Effects Of Monoacylglycerol Lipase Inhibition Research Articles

Protective Effects of Monoacylglycerol Lipase Inhibition in Rats with Severe Acute Pancreatitis and Its Possible Mechanism.

In the context of gastrointestinal diseases, the role of monoacylglycerol lipase (MAGL) is significant. Therefore, the objective of this study was to examine the protective effects of MAGL inhibition using JZL184 in rat models of severe acute pancreatitis (SAP) and to explore its mechanism. In this study, a rat model of SAP was established, and the rats were divided into three groups for treatment: the Control group (CON), the SAP group (SAP), and the SAP group treated with JZL184 (JZL184). The serum levels of amylase (AMS), alanine aminotransferase (ALT), creatinine (Cr), nitric oxide (NO), cyclic guanosine monophosphate (cGMP), and phosphodiesterase (PDE) were measured using enzyme-linked immunosorbent detection kits. The ascites volume was determined using the cotton ball weighing method. The levels of reactive oxygen species (ROS) were detected using the ROS Kit. Additionally, histological tissue changes were assessed through hematoxylin and eosin staining. The SAP group showed increased levels of AMS, ALT, Cr, ROS, and ascites volume compared to the CON group. Additionally, the SAP group exhibited congested and edematous lung and pancreatic tissues with inflammation. However, the JZL184 group, when compared to the SAP group, showed decreased levels of AMS, ALT, Cr, and ROS, reduced ascites volume, and significantly reduced lung tissue and pancreatic histopathology scores. In the NO/cGMP/PDE system, compared with the CON group, the levels of NO and PDE in the SAP group were higher and the levels of cGMP were lower. Compared with the SAP group, the JZL184 group decreased NO and PDE levels and increased cGMP levels. Indeed, the inhibition of MAGL with JZL184 has been found to have a protective effect on rats with SAP. Specifically, it has shown significant improvement in the pathological damage of lung and pancreatic tissues. Furthermore, JZL184 has also exhibited protective effects on the liver and kidney. The mechanism may be related to the effect of JZL184 on the NO/cGMP/ PDE signaling pathway.

The Monoacylglycerol Lipase Inhibitor ABX-1431 Does Not Improve Alcoholic Liver Disease.

Introduction: Excessive alcohol consumption can result in alcoholic liver disease (ALD). There is no FDA-approved drug to specifically treat ALD and current management approaches have limited efficacy. Past studies indicate that monoacylglycerol lipase (MAGL) inhibition can have a positive impact on nonalcoholic fatty liver disease. However, the effect of MAGL inhibition in ALD has not been reported. Materials and Methods: We tested the highly selective and clinically evaluated MAGL inhibitor ABX-1431 in the Lieber-DeCarli liquid alcohol diet-induced model of ALD in C57BL/6 mice. Results: ABX-1431 failed to reduce ALD-associated steatosis and elevated levels of liver enzymes associated with hepatic injury. Furthermore, survival rate declined with increasing doses of ABX-1431 when compared with mice administered vehicle only. Conclusion: These data suggest that MAGL inhibition does not improve ALD and is unlikely to be a good strategy for this condition.

Monoacylglycerol Lipase Inhibitor JJKK048 Ameliorates ABCG2 Transporter-Mediated Regorafenib Resistance Induced by Hypoxia in Triple Negative Breast Cancer Cells

Triple negative breast cancer (TNBC) is among the most aggressive and deadly cancer subtypes. Intra-tumoral hypoxia is associated with aggressiveness and drug resistance in TNBC. One of the underlying mechanisms of hypoxia-induced drug resistance is the elevated expression of efflux transporters such as breast cancer resistant protein (ABCG2). In the present study, we investigated the possibility of ameliorating ABCG2-mediated drug resistance in hypoxic TNBC cells by monoacylglycerol lipase (MAGL) inhibition and the consequent downregulation of ABCG2 expression.The effect of MAGL inhibition on ABCG2 expression, function, and efficacy of regorafenib, an ABCG2 substrate was investigated in cobalt dichloride (CoCl2) induced pseudohypoxic TNBC (MDA-MB-231) cells, using quantitative targeted absolute proteomics, qRT-PCR, anti-cancer drug accumulation in the cells, cell invasiveness and resazurin-based cell viability assays.Our results showed that hypoxia-induced ABCG2 expression led to low regorafenib intracellular concentrations, reduced the anti-invasiveness efficacy, and elevated half maximal inhibitory concentration (IC50) of regorafenib in vitro MDA-MB-231 cells. MAGL inhibitor, JJKK048, reduced ABCG2 expression, increased regorafenib cell accumulation, which led to higher regorafenib efficacy.In conclusion, hypoxia-induced regorafenib resistance due to ABCG2 over-expression in TNBC cells can be ameliorated by MAGL inhibition.

