Ability to Biosynthesize Eicosanoids, Docosanoids, the Endocannabinoid 2-Arachidonoyl-glycerol and Its Congeners.

High eosinophil (EOS) counts are a key feature of eosinophilic asthma. EOS notably affect asthmatic response by generating several lipid mediators. Mice have been utilized in hopes of defining new pharmacological targets to treat asthma. However, many pinpointed targets in mice did not translate into clinics, underscoring that key differences exist between the two species. In this study, we compared the ability of human (h) and mouse (m) EOS to biosynthesize key bioactive lipids derived from arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). hEOS were isolated from the blood of healthy subjects and mild asthmatics, while mEOSs were differentiated from the bone marrow. EOSs were treated with fatty acids and lipid mediator biosynthesis assessed by LC-MS/MS. We found that hEOS biosynthesized leukotriene (LT) C4 and LTB4 in a 5:1 ratio while mEOS almost exclusively biosynthesized LTB4. The biosynthesis of the 15-lipoxygenase (LO) metabolites 15-HETE and 12-HETE also differed, with a 15-HETE:12-HETE ratio of 6.3 for hEOS and 0.727 for mEOS. EOS biosynthesized some specialized pro-resolving mediators, and the levels from mEOS were 9-times higher than those of hEOS. In contrast, hEOS produced important amounts of the endocannabinoid 2-arachidonoyl-glycerol (2-AG) and its congeners from EPA and DHA, a biosynthetic pathway that was up to ~100-fold less prominent in mEOS. Our data show that hEOS and mEOS biosynthesize the same lipid mediators but in different amounts. Compared to asthmatics, mouse models likely have an amplified involvement of LTB4 and specialized pro-resolving mediators and a diminished impact of the endocannabinoid 2-arachidonoyl-glycerol and its congeners.

1-, 2- and 3-AG as substrates of the endocannabinoid enzymes and endogenous ligands of the cannabinoid receptor 1.

2-Arachidonoylglycerol (2-AG) is the most potent and abundant endocannabinoid that acts as a full agonist at the cannabinoid 1 (CB1) and 2 (CB2) receptors. It serves as a substrate for several serine hydrolases, including monoacylglycerol lipase (MGL), α/ß hydrolase domain 6 (ABHD6) and fatty acid amide hydrolase (FAAH). However, 2-AG's rapid conversion to 1-AG (the S stereoisomer) and 3-AG (the R stereoisomer) complicates in vivo signaling. Here, we present the interaction profiles of 2-AG and its isomerization products, 1- and 3-AG, with the endocannabinoid MGL, ABHD6 and FAAH enzymes as well as the CB1 receptor. The 1- and 3-AG enantiomers are less prone to isomerization, and their affinities to endocannabinoid enzymes and potencies at CB1 receptor are quite different compared to 2-AG. Although MGL is the principal hydrolytic enzyme of 2-AG, 3-AG (the R isomer) appears to be the best substrate for hMGL. Contrarily, 1-AG (the S isomer) demonstrates the worst substrate profile, indicating that the stereochemistry of 1(3)-monoacylglycerols is very important for MGL enzyme. On the other hand, both 1- and 3-AG (the sn1 monoacylglycerols) are efficiently hydrolyzed by hABHD6 without preference, while 2-AG (the sn2 monoacylglycerol) has the lowest rate of hydrolysis. FAAH, the principal hydrolytic enzyme for arachidonoylethanolamide (anandamide, AEA), catalyzes the hydrolysis of all three isomers with similar efficiencies. In a functional cAMP assay at CB1 receptor, all three isomers behaved as agonists, with 2-AG being the most potent, followed by 3-AG then 1-AG. The presented data provides stereochemical insights to design chemically stable AG analogs with preferential stability against enzymes of interest.

Neuropsychopharmacological profiling of scoparone in mice.

