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[Display omitted] • Encapsulation in lipid nanocapsules stabilizes retinoic acid. • Combining calcitriol and retinoic acid is more effective than each molecule alone. • Nose-to-brain delivery of calcitriol and retinoic acid enhances myelin repair. Intranasal administration is an efficient strategy for bypassing the BBB, favoring drug accumulation in the brain, and improving its efficiency. Lipid nanocapsules (LNC) are suitable nanocarriers for the delivery of lipophilic drugs via this route and can be used to encapsulate lipophilic molecules such as retinoic acid (RA) and calcitriol (Cal). As the hallmarks of multiple sclerosis (MS) are neuroinflammation and oligodendrocyte loss, our hypothesis was that by combining two molecules known for their pro-differentiating properties, encapsulated in LNC, and delivered by intranasal administration, we would stimulate oligodendrocyte progenitor cells (OPC) differentiation into oligodendrocytes and provide a new pro-remyelinating therapy. LNC loaded with RA (LNC-RA) and Cal (LNC-Cal) were stable for at least 8 weeks. The combination of RA and Cal was more efficient than the molecules alone, encapsulated or not, on OPC differentiation in vitro and decreased microglia cell activation in a dose-dependent manner. After the combined intranasal administration of LNC-RA and LNC-Cal in a mouse cuprizone model of demyelination, increased MBP staining was observed in the corpus callosum. In conclusion, intranasal delivery of lipophilic drugs encapsulated in LNC is a promising strategy for myelinating therapies. [ABSTRACT FROM AUTHOR]

Inflammation is a defensive response of the organism to traumatic, infectious, toxic, ischemic, and autoimmune injury. Inflammatory mediators are released to effectively eliminate the inflammatory trigger and restore homeostasis. However, failure of these processes can lead to chronic inflammatory conditions and diseases such as inflammatory bowel diseases, rheumatoid arthritis, inflammatory lung diseases, atherosclerosis, and neurodegenerative diseases. The cure of chronic inflammatory diseases remains challenging as current therapies have various limitations, such as pronounced side effects, progressive loss of efficacy, and high cost especially for biologics. In this context, phytochemicals (such as alkaloids, flavonoids, lignans, phenolic acids, saponins, terpenoids, and other classes) are considered as an interesting alternative approach. Among the numerous targets of phytochemicals, AMP-activated protein kinase (AMPK) can be considered as an interesting target in the context of inflammation. AMPK regulates inflammatory response by inhibiting inflammatory pathways (NF-κB, JAK/STAT, and MAPK) and regulating several other processes of the inflammatory response (oxidative stress, autophagy, and apoptosis). In this review, we summarize and discuss the studies focusing on phytochemicals that showed beneficial effects by blocking different inflammatory pathways implicating AMPK activation in chronic inflammatory disease models. We also highlight elements to consider when investigating AMPK in the context of phytochemicals.

Oxysterols are oxidized derivatives of cholesterol that are formed by enzymatic processes or through the action of reactive oxygen species. Several of these bioactive lipids have been shown to be affected and/or play a role in inflammatory processes. 4β-hydroxycholesterol is one of the major oxysterols in mice and humans and its levels are affected by inflammatory diseases. However, apart from its long half-life, little is known about its catabolism. By incubating 4β-hydroxycholesterol with mouse mitochondria-enriched liver fractions, as well as 25-hydroxycholesterol and 27-hydroxycholesterol with recombinant CYP3A4, we identified 4β,25-dihydroxycholesterol and 4β,27-dihydroxycholesterol as 4β-hydroxycholesterol metabolites. Supporting the biological relevance of this metabolism, we detected both metabolites after incubation of J774, primary mouse peritoneal macrophages and PMA-differentiated THP-1 cells with 4β-hydroxycholesterol. Across our experiments, the incubation of cells with lipopolysaccharides differentially affected the levels of the 25- and 27-hydroxylated metabolites of 4β-hydroxycholesterol. Finally, 4β,27-dihydroxycholesterol was also detected in mice liver and plasma after intraperitoneal administration of 4β-hydroxycholesterol. To our knowledge, this is the first report of the in vitro and in vivo detection and quantification of 4β-hydroxycholesterol metabolites., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Current treatments for inflammatory bowel disease (IBD) treatment consist of anti-inflammatory products. In this study, we sought to induce the physiological secretion of glucagon-like peptide 2, a peptide with intestinal growth-promoting activity, via nanoparticles while simultaneously providing with immunomodulation by tailoring the nanoparticle surface. To this end, we developed hybrid lipid hyaluronate-KPV conjugated nanoparticles loaded with teduglutide for combination therapy in IBD. The nanocarriers induced (or did not induce) immunosuppression depending on the presence (or absence) of a hyaluronan-KPV functionalization. This strategy holds promise as a nanoparticle platform for combined mucosal healing and immunomodulation in IBD treatment., Competing Interests: A.B., Y.X. and P.D.C. are inventors of a patent application (WO/2020/254083A1 - Lipid nanocapsules charged with incretin mimetics). P.D.C. is coinventor on patent applications dealing with the use of specific bacteria and components in the treatment of different diseases. P.D.C. was co-founder of The Akkermansia Company SA and Enterosys., (© 2023 The Authors.)

The newly identified bacterium Dysosmobacter welbionis J115 T improves host metabolism in high-fat diet (HFD)-fed mice. To investigate mechanisms, we used targeted lipidomics to identify and quantify bioactive lipids produced by the bacterium in the culture medium, the colon, the brown adipose tissue (BAT), and the blood of mice. In vitro, we compared the bioactive lipids produced by D. welbionis J115 T versus the probiotic strain Escherichia coli Nissle 1917. D. welbionis J115 T administration reduced body weight, fat mass gain, and improved glucose tolerance and insulin resistance in HFD-fed mice. In vitro, 19 bioactive lipids were highly produced by D. welbionis J115 T as compared to Escherichia coli Nissle 1917. In the plasma, 13 lipids were significantly changed by the bacteria. C18-3OH was highly present at the level of the bacteria, but decreased by HFD treatment in the plasma and normalized in D. welbionis J115 T -treated mice. The metabolic effects were associated with a lower whitening of the BAT. In the BAT, HFD decreased the 15-deoxy-Δ12,14-prostaglandin J2, a peroxisome proliferator-activated receptor (PPAR-γ) agonist increased by 700% in treated mice as compared to HFD-fed mice. Several genes controlled by PPAR-γ were upregulated in the BAT. In the colon, HFD-fed mice had a 60% decrease of resolvin D5, whereas D. welbionis J115 T -treated mice exhibited a 660% increase as compared to HFD-fed mice. In a preliminary experiment, we found that D. welbionis J115 T improves colitis. In conclusion, D. welbionis J115 T influences host metabolism together with several bioactive lipids known as PPAR-γ agonists., Competing Interests: Conflict of interest M. A. is research associate and P. D. C. is honorary research director at FRS-FNRS (Fonds de la Recherche Scientifique). P. D. C. and E. M. d. H. are inventors on patent applications dealing with the use of specific bacteria and components in the treatment of different diseases. P. D. C. was cofounder of The Akkermansia Company SA and Enterosys. The other authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Here, prostaglandin D 2 -glycerol ester (PGD 2 -G) was selected to target neuroinflammation. As PGD 2 -G is reported to have a short plasmatic half-life, we propose to use lipid nanocapsules (LNC) as vehicle to safely transport PGD 2 -G to the central nervous system (CNS). PGD 2 -G-loaded LNC (PGD 2 -G-LNC) reduced pro-inflammatory cytokine expression in activated microglial cells, even so after crossing a primary olfactory cell monolayer. A single nasal administration of PGD 2 -G-LNC in lipopolysaccharide (LPS)-treated mice reduced pro-inflammatory cytokine expression in the olfactory bulb. Coating LNC's surface with a cell-penetrating peptide, transactivator of transcription (TAT), increased its accumulation in the brain. Although TAT-coated PGD 2 -G-LNC modestly exerted its anti-inflammatory effect in a mouse model of multiple sclerosis similar to free PGD 2 -G after nasal administration, TAT-coated LNC surprisingly reduced the expression of pro-inflammatory chemokines in the CNS. These data propose LNC as an interesting drug delivery tool and TAT-coated PGD 2 -G-LNC remains a good candidate, in need of further work., 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 © 2022 Elsevier Inc. All rights reserved.)

