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High‐throughput drug screening enables the discovery of new anticancer drugs. Although monolayer cell cultures are commonly used for screening, their limited complexity and translational efficiency require alternative models. Three‐dimensional cell cultures, such as multicellular tumor spheroids (MCTS), mimic tumor architecture and offer promising opportunities for drug discovery. In this study, we developed a neuroblastoma MCTS model for high‐content drug screening. We also aimed to decipher the mechanisms underlying synergistic drug combinations in this disease model. Several agents from different therapeutic categories and with different mechanisms of action were tested alone or in combination with selective inhibition of prostaglandin E2 by pharmacological inhibition of microsomal prostaglandin E synthase‐1 (mPGES‐1). After a systematic investigation of the sensitivity of individual agents and the effects of pairwise combinations, GFP‐transfected MCTS were used in a confirmatory screen to validate the hits. Finally, inhibitory effects on multidrug resistance proteins were examined. In summary, we demonstrate how MCTS‐based high‐throughput drug screening has the potential to uncover effective drug combinations and provide insights into the mechanism of synergy between an mPGES‐1 inhibitor and chemotherapeutic agents.

High‐throughput drug screening enables the discovery of new anticancer drugs. Although monolayer cell cultures are commonly used for screening, their limited complexity and translational efficiency require alternative models. Three‐dimensional cell cultures, such as multicellular tumor spheroids (MCTS), mimic tumor architecture and offer promising opportunities for drug discovery. In this study, we developed a neuroblastoma MCTS model for high‐content drug screening. We also aimed to decipher the mechanisms underlying synergistic drug combinations in this disease model. Several agents from different therapeutic categories and with different mechanisms of action were tested alone or in combination with selective inhibition of prostaglandin E2 by pharmacological inhibition of microsomal prostaglandin E synthase‐1 (mPGES‐1). After a systematic investigation of the sensitivity of individual agents and the effects of pairwise combinations, GFP‐transfected MCTS were used in a confirmatory screen to validate the hits. Finally, inhibitory effects on multidrug resistance proteins were examined. In summary, we demonstrate how MCTS‐based high‐throughput drug screening has the potential to uncover effective drug combinations and provide insights into the mechanism of synergy between an mPGES‐1 inhibitor and chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Some novel triazole-bearing ketone and oxime derivatives were synthesized from Ibuprofen. In vitro cytotoxic activities of all synthesized molecules against five cancer lines (human breast cancer MCF-7, human lung cancer A549, human prostate cancer PC-3, human cervix cancer HeLa, and human chronic myelogenous leukemia K562 cell lines) were evaluated by MTT assay. In addition, mouse embryonic fibroblast cells (NIH/3T3) were also evaluated to determine the selectivity. Compounds 18, 36, and 45 were found to be the most cytotoxic, and their IC50 values were in the range of 17.46–68.76 µM, against the tested cancer cells. According to the results, compounds 7 and 13 demonstrated good anti-inflammatory activity against the microsomal enzyme prostaglandin E2 synthase-1 (mPGES-1) enzyme at IC50 values of 13.6 and 4.95 µM. The low cytotoxicity and non-mutagenity of these compounds were found interesting. Also, these compounds significantly prevented tube formation in angiogenesis studies. In conclusion, the anti-inflammatory and angiogenesis inhibitory activities of these compounds without toxicity suggested that they may be promising agents in anti-inflammatory treatment and they may be supportive agents for the cancer treatment. [ABSTRACT FROM AUTHOR]

Studies on the development of safe anti-inflammatory agents targeting the inhibition of the mPGES-1 enzyme responsible for PGE2 production are increasing day by day. Moreover, selective inhibition of the mPGES-1 enzyme which modulates the tumor microenvironment and inhibits tumor growth, making the mPGES-1 enzyme one of the important macromolecular targets in cancer therapy. The aim of our study was to develop selective mPGES-1 inhibitors and to determine their in silico mPGES-1 enzyme inhibition potential. In this study, the binding affinities of 14 novel designed 5-benzylidene-2-(arylsulfonylhydrazono)thiazolidine-4-one derivatives were investigated against mPGES-1 and COX-2 enzymes by computer-aided molecular modeling studies. Among the designed compounds 1-14, it was presented with in silico data that compound 8-14, which does not interact with the active site of the COX-2 enzyme, exhibited selective binding with mPGES-1 enzyme. Moreover, compounds 10-13 have been suggested as selective mPGES-1 inhibitors with a better in silico binding energy than the first discovered mPGES-1 inhibitor MK886. Finally, ADMET profiles of compounds 1-14 were calculated. None of these compounds violated the Lipinski and Veber rules. [ABSTRACT FROM AUTHOR]

mPGES-1 is an enzyme, which, when activated by inflammatory factors, can cause prostaglandin E synthesis. Traditional non-steroidal anti-inflammatory drugs are capable of inhibiting prostaglandin production, yet they can also cause gastrointestinal reactions and coagulation disorders. mPGES-1, the enzyme at the conclusion of prostaglandin production, does not cause any adverse reactions when inhibited. Numerous studies have demonstrated that mPGES-1 is more abundant in cancerous cells than in healthy cells, indicating that decreasing the expression of mPGES-1 could be a potential therapeutic strategy for cancer. Consequently, the invention of mPGES-1 inhibitors presents a fresh avenue for the treatment of inflammation and cancer. Incorporating a database of TCM compounds, we collected a batch of compounds that had an inhibitory effect on mPGES-1 and possessed IC50 value. Firstly, a pharmacophore model was constructed, and the TCM database was screened, and the compounds with score cut-off values of more than 1 were retained. Then, the compounds retained after being screened via the pharmacodynamic model were screened for docking at the mPGES-1 binding site, followed by high-throughput virtual screening [HTVS] and standard precision [SP] and super-precision [XP] docking, and the compounds in the top 20% of the XP docking score were selected to calculate the total free binding energy of MM-GBSA. The best ten compounds were chosen by comparing their score against the reference ligand 4U9 and the MM-GBSA_dG_Bind score. ADMET analysis resulted in the selection of ten compounds, three of which had desirable medicinal properties. Finally, the binding energy of the target protein mPGES-1 and the candidate ligand compound was analyzed using a 100 ns molecular dynamics simulation of the reference ligand 4U9 and three selected compounds. After a gradual screening study and analysis, we identified a structure that is superior to the reference ligand 4U9 in all aspects, namely compound 15643. Taken together, the results of this study reveal a structure that can be used to inhibit mPGES-1 compound 15643, thereby providing a new option for anti-inflammatory and anti-tumor drugs. [ABSTRACT FROM AUTHOR]

Background and Purpose: Heart failure with reduced ejection fraction (HFrEF) is a major consequence of myocardial infarction (MI). The microsomal prostaglandin E synthase‐1 (mPGES‐1)/PGE2 pathway has been shown to constrain reperfusion injury after acute myocardial ischaemia. However, it is unknown whether pharmacological inhibition of mPGES‐1, a target with lower risk of thrombosis compared with selective inhibition of cyclooxygenase‐2, affects chronic cardiac remodelling after MI. Experimental Approach: Mice were subjected to left anterior descending coronary artery ligation, followed by intraperitoneal treatment with the mPGES‐1 inhibitor compound III (CIII) or 118, celecoxib (cyclooxygenase‐2 inhibitor) or vehicle, once daily for 28 days. Urinary prostanoid metabolites were measured by liquid chromatography–tandem mass spectrometry. Key Results: Chronic administration of CIII improved cardiac function in mice after MI compared with vehicle or celecoxib. CIII did not affect thrombogenesis or blood pressure. In addition, CIII reduced infarct area, augmented scar thickness, decreased collagen I/III ratio, decreased the expression of fibrosis‐related genes and increased capillary density in the ischaemic area. Shunting to urinary metabolites of PGI2, not thromboxane B2 or PGD2, after inhibition of mPGES‐1 was positively correlated with cardiac function after MI. CIII administration significantly increased urinary PGI2/PGE2 metabolite ratio compared to vehicle or celecoxib. The PGI2/PGE2 metabolite ratio correlated positively with ejection fraction, fractional shortening and scar thickness. Treatment with 118 also improved cardiac function. Conclusion and Implications: Inhibition of mPGES‐1 prevented chronic adverse cardiac remodelling via an augmented PGI2/PGE2 metabolite ratio and therefore represents a potential therapeutic strategy for development of HFrEF after MI. [ABSTRACT FROM AUTHOR]