Scoparone (6,7-dimethoxycoumarin) is a simple coumarin from botanical drugs of Artemisia species used in Traditional Chinese Medicine and Génépi liquor. However, its bioavailability to the brain and potential central effects remain unexplored. We profiled the neuropharmacological effects of scoparone upon acute and subchronic intraperitoneal administration (2.5-25 mg/kg) in Swiss mice and determined its brain concentrations and its effects on the endocannabinoid system (ECS) and related lipids using LC-ESI-MS/MS. Scoparone showed no effect in the forced swimming test (FST) but, administered acutely, led to a bell-shaped anxiogenic-like behavior in the elevated plus-maze test and bell-shaped procognitive effects in the passive avoidance test when given subchronically and acutely. Scoparone rapidly but moderately accumulated in the brain (Cmax < 15 min) with an apparent first-order elimination (95% eliminated at 1 h). Acute scoparone administration (5 mg/kg) significantly increased brain arachidonic acid, prostaglandins, and N-acylethanolamines (NAEs) in the FST. Conversely, subchronic scoparone treatment (2.5 mg/kg) decreased NAEs and increased 2-arachidonoylglycerol. Scoparone differentially impacted ECS lipid remodeling in the brain independent of serine hydrolase modulation. Overall, the unexpectedly potent central effects of scoparone observed in mice could have toxicopharmacological implications for humans.

Butyric acid glycerides in the diet of broilers to replace conventional growth promoters: effects on performance, metabolism, and intestinal health.

This study aimed to determine whether butyric acid glycerides can replace conventional growth promoters, favour intestinal health, and improve performance. A total of 420 birds were used, divided into four groups with seven repetitions per group (n = 15), as follows: NC, negative control (no promoter); PC, positive control (basal diet + enramycin + salinomycin); MDT-BUT, a diet supplemented with mono-, di-, and triglycerides of butyric acid; TRI-BUT, a diet supplemented with tributyrin of butyric acid glycerides. Productive performance was measured on days 1, 21, 35, and 42. Excreta were collected for counting Escherichia coli and coliforms on days 21 and 42. Blood samples were collected at 42 days of age to analyse oxidant/antioxidant status, and the intestine was removed for intestinal morphometry. From 1 to 42 days, there was greater body weight, weight gain, and feed conversion in the PC, MDT-BUT, and TRI-BUT groups than in the NC group; the production efficiency index was 21.10% higher in all groups than in the NC group (p = 0.001). At 21 days, there were lower E. coli counts of 86.8% in the TRI-BUT and 99.7% in PC groups than in the NC and MDT-BUT groups (p < 0.001), while at 42 days, lower counts were found in the PC, MDT-BUT, and TRI-BUT groups than the NC group (p < 0.001). There were lower total protein and globulin levels in the MDT-BUT and TRI-BUT groups than in the NC group (p = 0.001). Cholesterol levels were lower in the TRI-BUT group, followed by MDT-BUT and PC groups, than in the NC group (p = 0.001), while lower triglyceride levels were found in the TRI-BUT group than in the NC and PC groups (p = 0.001). There were lower levels of lipid peroxidation and reactive oxygen species in the TRI-BUT group, followed by the PC group than the NC group (p < 0.001); on the other hand, there were higher protein thiol levels in the TRI-BUT group than the NC group (p = 0.041). The villus:crypt ratio increase was 79.4% in the TRI-BUT group, followed by the 45.1% PC and 19.8% MDT-BUT groups than the NC (p < 0.001). These findings suggest that adding butyric acid confers antimicrobial and antioxidant activity and improves birds' production efficiency, intestinal health, and metabolism. Butyric acid glycerides are an effective alternative to conventional growth promoters.

2-Arachidonoylglycerol mobilization following brief synaptic stimulation in the dorsal lateral striatum requires glutamatergic and cholinergic neurotransmission.

Several forms of endocannabinoid (eCB) signaling have been described in the dorsal lateral striatum (DLS), however most experimental protocols used to generate eCBs do not recapitulate the firing patterns of striatal-projecting pyramidal neurons in the cortex or firing patterns of striatal medium spiny neurons. Therefore, it is unclear if current models of eCB signaling in the DLS provide a reliable description of mechanisms engaged under physiological conditions. To address this uncertainty, we investigated mechanisms of eCB mobilization following brief synaptic stimulation that mimics in vivo patterns of neural activity in the DLS. To monitor eCB mobilization, the novel genetically encoded fluorescent eCB biosensor, GRABeCB2.0, was expressed presynaptically in corticostriatal afferents of C57BL6J mice and evoked eCB transients were measured in the DLS using a brain slice photometry technique. We found that brief bouts of synaptic stimulation induce long lasting eCB transients that were generated predominantly by 2-arachidonoylglycerol (2-AG) mobilization. Efficient 2-AG mobilization required coactivation of AMPA and NMDA ionotropic glutamate receptors and muscarinic M1 receptors. Dopamine D2 receptors expressed on cholinergic interneurons inhibited 2-AG mobilization by inhibiting acetylcholine release. Collectively, these data uncover unrecognized mechanisms underlying 2-AG mobilization in the DLS.

