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The leading cause of steroid-induced femoral head osteonecrosis (ONFH) is the imbalance of bone homeostasis. Bone marrow-derived mesenchymal stem cell (BMSC) differentiation and fate are closely associated with bone homeostasis imbalance. Blocking monoacylglycerol lipase (MAGL) could effectively ameliorate ONFH by mitigating oxidative stress and apoptosis in BMSCs induced by glucocorticoids (GC). Nevertheless, whether MAGL inhibition can modulate the balance during BMSC differentiation, and therefore improve ONFH, remains elusive. Our study indicates that MAGL inhibition can effectively rescue the enhanced BMSC adipogenic differentiation caused by GC and promote their differentiation toward osteogenic lineages. Cannabinoid receptor 2 (CB2) is the direct downstream target of MAGL in BMSCs, rather than cannabinoid receptor 1(CB1). Using RNA sequencing analyses and a series of in vitro experiments, we confirm that the MAGL blockade-induced enhancement of BMSC osteogenic differentiation is primarily mediated by the phosphoinositide 3-kinases (PI3K)/ the serine/threonine kinase (AKT)/ (glycogen synthase kinase-3 beta) GSK3β pathway. Additionally, MAGL blockade can also reduce GC-induced bone resorption by directly suppressing osteoclastogenesis and indirectly reducing the expression of receptor activator of nuclear factor kappa-Β ligand (RANKL) in BMSCs. Thus, our study proposes that the therapeutic effect of MAGL blockade on ONFH is partly mediated by restoring the balance of bone homeostasis and MAGL may be an effective therapeutic target for ONFH. [ABSTRACT FROM AUTHOR]

The endocannabinoid system, known for its regulatory role in various physiological processes, relies on the activities of several hydrolytic enzymes, such as fatty acid amide hydrolase (FAAH), N-acylethanolamine-hydrolyzing acid amidase (NAAA), monoacylglycerol lipase (MAGL), and α/β-hydrolase domains 6 (ABHD6) and 12 (ABHD12), to maintain homeostasis. Accurate measurement of these enzymes' activities is crucial for understanding their function and for the development of potential therapeutic agents. Fluorometric assays, which offer high sensitivity, specificity, and real-time monitoring capabilities, have become essential tools in enzymatic studies. This review provides a comprehensive overview of the principles behind these assays, the various substrates and fluorophores used, and advances in assay techniques used not only for the determination of the kinetic mechanisms of enzyme reactions but also for setting up kinetic assays for the high-throughput screening of each critical enzyme involved in endocannabinoid degradation. Through this comprehensive review, we aim to highlight the strengths and limitations of current fluorometric assays and suggest future directions for improving the measurement of enzyme activity in the endocannabinoid system. [ABSTRACT FROM AUTHOR]

AbstractThermophilic Geobacillus kaustophilus HTA426 genome possesses a monoacylglycerol lipase (MAGL) gene. MAGLs can synthesize emulsifiers for use in the food and pharmaceutical industries from fatty acids and glycerol. They can also be used to analyze monoacylglycerol (MAG) levels in serum and food. The MAGL gene from strain HTA426 was artificially synthesized and heterologously expressed in Escherichia coli BL21(DE3). The recombinant His-tag fused MAGL (GkMAGL) was purified using a Ni2+-affinity column. The purified enzyme showed a temperature optimum at 65 °C and was stable up to 75 °C after 30 min incubation. In addition, the enzyme exhibited a pH optimum of 7.5 and was stable from pH 5.0 to 11.0. The enzyme hydrolyzed monoacylglycerols and showed the highest activity toward 1-monolauroylglycerol. The enzyme was stable in the presence of various organic solvents and detergents. The addition of Triton X-100 significantly increased GkMAGL activity. The thermal stability of the enzyme was higher than that of thermostable MAGL from Geobacillus sp. 12AMOR1 (12AMOR1_MAGL). Circular dichroism spectral analysis showed that the conformational stability of the GkMAGL was higher than that of 12AMOR1_MAGL at higher temperatures. These results indicate that the GkMAGL has useful features that can be used for various biotechnological applications. [ABSTRACT FROM AUTHOR]

Jing Wang, Changqin Xu, Hongwei Xu, Ruixia Wang, Tong Su, Shulei Zhao Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021, People’s Republic of ChinaCorrespondence: Shulei Zhao, Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Weiqi Road, Jinan, 250021, People’s Republic of China, Email wenzhu24@126.comPurpose: To explore the molecular mechanisms of intestinal injury and treatment by analyzing changes in cellular heterogeneity and composition in rat ileal tissue during injury and treatment processes.Methods: We constructed a rat model of SAP and evaluated treatment with an injected of monoacylglycerol lipase (MAGL) inhibitor (JZL184) solution using three experimental groups: healthy male Sprague-Dawley (SD) rats injected with vehicle (CON), male SD SAP model rats injected with vehicle (SAP), and male SAP rats injected with JZL184. We obtained and prepared a single-cell suspension of ileal tissue of each rat for single-cell transcriptome sequencing.Results: This project classified changes in cellular heterogeneity and composition in rat ileal tissue during SAP-induced intestinal injury and MAGL treatment. We found that the number of fibroblast clusters was decreased in the SAP group relative to the CON group, and increased after JZL184 treatment. Further analysis of differences in gene expression between cell clusters in each group reveals that fibroblasts had the greatest number of differentially expressed genes. Most notably, expression of genes involved in communication between cells was found to vary during SAP-induced intestinal injury and JZL184 treatment. Among these changes, the degree of difference in expression of genes involved in communication between fibroblasts and other cells was the highest, indicating that fibroblasts in rat ileal tissue affect intestinal injury and repair through cell-to-cell communication. In addition, our results reveal that differentially expressed RNA-binding proteins in fibroblasts may affect their functions in intestinal injury and treatment by affecting the expression of genes regulating communication between cells.Conclusion: These findings emphasize the importance of understanding the interactions between fibroblasts and other cells in the context of intestinal injury, providing valuable insights for further exploring molecular mechanisms and insight for discovering new treatment targets and strategies.Keywords: single-cell RNA sequencing, cell heterogeneity, fibroblasts, monoacylglycerol lipase, intestinal injury, RNA-binding protein, severe acute pancreatitis

Objective: From the perspective of etiology, borderline personality disorder (BPD) is a multifactorial and complexdisorder, hence our understanding about the molecular basis and signaling of this disorder is extremely limited.The purpose of this study was evaluating the relationship between BPD and the Monoacylglycerol lipase (MGLL)polymorphism rs782440 in the population of Hamadan, Iran.Materials and Methods: In this case-control study, 106 participants including 53 patients with BPD and 53healthy control subjects were selected by psychiatrists in the Department of Psychiatry at Farshchian SinaHospital in Hamadan. The BPD patients were selected based on the Diagnostic and Statistical Manual of MentalDisorders (DSM-5) form for diagnosing BPD patients. For genotyping, polymerase chain reaction (PCR) wasused to amplify the desired region including the MGLL intronic C>T single nucleotide polymorphism (SNP)(rs782440) and afterward the amplicon was sequenced using the Sanger sequencing method. To determine thegenotype of these patients, their sequences were aligned with the reference sequence of MGLL through the CLCgenomic workbench software.Results: The results indicated that the frequency of TT in comparison to the CC genotype was significantly different(P=0.003) and the risk of BPD in change from the TT genotype to CC genotype was increased by 6.679%. Regardingthe frequency of allele in this group, no significant difference was observed.Conclusion: This paper, has studied and reports for the first time, the association between MGLL SNP (rs782440) withBPD. The findings of the current research revealed that the TT genotype increases the risk of BPD compared to the CCgenotype. Considering the lack of a suitable diagnostic biomarker for BPD, using this potential biomarker in the nearfuture can be promising.

Abstract Background CXC-chemokine receptor 2 (CXCR2) expression was found to be down-regulated on circulating monocytes of cancer patients. Here, we analyze the percentage of CD14+CXCR2+ monocyte subsets in hepatocellular carcinoma (HCC) patients, and investigate the mechanisms that regulate CXCR2 surface expression on monocytes and its biological function. Methods Flow cytometry was used to analyze the proportion of the CD14+CXCR2+ subset from the total circulating monocytes of HCC patients. Interleukin 8 (IL-8) levels were measured from serum and ascites, and their correlation with the CD14+CXCR2+ monocyte subset proportion was calculated. THP-1 cells were cultured in vitro and treated with recombinant human IL-8 and CXCR2 surface expression was analyzed. CXCR2 was knocked down to examine how it affects the antitumor activity of monocytes. Finally, a monoacylglycerol lipase (MAGL) inhibitor was added to analyze its effect on CXCR2 expression. Results A decrease in the proportion of the CD14+CXCR2+ monocyte subset was observed in HCC patients compared with healthy controls. CXCR2+ monocyte subset proportion was associated with the AFP value, TNM stage, and liver function. Overexpression of IL-8 was observed in the serum and ascites of HCC patients, and negatively correlated with CXCR2+ monocyte proportion. IL-8 decreased CXCR2 expression in THP-1 cells, contributing to decreased antitumor activity toward HCC cells. MAGL expression in THP-1 cells was up-regulated after IL-8 treatment, and the MAGL inhibitor partially reversed the effects of IL-8 on CXCR2 expression. Conclusions Overexpression of IL-8 drives CXCR2 down-regulation on circulating monocytes of HCC patients, which could be partially reversed by a MAGL inhibitor.