Aims Microsomal prostaglandin E synthase-1 (mPGES-1)/prostaglandin E2 (PGE2) induces angiogenesis through the prostaglandin E2 receptor (EP1–4). Among immune cells, regulatory T cells (Tregs), which inhibit immune responses, have been implicated in angiogenesis, and PGE2 is known to modulate the function and differentiation of Tregs. We hypothesized that mPGES-1/PGE2-EP signalling could contribute to recovery from ischaemic conditions by promoting the accumulation of Tregs. Methods and results Wild-type (WT), mPGES-1-deficient (mPges-1−/−), and EP4 receptor-deficient (Ep4−/−) male mice, 6–8 weeks old, were used. Hindlimb ischaemia was induced by femoral artery ligation. Recovery from ischaemia was suppressed in mPges-1−/− mice and compared with WT mice. The number of accumulated forkhead box protein P3 (FoxP3)+ cells in ischaemic muscle tissue was decreased in mPges-1−/− mice compared with that in WT mice. Expression levels of transforming growth factor-β (TGF-β) and stromal cell derived factor-1 (SDF-1) in ischaemic tissue were also suppressed in mPges-1−/− mice. The number of accumulated FoxP3+ cells and blood flow recovery were suppressed when Tregs were depleted by injecting antibody against folate receptor 4 in WT mice but not in mPges-1−/− mice. Recovery from ischaemia was significantly suppressed in Ep4−/− mice compared with that in WT mice. Furthermore, mRNA levels of Foxp3 and Tgf-β were suppressed in Ep4−/− mice. Moreover, the number of accumulated FoxP3+ cells in ischaemic tissue was diminished in Ep4−/− mice compared with that in Ep4+/+ mice. Conclusion These findings suggested that mPGES-1/PGE2 induced neovascularization from ischaemia via EP4 by promoting the accumulation of Tregs. Highly selective EP4 agonists could be useful for the treatment of peripheral artery disease. [ABSTRACT FROM AUTHOR]

A deep in silico investigation of various microsomal prostaglandin E2 synthase‐1 (mPGES‐1) protein systems is here reported using molecular dynamics (MD) simulations. Firstly, eight different proteins models (Models A−H) were built, starting from the active enzyme trimer system (Model A), namely that bound to three glutathione (GSH) cofactor molecules, and then gradually removing the GSHs (Models B−H), simulating each of them for 100 ns in explicit solvent. The analysis of the obtained data disclosed the structural role of GSH in the chemical architecture of mPGES‐1 enzyme, thus suggesting the unlikely displacement of this cofactor, in accordance with experimentally determined protein structures co‐complexed with small molecule inhibitors. Afterwards, Model A was submitted to microsecond‐scale molecular dynamics simulation (total simulation time=10 μs), in order to shed light about the dynamical behaviour of this enzyme at atomic level and to obtain further structural features and protein function information. We confirmed the structural stability of the enzyme machinery, observing a conformational rigidity of the protein, with a backbone RMSD of ∼3 Å along the simulation time, and highlighting the strong active contribution of GSH molecules due to their active role in packing the protein chains through a tight binding at monomer interfaces. Furthermore, the focused analysis on R73 residue disclosed its role in solvent exchange events, probably excluding its function as route for GSH to enter towards the endoplasmic reticulum membrane, in line with the recently reported function of cap domain residues F44‐D66 as gatekeeper for GSH entrance into catalytic site. [ABSTRACT FROM AUTHOR]

mPGES-1 is an enzyme, which, when activated by inflammatory factors, can cause prostaglandin E synthesis. Traditional non-steroidal anti-inflammatory drugs are capable of inhibiting prostaglandin production, yet they can also cause gastrointestinal reactions and coagulation disorders. mPGES-1, the enzyme at the conclusion of prostaglandin production, does not cause any adverse reactions when inhibited. Numerous studies have demonstrated that mPGES-1 is more abundant in cancerous cells than in healthy cells, indicating that decreasing the expression of mPGES-1 could be a potential therapeutic strategy for cancer. Consequently, the invention of mPGES-1 inhibitors presents a fresh avenue for the treatment of inflammation and cancer. Incorporating a database of TCM compounds, we collected a batch of compounds that had an inhibitory effect on mPGES-1 and possessed IC50 value. Firstly, a pharmacophore model was constructed, and the TCM database was screened, and the compounds with score cut-off values of more than 1 were retained. Then, the compounds retained after being screened via the pharmacodynamic model were screened for docking at the mPGES-1 binding site, followed by high-throughput virtual screening [HTVS] and standard precision [SP] and super-precision [XP] docking, and the compounds in the top 20% of the XP docking score were selected to calculate the total free binding energy of MM-GBSA. The best ten compounds were chosen by comparing their score against the reference ligand 4U9 and the MM-GBSA_dG_Bind score. ADMET analysis resulted in the selection of ten compounds, three of which had desirable medicinal properties. Finally, the binding energy of the target protein mPGES-1 and the candidate ligand compound was analyzed using a 100 ns molecular dynamics simulation of the reference ligand 4U9 and three selected compounds. After a gradual screening study and analysis, we identified a structure that is superior to the reference ligand 4U9 in all aspects, namely compound 15643. Taken together, the results of this study reveal a structure that can be used to inhibit mPGES-1 compound 15643, thereby providing a new option for anti-inflammatory and anti-tumor drugs.

Neuroblastoma (NB) is the most common pediatric extracranial solid tumor arising from neural crest cells of the developing sympathetic nervous system. Despite marked advances in cancer treatment, the survival rate of high-risk NB remains unsatisfactory. As a key pro-inflammatory mediator regulating tumor microenvironment, prostaglandin E2 (PGE2) promotes NB proliferation, angiogenesis, and immune evasion via acting on four G protein-coupled receptors, particularly the EP2 subtype. Recent studies have been vigorously focused on developing and evaluating compounds targeting PGE2-regulated tumor inflammation in animal models of NB. In this review, we revisit these translational efforts and examine the feasibility of pharmacological inhibition of enzymes responsible for PGE2 biosynthesis or its signaling receptors as emerging therapeutic strategies for NB. We also explore the potential downstream oncogenic pathways upon the activation of PGE2 receptors, aiming to bridge the knowledge gap between tumorigenesis and the role of elevated PGE2/EP2 signaling, which is widely observed in high-risk NBs.

Some novel triazole-bearing acetamide derivatives 9-26 were synthesized starting from carvacrol. All synthesized compounds were characterized by FTIR, ¹H-NMR, 13C-NMR and MS data. In vitro cytotoxic activities of all synthesized molecules against five cancer lines (human breast cancer MCF-7, human lung cancer A549, human prostate cancer PC-3, human chronic myelogenous leukemia K562, human neuroblastoma SH-SY5Y cell lines) were evaluated by MTT assay. Compounds were also tested on mouse embryonic fibroblast cells (NIH/3T3) to determine selectivity. Eighteen target compounds 9-26 were screened for their mPGES-1 and COX-1/2 inhibitory activities. Of these compounds, 26 (KUC16D425) showed the highest mPGES-1 inhibition at 10 µM. This compound has also been observed to induce apoptosis and inhibit cell migration in MCF-7 cells. In silico molecular docking calculations were performed to understand the binding interactions of compounds with target proteins. ADMET predictions were also done to evaluate drug-like properties of the novel compounds. [ABSTRACT FROM AUTHOR]

Background/Aim: Microsomal prostaglandin E synthase-1 (mPGES-1) is an enzyme, which catalyzes the final step of prostaglandin E2 (PGE2) synthesis. PGE2 in involved in wound-induced angiogenesis. Regulatory T cells (Tregs) regulate not only immune tolerance but also tissue repair and angiogenesis. We examined whether the mPGES-1/PGE2 axis contributes to wound-induced angiogenesis and granulation tissue formation through Treg accumulation. Materials and Methods: The dorsal subcutaneous tissues of male mPGES-1-deficient (mPGES-1-/-) and C57BL/6 wildtype (WT) mice were implanted with polyurethane sponge disks. Angiogenesis was estimated by determining the wet weight of sponge tissues and the expression of proangiogenic factors including CD31, vascular endothelial growth factor (VEGF), and transforming growth factor ß (TGF-ß) in granulation tissues. Results: Angiogenesis was suppressed in mPGES-1-/- mice compared with WT mice, which was associated with attenuated forkhead box P3 (Foxp3) expression and Foxp3+ Treg accumulation. The number of cells double-positive for Foxp3/TGFß and Foxp3/VEGF were lower in mPGES-1-/- mice than in WT mice. Neutralizing Tregs with antibodies (Abs) against CD25 or folate receptor 4 (FR4) inhibited the Foxp3+ Treg angiogenesis and accumulation in WT mice, but not in mPGES-1-/- mice. The topical application of PGE2 into the implanted sponge enhanced angiogenesis and accumulation of Tregs expressing TGFß and VEGF in WT and mPGES-1-/- mice. Conclusion: Tregs producing TGFß and VEGF accumulate in wounds and contribute to angiogenesis through mPGES-1-derived PGE2. mPGES-1 induction may control angiogenesis in skin wounds by recruiting Tregs. [ABSTRACT FROM AUTHOR]