Salvadora oleoides is used in Pakistani traditional medicine to treat inflammatory conditions, piles, boils, and ulcers. To evaluate the anti-inflammatory potential of S. oleoides (a mixture of aerial branches, leaves, and stem bark), we prepared crude extracts in Soxhlet apparatus by successively using different solvents and found the methanolic extract (OLM) to significantly inhibit the LPS-induced expression of pro-inflammatory cytokines and enzymes in J774 macrophages, at 50 µg/mL concentration. We also analysed the chemical constituents of OLM by dereplication, performed by HPLC-MS/MS and molecular networking. The major detected constituents were flavonoids and phenolic acids glycosides, most of them identified for the first time in S. oleoides . We also evaluated the toxicity of OLM against five cell lines, namely Caco-2, HepG2, HeLa, J774, and WI-38 by MTT assay. The IC 50 was found to be higher than 100 µg/mL against these five cell lines after 72 h treatment. Furthermore, OLM was tested in mice for acute and sub-acute oral toxicity according to the guidelines of the Organisation for Economic Co-operation and Development (OECD). OLM was found non-toxic, except for some fibrosis observed in the spleens of treated mice in the sub-acute oral toxicity test. Our results confirm the anti-inflammatory potential of OLM and that it could be tested in in vivo inflammatory models, but its effect on the spleen should be considered before designing the experiments., Competing Interests: 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., (© 2022 The Authors.)

Convolvulus arvensis is used in Pakistani traditional medicine to treat inflammation-related disorders. Its anti-inflammatory potential was evaluated on hexane, dichloromethane, ethyl acetate, methanol, and aqueous extracts of whole plant on pro-inflammatory mediators in LPS-activated murine macrophage J774 cells at the non-cytotoxic concentration of 50 µg/mL. Ethyl acetate (ARE) and methanol (ARM) extracts significantly decreased mRNA levels of IL-6, TNF-α, MCP-1, COX-2, and iNOS. Furthermore, both extracts dose dependently decreased IL-6, TNF-α, and MCP-1 secretion. Forty-five compounds were putatively identified in ARE and ARM by dereplication (using HPLC-UV-HRMS n analysis and molecular networking), most of them are reported for the first time in C. arvensis , as for example, nineteen phenolic derivatives. Rutin, kaempferol-3- O -rutinoside, chlorogenic acid, 3,5-di- O -caffeoylquinic acid, N - trans - p -coumaroyl-tyramine, and N - trans -feruloyl-tyramine were main constituents identified and quantified by HPLC-PDA in ARE and ARM. Furthermore, chlorogenic acid, tyramine derivatives, and the mixture of the six identified major compounds significantly decreased IL-6 secretion by LPS-activated J774 cells. The activity of N - trans - p -coumaroyl-tyramine is shown here for the first time. Our results indicate that ARE, ARM and major constituents significantly inhibited the expression of pro-inflammatory mediators, which supports the use of this plant to treat inflammatory diseases.

N-acylethanolamines (NAEs) are endogenous bioactive lipids reported to exert anti-inflammatory and neuroprotective effects mediated by cannabinoid receptors and peroxisome proliferator-activated receptors (PPARs), among others. Therefore, interfering with NAE signaling could be a promising strategy to decrease inflammation in neurological disorders such as multiple sclerosis (MS). Fatty acid amide hydrolase (FAAH) and N-acylethanolamine-hydrolyzing acid amidase (NAAA) are key modulators of NAE levels. This study aims to investigate and compare the effect of NAAA inhibition, FAAH inhibition, and dual inhibition of both enzymes in a mouse model of MS, namely the experimental autoimmune encephalomyelitis (EAE). Our data show that NAAA inhibition strongly decreased the hallmarks of the pathology. Interestingly, FAAH inhibition was less efficient in decreasing inflammatory hallmarks despite the increased NAE levels. Moreover, the inhibition of both NAAA and FAAH, using a dual-inhibitor or the co-administration of NAAA and FAAH inhibitors, did not show an added value compared to NAAA inhibition. Furthermore, our data suggest an important role of decreased activation of astrocytes and microglia in the effects of NAAA inhibition on EAE, while NAAA inhibition did not affect T cell recall. This work highlights the beneficial effects of NAAA inhibition in the context of central nervous system inflammation and suggests that the simultaneous inhibition of NAAA and FAAH has no additional beneficial effect in EAE., (© 2021. The American Society for Experimental NeuroTherapeutics, Inc.)

Inflammation is a critical component of many lung diseases including asthma and acute lung injury (ALI). Using high-performance liquid chromatography-mass spectrometry, we quantified the levels of oxysterols in two different murine models of lung diseases. These are lipid mediators derived from cholesterol and known to modulate immunity and inflammation. Interestingly, 25-hydroxycholesterol (25-OHC) was the only oxysterol with altered levels during lung inflammation, and its levels were differently affected according to the model. Therefore, we sought to assess how this oxysterol would affect lung inflammatory responses. In a model of lipopolysaccharide (LPS)-induced acute lung inflammation, 25-OHC levels were increased, and most of the hallmarks of the model (eg, leukocyte recruitment, mRNA expression, and secretion of inflammatory cytokines) were decreased following its intratracheal administration. We also found that, when administered in the lung, 25-OHC is metabolized locally into 25-hydroxycholesterol-3-sulfate and 7α,25-dihydroxycholesterol. Their administration in the lungs did not recapitulate all the effects of 25-OHC. Conversely, in a model of allergic asthma induced by intranasal administration of house dust mites (HDM), 25-OHC levels were decreased, and when intranasally administered, this oxysterol worsened the hallmarks of the model (eg, leukocyte recruitment, tissue remodeling [epithelium thickening and peribranchial fibrosis], and cytokine expression) and induced changes in leukotriene levels. Ex vivo, we found that 25-OHC decreases LPS-induced primary alveolar macrophage activation while having no effect on neutrophil activation. Its sulfated metabolite, 25-hydroxycholesterol-3-sulfate, decreased neutrophil, but not macrophage activation. Taken together, our data support a differential role of 25-OHC in ALI and allergic inflammation models., (© 2021 Federation of American Societies for Experimental Biology.)