Background and Purpose: The endocannabinoid (eCB) system plays an important homeostatic role in the regulation of stress circuits and has emerged as a therapeutic target to treat stress disorders and alcohol use disorder (AUD). Extensive research has elucidated a role for the eCB anandamide (AEA), but less is known about 2-arachidonoylglycerol (2-AG) mediated signalling. Experimental Approach: We pharmacologically enhanced eCB signalling by inhibiting the 2-AG metabolizing enzyme, monoacylglycerol lipase (MAGL), in male and female Marchigian Sardinian alcohol-preferring (msP) rats, a model of innate alcohol preference and stress hypersensitivity, and in control Wistar rats. We tested the acute effect of the selective MAGL inhibitor MJN110 in alleviating symptoms of alcohol drinking, anxiety, irritability and fear. Key Results: A single systemic administration of MJN110 increased 2-AG levels in the central amygdala, prelimbic and infralimbic cortex but did not acutely alter alcohol drinking. MAGL inhibition reduced aggressive behaviours in female msPs, and increased defensive behaviours in male msPs, during the irritability test. Moreover, in the novelty-induced hypophagia test, MJN110 selectively enhanced palatable food consumption in females, mitigating stress-induced food suppression. Lastly, msP rats showed increased conditioned fear behaviour compared with Wistar rats, and MJN110 reduced context-associated conditioned fear responses, but not cue-probed fear expression, in male msPs. Conclusions and Implications: Acute inhibition of MAGL attenuated some stressrelated responses in msP rats but not voluntary alcohol drinking. Our results provide new insights into the sex dimorphism documented in stress-induced responses. Sex-specific eCB-based approaches should be considered in the clinical development of therapeutics. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage injury, hyperplasia of bone and inflammatory lesions of synovium. Monoacylglycerol lipase (MAGL), a member of the α/β hydrolase superfamily, is involved in regulation of injury protection and immune-inflammation response. Autoinflammatory response of the synovium and the release of inflammatory mediators play critical roles in occurrence of early-stage OA. Fibroblast-like synoviocytes (FLSs) are resident mesenchymal cells of the synovial tissue. Considering that MAGL inhibition regulates the inflammatory signaling cascade, it is crucial to ascertain the biological effects and specific mechanisms of MAGL in alleviating inflammatory infiltration of OA FLSs. The aim of this study was to investigate the effect of MAGL on biological function in OA FLSs. Results from in vitro experiments showed that MAGL blockade not only effectively inhibited proliferation, invasion and migration of FLSs, but also downregulated expression of inflammatory-associated proteins. Sequencing results indicated that MAGL inhibition significantly suppressed NOX4-mediated oxidative stress, thus promoting Nrf2 nuclear accumulation and inhibiting generation of intracellular reactive oxygen species (ROS). Attenuation of NOX4 further alleviated redox dysplasia and ultimately improved tumor-like phenotypes, such as abnormal proliferation, migration and migration of FLSs. In vivo results corroborated this finding, with MAGL inhibition found to modulate pain and disease progression in an OA rat model. Collectively, these results indicate that MAGL administration is an ideal therapy treating OA. [Display omitted] • MAGL exerted a crucial influence on synovial inflammation and osteoarthritis. • MAGL blockade inhibited the secretion of inflammatory factors in synovial cells. • MAGL blockade regulated Nrf2 nuclear accumulation and the NOX4-Nrf2 redox balance. • MJN110 administration led to a reduction in synovial inflammation in osteoarthritis rats. [ABSTRACT FROM AUTHOR]

Objective: From the perspective of etiology, borderline personality disorder (BPD) is a multifactorial and complex disorder, hence our understanding about the molecular basis and signaling of this disorder is extremely limited. The purpose of this study was evaluating the relationship between BPD and the Monoacylglycerol lipase (MGLL) polymorphism rs782440 in the population of Hamadan, Iran. Materials and Methods: In this case-control study, 106 participants including 53 patients with BPD and 53 healthy control subjects were selected by psychiatrists in the Department of Psychiatry at Farshchian Sina Hospital in Hamadan. The BPD patients were selected based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) form for diagnosing BPD patients. For genotyping, polymerase chain reaction (PCR) was used to amplify the desired region including the MGLL intronic C>T single nucleotide polymorphism (SNP) (rs782440) and afterward the amplicon was sequenced using the Sanger sequencing method. To determine the genotype of these patients, their sequences were aligned with the reference sequence of MGLL through the CLC genomic workbench software. Results: The results indicated that the frequency of TT in comparison to the CC genotype was significantly different (P=0.003) and the risk of BPD in change from the TT genotype to CC genotype was increased by 6.679%. Regarding the frequency of allele in this group, no significant difference was observed. Conclusion: This paper, has studied and reports for the first time, the association between MGLL SNP (rs782440) with BPD. The findings of the current research revealed that the TT genotype increases the risk of BPD compared to the CC genotype. Considering the lack of a suitable diagnostic biomarker for BPD, using this potential biomarker in the near future can be promising. [ABSTRACT FROM AUTHOR]

JZL184, an inhibitor of monoacylglycerol lipase (MAGL) and thus of the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG), mediates various anticancer effects in preclinical studies. However, studies on the effect of this or other MAGL inhibitors under hypoxia, an important factor in tumor biology and response to cancer therapy, have not yet been performed in cancer cells. In the present study, the impact of the conditioned media (CM) of A549 and H358 lung cancer cells incubated with JZL184 under hypoxic conditions on the angiogenic properties of human umbilical vein endothelial cells (HUVECs) was investigated. Treatment of HUVECs with CM derived from cancer cells cultured for 48 h under hypoxic conditions was associated with a substantial increase in migration and tube formation compared with unconditioned medium, which was inhibited when cancer cells were incubated with JZL184. In this process, JZL184 led to a significant increase in 2-AG levels in both cell lines. Analysis of a panel of proangiogenic factors revealed inhibition of hypoxia-induced vascular endothelial growth factor (VEGF) expression by JZL184. Antiangiogenic and VEGF-lowering effects were also demonstrated for the MAGL inhibitor MJN110. Receptor antagonist experiments suggest partial involvement of the cannabinoid receptors CB1 and CB2 in the antiangiogenic and VEGF-lowering effects induced by JZL184. The functional importance of VEGF for angiogenesis in the selected system is supported by observations showing inhibition of VEGF receptor 2 (VEGFR2) phosphorylation in HUVECs by CM from hypoxic cancer cells treated with JZL184 or when hypoxic cancer cell-derived CM was spiked with a neutralizing VEGF antibody. On the other hand, JZL184 did not exert a direct effect on VEGFR2 activation induced by recombinant VEGF, so there seems to be no downstream effect on already released VEGF. In conclusion, these results reveal a novel mechanism of antiangiogenic action of JZL184 under conditions of hypoxic tumor–endothelial communication. [ABSTRACT FROM AUTHOR]

The endocannabinoid system is expressed in cells throughout the body and controls a variety of physiological and pathophysiological functions. We describe robust and reproducible UPLC-MS/MS-based methods for analyzing metabolism of the endocannabinoids, 2-arachidonoyl-sn-glycerol and arachidonoyl ethanolamide, and related monoacylglycerols (MAGs) and fatty acid ethanolamides (FAEs), respectively, in mouse mucosal tissues (i.e., intestine and lung). These methods are optimized for analysis of activity of the MAG biosynthetic enzyme, diacylglycerol lipase (DGL), and MAG degradative enzymes, monoacylglycerol lipase (MGL) and alpha/beta hydrolase domain containing-6 (ABHD6). Moreover, we describe a novel UPLC-MS/MS-based method for analyzing activity of the FAE degradative enzyme, fatty acid amide hydrolase (FAAH), that does not require use of radioactive substrates. In addition, we describe in vivo pharmacological methods to inhibit MAG biosynthesis selectively in the mouse small-intestinal epithelium. These methods will be useful for profiling endocannabinoid metabolism in rodent mucosal tissues in health and disease.