Effect of Monoacylglycerol Lipase Inhibition on Intestinal Permeability of Rats With Severe Acute Pancreatitis

Background: Endocannabinoid 2-arachidonoylglycerol (2-AG) is an anti-nociceptive lipid that is inactivated through cellular uptake and subsequent catabolism by monoacylglycerol lipase (MAGL). In this study, we investigated the effects of MAGL inhibition on intestinal permeability and explored the possible mechanism. Methods: A rat model of severe acute pancreatitis (SAP) was established. Rats were divided into three groups according to treatment. We analyzed intestinal permeability to fluorescein isothiocyanate-dextran and the levels of inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and 2-AG. Hematoxylin and eosin staining was used to assess histological tissue changes. In vivo intestinal permeability was evaluated by transmission electron microscopy. We obtained ileum tissues, extracted total RNA, and applied RNA-sequencing. Sequencing data were analyzed by bioinformatics. Results: Inflammatory factor levels were higher, while 2-AG levels were lower in the SAP group compared with the control group. Administration of JZL184 to rats with SAP increased the levels of 2-AG and lowered the levels of IL-6 and TNF-α. Notably, intestinal permeability was improved by JZL184 as demonstrated by fluorescein isothiocyanate-dextran measurement, hematoxylin and eosin staining, and transmission electron microscopy. RNA-sequencing showed significant transcriptional differences in SAP and JZL184 groups compared with the control group. KEGG analysis showed that the up- or downregulated genes in multiple comparison groups were enriched in two pathways, focal adhesion and PI3K-Akt signaling pathways. Differential alternative splicing (AS) genes, such as Myo9b, Lsp1, and Git2, have major functions in intestinal diseases. A total of 132 RNA-binding proteins (RBPs) were screened by crossing the identified abnormally expressed genes with the reported RBP genes. Among them, HNRNPDL coexpressed the most AS events as the main RBP. Conclusion: MAGL inhibition improved intestinal mucosal barrier injury in SAP rats and induced a large number of differentially expressed genes and alternative splicing events. HNRNPDL might play an important role in improving intestinal mucosal barrier injury by affecting alternative splicing events.

Cannabinoid CB2 receptors mediate the anxiolytic-like effects of monoacylglycerol lipase inhibition in a rat model of predator-induced fear

The endocannabinoid system is a key regulator of the response to psychological stress. Inhibitors of monoacylglycerol lipase (MGL), the enzyme that deactivates the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG), exert anxiolytic-like effects in rodent models via 2-AG-dependent activation of CB1 cannabinoid receptors. In the present study, we examined whether the MGL inhibitor JZL184 might modulate persistent predator-induced fear in rats, a model that captures features of human post-traumatic stress disorder. Exposure to 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), a volatile chemical that is innately aversive to some rodent species, produced in male rats a long-lasting anxiety-like state that was measured 7 days later in the elevated plus maze test. Systemic administration of JZL184 [4, 8 and 16 mg/kg, intraperitoneal (IP)] 4 h before testing caused dose-dependent inhibition of MGL activity and elevation of 2-AG content in brain tissue. Concomitantly, the inhibitor suppressed TMT-induced fear behaviors with a median effective dose (ED50) of 4 mg/kg. A similar behavioral response was observed with another MGL inhibitor, KML29 (4 and 16 mg/kg, IP). Surprisingly, the effect of JZL184 was prevented by co-administration of the CB2 inverse agonist AM630 (5 mg/kg, IP), but not the CB1 inverse agonist rimonabant (1 mg/kg, IP). Supporting mediation of the response by CB2 receptors, the CB2 agonist JWH133 (0.3, 1 and 3 mg/kg, IP) also produced anxiolytic-like effects in TMT-stressed rats, which were suppressed by AM630. Notably, (i) JWH133 was behaviorally ineffective in animals that had no prior experience with TMT; and (ii) CB2 mRNA levels in rat prefrontal cortex were elevated 7 days after exposure to the aversive odorant. The results suggest that JZL184 attenuates the behavioral consequences of predator stress through a mechanism that requires 2-AG-mediated activation of CB2 receptors, whose transcription may be induced by the stress itself.