Pain is one of the cardinal signs accompanying inflammation. The prostaglandins (PGs), synthetized from arachidonic acid by cyclooxygenase (COX)-2, are major bioactive lipids implicated in inflammation and pain. However, COX-2 is also able to metabolize other lipids, including the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), to give glycerol ester (PG-G) and ethanolamide (PG-EA) derivatives of the PGs. Consequently, COX-2 can be considered as a hub not only controlling PG synthesis, but also PG-G and PG-EA synthesis. As they were more recently characterized, these endocannabinoid metabolites are less studied in nociception compared to PGs. Interestingly R-profens, previously considered as inactive enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), are substrate-selective COX inhibitors. Indeed, R-flurbiprofen can selectively block PG-G and PG-EA production, without affecting PG synthesis from COX-2. Therefore, we compared the effect of R-flurbiprofen and S-flurbiprofen in models of inflammatory pain triggered by local administration of lipopolysaccharides (LPS) and carrageenan in mice. Remarkably, the effects of flurbiprofen enantiomers on mechanical hyperalgesia seem to depend on (i) the inflammatory stimuli, (ii) the route of administration, and (iii) the timing of administration. We also assessed the effect of administration of the PG-Gs, PG-EAs, and PGs on LPS-induced mechanical hyperalgesia. Our data support the interest of studying the nonhydrolytic endocannabinoid metabolism in the context of inflammatory pain., (© 2021 Federation of American Societies for Experimental Biology.)

Inflammatory bowel diseases (IBDs), such as Crohn's disease and ulcerative colitis, are lifelong diseases that remain challenging to treat. IBDs are characterized by alterations in intestinal barrier function and dysregulation of the innate and adaptive immunity. An increasing number of lipids are found to be important regulators of inflammation and immunity as well as gut physiology. Therefore, the study of lipid mediators in IBDs is expected to improve our understanding of disease pathogenesis and lead to novel therapeutic opportunities. Here, through selected examples - such as fatty acids, specialized proresolving mediators, lysophospholipids, endocannabinoids, and oxysterols - we discuss how lipid signaling is involved in IBD physiopathology and how modulating lipid signaling pathways could affect IBDs., (Copyright © 2020. Published by Elsevier B.V.)

Cortical lesions represent a hallmark of multiple sclerosis and are proposed as a predictor of disease severity. microRNAs are suggested to be important players in the disease pathogenesis and the experimental autoimmune encephalomyelitis animal model. We implemented a mouse model recapitulating more closely the human pathology as it is characterized by both an autoimmune heterogeneity and the presence of cortical lesions, two parameters missing in experimental autoimmune encephalomyelitis. In our model, mice clustered in two groups displaying high or low clinical scores. Upon cortical cytokine injection, lesions appeared with a specific topography while cortical miRNA profiles were altered. These two features differed according to disease severity. We evidenced changes in miRNA regulators and targets suggesting that miRNA alteration had functional repercussions that could explain the differences in cortical lesions. This model represents a crucial tool for the study of both miRNA involvement and cortical lesion formation in disease pathogenesis., Competing Interests: NO, OG, RC, PB, PH, MC, GO, MA, GM No competing interests declared, (© 2020, Orefice et al.)

There is good evidence that the N-acylethanolamine (NAE)/monoacylglycerol (MAG) signalling systems are involved in the pathogenesis of cancer. However, it is not known how prostate tumours affect these systems in the surrounding non-malignant tissue and vice versa. In the present study we have investigated at the mRNA level 11 components of these systems (three coding for anabolic enzymes, two for NAE/MAG targets and six coding for catabolic enzymes) in rat prostate tissue following orthotopic injection of low metastatic AT1 cells and high metastatic MLL cells. The MLL tumours expressed higher levels of Napepld, coding for a key enzyme in NAE synthesis, and lower levels of Naaa, coding for the NAE hydrolytic enzyme N-acylethanolamine acid amide hydrolase than the AT1 tumours. mRNA levels of the components of the NAE/MAG signalling systems studied in the tissue surrounding the tumours were not overtly affected by the tumours. AT1 cells in culture expressed Faah, coding for the NAE hydrolytic enzyme fatty acid amide hydrolase, at much lower levels than Naaa. However, the ability of the intact cells to hydrolyse the NAE arachidonoylethanolamide (anandamide) was inhibited by an inhibitor of FAAH, but not of NAAA. Treatment of the AT1 cells with interleukin-6, a cytokine known to be involved in the pathogenesis of prostate cancer, did not affect the expression of the components of the NAE/MAG system studied. It is thus concluded that in the model system studied, the tumours show different expressions of mRNA coding for key the components of the NAE/MAG system compared to the host tissue, but that these changes are not accompanied by alterations in the non-malignant tissue.

Interfering with endocannabinoid (eCB) metabolism to increase their levels is a proven anti-nociception strategy. However, because the eCB and prostanoid systems are intertwined, interfering with eCB metabolism will affect the prostanoid system and inversely. Key to this connection is the production of the cyclooxygenase (COX) substrate arachidonic acid upon eCB hydrolysis as well as the ability of COX to metabolize the eCBs anandamide (AEA) and 2-arachidonoylglycerol (2-AG) into prostaglandin-ethanolamides (PG-EA) and prostaglandin-glycerol esters (PG-G), respectively. Recent studies shed light on the role of PG-Gs and PG-EAs in nociception and inflammation. Here, we discuss the role of these complex systems in nociception and new opportunities to alleviate pain by interacting with them., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Lung inflammation plays a crucial role in the pathogenesis of many respiratory diseases that are in need of new therapeutic strategies. Previously, we showed that inhibition of α/β-hydrolase domain 6 (ABHD6) decreased macrophage activation and exerted anti-inflammatory effects. Therefore, we thought to assess the effects of ABHD6 inhibition in a mouse model of acute lung injury (ALI) induced by intratracheal administration of lipopolysaccharides. ABHD6 inhibition with N -methyl- N -{[3-(4-pyridinyl)phenyl]methyl}-carbamic acid 4'-(aminocarbonyl)(1,1'-biphenyl)-4-yl ester (WWL70) decreases most of the hallmarks of ALI, including neutrophil infiltration, cytokine secretion, and protein extravasation. mRNA expression of proinflammatory markers in the cells recovered in the bronchoalveolar lavage was also decreased. Interestingly, ABHD6 inhibition was more efficient than monoacylglycerol lipase inhibition by 4-nitrophenyl-4-[dibenzo(d)(14)dioxol-5-yl(hydroxy)methyl]piperidine-1-carboxylate. We also studied ABHD6 inhibition on primary alveolar macrophages and neutrophils to explore their potential implication in the effects of ABHD6 inhibition in vivo . Moreover, we quantified by high-performance liquid chromatography-mass spectrometry the levels of reported substrates of ABHD6 [ i.e. , 2-arachidonoylglycerol (2-AG) and lysophospholipids]. The potential implication of these lipid mediators in the effects of WWL70 was further investigated on primary alveolar macrophages. Taken together, these data support ABHD6 inhibition as an interesting anti-inflammatory strategy in acute lung inflammation and assess the possible contribution of 2-AG and lysophospholipids in the observed effects.-Bottemanne, P., Paquot, A., Ameraoui, H., Alhouayek, M., Muccioli, G. G. The α/β-hydrolase domain 6 inhibitor WWL70 decreases endotoxin-induced lung inflammation in mice, potential contribution of 2-arachidonoylglycerol, and lysoglycerophospholipids.