A Role for Peripheral Anandamide and 2-Arachidonoylglycerol in Short-Term Food Intake and Orexigenic Hypothalamic Responses in a Species with Continuous Nutrient Delivery.

The endocannabinoid system (ECS) plays a pivotal role in the complex control and regulation of food intake. Pharmacological ECS activation could improve health in energy-deficient stages by increasing food intake, at least in intermittent feeders. However, knowledge of the mechanism regulating appetite in species with continued nutrient delivery is incomplete. The objectives of this pilot study were to investigate the effect of the intraperitoneal (i.p.) administration of the endocannabinoids (ECs) anandamide (AEA) and 2-arachidonoylglycerol (2-AG) on food intake, plasma EC concentrations and hypothalamic orexigenic signaling, and to study how the circulatory EC tone changes in response to short-term food deprivation in dairy cows, a species with continuous nutrient delivery. The administration of EC resulted in higher food intake during the first hour after treatment. Plasma AEA concentrations were significantly increased 2.5 h after AEA injection, whereas plasma 2-AG concentrations remained unchanged 2.5 h after 2-AG injection. The hypothalamic immunoreactivity of cannabinoid receptor 1, agouti-related protein, and orexin-A was not affected by either treatment; however, neuropeptide Y and agouti-related protein mRNA abundances were downregulated in the arcuate nucleus of AEA-treated animals. Short-term food deprivation increased plasma 2-AG, while plasma AEA remained unchanged. In conclusion, i.p.-administered 2-AG and AEA increase food intake in the short term, but only AEA accumulates in the circulation. However, plasma 2-AG concentrations are more responsive to food deprivation than AEA.

Neuroprotective effects of minocycline and KML29, a potent inhibitor of monoacylglycerol lipase, in an experimental stroke model: a small-animal positron emission tomography study.

Hypoxia caused by ischemia induces acidosis and neuroexcitotoxicity, resulting in neuronal death in the central nervous system (CNS). Monoacylglycerol lipase (MAGL) is a modulator of 2-arachidonoylglycerol (2-AG), which is involved in retrograde inhibition of glutamate release in the endocannabinoid system. In the present study, we used positron emission tomography (PET) to monitor MAGL-positive neurons and neuroinflammation in the brains of ischemic rats. Additionally, we performed PET imaging to evaluate the neuroprotective effects of an MAGL inhibitor in an ischemic injury model. Methods: Ischemic-injury rat models were induced by intraluminal right middle cerebral artery occlusion (MCAO). PET studies of the brains of the ischemic rats were performed at several experimental time points (pre-occlusion, days 2, 4, and 7 after the MCAO surgery) using [11C]SAR127303 for MAGL and [18F]FEBMP for 18 kDa translocator protein (TSPO, a hall-mark of neuroinflammation). Medication using minocycline (a well-known neuroprotective agent) or KML29 (a potent MAGL inhibitor) was given immediately after the MCAO surgery and then daily over the subsequent three days. Results: PET imaging of the ischemic rats using [11C]SAR127303 showed an acute decline of radioactive accumulation in the ipsilateral side at two days after MCAO surgery (ratio of the area under the curve between the ipsilateral and contralateral sides: 0.49 ± 0.04 in the cortex and 0.73 ± 0.02 in the striatum). PET imaging with [18F]FEBMP, however, showed a moderate increase in accumulation of radioactivity in the ipsilateral hemisphere on day 2 (1.36 ± 0.11), and further increases on day 4 (1.72 ± 0.15) and day 7 (1.99 ± 0.06). Treatment with minocycline or KML29 eased the decline in radioactive accumulation of [11C]SAR127303 for MAGL (minocycline-treated group: 0.82 ± 0.06 in the cortex and 0.81 ± 0.05 in the striatum; KML29-treated group: 0.72 ± 0.07 in the cortex and 0.88 ± 0.04 in the striatum) and increased uptake of [18F]FEBMP for TSPO (minocycline-treated group: 1.52 ± 0.21 in the cortex and 1.56 ± 0.11 in the striatum; KML29-treated group: 1.63 ± 0.09 in the cortex and 1.50 ± 0.17 in the striatum). In MCAO rats, minocycline treatment showed a neuroprotective effect in the sensorimotor cortex suffering from severe hypoxic injury, whereas KML29 treatment saved neurons in the striatum, including bundles of myelinated axons. Conclusions: PET imaging allowed visualization of the different neuroprotective effects of minocycline and KML29, and indicated that combination pharmacotherapy using these drugs may be an effective therapy in acute ischemia.