Inhibition of microsomal prostaglandin E2 synthase-1 (mPGES-1) is promising for designing novel nonsteroidal anti-inflammatory drugs, as they lack side-effects associated with inhibition of cyclooxygenase enzymes. Azole compounds are nitrogen-containing heterocycles and have a wide use in medicine and are considered as promising compounds in medicinal chemistry. Various computer-aided drug design strategies are incorporated in this study. Structure-based virtual screening was performed employing various docking programs. Receiver operator characteristic (ROC) curves were used to evaluate the selectivity of each program. Furthermore, scoring power of Autodock4 and Autodock Vina was assessed by Pearson's correlation coefficients. Pharmacophore models were generated and Güner-Henry score of the best model was calculated as 0.89. Binding modes of the final 10 azole compounds were analyzed and further investigation of the best binding (− 8.38 kcal/mol) compound was performed using molecular dynamics simulation, revealing that furazan1224 (ZINC001142847306) occupied the binding site of the substrate, prostaglandin H2 (PGH2) and remained stable for 100 ns. Continuous hydrogen bonds and hydrophobic interactions with amino acids in the active site supported the stability of furazan1224 throughout the trajectory. Pharmacokinetic profile showed that furazan1224 lacks the risks of inhibiting cytochrome P450 3A4 enzyme and central nervous system-related side-effects. [ABSTRACT FROM AUTHOR]

Abstract Background To examine the effects of BI 1029539 (GS-248), a novel selective human microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor, in experimental models of acute lung injury (ALI) and sepsis in transgenic mice constitutively expressing the mPGES1 (Ptges) humanized allele. Methods Series 1: Lipopolysaccharide (LPS)-induced ALI. Mice were randomized to receive vehicle, BI 1029539, or celecoxib. Series 2: Cecal ligation and puncture-induced sepsis. Mice were randomized to receive vehicle or BI 1029539. Results Series 1: BI 1029539 or celecoxib reduced LPS-induced lung injury, with reduction in neutrophil influx, protein content, TNF-ɑ, IL-1β and PGE2 levels in bronchoalveolar lavage (BAL), myeloperoxidase activity, expression of mPGES-1, cyclooxygenase (COX)-2 and intracellular adhesion molecule in lung tissue compared with vehicle-treated mice. Notably, prostacyclin (PGI2) BAL concentration was only lowered in celecoxib-treated mice. Series 2: BI 1029539 significantly reduced sepsis-induced BAL inflammatory cell recruitment, lung injury score and lung expression of mPGES-1 and inducible nitric oxide synthase. Treatment with BI 1029539 also significantly prolonged survival of mice with severe sepsis. Anti-inflammatory and anti-migratory effect of BI 1029539 was confirmed in peripheral blood leukocytes from healthy volunteers. Conclusions BI 1029539 ameliorates leukocyte infiltration and lung injury resulting from both endotoxin-induced and sepsis-induced lung injury.

Here we report the application of a multi-disciplinary protocol for investigating thiazolidin-4-one-based compounds as new promising anti-inflammatory agents interfering with the eicosanoid biosynthesis pathways. The workflow foresaw the generation of a focused virtual library of ∼4.2 ​× ​104 molecules featuring the thiazolidin-4-one core based on the related one-pot synthetical combinatorial route. The built library was initially screened in silico against the microsomal prostaglandin E2 synthase-1 (mPGES-1) enzyme and, afterwards, 23 selected chemical items were synthesized for the subsequent biological screening, applying the one-pot multicomponent synthetic strategy. Preliminary results highlighted the moderate ability of several tested thiazolidin-4-one-based compounds in inhibiting mPGES-1. On the other hand, further computational repurposing investigations were performed on a set of synthesized compounds, highlighting the promising binding of a several items against the soluble epoxide hydrolase (sEH) enzyme, whose inhibition leads to an increase of epoxyeicosatrienoic acids (EETs) that are anti-inflammatory mediators. Three molecules (3, 9 and 21) were able to inhibit sEH featuring IC50 values in the low micromolar range. In order to further profile their anti-inflammatory properties, additional investigations of the three identified hits highlighted their ability to inhibit 5-lipoxygenase (5-LO) and thus to interfere with leukotriene biosynthesis in neutrophils, devoid of activity against cyclooxygenases (COXs) and cytotoxic effects on human monocytes. Our results, obtained by applying a multidisciplinary approach, highlight the thiazolidin-4-one-core as a valuable template for developing novel anti-inflammatory compounds able to synergistically inhibit different targets involved in the arachidonic acid cascade.

Background and Purpose: Microsomal prostaglandin E synthase‐1 (mPGES‐1) is an inducible isomerase responsible for prostaglandin E2 production in inflammatory conditions. We evaluated the role of mPGES‐1 in the development and the metabolic and cardiovascular alterations of obesity. Experimental Approach mPGES‐1+/+ and mPGES‐1−/− mice were fed with normal or high fat diet (HFD, 60% fat). The glycaemic and lipid profile was evaluated by glucose and insulin tolerance tests and colorimetric assays. Vascular function, structure and mechanics were assessed by myography. Histological studies, q‐RT‐PCR, and western blot analyses were performed in adipose tissue depots and cardiovascular tissues. Gene expression in abdominal fat and perivascular adipose tissue (PVAT) from patients was correlated with vascular damage. Key Results: Male mPGES‐1−/− mice fed with HFD were protected against body weight gain and showed reduced adiposity, better glucose tolerance and insulin sensitivity, lipid levels and less white adipose tissue and PVAT inflammation and fibrosis, compared with mPGES‐1+/+ mice. mPGES‐1 knockdown prevented cardiomyocyte hypertrophy, cardiac fibrosis, endothelial dysfunction, aortic insulin resistance, and vascular inflammation and remodelling, induced by HFD. Obesity‐induced weight gain and endothelial dysfunction of resistance arteries were ameliorated in female mPGES‐1−/− mice. In humans, we found a positive correlation between mPGES‐1 expression in abdominal fat and vascular remodelling, vessel stiffness, and systolic blood pressure. In human PVAT, there was a positive correlation between mPGES‐1 expression and inflammatory markers. Conclusions and Implications: mPGES‐1 inhibition might be a novel therapeutic approach to the management of obesity and the associated cardiovascular and metabolic alterations. [ABSTRACT FROM AUTHOR]

Background and Purpose: Recent biochemical and pharmacological studies have reported that in several tissues and cell types, microsomal PGE2 synthase (mPGES) and PPAR-γ expression are modulated by a variety of inflammatory factors and stimuli. Considering that very little is known about the biological effects promoted by IL-17 in the context of mPGES-1/PPAR-γ modulation, we sought to investigate the contribution of this unique cytokine on this integrated pathway during the onset of inflammation.Experimental Approach: We evaluated effects of PF 9184 (mPGES-1 inhibitor) and troglitazone (PPAR-γ agonist) in vitro, using the mouse macrophage cell line J774A.1. In vivo, the dorsal air pouch model in CD1 mice was used, and inflammatory infiltrates were analysed by flow cytometry. Locally produced cyto-chemokines and PGs were assessed using elisa assays. Western blots were also employed to determine the activity of various enzymes involved in downstream signalling pathways.Key Results: PF 9184 and troglitazone, in a time- and dose-dependent manner, modulated leukocyte infiltration, myeloperoxidase activity, and the expression of COX-2/mPGES-1, NF-кB/IкB-α, and mPTGDS-1/PPAR-γ, induced by IL-17. Moreover, both PF 9184 and troglitazone modulated PG (PGE2 , PGD2 , and PGJ2 ) production, the expression of different pro-inflammatory cyto-chemokines, and the recruitment of inflammatory monocytes, in response to IL-17.Conclusions and Implications: Our data suggest that IL-17 may constitute a specific modulator of inflammatory monocytes during later phases of the inflammatory response. The results of this study show, for the first time, that the IL-17/mPGES-1/PPAR-γ pathway could represent a potential therapeutic target for inflammatory-based and immune-mediated diseases.Linked Articles: This article is part of a themed issue on Inflammation, Repair and Ageing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.9/issuetoc. [ABSTRACT FROM AUTHOR]

Background: The microvasculature is a target organ for the early manifestations of cardiovascular disease. Therefore, a better understanding of the prostaglandin system and characterising the effects of mPGES‐1 inhibition and concomitant reduction of PGE2 in vascular beds are of interest. Experimental Approach The effects of mPGES‐1 inhibition on constriction and relaxation of resistance arteries (diameter: 100–400 μm) from patients with end stage kidney disease (ESKD) and controls (Non‐ESKD) were studied using wire‐myography in combination with immunological and mass‐spectrometry based analyses. Key Results: Inhibition of mPGES‐1 in arteries from ESKD patients and Non‐ESKD controls significantly reduced adrenergic vasoconstriction, which was unaffected by the COX‐2 inhibitors NS‐398 and Etoricoxib, or by the COX‐1/COX‐2 inhibitor Indomethacin tested in Non‐ESKD controls. However, a significant increase of acetylcholine‐induced dilatation was observed for mPGES‐1 inhibition. In IL‐1β treated arteries, inhibition of mPGES‐1 significantly reduced PGE2 levels while PGI2 levels remained unchanged. In contrast, COX‐2 inhibition blocked the formation of both prostaglandins. Blockade of PGI2 signalling with an IP receptor antagonist did not restore the reduced adrenergic constriction, neither did blocking PGE2‐EP4 or signalling through PPARγ. A biphasic effect was observed for PGE2, inducing dilatation at nanomolar and constriction at micromolar concentrations. Immunohistochemistry demonstrated expression of mPGES‐1, COX‐1, PGIS, weak expression for COX‐2, as well as receptor expression for PGE2 (EP1–4), thromboxane (TP) and PGI2 (IP) in ESKD and Non‐ESKD. Conclusion: Our study demonstrates vasodilating effects following mPGES‐1 inhibition in human microvasculature and suggests that several pathways besides shunting to PGI2 are involved. [ABSTRACT FROM AUTHOR]