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 (CoCl 2) 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 (IC 50) 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. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Electroacupuncture (EA) can effectively relieve visceral hypersensitivity (VH). However, its mechanisms are still unclear. Objective: To investigate the impact of EA on VH caused by ileitis, and whether EA relieves VH by modulating the endogenous cannabinoid system (ECS). Methods: Thirty male native goats were randomly divided into a saline-treated control group (Saline, n = 9) and three 2,4,6-trinitro-benzenesulfonic acid (TNBS)-treated VH model groups that underwent injection of TNBS into the ileal wall to induce VH and remained untreated (TNBS, n = 9) or received six sessions of EA (for 30 min every 3 days) (TNBS + EA, n = 6) or sham acupuncture (TNBS + Sham, n = 6). The visceromotor response (VMR) to colorectal distention (CRD) was measured after each EA treatment. Three goats in the Saline/TNBS groups were euthanized after 7 days for histopathological examination; the remaining 24 (n = 6/group) underwent sampling of the ileal wall, T11 spinal cord and brain nuclei/areas related to visceral regulation and ascending pain modulation system on day 22. Expression of cannabinoid receptor 1 (CB1R), fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) was detected by immunohistochemistry. Results: VMR to CRD was greater in TNBS-treated goats than in saline-treated goats (p < 0.01) from day 7 to 22. After day 7, EA-treated goats showed a decreased (p < 0.05) VMR compared with untreated TNBS-exposed goats. TNBS treatment decreased CB1R and increased FAAH and MAGL expression in the ileum and related nuclei/areas; this was reversed by EA. Conclusion: EA ameliorates VH, probably by regulating the ECS in the intestine and nuclei/areas related to visceral regulation and descending pain modulation systems. [ABSTRACT FROM AUTHOR]

Despite the well-described anticarcinogenic effects of endocannabinoids, the influence of the endocannabinoid system on tumor angiogenesis is still debated. In the present study, conditioned medium (CM) from A549 and H358 lung cancer cells treated with ascending concentrations of the monoacylglycerol lipase (MAGL) inhibitor JZL184 and 2-arachidonoylglycerol (2-AG), a prominent MAGL substrate, caused a concentration-dependent reduction in human umbilical vein endothelial cell (HUVEC) migration and tube formation compared with CM from vehicle-treated cancer cells. Comparative experiments with MAGL inhibitors JW651 and MJN110 showed the same results. On the other hand, the angiogenic properties of HUVECs were not significantly altered by direct stimulation with JZL184 or 2-AG or by exposure to CM of JZL184- or 2-AG-treated non-cancerous bronchial epithelial cells (BEAS-2B). Inhibition of HUVEC migration and tube formation by CM of JZL184- and 2-AG-treated A549 cells was abolished in the presence of the CB1 antagonist AM-251. Increased release of tissue inhibitor of metalloproteinase-1 (TIMP-1) from JZL184- or 2-AG-stimulated A549 or H358 cells was shown to exert an antiangiogenic effect on HUVECs, as confirmed by siRNA experiments. In addition, JZL184 caused a dose-dependent regression of A549 tumor xenografts in athymic nude mice, which was associated with a decreased number of CD31-positive cells and upregulation of TIMP-1-positive cells in xenograft tissue. In conclusion, our data suggest that elevation of 2-AG by MAGL inhibition leads to increased release of TIMP-1 from lung cancer cells, which mediates an antiangiogenic effect on endothelial cells. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects and mechanisms of monoacylglycerol lipase (MGLL) in tumor-associated macrophages (TAMs) for the progression of colorectal cancer peritoneal metastases (CRC-PM). Methods After macrophage MGLL conditional knockout (cKO) mice was constructed, a CRC-PM model was established in these cKO mice. The effects and mechanism of MGLL deficiency on TAMs were studies with cell biological and RNA-Seq assays. Results Compared with the control mice, macrophage MGLL deficiency significantly shortened the survival time of CRC-PC mice (P < 0.05), increased the weight of peritoneal tumor masses (P < 0.05), diminished the percentage of T cells in the tumor microenvironment (P < 0.01), while elevated the percentage of M2 macrophages in cKO mice (P < 0.05). And the results of RNA-seq showed that TRLs, PD-1/PDL-1, and HIF-1 signal pathways were significantly changed in MGLL deficiency macrophages. Conclusion In the process of CRC-PC, MGLL deficiency leads to macrophage activation towards an M2-type phenotype and further destroys T cell-based anti-tumor immunity capacity, and ultimately promotes the progression of CRC-PC. The mechanisms may be due to the changes in TRLs, PD-1/PDL-1, and HIF-1 signal pathways.

Abstract Background 2-Arachidonoylglycerol (2-AG) is the most abundant endogenous cannabinoid. Inhibition of 2-AG metabolism by inactivation of monoacylglycerol lipase (MAGL), the primary enzyme that degrades 2-AG in the brain, produces anti-inflammatory and neuroprotective effects in neurodegenerative diseases. However, the molecular mechanisms underlying these beneficial effects are largely unclear. Methods Hippocampal and cortical cells were isolated from cell type-specific MAGL knockout (KO) mice. Single-cell RNA sequencing was performed by 10 × Genomics platform. Cell Ranger, Seurat (v3.2) and CellChat (1.1.3) packages were used to carry out data analysis. Results Using single-cell RNA sequencing analysis, we show here that cell type-specific MAGL KO mice display distinct gene expression profiles in the brain. Inactivation of MAGL results in robust changes in expression of immune- and inflammation-related genes in microglia and astrocytes. Remarkably, upregulated expression of chemokines in microglia is more pronounced in mice lacking MAGL in astrocytes. In addition, expression of genes that regulate other cellular functions and Wnt signaling in astrocytes is altered in MAGL KO mice. Conclusions Our results provide transcriptomic evidence that cell type-specific inactivation of MAGL induces differential expression of immune-related genes and other fundamental cellular pathways in microglia and astrocytes. Upregulation of the immune/inflammatory genes suggests that tonic levels of immune/inflammatory vigilance are enhanced in microglia and astrocytes, particularly in microglia, by inhibition of 2-AG metabolism, which likely contribute to anti-inflammatory and neuroprotective effects produced by inactivation of MAGL in neurodegenerative diseases.

The use of opioids in pain management is hampered by the emergence of analgesic tolerance, which leads to increased dosing and side effects, both of which have contributed to the opioid epidemic. One promising potential approach to limit opioid analgesic tolerance is activating the endocannabinoid system in the CNS, via activation of CB1 receptors in the descending pain inhibitory pathway. In this review, we first discuss preclinical and clinical evidence revealing the potential of pharmacological activation of CB1 receptors in modulating opioid tolerance, including activation by phytocannabinoids, synthetic CB1 receptor agonists, endocannabinoid degradation enzyme inhibitors, and recently discovered positive allosteric modulators of CB1 receptors. On the other hand, as non‐pharmacological pain relief is advocated by the US‐NIH to combat the opioid epidemic, we also discuss contributions of peripheral neuromodulation, involving the electrostimulation of peripheral nerves, in addressing chronic pain and opioid tolerance. The involvement of supraspinal endocannabinoid systems in peripheral neuromodulation‐induced analgesia is also discussed. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc [ABSTRACT FROM AUTHOR]