Relatively little is known about the endocannabinoid system in human neuroblastoma cell lines. In the present study, we have investigated the expression of the genes coding for the enzymes involved in the synthesis and catabolism of endocannabinoids in the SH-SY5Y cell line. The expression of MGLL, the gene coding for the 2-arachidonoylglycerol hydrolytic enzyme monoacylglycerol lipase (MAGL), was found to be 85 and 340 fold lower than the expression levels for the genes coding for alpha/beta-hydrolase domain containing 6 and 12 (ABHD6, ABHD12), which are alternative hydrolytic enzymes for this endocannabinoid. In comparison, mRNA levels of MGLL were 1.5 fold higher than ABHD6 and 2 fold lower than the levels of ABHD12 in DU-145 human prostate cells. In functional assays, the hydrolysis of the 2-arachidonoylglycerol homologue 2-oleoylglycerol by intact SH-SY5Y cells was partially inhibited by the ABHD6 inhibitor WWL70, but not by the MAGL inhibitor JZL184, whereas the reverse was true in DU-145 cells. The combination of JZL184 + WWL70 did, however produce a significantly greater inhibition of 2-OG hydrolysis than seen with WWL70 alone in the SH-SY5Y cells. The low MGLL expression in the SH-SY5Y cells was not due to epigenetic silencing, since levels were not affected by treatment with the methylation inhibitor 5-aza-2'-deoxycytidine and/or the histone acetylase inhibitor trichostatin A. The low MGLL expression in SH-SY5Y cells should be taken into account when using these cells in experiments investigating the involvement of the endocannabinoid system in models of physiological and pathological processes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The large pore ion channel pannexin-1 (Panx1) has been reported to play a role in the cellular uptake and release of anandamide (AEA) in the hippocampus. It is not known whether this is a general mechanism or limited to the hippocampus. We have investigated this pharmacologically using T84 colon cancer cells. The cells expressed Panx1 at the mRNA level, and released ATP in a manner that could be reduced by treatment with the Panx1 inhibitors carbenoxolone and mefloquine and the Panx1 substrate SR101. However, no significant effects of these compounds upon the uptake or hydrolysis of exogenously applied AEA was seen. Uptake by T84 cells of the other main endocannabinoid 2-arachidonoylglycerol and the AEA homologue palmitoylethanolamide was similarly not affected by carbenoxolone or mefloquine. Total release of tritium from [ 3 H]AEA-prelabelled T84 cells over 10 min was increased, rather than inhibited by carbenoxolone and mefloquine. Finally, AEA uptake by PC3 prostate cancer and SH-SY5Y neuroblastoma cells, which express functional Panx1 channels, was not inhibited by carbenoxolone. Thus, in contrast to the hippocampus, Panx1 does not appear to play a role in AEA uptake and release from the cells studied under the conditions used.

Background and Purpose: Endocannabinoids and related N-acylethanolamines (NAEs) are involved in regulation of gut function, but relatively little is known as to whether inflammatory cytokines such as IFNγ affect their levels. We have investigated this in vitro using cultures of T84 colon cancer cells., Experimental Approach: T84 cells, when cultured in monolayers, differentiate to form adult colonic crypt-like cells with excellent permeability barrier properties. The integrity of the permeability barrier in these monolayers was measured using transepithelial electrical resistance (TEER). NAE levels were determined by ultra-performance liquid chromatography-tandem mass spectrometric analysis. Expression of the enzymes involved in NAE and 2-arachidonoylglycerol (2-AG) turnover were assessed with qPCR., Key Results: IFNγ treatment for 8 or 24 h increased levels of both endocannabinoids (anandamide and 2-AG) and the related NAEs. The treatment did not affect the rate of hydrolysis of either anandamide or palmitoylethanolamide by intact cells, and in both cases, fatty acid amide hydrolase (FAAH) rather than NAE-hydrolysing acid amidase (NAAA) was mainly responsible for the hydrolysis of these NAEs. IFNγ treatment reduced the TEER of the cells in a manner that was not prevented by inhibition of either FAAH or NAAA but was partially reversed by apical administration of the NAE palmitoylethanolamide., Conclusion and Implications: IFNγ treatment mobilized endocannabinoid and related NAE levels in T84 cells. However, blockade of anandamide or NAE hydrolysis was insufficient to negate the deleterious effects of this cytokine upon the permeability barrier of the cell monolayers., Linked Articles: This article is part of a themed section on 8 th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc., (© 2018 The British Pharmacological Society.)

Pain is one of the cardinal signs of inflammation and is present in many inflammatory conditions. Therefore, anti-inflammatory drugs such as NSAIDs also have analgesic properties. We previously showed that prostaglandin D 2 -glycerol ester (PGD 2 -G), endogenously produced by cyclooxygenase-2 from the endocannabinoid 2-arachidonoylglycerol, has anti-inflammatory effects in vitro and in vivo that are partly mediated by DP1 receptor activation. In this work, we investigated its effect in a model of carrageenan-induced inflammatory pain. PGD 2 -G decreased hyperalgesia and edema, leading to a faster recovery. Moreover, PGD 2 -G decreased carrageenan-induced inflammatory markers in the paw as well as inflammatory cell recruitment. The effects of PGD 2 -G were independent from metabolite formation (PGD 2 and 15d-PGJ 2 -G) or DP1 receptor activation in this model. Indeed PGD 2 delayed recovery from hyperalgesia while 15d-PGJ 2 -G worsened the edema. However, while PGD 2 -G decreased hyperalgesia in this model of inflammatory pain, it had no effect when tested in the capsaicin-induced pain model. While the targets mediating the effects of this bioactive lipid in inflammatory pain remain to be elucidated, our findings further support the interest of anti-inflammatory lipid mediators in the management of inflammatory pain., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background and Aims: Inflammatory bowel diseases [IBD] represent a challenging health issue with a complex aetiology involving genetic and environmental parameters. Although our understanding of the pathophysiology of IBD has improved, much remains to be explored. In this context, bioactive lipids, more specifically oxysterols, i.e. oxygenated derivatives of cholesterol, represent an interesting avenue to investigate. Indeed, oxysterols or their receptors are involved in inflammation and immune regulation. Therefore, we set out to study the oxysterome in IBD., Methods: We used both high-performance liquid chromatograph/mass spectroscopy and molecular biology tools to quantify oxysterol levels and the expression of their metabolic enzymes in several models of murine colitis [both acute and chronic], as well as in colon biopsies from patients with Crohn's disease and ulcerative colitis., Results: We found that the oxysterome is altered in IBD, in both acute and chronic murine models as well as in human IBD. Two of the oxysterols quantified, 4β-hydroxycholesterol and 25-hydroxycholesterol, were consistently altered in all our models and therefore could be of interest in this context. Hence, we administered them to mice with colitis. While 25-hydroxycholesterol had no effect, 4β-hydroxycholesterol worsened colon inflammation., Conclusions: Our study addresses the potential involvement of oxysterols in colitis and clearly points towards an active role as well as a clinical relevance for these bioactive lipids.

Little is known about the endocannabinoid (eCB) system in squamous cell carcinoma of the oral tongue (SCCOT). Here we have investigated, at the mRNA level, expression of genes coding for the components of the eCB system in tumour and non-malignant samples from SCCOT patients. Expression of NAPEPLD and PLA2G4E , coding for eCB anabolic enzymes, was higher in the tumour tissue than in non-malignant tissue. Among genes coding for eCB catabolic enzymes, expression of MGLL was lower in tumour tissue while PTGS2 was increased. It is concluded that the eCB system may be dysfunctional in SCCOT.