Chronic periodontitis (CP) is a bacteria-driven inflammatory disease characterized by the breakdown of gingival tissue, the periodontal ligament, and alveolar bone, leading ultimately to tooth loss. We previously reported the pleckstrin gene (PLEK) to be highly upregulated in gingival tissue of patients with CP and the only gene concurrently upregulated in other inflammatory diseases including rheumatoid arthritis and cardiovascular diseases. Using saliva from 169 individuals diagnosed with CP and healthy controls, we investigated whether pleckstrin could serve as a novel biomarker of periodontitis. Additionally, we explored signal pathways involved in the regulation of PLEK using human gingival fibroblasts (HGFs). Pleckstrin levels were significantly higher (p < 0.001) in the saliva samples of patients with CP compared to controls and closely associated with CP severity. Immunohistochemical analysis revealed the expression of pleckstrin in inflammatory cells and gingival fibroblasts of CP patients. To explore the signal pathways involved in pleckstrin regulation, we stimulated HGFs with either interleukin-1β (IL-1β) or lipopolysaccharides (LPS) alone, or in combination with inhibitors targeting c-Jun N-terminal kinase, tyrosine kinase, protein kinase C, or p38 MAP kinase. Results showed that IL-1β and LPS significantly increased PLEK mRNA and pleckstrin protein levels. VX-745, the p38 MAP kinase inhibitor significantly decreased IL-1β- and LPS-induced pleckstrin levels at both the mRNA and the protein level. Together, these findings show that pleckstrin could serve as a salivary biomarker for the chronic inflammatory disease periodontitis and a regulator of inflammation via the p38 MAP kinase pathway. [ABSTRACT FROM AUTHOR]

Abstract Background Dual inhibitors of the 5-lipoxygenase-activating protein (FLAP) and the microsomal prostaglandin E2 synthase-1 (mPGES-1) may exert better anti-inflammatory efficacy and lower risks of adverse effects versus non-steroidal anti-inflammatory drugs. Despite these advantages, many dual FLAP/mPGES-1 inhibitors are acidic lipophilic molecules with low solubility and strong tendency for plasma protein binding that limit their bioavailability and bioactivity. Here, we present the encapsulation of the dual FLAP/mPGES-1 inhibitor BRP-187 into the biocompatible polymers acetalated dextran (Acdex) and poly(lactic-co-glycolic acid) (PLGA) via nanoprecipitation. Results The nanoparticles containing BRP-187 were prepared by the nanoprecipitation method and analyzed by dynamic light scattering regarding their hydrodynamic diameter, by scanning electron microscopy for morphology properties, and by UV–VIS spectroscopy for determination of the encapsulation efficiency of the drug. Moreover, we designed fluorescent BRP-187 particles, which showed high cellular uptake by leukocytes, as analyzed by flow cytometry. Finally, BRP-187 nanoparticles were tested in human polymorphonuclear leukocytes and macrophages to determine drug uptake, cytotoxicity, and efficiency to inhibit FLAP and mPGES-1. Conclusion Our results demonstrate that encapsulation of BRP-187 into Acdex and PLGA is feasible, and both PLGA- and Acdex-based particles loaded with BRP-187 are more efficient in suppressing 5-lipoxygenase product formation and prostaglandin E2 biosynthesis in intact cells as compared to the free compound, particularly after prolonged preincubation periods.

Caesalpinia digyna (Rottl.) (Family: Fabaceae) is well known for its numerous medicinal values against several human disorders including fever, senile pruritis, diarrhea, tuberculosis, tonic disorder, diabetes, etc. The current study is intended to investigate the in vivo antipyretic activity of the methanol extract of C. digyna leaves (MECD) and its carbon-tetrachloride (CTCD) and butanol fraction (BTCD). Besides, in silico molecular docking and ADME/T profiling of the selective identified bioactive compounds of C. digyna has been also studied to validate the experimental outcomes and establish a better insight into the possible receptor-ligand interaction affinity. In vivo antipyretic activity of MECD, CTCD and BTCD were evaluated by employing yeast induced pyrexia technique in mice model and in silico analysis of the identified compounds of C. digyna has been implemented using PyRx autodock vina, Discovery Studio 2020, UCSF Chimera software and ADME/T online tools. MECD and BTCD unveiled significant antipyretic activity in dose dependent manner whereas, CTCD failed to exhibit significant antipyretic activity. Comparing to other test sample, MECD (400 mg/kg; b.w) (p < 0.001) displayed maximum inhibition of pyrexia. In molecular docking approach, docking score between −6.60 to −10.20 kcal/mol have been revealed. Besides, in ADME/T analysis, no compound violated the lipiniski's 5 rules and displayed any toxicity. Biological and computational approaches ascertain the ethno-botanical use of C. digyna as a good agent against pyrexia and the compounds of C. digyna are primarily proved as safe. Hereafter, further analysis is suggested to validate this research. [ABSTRACT FROM AUTHOR]

Background: To examine the effects of BI 1029539 (GS-248), a novel selective human microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor, in experimental models of acute lung injury (ALI) and sepsis in transgenic mice constitutively expressing the mPGES1 (Ptges) humanized allele.Methods: Series 1: Lipopolysaccharide (LPS)-induced ALI. Mice were randomized to receive vehicle, BI 1029539, or celecoxib. Series 2: Cecal ligation and puncture-induced sepsis. Mice were randomized to receive vehicle or BI 1029539.Results: Series 1: BI 1029539 or celecoxib reduced LPS-induced lung injury, with reduction in neutrophil influx, protein content, TNF-ɑ, IL-1β and PGE2 levels in bronchoalveolar lavage (BAL), myeloperoxidase activity, expression of mPGES-1, cyclooxygenase (COX)-2 and intracellular adhesion molecule in lung tissue compared with vehicle-treated mice. Notably, prostacyclin (PGI2) BAL concentration was only lowered in celecoxib-treated mice. Series 2: BI 1029539 significantly reduced sepsis-induced BAL inflammatory cell recruitment, lung injury score and lung expression of mPGES-1 and inducible nitric oxide synthase. Treatment with BI 1029539 also significantly prolonged survival of mice with severe sepsis. Anti-inflammatory and anti-migratory effect of BI 1029539 was confirmed in peripheral blood leukocytes from healthy volunteers.Conclusions: BI 1029539 ameliorates leukocyte infiltration and lung injury resulting from both endotoxin-induced and sepsis-induced lung injury. [ABSTRACT FROM AUTHOR]

DNA mismatch-repair gene mutations, with consequent loss of functional protein expression, result in microsatellite instability (MSI). Microsatellite sequences are found in coding regions and in regulatory regions of genes (i.e., 5'-UTRs and 3'-UTRs). In addition to being a surrogate marker of defective mismatch repair, deletion or insertion microsatellite sequences can dysregulate gene expression in MSI-H (microsatellite instability-high) tumors. The microsomal prostaglandin E synthase-1 (mPGES-1) gene product, mPGES-1, participates in prostaglandin E2 (PGE2) production. Moreover, mPGES-1 is often overexpressed in human colorectal tumors, and is thought to contribute to progression of these tumors. Here we identified a dinucleotide repeat, (GT)24, in the mPGES-1 gene 3' untranslated region (3'-UTR), and analyzed its mutation frequencies in MSI-H and microsatellite stable (MSS) tumors. The (GT)24 repeat exhibited instability in all MSI-H tumors examined (14), but not in any of the MSS tumors (13). In most cases, (GT)24 repeat instability resulted in insertion of additional GT units. We also determined mPGES-1 mRNA levels in MSI-H and MSS colorectal cancer cell lines. Three of four previously designated "MSI-H" cell lines showed higher mPGES-1 mRNA levels compared to MSS cell lines; correlations between elevated mPGES-1 mRNA levels and microsatellite (GT)24 repeat characteristics are present for all six cell lines. Our results demonstrate that mPGES-1 is a target gene of defective mismatch repair in human colorectal cancer, with functional consequence.