Background: 2-Arachidonoylglycerol (2-AG) is the most abundant endogenous cannabinoid. Inhibition of 2-AG metabolism by inactivation of monoacylglycerol lipase (MAGL), the primary enzyme that degrades 2-AG in the brain, produces anti-inflammatory and neuroprotective effects in neurodegenerative diseases. However, the molecular mechanisms underlying these beneficial effects are largely unclear. Methods: Hippocampal and cortical cells were isolated from cell type-specific MAGL knockout (KO) mice. Single-cell RNA sequencing was performed by 10 × Genomics platform. Cell Ranger, Seurat (v3.2) and CellChat (1.1.3) packages were used to carry out data analysis. Results: Using single-cell RNA sequencing analysis, we show here that cell type-specific MAGL KO mice display distinct gene expression profiles in the brain. Inactivation of MAGL results in robust changes in expression of immune- and inflammation-related genes in microglia and astrocytes. Remarkably, upregulated expression of chemokines in microglia is more pronounced in mice lacking MAGL in astrocytes. In addition, expression of genes that regulate other cellular functions and Wnt signaling in astrocytes is altered in MAGL KO mice. Conclusions: Our results provide transcriptomic evidence that cell type-specific inactivation of MAGL induces differential expression of immune-related genes and other fundamental cellular pathways in microglia and astrocytes. Upregulation of the immune/inflammatory genes suggests that tonic levels of immune/inflammatory vigilance are enhanced in microglia and astrocytes, particularly in microglia, by inhibition of 2-AG metabolism, which likely contribute to anti-inflammatory and neuroprotective effects produced by inactivation of MAGL in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Purpose: The monoacylglycerol lipase (MAGL) plays a pivotal role in modulating the endocannabinoid system and is considered an attractive therapeutic target for diseases in both the central nervous system and periphery. The current study aimed to develop and evaluate a suitable carbon-11 labeled tracer for imaging MAGL in preclinical studies.(R)-YH168 was synthesized via a multi-step pathway and its half-maximal inhibitory concentration (IC50) values were measured using an enzymatic assay. Radiosynthesis of (R)-[11C]YH168 was accomplished by 11C-methylation via Suzuki cross-coupling of a pinacol boron precursor. In vitro autoradiography was performed using brain tissues from MAGL knockout and the corresponding wild-type mice. The metabolic stability of (R)-[11C]YH168 in mouse brain and plasma was assessed 5 min after injection. Dynamic PET scans were conducted on anesthetized mice and rhesus monkey. For studies in non-human primates, arterial blood samples were analyzed to obtain the input function for kinetic modeling. Blocking studies with the irreversible MAGL inhibitor PF-06795071 were performed to assess the binding specificity of (R)-[11C]YH168.(R)-[11C]YH168 was synthesized via Suzuki coupling of the phenyl boronic ester with [11C]CH3I in the presence of palladium catalyst. In vitro autoradiography revealed a heterogeneous distribution pattern of (R)-[11C]YH168 with higher binding to MAGL-rich brain regions in wild-type mouse brain slices compared to that of MAGL knockout mice. Dynamic PET imaging in wild-type and MAGL knockout mice confirmed its high specificity and selectivity in mouse brains. In the rhesus monkey, (R)-[11C]YH168 displayed good brain permeability. High levels of radioactivity uptake were seen in the cingulate cortex, frontal cortex, cerebellum, occipital cortex, and hippocampus, consistent with MAGL expression. The one-tissue compartment model was appropriate for fitting the regional time-activity curves and provided reliable volume of distribution values across all brain regions. Pretreatment with PF-06795071 (0.1 mg/kg) resulted in almost complete blockade (> 95%) of radioactivity uptake, demonstrating binding specificity of (R)-[11C]YH168 to MAGL in the non-human primate brain. The regional non-displaceable binding potential follows the rank order of cingulate cortex ~ frontal cortex ~ insula > putamen > temporal cortex > caudate ~ occipital cortex ~ thalamus > nucleus accumbens ~ hippocampus ~ cerebellum ~ globus pallidus > substantia nigra > amygdala.(R)-[11C]YH168 is a promising PET probe for imaging and quantifying MAGL in the brains of mice and non-human primates. This 11C-labeled tracer holds great potential for translation into human subjects and offers the possibility of performing multiple PET scans on the same subject within a single day.Methods: The monoacylglycerol lipase (MAGL) plays a pivotal role in modulating the endocannabinoid system and is considered an attractive therapeutic target for diseases in both the central nervous system and periphery. The current study aimed to develop and evaluate a suitable carbon-11 labeled tracer for imaging MAGL in preclinical studies.(R)-YH168 was synthesized via a multi-step pathway and its half-maximal inhibitory concentration (IC50) values were measured using an enzymatic assay. Radiosynthesis of (R)-[11C]YH168 was accomplished by 11C-methylation via Suzuki cross-coupling of a pinacol boron precursor. In vitro autoradiography was performed using brain tissues from MAGL knockout and the corresponding wild-type mice. The metabolic stability of (R)-[11C]YH168 in mouse brain and plasma was assessed 5 min after injection. Dynamic PET scans were conducted on anesthetized mice and rhesus monkey. For studies in non-human primates, arterial blood samples were analyzed to obtain the input function for kinetic modeling. Blocking studies with the irreversible MAGL inhibitor PF-06795071 were performed to assess the binding specificity of (R)-[11C]YH168.(R)-[11C]YH168 was synthesized via Suzuki coupling of the phenyl boronic ester with [11C]CH3I in the presence of palladium catalyst. In vitro autoradiography revealed a heterogeneous distribution pattern of (R)-[11C]YH168 with higher binding to MAGL-rich brain regions in wild-type mouse brain slices compared to that of MAGL knockout mice. Dynamic PET imaging in wild-type and MAGL knockout mice confirmed its high specificity and selectivity in mouse brains. In the rhesus monkey, (R)-[11C]YH168 displayed good brain permeability. High levels of radioactivity uptake were seen in the cingulate cortex, frontal cortex, cerebellum, occipital cortex, and hippocampus, consistent with MAGL expression. The one-tissue compartment model was appropriate for fitting the regional time-activity curves and provided reliable volume of distribution values across all brain regions. Pretreatment with PF-06795071 (0.1 mg/kg) resulted in almost complete blockade (> 95%) of radioactivity uptake, demonstrating binding specificity of (R)-[11C]YH168 to MAGL in the non-human primate brain. The regional non-displaceable binding potential follows the rank order of cingulate cortex ~ frontal cortex ~ insula > putamen > temporal cortex > caudate ~ occipital cortex ~ thalamus > nucleus accumbens ~ hippocampus ~ cerebellum ~ globus pallidus > substantia nigra > amygdala.(R)-[11C]YH168 is a promising PET probe for imaging and quantifying MAGL in the brains of mice and non-human primates. This 11C-labeled tracer holds great potential for translation into human subjects and offers the possibility of performing multiple PET scans on the same subject within a single day.Results: The monoacylglycerol lipase (MAGL) plays a pivotal role in modulating the endocannabinoid system and is considered an attractive therapeutic target for diseases in both the central nervous system and periphery. The current study aimed to develop and evaluate a suitable carbon-11 labeled tracer for imaging MAGL in preclinical studies.(R)-YH168 was synthesized via a multi-step pathway and its half-maximal inhibitory concentration (IC50) values were measured using an enzymatic assay. Radiosynthesis of (R)-[11C]YH168 was accomplished by 11C-methylation via Suzuki cross-coupling of a pinacol boron precursor. In vitro autoradiography was performed using brain tissues from MAGL knockout and the corresponding wild-type mice. The metabolic stability of (R)-[11C]YH168 in mouse brain and plasma was assessed 5 min after injection. Dynamic PET scans were conducted on anesthetized mice and rhesus monkey. For studies in non-human primates, arterial blood samples were analyzed to obtain the input function for kinetic modeling. Blocking studies with the irreversible MAGL inhibitor PF-06795071 were performed to assess the binding specificity of (R)-[11C]YH168.(R)-[11C]YH168 was synthesized via Suzuki coupling of the phenyl boronic ester with [11C]CH3I in the presence of palladium catalyst. In vitro autoradiography revealed a heterogeneous distribution pattern of (R)-[11C]YH168 with higher binding to MAGL-rich brain regions in wild-type mouse brain slices compared to that of MAGL knockout mice. Dynamic PET imaging in wild-type and MAGL knockout mice confirmed its high specificity and selectivity in mouse brains. In the rhesus monkey, (R)-[11C]YH168 displayed good brain permeability. High levels of radioactivity uptake were seen in the cingulate cortex, frontal cortex, cerebellum, occipital cortex, and hippocampus, consistent with MAGL expression. The one-tissue compartment model was appropriate for fitting the regional time-activity curves and provided reliable volume of distribution values across all brain regions. Pretreatment with PF-06795071 (0.1 mg/kg) resulted in almost complete blockade (> 95%) of radioactivity uptake, demonstrating binding specificity of (R)-[11C]YH168 to MAGL in the non-human primate brain. The regional non-displaceable binding potential follows the rank order of cingulate cortex ~ frontal cortex ~ insula > putamen > temporal cortex > caudate ~ occipital cortex ~ thalamus > nucleus accumbens ~ hippocampus ~ cerebellum ~ globus pallidus > substantia nigra > amygdala.(R)-[11C]YH168 is a promising PET probe for imaging and quantifying MAGL in the brains of mice and non-human primates. This 11C-labeled tracer holds great potential for translation into human subjects and offers the possibility of performing multiple PET scans on the same subject within a single day.Conclusion: The monoacylglycerol lipase (MAGL) plays a pivotal role in modulating the endocannabinoid system and is considered an attractive therapeutic target for diseases in both the central nervous system and periphery. The current study aimed to develop and evaluate a suitable carbon-11 labeled tracer for imaging MAGL in preclinical studies.(R)-YH168 was synthesized via a multi-step pathway and its half-maximal inhibitory concentration (IC50) values were measured using an enzymatic assay. Radiosynthesis of (R)-[11C]YH168 was accomplished by 11C-methylation via Suzuki cross-coupling of a pinacol boron precursor. In vitro autoradiography was performed using brain tissues from MAGL knockout and the corresponding wild-type mice. The metabolic stability of (R)-[11C]YH168 in mouse brain and plasma was assessed 5 min after injection. Dynamic PET scans were conducted on anesthetized mice and rhesus monkey. For studies in non-human primates, arterial blood samples were analyzed to obtain the input function for kinetic modeling. Blocking studies with the irreversible MAGL inhibitor PF-06795071 were performed to assess the binding specificity of (R)-[11C]YH168.(R)-[11C]YH168 was synthesized via Suzuki coupling of the phenyl boronic ester with [11C]CH3I in the presence of palladium catalyst. In vitro autoradiography revealed a heterogeneous distribution pattern of (R)-[11C]YH168 with higher binding to MAGL-rich brain regions in wild-type mouse brain slices compared to that of MAGL knockout mice. Dynamic PET imaging in wild-type and MAGL knockout mice confirmed its high specificity and selectivity in mouse brains. In the rhesus monkey, (R)-[11C]YH168 displayed good brain permeability. High levels of radioactivity uptake were seen in the cingulate cortex, frontal cortex, cerebellum, occipital cortex, and hippocampus, consistent with MAGL expression. The one-tissue compartment model was appropriate for fitting the regional time-activity curves and provided reliable volume of distribution values across all brain regions. Pretreatment with PF-06795071 (0.1 mg/kg) resulted in almost complete blockade (> 95%) of radioactivity uptake, demonstrating binding specificity of (R)-[11C]YH168 to MAGL in the non-human primate brain. The regional non-displaceable binding potential follows the rank order of cingulate cortex ~ frontal cortex ~ insula > putamen > temporal cortex > caudate ~ occipital cortex ~ thalamus > nucleus accumbens ~ hippocampus ~ cerebellum ~ globus pallidus > substantia nigra > amygdala.(R)-[11C]YH168 is a promising PET probe for imaging and quantifying MAGL in the brains of mice and non-human primates. This 11C-labeled tracer holds great potential for translation into human subjects and offers the possibility of performing multiple PET scans on the same subject within a single day. [ABSTRACT FROM AUTHOR]