Lysophosphatidylinositols (LPI) are bioactive lipids that are implicated in several pathophysiological processes such as cell proliferation, migration and tumorigenesis and were shown to play a role in obesity and metabolic disorders. Often, these effects of LPI were due to activation of the G protein-coupled receptor GPR55. However, the role of LPI and GPR55 in inflammation and macrophage activation remains unclear. Therefore, we thought to study the effect of macrophage activation and inflammation on LPI levels and metabolism. To do so, we used J774 and BV2 cells in culture activated with lipopolysaccharides (LPS, 100 ng/mL) as well as primary mouse alveolar and peritoneal macrophages. We also quantified LPI levels in the cerebellum, lung, liver, spleen and colon of mice with a systemic inflammation induced by LPS (300 μg/kg) and in the colon of mice with acute colitis induced by dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) and chronic DSS-induced colitis. Our data show that LPS-induced macrophage activation leads to altered LPI levels in both the cells and culture medium. We also show that cytosolic phospholipase A2α (cPLA2α) and α/β‑hydrolase domain 6 (ABHD6) are among the enzymes implicated in LPI metabolism in J774 macrophages. Indeed, ABHD6 and cPLA2α inhibition increased 20:4-LPI levels in LPS-activated macrophages. Furthermore, incubation of LPS-activated cells with LPI decreased J774 activation in a GPR55-dependent manner. In vivo, LPI levels were altered by inflammation in the liver, spleen and colon. These alterations are tissue dependent and could highlight a potential role for LPI in inflammatory processes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The prevalence of obesity has increased at an alarming rate during past decades. Obesity is associated with pathophysiological disorders that can evolve and increase the risk of heart disease, diabetes and hypertension. While the impact of diabetes on post-operative recovery is now known, the consequences of obesity on post-operative pain remain much less explored. Here, we show that obesity affects post-operative pain resolution and leads to a chronic pain state in mice. Several mechanisms were identified as implicated in the prolonged post-operative pain. Indeed, we found that following a hind paw incision, high fat diet prolonged glial cell activation in the spinal cord. It also altered the expression of neurotrophins and increased inflammatory and endoplasmic reticulum stress markers in both central and peripheral nervous systems. Moreover, we show that a dietary intervention, leading to weight reduction and decreased inflammation, was able to restore normal pain sensitivity in mice suffering from chronic pain for more than 10 weeks. In conclusion, our data demonstrate that obesity is responsible for pain chronicization. This is clearly of importance in a clinical post-operative setting., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cyclooxygenase-2 (COX-2) has long been implicated in the pathogenesis of inflammatory bowel diseases (IBDs). COX-2 is mostly known for the production of prostaglandins (PGs) from arachidonic acid. However, it also metabolizes the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide into the less well-studied bioactive lipids PG-glycerol esters (PG-Gs) and PG-ethanolamides (PG-EAs or prostamides). We previously showed that PGD 2 -G, a product of 2-AG oxygenation by COX-2, has anti-inflammatory effects. Therefore, we used the dextran sulfate sodium (DSS)-induced model of colitis in mice to explore the role of PGD 2 -G in murine models of IBD. Colon inflammation was assessed using macroscopic and histologic scores, myeloperoxidase activity, and expression of inflammatory mediators by real-time quantitative PCR and ELISA. We also compared the effects of PGD 2 -G with those of PGD 2 and PGD 2 -EA. Finally, we used receptor antagonists to gain mechanistic insight into the receptors responsible for the observed effects. PGD 2 -G reduced DSS-induced colitis, but PGD 2 and PGD 2 -EA did not have the same effect. Furthermore, we showed that PGD 2 -G is an agonist of the PGD 2 receptor 1 (DP1) and that some of the effects of PGD 2 -G were blocked by antagonism of peroxisome proliferator-activated receptor γ and DP1. Therefore, PGD 2 -G could be one of the products from the COX-2/prostaglandin D synthase axis to exert beneficial effects in colitis.-Alhouayek, M., Buisseret, B., Paquot, A., Guillemot-Legris, O., Muccioli, G. G. The endogenous bioactive lipid prostaglandin D 2 -glycerol ester reduces murine colitis via DP1 and PPARγ receptors.

N-acylethanolamines (NAEs) (e.g., N-palmitoylethanolamine, N-arachidonoylethanolamine, N-oleoylethanolamine) are bioactive lipids involved in many physiological processes including pain, inflammation, anxiety, cognition and food intake. Two enzymes are responsible for the hydrolysis of NAEs and therefore regulate their endogenous levels and effects: fatty acid amide hydrolase (FAAH) and N-acylethanolamine-hydrolyzing acid amidase (NAAA). As discussed here, extensive biochemical characterization of NAAA was carried out over the years that contributed to a better understanding of NAAA enzymology. An increasing number of studies describe the synthesis and pharmacological characterization of NAAA inhibitors. Recent medicinal chemistry efforts have led to the development of potent and stable inhibitors that enable studying the effects of NAAA inhibition in preclinical disease models, notably in the context of pain and inflammation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In the original publication, sixth author's surname was incorrectly published as "Llyod" instead of "Lloyd". The correct name should read as "Amy Lloyd".

Secondary damage following spinal cord injury leads to non-reversible lesions and hampering of the reparative process. The local production of pro-inflammatory cytokines such as TNF-α can exacerbate these events. Oligodendrocyte death also occurs, followed by progressive demyelination leading to significant tissue degeneration. Dental stem cells from human apical papilla (SCAP) can be easily obtained at the removal of an adult immature tooth. This offers a minimally invasive approach to re-use this tissue as a source of stem cells, as compared to biopsying neural tissue from a patient with a spinal cord injury. We assessed the potential of SCAP to exert neuroprotective effects by investigating two possible modes of action: modulation of neuro-inflammation and oligodendrocyte progenitor cell (OPC) differentiation. SCAP were co-cultured with LPS-activated microglia, LPS-activated rat spinal cord organotypic sections (SCOS), and LPS-activated co-cultures of SCOS and spinal cord adult OPC. We showed for the first time that SCAP can induce a reduction of TNF-α expression and secretion in inflamed spinal cord tissues and can stimulate OPC differentiation via activin-A secretion. This work underlines the potential therapeutic benefits of SCAP for spinal cord injury repair.