Background: Microsomal prostaglandin E synthase-1 (mPGES-1)-derived prostaglandin E2 (PGE2) is a chief mediator of inflammation. However, the role and mechanism of mPGES-1 in peritoneal dialysis (PD)-associated peritoneal fibrosis have not been investigated.Material and Methods: In PD patients, mPGES-1 expression in peritoneum tissues and the levels of PGE2, IL-1β, and IL-18 in the dialysate were examined. In rat peritoneal mesothelial cells (RPMCs), the regulation and function of mPGES-1 and NLRP3 inflammasome were investigated. The expression of extracellular matrix proteins and the components of NLRP3 inflammasome were detected by Western blotting or real-time quantitative PCR.Results: In PD patients with ultrafiltration failure (UFF), mPGES-1 was enhanced in the peritoneum, which was associated with the degree of peritoneal fibrosis. Accordingly, the intraperitoneal PGE2 levels were also positively related to the PD duration, serum C-reactive protein levels, and serum creatinine levels in incident PD patients. In RPMCs, high-glucose treatment significantly induced mPGES-1 expression and PGE2 secretion without affecting the expressions of mPGES-2 and cPGES. Inhibition of mPGES-1 via short hairpin RNA significantly ameliorated the expression of extracellular matrix proteins of RPMCs induced by high glucose. Additionally, high glucose markedly activated NLRP3 inflammasome in RPMCs that was blunted by mPGES-1 inhibition. Furthermore, silencing NLRP3 with siRNA significantly abrogated the expression of extracellular matrix proteins in RPMCs treated with high glucose. Finally, we observed increased IL-1β and IL-18 levels in the dialysate of incident PD patients, showing a positive correlation with PGE2.Conclusion: These data demonstrate that mPGES-1-derived PGE2 plays a critical role in PD-associated peritoneal fibrosis through activation of the NLRP3 inflammasome. Targeting mPGES-1 may offer a novel strategy to treat peritoneal fibrosis during PD.

As a new approach to the management of inflammatory disorders, a series of chromone-based derivatives containing a (carbamate)hydrazone moiety was designed and synthesized. The compounds were assessed for their ability to inhibit COX-1/2, 15-LOX, and mPGES-1, as a combination that should effectively impede the arachidonate pathway. Results revealed that the benzylcarbazates (2a-c) demonstrated two-digit nanomolar COX-2 inhibitory activities with reasonable selectivity indices. They also showed appreciable 15-LOX inhibition, in comparison to quercetin. Further testing of these compounds for mPGES-1 inhibition displayed promising activities. Intriguingly, compounds 2a-c were capable of suppressing edema in the formalin-induced rat paw edema assay. They exhibited an acceptable gastrointestinal safety profile regarding ulcerogenic liabilities in gross and histopathological examinations. Additionally, upon treatment with the test compounds, the expression of the anti-inflammatory cytokine IL-10 was elevated, whereas that of TNF-α, iNOS, IL-1β, and COX-2 were downregulated in LPS-challenged RAW264.7 macrophages. Docking experiments into the three enzymes showed interesting binding profiles and affinities, further substantiating their biological activities. Their in silico physicochemical and pharmacokinetic parameters were advantageous. [Display omitted] • A new series of chromone-acylhydrazones was designed and synthesized. • Benzylcarbazates 2a-c proved to be triple inhibitors of COX-2, 15-LOX and mPGES-1. • In cellular assay, they reduced pro-inflammatory mediators similarly to celecoxib. • They decreased formalin-induced rat paw edema in vivo without ulcerogenic effects. • Benzylcarbazates 2a-c could be promising multipotent anti-inflammatory prototypes. [ABSTRACT FROM AUTHOR]

mPGES-1 is a terminal rate-limiting enzyme responsible for inflammation-induced PGE2 production. The inhibition of mPGES-1 has been considered as a safe and effective target for the treatment of inflammation and cancer. However, a specific, efficient, and simple method for high-throughput screening of mPGES-1 inhibitors is still lacking. In this study, we developed a fluorescence imaging strategy to monitor the expression of mPGES-1 via CRISPR/Cas9 knock-in system. Immunofluorescence colocalisation, Sanger sequencing, RNAi, and IL-1β treatment all confirmed the successful construction of mPGES-1 reporter cells. The fluorescence signal intensity of the reporter cells treated with four conventional mPGES-1 inhibitors was considerably attenuated via flow cytometry and fluorescent microplate reader, demonstrating that the reporter cells can be used as an efficient and convenient means for screening and optimising mPGES-1 inhibitors. Moreover, it provides a new technical support for the development of targeted small molecule compounds for anti-inflammatory and tumour therapy.

Inflammation is a protective response that develops against tissue injury and infection. Chronic inflammation, on the other hand, is the key player in the pathogenesis of many inflammatory disorders including cancer. The cytokine storm, an inflammatory response flaring out of control, is mostly responsible for the mortality in COVID-19 patients. Anti-inflammatory drugs inhibit cyclooxygenases (COX), which are involved in the biosynthesis of prostaglandins that promote inflammation. The conventional non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastric and renal side-effects, as they inhibit both the constitutive COX-1 and the inducible COX-2. The majority of selective COX-2 inhibitors (COXIBs) are without gastric side-effects but are associated with cardiac side-effects on long-term use. The search for anti-inflammatory drugs without side-effects, therefore, has become a dream and ongoing effort of the Pharma companies. As PGE2 is the key mediator of inflammatory disorders, coming up with a strategy to reduce the levels of PGE2 alone without affecting other metabolites may form a better choice for the development of next generation anti-inflammatory drugs. In this direction the options being explored are on synthesis of PGE2-mPGES-1; PGE2 degradation through a specific PG dehydrogenase, 15-PGDH, and by blocking its activity mediated through a specific PGE receptor, EP4. As leukotrienes formed via the 5-lipoxygenase (5-LOX) pathway also play an important role in the mediation of inflammation, efforts are also being made to target both COX and LOX pathways. This review focuses on addressing the following three points: 1) How NSAIDs and COXIBs are associated with gastric, renal and cardiac side-effects; 2) Should the focus be on the targets upstream or downstream of PGE2; and 3) the status of alternative targets being explored for the discovery and development of anti-inflammatory drugs without side-effects. [ABSTRACT FROM AUTHOR]

Prostanoids and PGE2 in particular have been long viewed as one of the major mediators of inflammation in arthritis. However, experimental data indicate that PGE2 can serve both pro- and anti-inflammatory functions. We have previously shown (Kojima et al., J. Immunol. 180 (2008) 8361-8368) that microsomal prostaglandin E synthase-1 (mPGES-1) deletion, which regulates PGE2 production, resulted in the suppression of collagen-induced arthritis (CIA) in mice. This suppression was attributable, at least in part, to the impaired generation of type II collagen autoantibodies. In order to examine the function of mPGES-1 and PGE2 in a non-autoimmune form of arthritis, we used the collagen antibody-induced arthritis (CAIA) model in mice deficient in mPGES-1, thereby bypassing the engagement of the adaptive immune response in arthritis development. Here we report that mPGES-1 deletion significantly increased CAIA disease severity. The latter was associated with a significant (~3.6) upregulation of neutrophil, but not macrophage, recruitment to the inflamed joints. The lipidomic analysis of the arthritic mouse paws by quantitative liquid chromatography/tandem mass-spectrometry (LC/MS/MS) revealed a dramatic (~59-fold) reduction of PGE2 at the peak of arthritis. Altogether, this study highlights mPGES-1 and its product PGE2 as important negative regulators of neutrophil-mediated inflammation and suggests that specific mPGES-1 inhibitors may have differential effects on different types of inflammation. Furthermore, neutrophil-mediated diseases could be exacerbated by inhibition of mPGES-1.

MicroRNAs (miRs) are one of the most important post-transcriptional repressors of gene expression. However, miR-574-5p has recently been shown to positively regulate the expression of microsomal prostaglandin E-synthase-1 (mPGES-1), a key enzyme in the prostaglandin E2 (PGE2) biosynthesis, by acting as decoy to the RNA-binding protein CUG-RNA binding protein 1 (CUGBP1) in human lung cancer. miR-574-5p exhibits oncogenic properties and promotes lung tumor growth in vivo via induction of mPGES-1-derived PGE2 synthesis. In a mass spectrometry-based proteomics study, we now attempted to characterize this decoy mechanism in A549 lung cancer cells at a cellular level. Besides the identification of novel CUGBP1 targets, we identified that the interaction between miR-574-5p and CUGBP1 specifically regulates mPGES-1 expression. This is supported by the fact that CUGBP1 and miR-574-5p are located in the nucleus, where CUGBP1 regulates alternative splicing. Further, in a bioinformatical approach we showed that the decoy-dependent mPGES-1 splicing pattern is unique. The specificity of miR-574-5p/CUGBP1 regulation on mPGES-1 expression supports the therapeutic strategy of pharmacological inhibition of PGE2 formation, which may provide significant therapeutic value for NSCLC patients with high miR-574-5p levels.