Monoacylglycerol lipase (MAGL) can regulate the endocannabinoid system and thus becomes a target of antidepressant drugs. In this paper, molecular docking and molecular dynamics simulations, combined with binding free energy calculation, were employed to investigate the inhibitory mechanism and binding modes of four aryl formyl piperidine derivative inhibitors with different 1-substituents to MAGL. The results showed that in the four systems, the main four regions where the enzyme bound to the inhibitor included around the head aromatic ring, the head carbonyl oxygen, the tail amide bond, and the tail benzene ring. The significant conformational changes in the more flexible lid domain of the enzyme were caused by 1-substituted group differences of inhibitors and resulted in different degrees of flipping in the tail of the inhibitor. The flipping led to a different direction of the tail amide bond and made a greater variation in its interaction with some of the charged residues in the enzyme, which further contributed to a different swing of the tail benzene ring. If the swing is large enough, it can weaken the binding strength of the head carbonyl oxygen to its nearby residues, and even the whole inhibitor with the enzyme so that the inhibition decreases. [ABSTRACT FROM AUTHOR]

Degumming is essential to eliminate undesired phospholipids from crude vegetable oils before being processed into high-quality products. The degumming efficiency is hampered by the separation of oil and water. To overcome this problem, we introduced an innovative enzymatic degumming strategy for various vegetable oils (rice bran, peanut and flaxseed oil) by combining phospholipase A1 with monoacylglycerol lipase. Compared to using phospholipase A1, the combination of the two enzymes significantly reduced phosphorus content, indicating better hydrolysis of phospholipids. Additionally, the primary hydrolysates by the combined enzymes were glycerylphosphorylcholine and glycerylphosphorylethanolamine that were more affinitive to water to improve oil-water separation and oil yield. Characteristic markers obtained from Partial Least Squares Discriminant Analysis model confirmed the advantages of combined enzymes over single enzyme. This advantage of combined enzymes was further validated in a simulated degumming process. Our findings provide a new enzymatic degumming strategy to expand the toolkit for crude oil refinery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Evidence suggests that monoacylglycerol lipase (MAGL) inhibitors can potentially treat HIV symptoms by increasing the concentration of 2-arachidonoylglycerol (2-AG). We examined a selective MAGL inhibitor ABX1431 in the context of neuroHIV. Methods: To assess the effects of ABX1431, we conducted in vitro and in vivo studies. In vitro calcium imaging on frontal cortex neuronal cultures was performed to evaluate the role of ABX1431 (10, 30, 100 nM) on transactivator of transcription (Tat)-induced neuronal hyperexcitability. Following in vitro experiments, in vivo experiments were performed using Tat transgenic male mice. Mice were treated with 4 mg/kg ABX1431 and assessed for antinociception using tail-flick and hot plate assays followed by locomotor activity. After the behavioral experiments, their brains were harvested to quantify endocannabinoids (eCB) and related lipids through mass spectrometry, and cannabinoid type-1 and -2 receptors (CB 1 R and CB 2 R) were quantified through western blot. Results: In vitro studies revealed that adding Tat directly to the neuronal cultures significantly increased intracellular calcium concentration, which ABX1431 completely reversed at all concentrations. Preincubating the cultures with CB 1 R and CB 2 R antagonists showed that ABX1431 exhibited its effects partially through CB 1 R. In vivo studies demonstrated that acute ABX1431 increased overall total distance traveled and speed of mice regardless of their genotype. Mass spectrometry and western blot analyses revealed differential effects on the eCB system based on Tat expression. The 2-AG levels were significantly upregulated following ABX1431 treatment in the striatum and spinal cord. Arachidonic acid (AA) was also upregulated in the striatum of vehicle-treated Tat(+) mice. No changes were noted in CB 1 R expression levels; however, CB 2 R levels were increased in ABX1431-treated Tat(-) mice only. Conclusion: Findings indicate that ABX1431 has potential neuroprotective effects in vitro partially mediated through CB 1 R. Acute treatment of ABX1431 in vivo shows antinociceptive effects, and seems to alter locomotor activity, with upregulating 2-AG levels in the striatum and spinal cord.

Carbamate has been extensively used as a scaffold in the recent era of drug discovery and is a common structural motif of many approved drugs. The carbamate moiety's unique amide-ester hybrid (-O-CO-NH-) feature offers the designing of specific drug-target interactions. Despite the discovery of numerous carbamate derivatives that act on the endocannabinoid system (ECS), the development of clinically effective carbamates remains a challenge. In this review, we highlight the therapeutic potential of carbamate inhibitors of endocannabinoid degrading enzymes as a breakthrough in discovering neurotherapeutic drugs. We discuss the design strategies and medicinal chemistry aspects involved in developing carbamate-based molecular architectures that modulate the endocannabinoid signaling pathway by interfering with fatty acid amide hydrolase (FAAH), monoacylglycerol lipase (MAGL), and α/β-Hydrolase domain-containing 6 (ABHD6). Additionally, we highlight the dual activity profile of carbamates against FAAH and MAGL, FAAH and cholinesterase, and FAAH and TRPV1 channels. Furthermore, we illustrate the pharmacophores of O-functionalized carbamates and N-cyclic carbamates that are crucial for FAAH and MAGL inhibitory activities, respectively., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Osteoarthritis (OA) is a progressive degenerative joint disease that presents with significant pain and functional disability. The endocannabinoid 2-arachidonoylglycerol activates cannabinoid receptors to reduce pain while its hydrolysis by the enzyme monoacylglycerol lipase (MAGL) generates arachidonic acid, the direct precursor to proalgesic eicosanoids synthesized by cyclooxygenase-2 (COX-2), highlighting the potential for crosstalk between MAGL and COX-2. While COX-2 expression in human OA cartilage has been described, the distribution of MAGL in knee osteochondral tissue has not been reported and was the goal of the current study. Methods: MAGL and COX-2 expression in International Cartilage Repair Society grade II and grade IV knee osteochondral tissue obtained from male and female subjects with OA was investigated through immunohistochemistry. Immunolocalization of both proteins was investigated within articular cartilage and subchondral bone. Results: MAGL is expressed throughout the cartilage of grade II arthritic tissue, with prominent distribution in the superficial and deep zones. Elevated expression of MAGL was evident in grade IV samples, with additional distribution observed in subchondral bone. COX-2 expression followed a similar pattern, with uniform distribution in cartilage and increased expression in grade IV tissue. Conclusions: This study establishes MAGL expression in arthritic cartilage and subchondral bone of subjects with OA. The proximity between MAGL and COX-2 suggests the potential for crosstalk between endocannabinoid hydrolysis and eicosanoid signaling in the maintenance of OA pain.