Lysophosphatidylinositols (LPIs) are membrane constituents that alter the properties of said membranes. However, recent data showing that the once orphan receptor, GPR55, can act as a receptor for LPIs has sparked a renewed interest in LPIs as bioactive lipids. As evidence supporting the importance of LPIs and/or GPR55 is continuously accumulating and because LPI levels are altered in a number of pathologies such as obesity and cancer, the coming years should bring new, exciting discoveries to this field. In this review, we discuss the recent work on LPIs and on their molecular target, the GPR55 receptor. First, we summarize the metabolism of LPIs before outlining the cellular pathways activated by GPR55. Then, we review the actions of LPIs and GPR55 that could have potential pharmacological or therapeutic applications in several pathophysiological settings, such as cancer, obesity, pain, and inflammation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Monoacylglycerol lipase (MAGL) is the principle enzyme for metabolizing endogenous cannabinoid ligand 2-arachidonoyglycerol (2-AG). Blockade of MAGL increases 2-AG levels, resulting in subsequent activation of the endocannabinoid system, and has emerged as a novel therapeutic strategy to treat drug addiction, inflammation, and neurodegenerative diseases. Herein we report a new series of MAGL inhibitors, which were radiolabeled by site-specific labeling technologies, including 11 C-carbonylation and spirocyclic iodonium ylide (SCIDY) radiofluorination. The lead compound [ 11 C]10 (MAGL-0519) demonstrated high specific binding and selectivity in vitro and in vivo. We also observed unexpected washout kinetics with these irreversible radiotracers, in which in vivo evidence for turnover of the covalent residue was unveiled between MAGL and azetidine carboxylates. This work may lead to new directions for drug discovery and PET tracer development based on azetidine carboxylate inhibitor scaffold.

Background: Oxysterols are cholesterol derivatives that have been suggested to play a role in inflammatory diseases such as obesity, atherosclerosis, or neuroinflammatory diseases. However, the effect of neuroinflammation on oxysterol levels has only been partially studied so far., Methods: We used an HPLC-MS method to quantify over ten oxysterols both in in vitro and in vivo models of neuroinflammation. In the same models, we used RT-qPCR to analyze the expression of the enzymes responsible for oxysterol metabolism. Using the BV2 microglial cell line, we explored the effect of lipopolysaccharide (LPS)-induced (M1-type) and IL-4-induced (M2-type) cell activation on oxysterol levels. We also used LPS-activated co-cultures of mouse primary microglia and astrocytes. In vivo, we induced a neuroinflammation by administering LPS to mice. Finally, we used a mouse model of multiple sclerosis, namely the experimental autoimmune encephalomyelitis (EAE) model, that is characterized by demyelination and neuroinflammation., Results: In vitro, we found that LPS activation induces profound alterations in oxysterol levels. Interestingly, we could discriminate between control and LPS-activated cells based on the changes in oxysterol levels both in BV2 cells and in the primary co-culture of glial cells. In vivo, the changes in oxysterol levels were less marked than in vitro. However, we found in both models increased levels of the GPR183 agonist 7α,25-dihydroxycholesterol. Furthermore, we studied in vitro the effect of 14 oxysterols on the mRNA expression of inflammatory markers in LPS-activated co-culture of microglia and astrocytes. We found that several oxysterols decreased the LPS-induced expression of pro-inflammatory markers., Conclusions: These data demonstrate that inflammation profoundly affects oxysterol levels and that oxysterols can modulate glial cell activation. This further supports the interest of a large screening of oxysterol levels when studying the interplay between neuroinflammation and bioactive lipids.

Background and Purpose: CYP1B1 and CYP1A1 are important extra-hepatic cytochromes, expressed in the colon and involved in the metabolism of dietary constituents and exogenous compounds. CYP1B1 expression is increased by pro-inflammatory cytokines, and it has been recently implicated in regulation of blood brain barrier function. We investigated its involvement in the increased permeability of the intestinal epithelial barrier observed in inflammatory conditions., Experimental Approach: Epithelial monolayers formed by human T84 colon carcinoma cells cultured on transwells, were disrupted by incubation with IFNγ (10 ng·mL -1 ). Monolayer integrity was measured using transepithelial electrical resistance. CYP1A1 and CYP1B1 inhibitors or inducers were applied apically. Potential mechanisms of action were investigated using RT-qPCR., Key Results: IFNγ disrupts the barrier integrity of the T84 monolayers and increases CYP1B1 and HIF1α mRNA expression. CYP1B1 induction is inhibited by the NF-κB inhibitor ammonium pyrrolidinedithiocarbamate (100 μM) but not by the HIF1α inhibitor 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (50 μM). Inhibition of CYP1B1 with the selective inhibitor 2,4,3',5'-tetramethoxystilbene (100 nM) partly reverses the effects of IFNγ on epithelial permeability., Conclusions and Implications: These data suggest that increased expression of CYP1B1 is involved in the effects of IFNγ on epithelial permeability. Inhibition of CYP1B1 counteracts the alterations of epithelial barrier integrity induced by IFNγ and could thus have a therapeutic potential in disorders of intestinal permeability associated with inflammation., (© 2017 The British Pharmacological Society.)

L cells are enteroendocrine cells located throughout the gastrointestinal tract that secrete physiologically important peptides. The most characterized peptides secreted by L cells are the peptide YY (PYY) and the glucagon-like peptides 1 (GLP-1) and 2 (GLP-2). These peptides are released rapidly into the circulation after oral nutrient ingestion. Recently, lipid-based nanoparticles (NP) have been described as triggers for GLP-1 secretion by L cells. NP physicochemical properties play a key role in the NP-cell interaction, and drive NP cell internalization. We herein hypothesize that lipid-based NP with appropriate size would not only be able to deliver drugs into blood circulation but also act like endogenous ligands to stimulate GLP-1 secretion. We tested five different size (25, 50, 100, 150, and 200 nm) lipid nanocapsules (LNC) on murine L cells in vitro to confirm this hypothesis. Our study showed that GLP-1 secretion was induced only by the 200 nm size LNC, highlighting the importance of LNC particle size on the secretion of GLP-1 by L cells. The different formulations did not affect proglucagon mRNA expression, suggesting that there was not an increased GLP-1 synthesis. As a proof of concept, we further demonstrated in normoglycemic mice that 200 nm LNC administration increases GLP-1 levels by 4- and 3-fold compared to untreated control mice 60 and 180 min after the administration, respectively. Our study suggests that 200 nm LNC as a nanocarrier to encapsulate drug candidates and as a ligand to induce endogenous GLP-1 secretion might represent a promising strategy for type 2 diabetes mellitus treatment.

TLR4 respond to bacterial LPS to produce inflammatory cytokines. TLR4 are expressed in dorsal root ganglia and play a role in pain. F11 dorsal root ganglia × mouse neuroblastoma cells possess many of the properties seen in nociceptive dorsal root ganglia neuronal cells. Here, we investigated the effect of 2 h and 6 h treatment with LPS upon the expression of inflammatory proteins in undifferentiated and differentiated F11 cells. The cells expressed mRNA for TRL4 (mouse, not rat) and proteins involved in TLR4 signaling. TLR4 expression was confirmed using immunohistochemistry. LPS produced modest increases in mouse and rat IL-6 and in mouse cyclooxygenase-2 levels in undifferentiated cells, but did not significantly affect mouse TNF-α expression. This contrasts with the robust effects of LPS upon cyclooxygenase-2 expression in cultured dorsal root ganglia neurons. F11 cells expressed the endocannabinoid metabolizing enzymes fatty acid amide hydrolase and N-acylethanolamine acid amidase (both murine), which were functionally active. These data suggest that F11 cells are not a useful model for the study of LPS-mediated effects but may be useful for the study of endocannabinoid catabolism.