【目的】探讨RNA干扰膜结合型前列腺素E2合酶1（mPGES-1）对阿霉素耐药的人红白血病细胞株K562/A细胞增殖、凋亡及耐药性的影响及其可能的机制。【方法】通过RNA干扰技术抑制K562/A细胞中mPGES-1表达。分组：①未处理组（K562/A），②干扰后的阴性对照组（K562/A-NC），③干扰组（K562/A-KD），④干扰后加入外源性PGE2组（K562/A-KD+PGE2）；CCK-8法检测细胞活力；流式细胞术检测细胞凋亡；ELISA法检测PGE2浓度；Western blot检测蛋白水平。【结果】RNA干扰可明显下调K562/A细胞mPGES-1表达，抑制PGE2合成（

Background: Accumulation of myeloid-derived suppressor cells (MDSCs) to tumors is related to cancer prognosis. We investigated the contribution of host stromal microsomal prostaglandin E synthase-1 (mPGES-1) to the accumulation of MDSCs in metastasized lungs of prostate cancer in mice. Material and methods: Eight-week-old male C57Bl/6 wild type (WT) mice and mPGES-1 knock out mice (mPGES-1KO) were injected with RM9 murine prostate cancer cell line (5 × 106 cells/mL). Lung metastasis was evaluated by the number of colonies, the weight of the lung, and the number of MDSCs (CD11b+Gr1+ cells) in the lung. Results: Intravenous injections of RM9, a murine prostate cancer cell line to WT mice revealed that lung metastasis and accumulation of MDCSs were suppressed with treatments with a Gr1 antibody, a COX-2 inhibitor, and an mPGES-1 inhibitor. Lung metastasis and accumulation of CD11b+Gr1+MDSCs were suppressed in mPGES-1KO mice. The mRNA level of stromal cell-derived factor-1 (SDF-1) in the lung and the number of accumulated SDF-1-expressing CD11b+Gr1+ MDSCs were elevated at an early stage in lung metastasis of C-X-C chemokine receptor type 4 (CXCR4)-expressing RM9 in an mPGES-1-dependent manner. The number of CXCR4-expressing CD11b+Gr1+MDSCs in WT mice was higher than that in mPGES-1KO mice. RM9 lung metastasis and accumulation of CD11b+Gr1+MDSCs were suppressed by CXCR4 antibody in WT mice but not in mPGES-1KO. WT mice transplanted with mPGES-1 KO bone marrow (BM) showed a significant reduction in lung metastasis and accumulation of CD11b+Gr1+MDSCs. Conclusion: These results suggest that mPGES-1 enhances tumor metastasis by inducing accumulation of BM-derived MDSCs. Selective mPGES-1 inhibitors might, therefore, represent valuable therapeutic tools for the suppression of tumor metastasis.

Tanshinone IIA (TIIA) and cryptotanshinone (CRY) from Salvia miltiorrhiza Bunge were investigated for their inhibitory activity against the cyclooxygenase-2 (COX-2)/microsomal prostaglandin E synthase-1 (mPGES-1)/endothelial prostaglandin 3 (EP3) pathway using in silico, in vitro, in vivo, and ex vivo assays. From the analysis of the docking poses, both diterpenoids were able to interact significantly with COX-2, 5-lipoxygenase (5-LO), platelet-activating factor receptor (PAFR), and mPGES-1. This evidence was further corroborated by data obtained from a cell-free assay, where CRY displayed a significant inhibitory potency against mPGES-1 (IC50 = 1.9 ± 0.4 µM) and 5-LO (IC50 = 7.1 µM), while TIIA showed no relevant inhibition of these targets. This was consistent with their activity to increase mice bleeding time (CRY: 2.44 ± 0.13 min, p ≤ 0.001; TIIA: 2.07 ± 0.17 min p ≤ 0.01) and with the capability to modulate mouse clot retraction (CRY: 0.048 ± 0.011 g, p ≤ 0.01; TIIA: 0.068 ± 0.009 g, p ≤ 0.05). For the first time, our results show that TIIA and, in particular, CRY are able to interact significantly with the key proteins involved not only in the onset of inflammation but also in platelet activity (and hyper-reactivity). Future preclinical and clinical investigations, together with this evidence, could provide the scientific basis to consider these compounds as an alternative therapeutic approach for thrombotic- and thromboembolic-based diseases.

Background and Purpose: mPGES1 catalyses the production of PGE2 , the most abundant prostanoid related to inflammation and pain in arthritis. mPGES1 is suggested to be a safer and more selective drug target in inflammatory conditions compared to the COX enzymes inhibited by NSAIDs. In the present study, we investigated the effects of the selective mPGES1 inhibitor MF63 on gene expression in primary human chondrocytes from patients with osteoarthritis (OA).Experimental Approach: Chondrocytes were isolated from articular cartilage obtained from osteoarthritis patients undergoing knee replacement surgery. The effects of MF63 were studied in the primary chondrocytes with RNA-sequencing based genome-wide expression analysis. The main results were confirmed with qRT-PCR and compared with the effects of the NSAID ibuprofen. Functional analysis was performed with the GO database and interactions between the genes were studied with STRING.Key Results: MF63 enhanced the expression of multiple metallothionein 1 (MT1) isoforms as well as endogenous antagonists of IL-1 and IL-36. The expression of IL-6, by contrast, was down-regulated. These genes were also essential in functional and interaction network analyses. The effects of MF63 were consistent in qRT-PCR analysis, whereas the effects of ibuprofen overlapped only partly with MF63. There were no evident findings of catabolic effects by MF63.Conclusion and Implications: Metallothionein 1 has been suggested to have anti-inflammatory and protective effects in cartilage. Up-regulation of the antagonists of IL-1 superfamily and down-regulation of the pro-inflammatory cytokine IL-6 also support novel anti-inflammatory and possibly disease-modifying effects of mPGES1 inhibitors in arthritis. [ABSTRACT FROM AUTHOR]

Eicosanoids are potent lipid mediators involved in central physiological processes such as hemostasis, renal function and parturition. When formed in excess, eicosanoids become critical players in a range of pathological conditions, in particular pain, fever, arthritis, asthma, cardiovascular disease and cancer. Eicosanoids are generated via oxidative metabolism of arachidonic acid along the cyclooxygenase (COX) and lipoxygenase (LOX) pathways. Specific lipid species are formed downstream of COX and LOX by specialized synthases, some of which reside on the nuclear and endoplasmic reticulum, including mPGES-1, FLAP, LTC4 synthase, and MGST2. These integral membrane proteins are members of the family "membrane-associated proteins in eicosanoid and glutathione metabolism" (MAPEG). Here we focus on this enzyme family, which encompasses six human members typically catalyzing glutathione dependent transformations of lipophilic substrates. Enzymes of this family have evolved to combat the topographical challenge and unfavorable energetics of bringing together two chemically different substrates, from cytosol and lipid bilayer, for catalysis within a membrane environment. Thus, structural understanding of these enzymes are of utmost importance to unravel their molecular mechanisms, mode of substrate entry and product release, in order to facilitate novel drug design against severe human diseases. Unlabelled Image [ABSTRACT FROM AUTHOR]

The majority of anti‐cancer therapies target the proliferating tumor cells, while the tumor stroma, principally unaffected, survives, and provide a niche for surviving tumor cells. Combining tumor cell and stroma‐targeting therapies thus have a potential to improve patient outcome. The neuroblastoma stroma contains cancer‐associated fibroblasts expressing microsomal prostaglandin E synthase‐1 (mPGES‐1). mPGES‐1‐derived prostaglandin E2 (PGE2) is known to promote tumor growth through increased proliferation and survival of tumor cells, immune suppression, angiogenesis, and therapy resistance, and we, therefore, hypothesize that mPGES‐1 constitutes an interesting stromal target. Here, we aimed to develop a relevant in vitro model to study combination therapies. Co‐culturing of neuroblastoma and fibroblast cells in 3D tumor spheroids mimic neuroblastoma tumors with regard to the cyclooxygenase/mPGES‐1/PGE2 pathway. Using the spheroid model, we show that the inhibition of fibroblast‐derived mPGES‐1 enhanced the cytotoxic effect of doxorubicin and vincristine and significantly reduced tumor cell viability and spheroid growth. Cyclic treatment with vincristine in combination with an mPGES‐1 inhibitor abrogated cell repopulation. Moreover, inhibition of mPGES‐1 potentiated the cytotoxic effect of vincristine on established neuroblastoma allografts in mice. In conclusion, we established a 3D neuroblastoma model, highlighting the potential of combining stromal targeting of mPGES‐1 with tumor cell targeting drugs like vincristine. [ABSTRACT FROM AUTHOR]