Magnesium Isoglycyrrhizinate Reduces Hepatic Lipotoxicity through Regulating Metabolic Abnormalities.

The excessive accumulation of lipids in hepatocytes induces a type of cytotoxicity called hepatic lipotoxicity, which is a fundamental contributor to liver metabolic diseases (such as NAFLD). Magnesium isoglycyrrhizinate (MGIG), a magnesium salt of the stereoisomer of natural glycyrrhizic acid, is widely used as a safe and effective liver protectant. However, the mechanism by which MGIG protects against NAFLD remains unknown. Based on the significant correlation between NAFLD and the reprogramming of liver metabolism, we aimed to explore the beneficial effects of MGIG from a metabolic viewpoint in this paper. We treated HepaRG cells with palmitic acid (PA, a saturated fatty acid of C16:0) to induce lipotoxicity and then evaluated the antagonistic effect of MGIG on lipotoxicity by investigating the cell survival rate, DNA proliferation rate, organelle damage, and endoplasmic reticulum stress (ERS). Metabolomics, lipidomics, and isotope tracing were used to investigate changes in the metabolite profile, lipid profile, and lipid flux in HepaRG cells under different intervention conditions. The results showed that MGIG can indeed protect hepatocytes against PA-induced cytotoxicity and ERS. In response to the metabolic abnormality of lipotoxicity, MGIG curtailed the metabolic activation of lipids induced by PA. The content of total lipids and saturated lipids containing C16:0 chains increased significantly after PA stimulation and then decreased significantly or even returned to normal levels after MGIG intervention. Lipidomic data show that glycerides and glycerophospholipids were the two most affected lipids. For excessive lipid accumulation in hepatocytes, MGIG can downregulate the expression of the metabolic enzymes (GPATs and DAGTs) involved in triglyceride biosynthesis. In conclusion, MGIG has a positive regulatory effect on the metabolic disorders that occur in hepatocytes under lipotoxicity, and the main mechanisms of this effect are in lipid metabolism, including reducing the total lipid content, reducing lipid saturation, inhibiting glyceride and glycerophospholipid metabolism, and downregulating the expression of metabolic enzymes in lipid synthesis.

Altered endocannabinoid-dynamics in craniopharyngioma patients and their association with HPA-axis disturbances.

OBJECTIVE: Patients with craniopharyngioma (CP) frequently suffer from morbid obesity. Endocannabinoids (ECs) are involved in weight gain and rewarding behavior but have not been investigated in this context. DESIGN: Cross-sectional single-center study. METHODS: Eighteen patients with CP and 16 age- and sex-matched controls were included. Differences in endocannabinoids (2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)) and endocannabinoid-like molecules (oleoyl ethanolamide (OEA), palmitoylethanolamide (PEA), and arachidonic acid (AA) were measured at baseline and following endurance exercise. We further explored ECs-dynamics in relation to markers of HPA-axis activity (ACTH, cortisol, copeptin) and hypothalamic damage. RESULTS: Under resting conditions, independent of differences in BMI, 2-AG levels were more than twice as high in CP patients compared to controls. In contrast, 2-AG and OEA level increased in response to exercise in controls but not in CP patients, while AEA levels decreased in controls. As expected, exercise increased ACTH and copeptin levels in controls only. In a mixed model analysis across time and group, HPA measures did not provide additional information for explaining differences in 2-AG levels. However, AEA levels were negatively influenced by ACTH and copeptin levels, while OEA levels were negatively predicted by copeptin levels only. There were no significant differences in endocannabinoids depending on hypothalamic involvement. CONCLUSION: Patients with CP show signs of a dysregulated endocannabinoid system under resting conditions as well as following exercise in comparison to healthy controls. Increased 2-AG levels under resting conditions and the missing response to physical activity could contribute to the metabolic phenotype of CP patients.