JZL184, an inhibitor of monoacylglycerol lipase (MAGL) and thus of the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG), mediates various anticancer effects in preclinical studies. However, studies on the effect of this or other MAGL inhibitors under hypoxia, an important factor in tumor biology and response to cancer therapy, have not yet been performed in cancer cells. In the present study, the impact of the conditioned media (CM) of A549 and H358 lung cancer cells incubated with JZL184 under hypoxic conditions on the angiogenic properties of human umbilical vein endothelial cells (HUVECs) was investigated. Treatment of HUVECs with CM derived from cancer cells cultured for 48 h under hypoxic conditions was associated with a substantial increase in migration and tube formation compared with unconditioned medium, which was inhibited when cancer cells were incubated with JZL184. In this process, JZL184 led to a significant increase in 2-AG levels in both cell lines. Analysis of a panel of proangiogenic factors revealed inhibition of hypoxia-induced vascular endothelial growth factor (VEGF) expression by JZL184. Antiangiogenic and VEGF-lowering effects were also demonstrated for the MAGL inhibitor MJN110. Receptor antagonist experiments suggest partial involvement of the cannabinoid receptors CB1 and CB2 in the antiangiogenic and VEGF-lowering effects induced by JZL184. The functional importance of VEGF for angiogenesis in the selected system is supported by observations showing inhibition of VEGF receptor 2 (VEGFR2) phosphorylation in HUVECs by CM from hypoxic cancer cells treated with JZL184 or when hypoxic cancer cell-derived CM was spiked with a neutralizing VEGF antibody. On the other hand, JZL184 did not exert a direct effect on VEGFR2 activation induced by recombinant VEGF, so there seems to be no downstream effect on already released VEGF. In conclusion, these results reveal a novel mechanism of antiangiogenic action of JZL184 under conditions of hypoxic tumor–endothelial communication.

The endocannabinoid 2-arachidonoylglycerol (2-AG) is predominantly metabolized by monoacylglycerol lipase (MAGL) in the brain. Selective inhibitors of MAGL provide valuable insights into the role of 2-AG in a variety of (patho)physiological processes and are potential therapeutics for the treatment of diseases such as neurodegenerative disease and inflammation, pain, as well as cancer. Despite a number of MAGL inhibitors been reported, inhibitors with new chemotypes are still required. Here, we developed a substrate-based fluorescence assay by using a new fluorogenic probe AA-HNA and successfully screened a focused library containing 320 natural organic compounds. Furthermore, we applied activity-based protein profiling (ABPP) as an orthogonal method to confirm the inhibitory activity against MAGL in the primary substrate-based screening. Our investigations culminated in the identification of two major compound classes, including quinoid diterpene (23, cryptotanshinone) and β-carbolines (82 and 93, cis- and trans-isomers), with significant potency towards MAGL and good selectivity over other 2-AG hydrolases (ABHD6 and ABHD12). Moreover, these compounds also showed antiproliferative activities against multiple cancer cells, including A431, H1975, B16-F10, OVCAR-3, and A549. Remarkably, 23 achieved complete inhibition towards endogenous MAGL in most cancer cells determined by ABPP. Our results demonstrate the potential utility of the substrate-based fluorescence assay in combination with ABPP for rapidly discovering MAGL inhibitors, as well as providing an effective approach to identify potential targets for compounds with significant biological activities. [ABSTRACT FROM AUTHOR]

Background: Endocannabinoid 2-arachidonoylglycerol (2-AG) is an anti-nociceptive lipid that is inactivated through cellular uptake and subsequent catabolismby 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-a (TNF-a) 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-a. Notably, intestinal permeability was improved by JZL184 as demonstrated by fluorescein isothiocyanatedextran 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. [ABSTRACT FROM AUTHOR]

Purpose: Monoacylglycerol lipase (MAGL) regulates cannabinoid neurotransmission and the pro-inflammatory arachidonic acid pathway by degrading endocannabinoids. MAGL inhibitors may accordingly act as cannabinoid-potentiating and anti-inflammatory agents. Although MAGL dysfunction has been implicated in neuropsychiatric disorders, it has never been visualized in vivo in human brain. The primary objective of the current study was to visualize MAGL in the human brain using the novel PET ligand 18F-T-401. Methods: Seven healthy males underwent 120-min dynamic 18F-T-401-PET scans with arterial blood sampling. Six subjects also underwent a second PET scan with 18F-T-401 within 2 weeks of the first scan. For quantification of MAGL in the human brain, kinetic analyses using one- and two-tissue compartment models (1TCM and 2TCM, respectively), along with multilinear analysis (MA1) and Logan graphical analysis, were performed. Time-stability and test–retest reproducibility of 18F-T-401-PET were also evaluated. Results: 18F-T-401 showed rapid uptake and gradual washout from the brain. Logan graphical analysis showed linearity in all subjects, indicating reversible radioligand kinetics. Using a metabolite-corrected arterial input function, MA1 estimated regional total distribution volume (VT) values by best identifiability. VT values were highest in the cerebral cortex, moderate in the thalamus and putamen, and lowest in white matter and the brainstem, which was in agreement with regional MAGL expression in the human brain. Time-stability analysis showed that MA1 estimated VT values with a minimal bias even using truncated 60-min scan data. Test–retest reliability was also excellent with the use of MA1. Conclusions: Here, we provide the first demonstration of in vivo visualization of MAGL in the human brain. 18F-T-401 showed excellent test–retest reliability, reversible kinetics, and stable estimation of VT values consistent with known regional MAGL expressions. PET with 18F-T-401-PET is promising tool for measurement of central MAGL. [ABSTRACT FROM AUTHOR]

Despite the well-described anticarcinogenic effects of endocannabinoids, the influence of the endocannabinoid system on tumor angiogenesis is still debated. In the present study, conditioned medium (CM) from A549 and H358 lung cancer cells treated with ascending concentrations of the monoacylglycerol lipase (MAGL) inhibitor JZL184 and 2-arachidonoylglycerol (2-AG), a prominent MAGL substrate, caused a concentration-dependent reduction in human umbilical vein endothelial cell (HUVEC) migration and tube formation compared with CM from vehicle-treated cancer cells. Comparative experiments with MAGL inhibitors JW651 and MJN110 showed the same results. On the other hand, the angiogenic properties of HUVECs were not significantly altered by direct stimulation with JZL184 or 2-AG or by exposure to CM of JZL184- or 2-AG-treated non-cancerous bronchial epithelial cells (BEAS-2B). Inhibition of HUVEC migration and tube formation by CM of JZL184- and 2-AG-treated A549 cells was abolished in the presence of the CB1 antagonist AM-251. Increased release of tissue inhibitor of metalloproteinase-1 (TIMP-1) from JZL184- or 2-AG-stimulated A549 or H358 cells was shown to exert an antiangiogenic effect on HUVECs, as confirmed by siRNA experiments. In addition, JZL184 caused a dose-dependent regression of A549 tumor xenografts in athymic nude mice, which was associated with a decreased number of CD31-positive cells and upregulation of TIMP-1-positive cells in xenograft tissue. In conclusion, our data suggest that elevation of 2-AG by MAGL inhibition leads to increased release of TIMP-1 from lung cancer cells, which mediates an antiangiogenic effect on endothelial cells.

[Display omitted] • A series of naphthyl amide derivatives were designed and synthesized as a another type of reversible MAGL inhibitors. • The naphthyl amide derivative ± 34 , were identified as potent reversible MAGL inhibitor. • Compound ± 34 showed appreciable antiproliferative activities against several cancer cells, including H460, HT29, CT-26, Huh7 and HCCLM-3. Monoacylglycerol lipase (MAGL) is a key enzyme responsible for the metabolism of the endocannabinoid 2-arachidonoylglycerol (2-AG), and has attracted great interest due to its involvement in various physiological and pathological processes, such as cancer progression. In the past, a number of covalent irreversible inhibitors have been reported for MAGL, however, experimental evidence highlighted some drawbacks associated with the use of these irreversible agents. Therefore, efforts were mainly focused on the development of reversible MAGL inhibitor in recent years. Here, we designed and synthesized a series of naphthyl amide derivatives (12 – 39) as another type of reversible MAGL inhibitors, exemplified by ± 34 , which displayed good MAGL inhibition with a pIC 50 of 7.1, and the potency and selectivity against endogenous MAGL were further demonstrated by competitive ABPP. Moreover, the compound showed appreciable antiproliferative activities against several cancer cells, including H460, HT29, CT-26, Huh7 and HCCLM-3. The investigations culminated in the discovery of the naphthyl amide derivative ± 34 , and it may represent as a new scaffold for MAGL inhibitor development, particularly for the reversible ones. [ABSTRACT FROM AUTHOR]