Acute inflammation is characterized by granulocyte infiltration followed by efferocytosing mononuclear phagocytes, which pave the way for inflammatory resolution. Until now, it was believed that resolution then leads back to homeostasis, the physiological state tissues experience before inflammation occurred. However, we discovered that resolution triggered a prolonged phase of immune suppression mediated by prostanoids. Specifically, once inflammation was switched off, natural killer cells, secreting interferon γ (IFNγ), infiltrated the post-inflamed site. IFNγ upregulated microsomal prostaglandin E synthase-1 (mPGES-1) alongside cyclo-oxygenase (COX-1) within macrophage populations, resulting in sustained prostaglandin (PG)E 2 biosynthesis. Whereas PGE 2 suppressed local innate immunity to bacterial infection, it also inhibited lymphocyte function and generated myeloid-derived suppressor cells, the net effect of which was impaired uptake/presentation of exogenous antigens. Therefore, we have defined a sequence of post-resolution events that dampens the propensity to develop autoimmune responses to endogenous antigens at the cost of local tissue infection., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Tumour necrosis factor α (TNFα) is involved in the pathogenesis of prostate cancer, a disease where disturbances in the endocannabinoid system are seen. In the present study we have investigated whether treatment of DU145 human prostate cancer cells affects anandamide (AEA) catabolic pathways. Additionally, we have investigated whether cyclooxygenase-2 (COX-2) can regulate the uptake of AEA into cells. Levels of AEA synthetic and catabolic enzymes were determined by qPCR. AEA uptake and hydrolysis in DU145 and RAW264.7 macrophage cells were assayed using AEA labeled in the arachidonic and ethanolamine portions of the molecule, respectively. Levels of AEA, related N-acylethanolamines (NAEs), prostaglandins (PG) and PG-ethanolamines (PG-EA) in DU145 cells and medium were quantitated by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. TNFα treatment of DU145 cells increased mRNA levels of PTSG2 (gene of COX-2) and decreased the mRNA of the AEA synthetic enzyme N-acyl-phosphatidylethanolamine selective phospholipase D. mRNA levels of the AEA hydrolytic enzymes fatty acid amide hydrolase (FAAH) and N-acylethanolamine-hydrolyzing acid amidase were not changed. AEA uptake in both DU145 and RAW264.7 cells was inhibited by FAAH inhibition, but not by COX-2 inhibition, even in RAW264.7 cells where the expression of this enzyme had greatly been induced by lipopolysaccharide + interferon γ treatment. AEA and related NAEs were detected in DU145 cells, but PGs and PGE2-EA were only detected when the cells had been preincubated with 100 nM AEA. The data demonstrate that in DU145 cells, TNFα treatment changes the relative expression of the enzymes involved in the hydrolytic and oxygenation catabolic pathways for AEA. In RAW264.7 cells, COX-2, in contrast to FAAH, does not regulate the cellular accumulation of AEA. Further studies are necessary to determine the extent to which inflammatory mediators are involved in the abnormal endocannabinoid signalling system in prostate cancer.

N-acylethanolamines (NAEs) such as N-palmitoylethanolamine and anandamide are endogenous bioactive lipids having numerous functions, including the control of inflammation. Their levels and therefore actions can be controlled by modulating the activity of two hydrolytic enzymes, N-acylethanolamine-hydrolyzing acid amidase (NAAA) and fatty acid amide hydrolase (FAAH). As macrophages are key to inflammatory processes, we used lipopolysaccharide-activated J774 macrophages, as well as primary mouse alveolar macrophages, to study the effect of FAAH and NAAA inhibition, using PF-3845 and AM9053 respectively, on macrophage activation and NAE levels measured by HPLC-MS. Markers of macrophage activation were measured by qRT-PCR and ELISA. Activation of macrophages decreased NAAA expression and NAE hydrolytic activity. FAAH and NAAA inhibition increased the levels of the different NAEs, although with different magnitudes, whether in control condition or following LPS-induced macrophage activation. Both inhibitors reduced several markers of macrophage activation, such as mRNA expression of inflammatory mediators, as well as cytokine and prostaglandin production, with however some differences between FAAH and NAAA inhibition. Most of the NAEs tested - including N-docosatetraenoylethanolamine and N-docosahexaenoylethanolamine - also reduced LPS-induced mRNA expression of inflammatory mediators, again with differences depending on the marker and the NAE, thus offering a potential explanation for the differential effect of the inhibitors on macrophage activation markers. In conclusion, we show different and complementary effects of NAE on lipopolysaccharide-induced macrophage activation. Our results support an important role for inhibition of NAE hydrolysis and NAAA inhibition in particular in controlling macrophage activation, and thus inflammation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The anti-inflammatory agent palmitoylethanolamide (PEA) reduces cyclooxygenase (COX) activity in vivo in a model of inflammatory pain. It is not known whether the compound reduces prostaglandin production in RAW264.7 cells, whether such an action is affected by compounds preventing the breakdown of endogenous PEA, whether other oxylipins are affected, or whether PEA produces direct effects upon the COX-2 enzyme. RAW264.7 cells were treated with lipopolysaccharide and interferon- γ to induce COX-2. At the level of mRNA, COX-2 was induced >1000-fold following 24 h of the treatment. Coincubation with PEA (10  μ mol/L) did not affect the levels of COX-2, but reduced the levels of prostaglandins D 2 and E 2 as well as 11- and 15-hydroxyeicosatetraenoic acid, which can also be synthesised by a COX-2 pathway in macrophages. These effects were retained when hydrolysis of PEA to palmitic acid was blocked. Linoleic acid-derived oxylipin levels were not affected by PEA. No direct effects of PEA upon the oxygenation of either arachidonic acid or 2-arachidonoylglycerol by COX-2 were found. It is concluded that in lipopolysaccharide and interferon- γ -stimulated RAW264.7 cells, PEA reduces the production of COX-2-derived oxylipins in a manner that is retained when its metabolism to palmitic acid is inhibited.

L cells have attracted particular interest because of the pleiotropic effects of their secreted peptides (i.e., glucagon-like peptide (GLP) 1 and 2, peptide YY (PYY)). L cells express different G-protein-coupled receptors (GPCRs) that can be activated by endogenous ligands found in the gut lumen. We herein hypothesized that lipid-based nanoparticles could mimic endogenous ligands and thus activate GLP-1 secretion in type 2 diabetes mellitus treatment. To assess this hypothesis, lipid-based nanoparticles (nanostructured lipid carriers (NLC), lipid nanocapsules (LNC), and liposomes) and PLGA nanoparticles were added to the L cells and GLP-1 secretion was quantified. Among these nanoparticles, only NLC resulted effective at inducing GLP-1 secretion in both murine and human L cells in vitro. The mRNA expression of proglucagon showed that this effect was due to an increased GLP-1 secretion and not to an increased GLP-1 synthesis. The mechanism by which NLC triggered GLP-1 secretion by L cells revealed an extracellular interaction of NLC, exerting a physiological GLP-1 secretion. We herein demonstrate that nanomedicine can be used to induce GLP-1 secretion from murine and human L cells.