Inhibition of 2-Arachidonoylglycerol Metabolism Alleviates Neuropathology and Improves Cognitive Function in a Tau Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common cause of dementia, which affects more than 5 million individuals in the USA. Unfortunately, no effective therapies are currently available to prevent development of AD or to halt progression of the disease. It has been proposed that monoacylglycerol lipase (MAGL), the key enzyme degrading the endocannabinoid 2-arachidonoylglycerol (2-AG) in the brain, is a therapeutic target for AD based on the studies using the APP transgenic models of AD. While inhibition of 2-AG metabolism mitigates ß-amyloid (Aß) neuropathology, it is still not clear whether inactivation of MAGL alleviates tauopathies as accumulation and deposition of intracellular hyperphosphorylated tau protein are the neuropathological hallmark of AD. Here we show that JZL184, a potent MAGL inhibitor, significantly reduced proinflammatory cytokines, astrogliosis, phosphorylated GSK3ß and tau, cleaved caspase-3, and phosphorylated NF-kB while it elevated PPARγ in P301S/PS19 mice, a tau mouse model of AD. Importantly, tau transgenic mice treated with JZL184 displayed improvements in spatial learning and memory retention. In addition, inactivation of MAGL ameliorates deteriorations in expression of synaptic proteins in P301S/PS19 mice. Our results provide further evidence that MAGL is a promising therapeutic target for AD.

Untapped endocannabinoid pharmacological targets: Pipe dream or pipeline?

It has been established that the endogenous cannabinoid (endocannabinoid) system plays key modulatory roles in a wide variety of pathological conditions. The endocannabinoid system comprises both cannabinoid receptors, their endogenous ligands including 2-arachidonoylglycerol (2-AG), N-arachidonylethanolamine (anandamide, AEA), and enzymes that regulate the synthesis and degradation of endogenous ligands which include diacylglycerol lipase alpha (DAGL-α), diacylglycerol lipase beta (DAGL-ß), fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), α/ß hydrolase domain 6 (ABHD6). As the endocannabinoid system exerts considerable involvement in the regulation of homeostasis and disease, much effort has been made towards understanding endocannabinoid-related mechanisms of action at cellular, physiological, and pathological levels as well as harnessing the various components of the endocannabinoid system to produce novel therapeutics. However, drug discovery efforts within the cannabinoid field have been slower than anticipated to reach satisfactory clinical endpoints and raises an important question into the validity of developing novel ligands that therapeutically target the endocannabinoid system. To answer this, we will first examine evidence that supports the existence of an endocannabinoid system role within inflammatory diseases, neurodegeneration, pain, substance use disorders, mood disorders, as well as metabolic diseases. Next, this review will discuss recent clinical studies, within the last 5 years, of cannabinoid compounds in context to these diseases. We will also address some of the challenges and considerations within the cannabinoid field that may be important in the advancement of therapeutics into the clinic.

Metabolite profiles associated with disease progression in influenza infection.

BACKGROUND: We performed metabolomic profiling to identify metabolites that correlate with disease progression and death. METHODS: We performed a study of adults hospitalized with Influenza A(H1N1)pdm09. Cases (n = 32) were defined by a composite outcome of death or transfer to the intensive care unit during the 60-day follow-up period. Controls (n = 64) were survivors who did not require transfer to the ICU. Four hundred and eight metabolites from eight families were measured on plasma sample at enrollment using a mass spectrometry based Biocrates platform. Conditional logistic regression was used to summarize the association of the individual metabolites and families with the composite outcome and its major two components. RESULTS: The ten metabolites with the strongest association with disease progression belonged to five different metabolite families with sphingolipids being the most common. The acylcarnitines, glycerides, sphingolipids and biogenic metabolite families had the largest odds ratios based on the composite endpoint. The tryptophan odds ratio for the composite is largely associated with death (OR 17.33: 95% CI, 1.60-187.76). CONCLUSIONS: Individuals that develop disease progression when infected with Influenza H1N1 have a metabolite signature that differs from survivors. Low levels of tryptophan had a strong association with death. REGISTRY: ClinicalTrials.gov Identifier: NCT01056185.