Monoacylglycerol lipase (MAGL) is a serine hydrolase that plays an important role in the endocannabinoid degradation in the brain. It has recently emerged as a promising therapeutic target in the treatment of neuroinflammatory and neurodegenerative diseases, such as multiple sclerosis, Alzheimer's disease and Parkinson's disease. Development of MAGL-specific radioligands for non-invasive imaging by positron-emission tomography (PET) would deepen our knowledge on the relevant pathological changes in diseased states and accelerate drug discovery. In this study, we report the selection and synthesis of two morpholine-3-one derivatives as potential reversible MAGL PET tracer candidates based on their multiparameter optimization scores. Both compounds ([11C] 1 , [11C] 2) were radiolabeled by direct [11C]CO 2 fixation and the in vitro autoradiographic studies demonstrated their specificity and selectivity towards MAGL. Dynamic PET imaging using MAGL knockout and wild-type mice confirmed the in vivo specificity of [11C] 2. Our preliminary results indicate that morpholine-3-one derivative [11C] 2 ([11C] RO7279991) binds to MAGL in vivo , and this molecular scaffold could serve as an alternative lead structure to image MAGL in the central nervous system. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction Tourette syndrome (TS) is a complex neurodevelopmental disorder characterized by chronic motor and vocal tics. While consistently effective treatment is lacking, evidence indicates that the modulation of endocannabinoid system is potentially beneficial. Lu AG06466 (previously ABX-1431) is a highly selective inhibitor of monoacylglycerol lipase, the primary enzyme responsible for the degradation of the endocannabinoid ligand 2-arachidonoylglycerol. This exploratory study aimed to determine the effect of Lu AG06466 versus placebo on tics and other symptoms in patients with TS. Methods In this phase 1b cross-over study, 20 adult patients with TS on standard-of-care medications were randomized to a single fasted dose of Lu AG06466 (40 mg) or placebo in period 1, followed by the other treatment in period 2. The effects on tics, premonitory urges, and psychiatric comorbidities were evaluated using a variety of scaled approaches at different time points before and after treatment. Results All scales showed an overall trend of tic reduction, with two out of three tic scales (including the Total Tic Score of the Yale Global Tic Severity Score) showing a significant effect of a single dose of Lu AG06466 versus placebo at various timepoints. Treatment with Lu AG06466 resulted in a significant reduction in premonitory urges versus placebo. Single doses of Lu AG06466 were generally well-tolerated, and the most common adverse events were headache, somnolence, and fatigue. Conclusion In this exploratory trial, a single dose of Lu AG06466 showed statistically significant positive effects on key measures of TS symptoms. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

RATIONALE: The endocannabinoid system is an important modulator of brain reward signaling. Investigations have focused on cannabinoid (CB1) receptors, because dissection of specific contributions of individual endocannabinoids has been limited by the available toolset. While we recently described an important role for the endocannabinoid anandamide in the regulation of social reward, it remains to be determined whether the other major endocannabinoid, 2-arachidonoyl-sn-glycerol (2-AG), serves a similar or different function. OBJECTIVES: To study the role of 2-AG in natural reward, we used a transgenic mouse model (MGL-Tg mice) in which forebrain 2-AG levels are selectively reduced. We complemented behavioral analysis with measurements of brain 2-AG levels. METHODS: We tested male MGL-Tg mice in conditioned place preference (CPP) tasks for high-fat food, social contact, and cocaine. We measured 2-AG content in the brain regions of interest by liquid chromatography/mass spectrometry. RESULTS: Male MGL-Tg mice are impaired in developing CPP for high-fat food and social interaction, but do develop CPP for cocaine. Furthermore, compared to isolated mice, levels of 2-AG in socially stimulated wild-type mice are higher in the nucleus accumbens and ventral hippocampus (183 and 140 % of controls, respectively), but unchanged in the medial prefrontal cortex. CONCLUSIONS: The results suggest that reducing 2-AG-mediated endocannabinoid signaling impairs social and high-fat food reward in male mice, and that social stimulation mobilizes 2-AG in key brain regions implicated in the control of motivated behavior. The time course of this response differentiates 2-AG from anandamide, whose role in mediating social reward was previously documented.

Monoacylglycerol lipase (MGL) is a serine hydrolase involved in the biological deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). 2-AG is one of the main endogenous lipid agonists for cannabinoid receptors in the brain and elsewhere in the body. In the central nervous system (CNS), MGL is localized to presynaptic nerve terminals of both excitatory and inhibitory synapses, where it helps control the regulatory actions of 2-AG on synaptic transmission and plasticity. In this chapter, we describe an in vitro method to assess MGL activity by liquid chromatography/mass spectrometry (LC/MS)-based quantitation of the reaction product. This method may be used to determine the basal or altered MGL activity in various cells or animal tissues after pharmacological, genetic, or biological manipulations. In addition, this assay can be used for MGL inhibitor screening using purified recombinant enzyme or MGL-overexpressing cells.

BACKGROUND: Breast cancer (BC) is one of the most life-threatening cancer types among women. Despite major developments in medical sciences and technologies, the incidence and mortality rates of BC cases are still increasing. One of the reasons for this increase is the absence of an easy to perform early-diagnostic tool. Although there are defined BC biomarkers routinely used for diagnostic and prognostic purposes, none of these biomarkers is useful for early diagnosis. Therefore, early diagnosis of BC remains an important challenge and there is a great need for the early-diagnostic biomarker(s). OBJECTIVE: In this study, we aimed to evaluate the diagnostic and prognostic values of glycerol-3-phosphate dehydrogenase (GPD1) and monoacylglycerol lipase (MAGL) proteins as non-invasive serum biomarkers. METHODS: GPD1 and MAGL serum levels were determined by ELISA for BC patients (n = 100) from five different subtypes, and healthy controls (n = 20), and a comparative analysis was performed to determine statistically significant expression differences among the groups. RESULTS: The results provided evidence that GPD1 acted as a diagnostic biomarker in distinguishing triple-negative breast cancer (TNBC) patients from other subtypes, and MAGL acted as a diagnostic biomarker in distinguishing healthy individuals from BC patients. CONCLUSION: GPD1 and MAGL might be proposed as non-invasive diagnostic biomarkers for BC with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Traumatic brain injury is an important risk factor for development of Alzheimer's disease and dementia. Unfortunately, no effective therapies are currently available for prevention and treatment of the traumatic brain injury-induced Alzheimer's disease-like neurodegenerative disease. This is largely due to our limited understanding of the mechanisms underlying traumatic brain injury-induced neuropathology. Previous studies showed that pharmacological inhibition of monoacylglycerol lipase, a key enzyme degrading the endocannabinoid 2-arachidonoylglycerol, attenuates traumatic brain injury-induced neuropathology. However, the mechanism responsible for the neuroprotective effects produced by inhibition of monoacylglycerol lipase in traumatic brain injury remains unclear. Here we first show that genetic deletion of monoacylglycerol lipase reduces neuropathology and averts synaptic and cognitive declines in mice exposed to repeated mild closed head injury. Surprisingly, these neuroprotective effects result primarily from inhibition of 2-arachidonoylglycerol metabolism in astrocytes, rather than in neurons. Single-cell RNA-sequencing data reveal that astrocytic monoacylglycerol lipase knockout mice display greater resilience to traumatic brain injury-induced changes in expression of genes associated with inflammation or maintenance of brain homeostasis in astrocytes and microglia. The monoacylglycerol lipase inactivation-produced neuroprotection is abrogated by deletion of the cannabinoid receptor-1 or by adeno-associated virus vector-mediated silencing of astrocytic peroxisome proliferator-activated receptor-γ. This is further supported by the fact that overexpression of peroxisome proliferator-activated receptor-γ in astrocytes prevents traumatic brain injury-induced neuropathology and impairments in spatial learning and memory. Our results reveal a previously undefined cell type-specific role of 2-arachidonoylglycerol metabolism and signalling pathways in traumatic brain injury-induced neuropathology, suggesting that enhanced 2-arachidonoylglycerol signalling in astrocytes is responsible for the monoacylglycerol lipase inactivation-produced alleviation of neuropathology and deficits in synaptic and cognitive functions in traumatic brain injury. [ABSTRACT FROM AUTHOR]