Background: Obesity and its associated disorders are becoming a major health issue in many countries. The resulting low-grade inflammation not only affects the periphery but also the central nervous system. We set out to study, in a time-dependent manner, the effects of a high-fat diet on different regions of the central nervous system with regard to the inflammatory tone., Methods: We used a diet-induced obesity model and compared at several time-points (1, 2, 4, 6, 8, and 16 weeks) a group of mice fed a high-fat diet with its respective control group fed a standard diet. We also performed a large-scale analysis of lipids in the central nervous system using HPLC-MS, and we then tested the lipids of interest on a primary co-culture of astrocytes and microglial cells., Results: We measured an increase in the inflammatory tone in the cerebellum at the different time-points. However, at week 16, we evidenced that the inflammatory tone displayed significant differences in two different regions of the central nervous system, specifically an increase in the cerebellum and no modification in the cortex for high-fat diet mice when compared with chow-fed mice. Our results clearly suggest region-dependent as well as time-dependent adaptations of the central nervous system to the high-fat diet. The differences in inflammatory tone between the two regions considered seem to involve astrocytes but not microglial cells. Furthermore, a large-scale lipid screening coupled to ex vivo testing enabled us to identify three classes of lipids-phosphatidylinositols, phosphatidylethanolamines, and lysophosphatidylcholines-as well as palmitoylethanolamide, as potentially responsible for the difference in inflammatory tone., Conclusions: This study demonstrates that the inflammatory tone induced by a high-fat diet does not similarly affect distinct regions of the central nervous system. Moreover, the lipids identified and tested ex vivo showed interesting anti-inflammatory properties and could be further studied to better characterize their activity and their role in controlling inflammation in the central nervous system.

Selective drug delivery to inflamed tissues is of widespread interest for the treatment of inflammatory bowel disease (IBD). Because a lack of physiological lipids has been described in patients suffering IBD, and some lipids present immunomodulatory properties, we hypothesize that the combination of lipids and anti-inflammatory drugs together within a nanocarrier may be a valuable strategy for overcoming IBD. In the present study, we investigated and compared the in vitro and in vivo efficacy of three lipid-based nanocarriers containing curcumin (CC) as an anti-inflammatory drug for treating IBD in a murine DSS-induced colitis model. These nanocarriers included self-nanoemulsifying drug delivery systems (SNEDDS), nanostructured lipid carriers (NLC) and lipid core-shell protamine nanocapsules (NC). In vitro, a 30-fold higher CC permeability across Caco-2 cell monolayers was obtained using NC compared to SNEDDS (NC>SNEDDS>NLC and CC suspension). The CC SNEDDS and CC NLC but not the CC NC or CC suspension significantly reduced TNF-α secretion by LPS-activated macrophages (J774 cells). In vivo, only CC NLC were able to significantly decrease neutrophil infiltration and TNF-α secretion and, thus, colonic inflammation. Our results show that a higher CC permeability does not correlate with a higher efficacy in IBD treatment, which suggests that lipidic nanocarriers exhibiting increased CC retention at the intestinal site, rather than increased CC permeability are efficient treatments of IBD., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Cyclosporine A (CsA) is a well-known immunosuppressive agent used as rescue therapy in severe steroid-refractory ulcerative colitis (UC). However, toxicity issues associated with CsA when administered in its commercially available formulations have been reported in clinical practice. Since nanotechnology has been proposed as a promising strategy to improve safety and efficacy in the treatment of inflammatory bowel disease (IBD), the main purpose of this study was to evaluate the effect of oral administration of CsA-loaded lipid nanoparticles (LN) in the dextran sodium sulfate (DSS)-induced colitis mouse model using Sandimmune Neoral(®) as reference. The results showed that the formulations used did not decrease colon inflammation in terms of myeloperoxidase activity (MPO), tumor necrosis factor (TNF)-α expression, or histological scoring in the acute stage of the disease. However, further studies are needed in order to corroborate the efficacy of these formulations in the chronic phase of the disease., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Palmitoylethanolamide (PEA) is an endogenous lipid mediator known to reduce pain and inflammation. However, only limited clinical studies have evaluated the effects of PEA in neuroinflammatory and neurodegenerative diseases. Multiple sclerosis (MS) is a chronic autoimmune and inflammatory disease of the central nervous system. Although subcutaneous administration of interferon (IFN)-β1a is approved as first-line therapy for the treatment of relapsing-remitting MS (RR-MS), its commonly reported adverse events (AEs) such as pain, myalgia, and erythema at the injection site, deeply affect the quality of life (QoL) of patients with MS. In this randomized, double-blind, placebo-controlled study, we tested the effect of ultramicronized PEA (um-PEA) added to IFN-β1a in the treatment of clinically defined RR-MS. The primary objectives were to estimate whether, with um-PEA treatment, patients with MS perceived an improvement in pain and a decrease of the erythema width at the IFN-β1a injection site in addition to an improvement in their QoL. The secondary objectives were to evaluate the effects of um-PEA on circulating interferon-γ, tumor necrosis factor-α, and interleukin-17 serum levels, N-acylethanolamine plasma levels, Expanded Disability Status Scale (EDSS) progression, and safety and tolerability after 1 year of treatment. Patients with MS receiving um-PEA perceived an improvement in pain sensation without a reduction of the erythema at the injection site. A significant improvement in QoL was observed. No significant difference was reported in EDSS score, and um-PEA was well tolerated. We found a significant increase of palmitoylethanolamide, anandamide and oleoylethanolamide plasma levels, and a significant reduction of interferon-γ, tumor necrosis factor-α, and interleukin-17 serum profile compared with the placebo group. Our results suggest that um-PEA may be considered as an appropriate add-on therapy for the treatment of IFN-β1a-related adverse effects in RR-MS.

Obesity is a pandemic disease associated with many metabolic alterations and involves several organs and systems. The endocannabinoid system (ECS) appears to be a key regulator of energy homeostasis and metabolism. Here we show that specific deletion of the ECS synthesizing enzyme, NAPE-PLD, in adipocytes induces obesity, glucose intolerance, adipose tissue inflammation and altered lipid metabolism. We report that Napepld-deleted mice present an altered browning programme and are less responsive to cold-induced browning, highlighting the essential role of NAPE-PLD in regulating energy homeostasis and metabolism in the physiological state. Our results indicate that these alterations are mediated by a shift in gut microbiota composition that can partially transfer the phenotype to germ-free mice. Together, our findings uncover a role of adipose tissue NAPE-PLD on whole-body metabolism and provide support for targeting NAPE-PLD-derived bioactive lipids to treat obesity and related metabolic disorders.

N-Palmitoylethanolamine or palmitoylethanolamide (PEA) is an anti-inflammatory compound that was recently shown to exert peroxisome proliferator-activated receptor-α-dependent beneficial effects on colon inflammation. The actions of PEA are terminated following hydrolysis by 2 enzymes: fatty acid amide hydrolase (FAAH), and the less-studied N-acylethanolamine-hydrolyzing acid amidase (NAAA). This study aims to investigate the effects of inhibiting the enzymes responsible for PEA hydrolysis in colon inflammation in order to propose a potential therapeutic target for inflammatory bowel diseases (IBDs). Two murine models of IBD were used to assess the effects of NAAA inhibition, FAAH inhibition, and PEA on macroscopic signs of colon inflammation, macrophage/neutrophil infiltration, and the expression of proinflammatory mediators in the colon, as well as on the colitis-related systemic inflammation. NAAA inhibition increases PEA levels in the colon and reduces colon inflammation and systemic inflammation, similarly to PEA. FAAH inhibition, however, does not increase PEA levels in the colon and does not affect the macroscopic signs of colon inflammation or immune cell infiltration. This is the first report of an anti-inflammatory effect of a systemically administered NAAA inhibitor. Because NAAA is the enzyme responsible for the control of PEA levels in the colon, we put forth this enzyme as a potential therapeutic target in chronic inflammation in general and IBD in particular., (© FASEB.)