Background: Dual inhibitors of the 5-lipoxygenase-activating protein (FLAP) and the microsomal prostaglandin E2 synthase-1 (mPGES-1) may exert better anti-inflammatory efficacy and lower risks of adverse effects versus non-steroidal anti-inflammatory drugs. Despite these advantages, many dual FLAP/mPGES-1 inhibitors are acidic lipophilic molecules with low solubility and strong tendency for plasma protein binding that limit their bioavailability and bioactivity. Here, we present the encapsulation of the dual FLAP/mPGES-1 inhibitor BRP-187 into the biocompatible polymers acetalated dextran (Acdex) and poly(lactic-co-glycolic acid) (PLGA) via nanoprecipitation. Results: The nanoparticles containing BRP-187 were prepared by the nanoprecipitation method and analyzed by dynamic light scattering regarding their hydrodynamic diameter, by scanning electron microscopy for morphology properties, and by UV–VIS spectroscopy for determination of the encapsulation efficiency of the drug. Moreover, we designed fluorescent BRP-187 particles, which showed high cellular uptake by leukocytes, as analyzed by flow cytometry. Finally, BRP-187 nanoparticles were tested in human polymorphonuclear leukocytes and macrophages to determine drug uptake, cytotoxicity, and efficiency to inhibit FLAP and mPGES-1. Conclusion: Our results demonstrate that encapsulation of BRP-187 into Acdex and PLGA is feasible, and both PLGA- and Acdex-based particles loaded with BRP-187 are more efficient in suppressing 5-lipoxygenase product formation and prostaglandin E2 biosynthesis in intact cells as compared to the free compound, particularly after prolonged preincubation periods. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRs) are one of the most important post-transcriptional repressors of gene expression. However, miR-574-5p has recently been shown to positively regulate the expression of microsomal prostaglandin E-synthase-1 (mPGES-1), a key enzyme in the prostaglandin E2 (PGE2) biosynthesis, by acting as decoy to the RNA-binding protein CUG-RNA binding protein 1 (CUGBP1) in human lung cancer. miR-574-5p exhibits oncogenic properties and promotes lung tumor growth in vivo via induction of mPGES-1-derived PGE2 synthesis. In a mass spectrometry-based proteomics study, we now attempted to characterize this decoy mechanism in A549 lung cancer cells at a cellular level. Besides the identification of novel CUGBP1 targets, we identified that the interaction between miR-574-5p and CUGBP1 specifically regulates mPGES-1 expression. This is supported by the fact that CUGBP1 and miR-574-5p are located in the nucleus, where CUGBP1 regulates alternative splicing. Further, in a bioinformatical approach we showed that the decoy-dependent mPGES-1 splicing pattern is unique. The specificity of miR-574-5p/CUGBP1 regulation on mPGES-1 expression supports the therapeutic strategy of pharmacological inhibition of PGE2 formation, which may provide significant therapeutic value for NSCLC patients with high miR-574-5p levels. [ABSTRACT FROM AUTHOR]

mPGES-1 is a terminal rate-limiting enzyme responsible for inflammation-induced PGE2 production. The inhibition of mPGES-1 has been considered as a safe and effective target for the treatment of inflammation and cancer. However, a specific, efficient, and simple method for high-throughput screening of mPGES-1 inhibitors is still lacking. In this study, we developed a fluorescence imaging strategy to monitor the expression of mPGES-1 via CRISPR/Cas9 knock-in system. Immunofluorescence colocalisation, Sanger sequencing, RNAi, and IL-1β treatment all confirmed the successful construction of mPGES-1 reporter cells. The fluorescence signal intensity of the reporter cells treated with four conventional mPGES-1 inhibitors was considerably attenuated via flow cytometry and fluorescent microplate reader, demonstrating that the reporter cells can be used as an efficient and convenient means for screening and optimising mPGES-1 inhibitors. Moreover, it provides a new technical support for the development of targeted small molecule compounds for anti-inflammatory and tumour therapy. [ABSTRACT FROM AUTHOR]

The search of novel mPGES-1 inhibitors has recently intensified probably due to the superior safety in comparison to existing anti-inflammatory drugs. Although two mPGES-1 inhibitors have entered clinical trials, none has yet reached the market. In this study, we performed modifications guided by 3D-QSAR CoMFA on 2 , which is an unsymmetrical curcumin derivative with low binding affinity towards mPGES-1. To counter the PAINS properties predicted for 2 , the diketone linker was replaced with a pyrazole ring. On the other hand, both prenyl and carboxylate ester groups were introduced to improve the activity. When tested in vitro , 11 suppressed PGE 2 biosynthesis in activated macrophages and showed promising human mPGES-1 inhibition in microsomes of interleukin-1β-stimulated A549 cells. Altogether, 11 has been identified as a potential mPGES-1 inhibitor and could be a promising lead for a novel class of mPGES-1 inhibitors. To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Image 1 • A novel mPGES-1 lead inhibitor has been designed and synthesized guided by in silico 3D-QSAR CoMFA studies of MK-886 derivatives. • Compound 11 inhibited mPGES-1 activity. • The binding interactions of compound 11 with mPGES-1 was analyzed using MDS. [ABSTRACT FROM AUTHOR]

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been used clinically to treat inflammatory diseases clinically. However, the adverse effects of NSAIDs cannot be ignored. Therefore, it is critical for us to find alternative anti-inflammatory drugs that can reduce adverse reactions to herbal medicine, such as Iris tectorum Maxim., which has therapeutic effects and can treat inflammatory diseases and liver-related diseases. This study aimed to isolate active compounds from I. tectorum and investigate their anti-inflammatory effects and action mechanisms. Fourteen compounds were isolated from I. tectorum using silica gel column chromatography, Sephadex LH-20, ODS and high performance liquid chromatography, and their structures were identified by examining physicochemical properties, ultraviolet spectroscopy, infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. Classical inflammatory cell models were established using lipopolysaccharide (LPS)-stimulated RAW264.7 cells and rat primary peritoneal macrophages to examine the effect of these compounds. To examine the action mechanisms, the nitric oxide (NO) levels were measured by Griess reagent and the levels of inflammatory cytokines in the supernatant were measured by ELISA; The expressions of major proteins in prostaglandin E 2 (PGE 2) synthesis and the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were examined by Western blotting, and the mRNA expression levels were measured by quantitative real-time polymerase chain reaction; and the nuclear translocation of p65 was examined by high content imaging. Molecular docking was used to predict the binding of active compound to target protein. Our findings revealed that Iristectorigenin C (IT24) significantly inhibited the levels of NO and PGE 2 without affecting cyclooxygenase (COX)-1/COX-2 expression in LPS-induced RAW264.7 cells and rat peritoneal macrophages. Furthermore, IT24 was shown to decrease the expression of microsomal prostaglandin synthetase-1 (mPGES-1) in LPS-induced rat peritoneal macrophages. IT24 did not suppress the phosphorylation and nuclear translocation of proteins in the NF-κB pathway, but it inhibited the phosphorylation of p38/JNK in LPS-stimulated RAW264.7 cells. Additionally, molecular docking analysis indicated that IT24 may directly bind to the mPGES-1 protein. IT24 might inhibit mPGES-1 and the p38/JNK pathway to exert its anti-inflammatory effects and could be also developed as an inhibitor of mPGES-1 to prevent and treat mPGES-1-related diseases, such as inflammatory diseases, and holds promise for further research and drug development. [Display omitted] • Iristectorigenin C is a new compound isolated from Iris tectorum Maxim. • Iristectorigenin C exerts an anti-inflammatory effect by regulating mPGES-1 expression and p38/JNK pathway. • Targeting mPGES-1 without affecting COX-1 and COX-2 is a promising approach for controlling different diseases. [ABSTRACT FROM AUTHOR]

Sinomenine (SIN) is the main pharmacologically active component of Sinomenii Caulis and protects against rheumatoid arthritis (RA). In recent years, many studies have been conducted to elucidate the pharmacological mechanisms of SIN in the treatment of RA. However, the molecular mechanism of SIN in RA has not been fully elucidated. To summarize the pharmacological effects and molecular mechanisms of SIN in RA and clarify the most valuable regulatory mechanisms of SIN to provide clues and a basis for basic research and clinical applications. We systematically searched SciFinder, Web of Science, PubMed, China National Knowledge Internet (CNKI), the Wanfang Databases, and the Chinese Scientific Journal Database (VIP). We organized our work based on the PRISMA statement and selected studies for review based on predefined selection criteria. After screening, we identified 201 relevant studies, including 88 clinical trials and 113 in vivo and in vitro studies on molecular mechanisms. Among these studies, we selected key results for reporting and analysis. We found that most of the known pharmacological mechanisms of SIN are indirect effects on certain signaling pathways or proteins. SIN was manifested to reduce the release of inflammatory cytokines such as Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), and IL-1β, thereby reducing the inflammatory response, and apparently blocking the destruction of bone and cartilage. The regulatory effects on inflammation and bone destruction make SIN a promising drug to treat RA. More notably, we believe that the modulation of α7nAChR and the regulation of methylation levels at specific GCG sites in the mPGES-1 promoter by SIN, and its mechanism of directly targeting GBP5, certainly enriches the possibilities and the underlying rationale for SIN in the treatment of inflammatory immune-related diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