Osteosarcoma is a primary malignancy of mesenchymal origin, and its metastasis and multidrug resistance remain major problems affecting the therapeutic effect. This study aimed to evaluate the efficacy and underlying mechanism of monoacylglycerol lipase (MAGL) on osteosarcoma progression. MAGL expression was downregulated by shMAGL or JZL184 (an MAGL inhibitor) and upregulated through plasmid. RT-PCR and Western blot were utilized to determine the expression of target molecules. CCK-8 assay, transwell assay and ROS assay were performed to investigate the inhibitory effect of MAGL on the growth and metastasis of osteosarcoma cells. The role of JZL184 on tumor growth was examined in cisplatin-resistant MG-63 (MG-63/R) xenograft model. MAGL was highly expressed in osteosarcoma cells and tissues. MAGL knockdown significantly impeded the proliferation, clone formation, invasion and migration of MG-63 cells, whereas opposite result was observed in 143B cells with MAGL overexpression. Likewise, an MAGL inhibitor JZL184 displayed reduced viability, clone formation, invasion and migration of osteosarcoma cells. Western blot of the epithelial mesenchymal transition (EMT)-related proteins indicated that MAGL knockdown or JZL184 could upregulated E-cadherin expression and downregulated vimentin expression. In vitro and in vivo experiments indicated that JZL184 re-sensitized MG-63/R cells to cisplatin. In summary, MAGL regulated osteosarcoma by modulating EMT, and JZL184 might be a promising agent for osteosarcoma patients who are resistant to cisplatin. [ABSTRACT FROM AUTHOR]

2-Arachidonoylglycerol (2-AG) is the most prevalent endocannabinoid involved in maintaining brain homeostasis. Previous studies have demonstrated that inactivating monoacylglycerol lipase (MAGL), the primary enzyme responsible for degrading 2-AG in the brain, alleviates neuropathology and prevents synaptic and cognitive decline in animal models of neurodegenerative diseases. However, we show that selectively inhibiting 2-AG metabolism in neurons impairs cognitive function in mice. This cognitive impairment appears to result from decreased expression of synaptic proteins and synapse numbers, impaired long-term synaptic plasticity and cortical circuit functional connectivity, and diminished neurogenesis. Interestingly, the synaptic and cognitive deficits induced by neuronal MAGL inactivation can be counterbalanced by inhibiting astrocytic 2-AG metabolism. Transcriptomic analyses reveal that inhibiting neuronal 2-AG degradation leads to widespread changes in expression of genes associated with synaptic function. These findings suggest that crosstalk in 2-AG signaling between astrocytes and neurons is crucial for maintaining synaptic and cognitive functions and that excessive 2-AG in neurons alone is detrimental to cognitive function.

We aimed to explore the activation of monoacylglycerol lipase (MAGL)/cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) axis in hepatocellular carcinoma (HCC), evaluating circulating PGE2 as prognostic biomarker in HCC patients. PGE2 levels were measured in blood samples from 24 cirrhotics, and 34 HCC patients were consecutively collected between January 2016 and December 2017. In a subgroup of patients, tissue expression of MAGL mRNA and immunohistochemistry for MAGL and COX-2 were obtained. Despite tumor tissues showing overexpression of MAGL mRNA and higher levels of both MAGL and COX-2 at immunohistochemistry, PGE2 levels were not significantly different in HCC and cirrhotics. HCC patients with circulating PGE2 levels > 14 pg/mL had a significantly shorter overall survival (19.4 vs. 49.9 months; p = 0.03), the finding being confirmed by the multivariate analysis (HR 3.37 [95% CI 1.00–11.60]; p = 0.05). The MAGL/COX-2/PGE2 axis is activated in HCC, and circulating PGE2 proved to be a potential prognostic biomarker. [ABSTRACT FROM AUTHOR]

Monoacylglycerol lipase (MAGL) can regulate the endocannabinoid system and thus becomes a target of antidepressant drugs. In this paper, molecular docking and molecular dynamics simulations, combined with binding free energy calculation, were employed to investigate the inhibitory mechanism and binding modes of four aryl formyl piperidine derivative inhibitors with different 1-substituents to MAGL. The results showed that in the four systems, the main four regions where the enzyme bound to the inhibitor included around the head aromatic ring, the head carbonyl oxygen, the tail amide bond, and the tail benzene ring. The significant conformational changes in the more flexible lid domain of the enzyme were caused by 1-substituted group differences of inhibitors and resulted in different degrees of flipping in the tail of the inhibitor. The flipping led to a different direction of the tail amide bond and made a greater variation in its interaction with some of the charged residues in the enzyme, which further contributed to a different swing of the tail benzene ring. If the swing is large enough, it can weaken the binding strength of the head carbonyl oxygen to its nearby residues, and even the whole inhibitor with the enzyme so that the inhibition decreases.

While current therapeutic strategies for people living with human immunodeficiency virus type 1 (HIV-1) suppress virus replication peripherally, viral proteins such as transactivator of transcription (Tat) enter the central nervous system early upon infection and contribute to chronic inflammatory conditions even alongside antiretroviral treatment. As demand grows for supplemental strategies to combat virus-associated pathology presenting frequently as HIV-associated neurocognitive disorders (HAND), the present study aimed to characterize the potential utility of inhibiting monoacylglycerol lipase (MAGL) activity to increase inhibitory activity at cannabinoid receptor-type 1 receptors through upregulation of 2-arachidonoylglycerol (2-AG) and downregulation of its degradation into proinflammatory metabolite arachidonic acid (AA). The MAGL inhibitor MJN110 significantly reduced intracellular calcium and increased dendritic branching complexity in Tat-treated primary frontal cortex neuron cultures. Chronic MJN110 administration in vivo increased 2-AG levels in the prefrontal cortex (PFC) and striatum across Tat(+) and Tat(–) groups and restored PFC N-arachidonoylethanolamine (AEA) levels in Tat(+) subjects. While Tat expression significantly increased rate of reward-related behavioral task acquisition in a novel discriminative stimulus learning and cognitive flexibility assay, MJN110 altered reversal acquisition specifically in Tat(+) mice to rates indistinguishable from Tat(–) controls. Collectively, our results suggest a neuroprotective role of MAGL inhibition in reducing neuronal hyperexcitability, restoring dendritic arborization complexity, and mitigating neurocognitive alterations driven by viral proteins associated with latent HIV-1 infection.

The endocannabinoid system is expressed in cells throughout the body and controls a variety of physiological and pathophysiological functions. We describe robust and reproducible UPLC-MS/MS-based methods for analyzing metabolism of the endocannabinoids, 2-arachidonoyl-sn-glycerol and arachidonoyl ethanolamide, and related monoacylglycerols (MAGs) and fatty acid ethanolamides (FAEs), respectively, in mouse mucosal tissues (i.e., intestine and lung). These methods are optimized for analysis of activity of the MAG biosynthetic enzyme, diacylglycerol lipase (DGL), and MAG degradative enzymes, monoacylglycerol lipase (MGL) and alpha/beta hydrolase domain containing-6 (ABHD6). Moreover, we describe a novel UPLC-MS/MS-based method for analyzing activity of the FAE degradative enzyme, fatty acid amide hydrolase (FAAH), that does not require use of radioactive substrates. In addition, we describe in vivo pharmacological methods to inhibit MAG biosynthesis selectively in the mouse small-intestinal epithelium. These methods will be useful for profiling endocannabinoid metabolism in rodent mucosal tissues in health and disease.

While current therapeutic strategies for people living with human immunodeficiency virus type 1 (HIV-1) suppress virus replication peripherally, viral proteins such as transactivator of transcription (Tat) enter the central nervous system early upon infection and contribute to chronic inflammatory conditions even alongside antiretroviral treatment. As demand grows for supplemental strategies to combat virus-associated pathology presenting frequently as HIV-associated neurocognitive disorders (HAND), the present study aimed to characterize the potential utility of inhibiting monoacylglycerol lipase (MAGL) activity to increase inhibitory activity at cannabinoid receptor-type 1 receptors through upregulation of 2-arachidonoylglycerol (2-AG) and downregulation of its degradation into proinflammatory metabolite arachidonic acid (AA). The MAGL inhibitor MJN110 significantly reduced intracellular calcium and increased dendritic branching complexity in Tat-treated primary frontal cortex neuron cultures. Chronic MJN110 administration in vivo increased 2-AG levels in the prefrontal cortex (PFC) and striatum across Tat(+) and Tat(–) groups and restored PFC N-arachidonoylethanolamine (AEA) levels in Tat(+) subjects. While Tat expression significantly increased rate of reward-related behavioral task acquisition in a novel discriminative stimulus learning and cognitive flexibility assay, MJN110 altered reversal acquisition specifically in Tat(+) mice to rates indistinguishable from Tat(–) controls. Collectively, our results suggest a neuroprotective role of MAGL inhibition in reducing neuronal hyperexcitability, restoring dendritic arborization complexity, and mitigating neurocognitive alterations driven by viral proteins associated with latent HIV-1 infection. [ABSTRACT FROM AUTHOR]

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 β-amyloid (Aβ) 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 GSK3β 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. [ABSTRACT FROM AUTHOR]