Effect of monoacylglycerol lipase inhibition on intestinal permeability in chronic stress model

The endocannabinoid 2-arachidonoylglycerol (2-AG) is an anti-nociceptive lipid, which is inactivated through cellular uptake and subsequent catabolism by monoacylglycerol lipase (MAGL). The present study aimed to explore the effects of inhibition of MAGL on intestinal permeability. We first tested it in differentiated CaCO2 cells after 21 days’ culture. The rat model of water avoidance stress (WAS) was established, and rats were divided into four groups according to intervention. Rats received intraperitoneal injection (i.p.) of an MAGL inhibitor (JZL184) alone, JZL184 and a the cannabinoid receptor 1 (CB1) receptor antagonist (SR141716A), JZL184 and a cannabinoid receptor 2 (CB2) receptor antagonist (AM630) or vehicle alone (control). We analyzed the fluorescein isothiocyanate-dextran (FD4) permeability and 2-AG level. Expression of MAGL and tight-junction-associated proteins were detected by western blot. Compared with the control group, MAGL expression was higher and 2-AG levels lower among WAS rats. Intestinal permeability was increased following administration of JZL184 which occurred due to up-regulation of tight-junction-associated proteins Claudin-1, Claudin-2, Claudin-5 and Occludin. The effects of MAGL inhibition were mediated by CB1, indicating that MAGL may represent a novel target for the treatment of reduced intestinal permeability in the context of chronic stress.

Inhibition of 2-AG hydrolysis differentially regulates blood brain barrier permeability after injury

BackgroundAcute neurological insults caused by infection, systemic inflammation, ischemia, or traumatic injury are often associated with breakdown of the blood-brain barrier (BBB) followed by infiltration of peripheral immune cells, cytotoxic proteins, and water. BBB breakdown and extravasation of these peripheral components into the brain parenchyma result in inflammation, oxidative stress, edema, excitotoxicity, and neurodegeneration. These downstream consequences of BBB dysfunction can drive pathophysiological processes and play a substantial role in the morbidity and mortality of acute and chronic neurological insults, and contribute to long-term sequelae. Preserving or rescuing BBB integrity and homeostasis therefore represents a translational research area of high therapeutic potential.MethodsInduction of general and localized BBB disruption in mice was carried out using systemic administration of LPS and focal photothrombotic ischemic insult, respectively, in the presence and absence of the monoacylglycerol lipase (MAGL) inhibitor, CPD-4645. The effects of CPD-4645 treatment were assessed by gene expression analysis performed on neurovascular-enriched brain fractions, cytokine and inflammatory mediator measurement, and functional assessment of BBB permeability. The mechanism of action of CPD-4645 was studied pharmacologically using inverse agonists/antagonists of the cannabinoid receptors CB1 and CB2.ResultsHere, we demonstrate that the neurovasculature exhibits a unique transcriptional signature following inflammatory insults, and pharmacological inhibition of MAGL using a newly characterized inhibitor rescues the transcriptional profile of brain vasculature and restores its functional homeostasis. This pronounced effect of MAGL inhibition on blood-brain barrier permeability is evident following both systemic inflammatory and localized ischemic insults. Mechanistically, the protective effects of the MAGL inhibitor are partially mediated by cannabinoid receptor signaling in the ischemic brain insult.ConclusionsOur results support considering MAGL inhibitors as potential therapeutics for BBB dysfunction and cerebral edema associated with inflammatory brain insults.

Inhibition of monoacylglycerol lipase: Another signalling pathway for potential therapeutic targets in migraine?

Background Drugs that modulate endocannabinoid signalling are effective in reducing nociception in animal models of pain and may be of value in the treatment of migraine. Methods We investigated the anti-nociceptive effects of inhibition of monoacylglycerol lipase (MGL), a key enzyme in the hydrolysis of the 2-arachidonoylglycerol, in a rat model of migraine based on nitroglycerin (NTG) administration. We evaluated c-fos expression in specific brain areas and nociceptive behavior in trigeminal and extra-trigeminal body areas. Results URB602, a reversible MGL inhibitor, did not show any analgesic effect in the tail flick test, but it inhibited NTG-induced hyperalgesia in both the tail flick test and the formalin test applied to the hind paw or to the orofacial area. Quite unexpectedly, URB602 potentiated formalin-induced hyperalgesia in the trigeminal area when used alone. The latter result was also confirmed using a structurally distinct, irreversible MGL inhibitor, JZL184. URB602 did not induce neuronal activation in the area of interest, but significantly reduced the NTG-induced neuronal activation in the ventrolateral column of the periaqueductal grey and the nucleus trigeminalis caudalis. Conclusions These findings support the hypothesis that modulation of the endocannabinoid system may be a valuable approach for the treatment of migraine. The topographically segregated effect of MGL inhibition in trigeminal/extra-trigeminal areas calls for further mechanistic research.