Fatty acid-binding proteins (FABPs) regulate the intracellular dynamics of fatty acids, mediate lipid metabolism and participate in signaling processes. However, the therapeutic efficacy of targeting FABPs as novel therapeutic targets for cerebral ischemia is not well established. Previously, we synthesized a novel FABP inhibitor, i.e., FABP ligand 6 [4-(2-(5-(2-chlorophenyl)-1-(4-isopropylphenyl)-1H-pyrazol-3-yl)-4-fluorophenoxy)butanoic acid] (referred to here as MF6). In this study, we analyzed the ability of MF6 to ameliorate transient middle cerebral artery occlusion (tMCAO) and reperfusion-induced injury in mice. A single MF6 administration (3.0 mg/kg, per os) at 0.5 h post-reperfusion effectively reduced brain infarct volumes and neurological deficits. The protein-expression levels of FABP3, FABP5 and FABP7 in the brain gradually increased after tMCAO. Importantly, MF6 significantly suppressed infarct volumes and the elevation of FABP-expression levels at 12 h post-reperfusion. MF6 also inhibited the promotor activity of FABP5 in human neuroblastoma cells (SH-SY5Y). These data suggest that FABPs elevated infarct volumes after ischemic stroke and that inhibiting FABPs ameliorated the ischemic injury. Moreover, MF6 suppressed the inflammation-associated prostaglandin E2 levels through microsomal prostaglandin E synthase-1 expression in the ischemic hemispheres. Taken together, the results imply that the FABP inhibitor MF6 can potentially serve as a neuroprotective therapeutic for ischemic stroke.

Background/Aims: We previously reported that indoxyl sulfate (IS) could cause mesangial cell (MC) proliferation via a cyclooxygenase (COX)-2-dependent mechanism. However, the specific prostaglandin contributing to COX-2 effect on IS-induced MC proliferation remained unknown. Thus, the present study was undertaken to examine the role of microsomal prostaglandin E synthase-1 (mPGES-1)-derived Prostaglandin E2 (PGE2) in IS-induced MC proliferation. Methods: IS was administered to the MCs with or without mPGES-1 siRNA pretreatment to induce the MC proliferation which was determined by cell cycle analysis, DNA synthesis, and the expressions of cyclins. In another experimental setting, PGE2 was applied to the MCs to examine its direct effect on MC proliferation, as well as the regulation of prostaglandin E receptors (EPs) by qRT-PCR. Results: With the administration of IS, mPGES-1(not mPGES-2 and cytosolic PGES) was significantly upregulated at both protein and mRNA levels in line with a promoted MC proliferation. Interestingly, silencing mPGES-1 reduced cell number in S and G2 phases and blocked the upregulation of cyclin A2 and cyclin D1 in parallel with blunted PGE2 release after IS treatment, indicating that mPGES-1-derived PGE2 could contribute to MC proliferation. Furthermore, we confirmed that exogenous PGE2 could directly trigger the proliferative response in MCs. Lastly, we observed a selective upregulation of EP2 after PGE2 treatment and enhanced phosphorylation of NF-κB following IS administration in MCs, suggesting the potential involvements of EP2 and NF-κB in this pathological process. Conclusion: mPGES-1-derived PGE2 contributed to IS-induced mesangial cell proliferation.

Here we report on novel and potent pyridyl-cycloalkyl-carboxylic acid inhibitors of microsomal prostaglandin E synthase-1 (PTGES). PTGES produces, as part of the prostaglandin pathway, prostaglandin E2 which is a well-known driver for pain and inflammation. This fact together with the observed upregulation of PTGES during inflammation suggests that blockade of the enzyme might provide a beneficial treatment option for inflammation related conditions such as endometriosis. Compound 5a , a close analogue of the screening hit, potently inhibited PTGES in vitro , displayed excellent PK properties in vitro and in vivo and demonstrated efficacy in a CFA-induced pain model in mice and in a rat dyspareunia endometriosis model and was therefore selected for further studies. [ABSTRACT FROM AUTHOR]

5-Aminolevulinic acid (5-ALA) induces the accumulation of a large amount of protoporphyrin IX (PpIX) in tumors, which has been used in the treatment of several cancers. 5-ALA is commonly used for fluorescence-guided tumor resection in clinical neurosurgery and for photodynamic therapy based on the generation of cytotoxic oxygen. The purpose of this study was to identify the mechanisms of 5-ALA-induced immune response in macrophages in malignant glioma. Intracellular levels of 5-ALA-induced PpIX in C3H/HeN murine peritoneal macrophages were measured by the median fluorescence intensity using flow cytometry and confocal laser scanning microscopy. Macrophages were cultured in vitro with or without 0.5 mM 5-ALA, 0.1 μg/mL lipopolysaccharide, and 20% glioma-conditioned medium. Levels of immunosuppressive prostaglandin E 2 (PGE 2), interleukin-10, and transforming growth factor β were measured using enzyme immunoassay in the culture supernatant. In addition, macrophages and RSV-M mouse glioma cells were co-cultured in vitro with cell culture inserts with or without 5-ALA (0.1 and 0.5 mM) and lipopolysaccharide (0.1 μg/mL). We found that 5-ALA-induced PpIX accumulated in macrophages and significantly suppressed PGE 2 production and expression of both cyclooxygenase-2 and microsomal prostaglandin E synthase-1. 5-ALA treatment also suppressed PGE 2 production by glioma-conditioned medium. 5-ALA suppressed RSV-M glioma cell proliferation in a concentration-dependent manner. These results indicate that 5-ALA suppressed PGE 2 production by macrophages via the downregulation of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 expression levels. This is a novel mechanism to induce effective immune response against glioma in macrophages. [ABSTRACT FROM AUTHOR]

Microsomal prostaglandin E synthase-1 (mPGES-1) catalyses the formation of PGE 2 in inflammatory tissues. It is considered a potential drug target in inflammatory conditions to achieve clinical benefits comparable to NSAIDs with a better tolerability. Inhibitors of mPGES-1 are under development but the pharmacological regulation of mPGES-1 expression remains poorly known. MAP kinase phosphatase-1 (MKP-1) is an enzyme that limits the activity of pro-inflammatory MAP kinases p38 and JNK. In the present study, we discovered that dexamethasone down-regulates mPGES-1 expression in articular chondrocytes in an MKP-1 and p38 kinase dependent manner. Primary human chondrocytes were isolated from cartilage samples obtained from osteoarthritis (OA) patients undergoing knee replacement surgery. Primary mouse chondrocytes were isolated from cartilage samples of MKP-1 deficient (knock-out, KO) and corresponding wild type (WT) mice. Expression of mPGES-1 and MKP-1 were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot, and MAP kinase phosphorylation by Western blot. Dexamethasone inhibited the expression of mPGES-1 in primary human chondrocytes and in chondrocytes from wild type but not from MKP-1 deficient mice. Dexamethasone enhanced MKP-1 expression in chondrocytes from wild type mice as well as in primary human OA chondrocytes. Dexamethasone induced the dephosphorylation of both p38 and JNK, whereas mPGES-1 expression was downregulated by selective inhibitors of p38 only. The results show that MKP-1 is a crucial mediator of pharmacological control of inflammatory mPGES-1 expression by glucocorticoids, and underline MKP-1 as a potential anti-inflammatory drug target. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is one of the main locomotor disorders in horses. Although nonsteroidal anti-inflammatory drugs are the first-line treatment for OA, opioids could also be used. In previous studies, opioids showed promising anti-inflammatory and analgesic effects. In this study, we aimed to investigate the effects of two opioids (morphine and methadone) against inflammation in lipopolysaccharide (LPS)-stimulated synoviocytes by analyzing microsomal prostaglandin E synthase-1 (mPGES-1) and prostaglandin-endoperoxide synthase 2 (PTGS2) expression. Synoviocytes were obtained from the joints at the distal limbs of dead animals. The cytotoxic effects of LPS, morphine, and methadone were investigated by using a cell viability assay with crystal violet dye. Synoviocytes were treated with LPS, LPS plus morphine, or LPS plus methadone for 3, 6, and 12 h, and mPGES-1 and PTGS2 expression was measured using real-time polymerase chain reaction. LPS, and morphine did not affect the viability of synoviocytes, even at high concentrations. LPS treatment increased mPGES-1 and PTGS2 expression, whereas morphine inhibited the increase in mPGES-1 and PTGS2 expression in LPS-stimulated synoviocytes. Methadone did not inhibit mPGES-1 or PTGS2 expression. These results suggest that morphine may exhibit anti-inflammatory effect; therefore, it might be beneficial for the treatment of OA. • LPS and morphine did not affect the viability of synoviocytes, even at high concentrations. • A concentration of 10−6 M of methadone showed some synoviocyte toxicity. • LPS-stimulated synoviocytes showed higher mPGES-1 and PTGS2 expression than the non-stimulated synoviocytes. • Morphine inhibited the increase of mPGES-1 and PTGS2 expression in LPS-stimulated synoviocytes. [ABSTRACT FROM AUTHOR]