161. Effects of MAGL inhibition and the CB1 and CB2 cannabinoids receptors participation in the neutrophils recruitment and activity in a murine model of acute lung injury induced by LPS

Endocannabinoid signaling is terminated by enzymatic hydrolysis; process that 2-Arachidonoylglycerol (2-AG) is mediated by monoacylglycerol lipase (MAGL). The MAGL inhibition increases 2-AG levels, an endocannabinoid that acts on CB1 and CB2 receptors. In inflammation, the neutrophils are the first leukocytes to migrate to the injury focus. The aim was to investigate the effects of MAGL inhibition (with JZL184) in the neutrophils recruitment and activity in a murine model of acute lung injury (ALI) induced by LPS. Fifty C57BL/6 male mice were used (5–10/group) and divided into vehicle + saline, vehicle + LPS, and JZL184 + LPS groups. Mice were treated with JZL184 (16 mg/kg) or vehicle and after 60 min they received a LPS intranasal instillation (100 μg/ mL; 1 μL/g) or saline. Six, 24 and 48 h later mice were euthanized and bronchoalveolar lavage fluid and lungs were harvested to KC, MIP-2 and MPO analysis. The LPS was able to increase the KC, MIP-2 and MPO levels and the JZL184 treatment prevented all these parameters. The treatment with AM281 and AM230 (CB1 and CB2 antagonists, respectively), administered i.p. (2,5 and/or 5 mg/kg) 30 min before JZL184 treatment, showed that antagonists prevented the JZL184 anti-inflammatory effects. ALI establishment was evident 6, 24 and 48 h after LPS intranasal instillation and the MAGL inhibition has anti-inflammatory effects. CB1 and CB2 receptors were connected with JZL184 anti-inflammatory effects in ALI murine model. FAPESP2011/10181-7;2009/51886-3.

50. Monoacylglycerol lipase inhibition reduces inflammation in a murine model of acute lung injury

Endocannabinoid signaling is terminated by enzymatic hydrolysis, a process that for 2-Arachidonoylglycerol (2-AG) is mediated by monoacylglycerol lipase (MAGL). The JZL184 (drug) inhibits MAGL with potency and selectivity. It increases 2-AG levels, an endocannabinoid that acts on CB1 and CB2 cannabinoid receptors. The aim of this work was to investigate the effects of MAGL inhibition in a murine model of acute lung injury (ALI) induced by LPS. Twenty C57BL/6 male mice were used (5–8/group); mice were divided into 3 groups, vehicle + saline (V), vehicle + LPS (L), and JZL184 + LPS (J). Mice were treated with JZL184 (16 mg/kg) or vehicle and after 60 min they received a LPS intranasal instillation (100 μg/mL; 1 μL/g) or sterile saline. Six hours later all mice were euthanized and blood, bone marrow and bronchoalveolar lavage fluid (BAL) were harvested. L group showed an increase in the leukocyte count in the BAL especially neutrophils; JZL184 treatment decreased these two parameters. Lymphocytes count in the blood were increased in L group and that treatment with JZL184 prevented these changes. JZL184 did not prevented the decrease of granulocytes number in bone marrow. JZL184 reduced vascular permeability. JZL184 also decreased β2-integrin and increased L-selectin expression in neutrophils in blood. JZL184 treatment decreased IL-6 and MCP-1 concentration in the BAL. ALI establishment is evident 6 h after LPS nasal instillation and that MAGL inhibition has anti-inflammatory effects in this ALI murine model.FAPESP2011/10181–7;2009/51886–3

The temporal dynamics of the effects of monoacylglycerol lipase blockade on locomotion, anxiety, and body temperature

Studies with the monoacylglycerol lipase blocker JZL184 have suggested that enhanced 2-arachidonoylglycerol signaling suppresses locomotion, lowers body temperature, and decreases anxiety. Although the neurochemical effects of JZL184 develop within 30 min, its behavioral and autonomic effects have been studied much later. To clarify temporal dynamics, we studied the effects of intraperitoneal injections of JZL184 in mice on home-cage locomotion and body temperature for 120 min using in-vivo biotelemetry. We also studied the effects of 4, 8, and 16 mg/kg JZL184 in the open field and elevated plus maze at various time points. In the home cage, JZL184 blunted injection-induced body temperature increases but exerted no long-term effects. Vehicle injections increased the duration of rapid movements whereas the duration of motionless periods was decreased, a pattern also abolished by JZL184. Although the highest dose exerted a mild long-term effect on the relative duration of motionless periods, JZL184 seemed to have phasic rather than tonic effects in the home cage. By contrast, open field and plus maze behavior was affected 80 and 120 min but not 40 min after treatments, which may indicate tonic rather than phasic effects in these tests. Our findings confirm earlier reports of a mild anxiolytic effect of JZL184, but surprisingly, the compound markedly and dose dependently increased locomotion in the open field in both CD1 and C57BL/6J mice. These findings are difficult to reconcile at present, but suggest that the effects of monoacylglycerol lipase inhibition are more complex than previously believed and may depend strongly on as yet unidentified factors such as environmental conditions, the time of testing, species/strains, etc.