Inhibition Of Prostaglandin E2 Production Research Articles

#2814 Characterization of cardiological manifestations in patients with sodium-wasting tubulopathies

Abstract Background and Aims Bartter (BS) and Gitelman (GS) syndromes are rare tubulopathies caused by mutations affecting renal NaCl transporters, resulting in similar symptoms like muscle weakness, cramps, and electrolyte imbalances, with GS also presenting with hypomagnesemia. Treatment focuses on electrolyte and fluid balance, using supplements and drugs to inhibit prostaglandin production and RAAS activation. Electrolyte deficits in these conditions can extend the QT interval and increase the risk of potentially fatal cardiac arrhythmias. This study aims to profile BS and GS patients followed at our hospital, focusing on cardiological phenotyping. We assessed diagnostic, clinical, and lab data, particularly examining the link between electrolyte imbalances (like hypokalemia or hypomagnesemia) and electrocardiographic changes or cardiac symptoms during follow-up. Method We screened all BS and GS patients for study inclusion, requiring a genetic diagnosis with disease-causing mutations and comprehensive clinical and electrocardiographic data. We excluded cases lacking sufficient data. We gathered demographic and health information retrospectively, categorizing patients based on electrocardiographic results into groups: 1) persistent long QT interval, 2) transient long QT interval, and 3) no long QT interval. Data were summarized with medians, interquartile ranges, and frequencies. Results A total of 27 patients were enrolled in the study, 16 with Bartter Syndrome (BS) and 11 with Gitelman Syndrome (GS); median length of follow-up was 6 years (range 3-19). Only one patient was classified in group 1, with a constant QTc prolongation (446.3 ms); 8 patients (34.8%) fell into group 2 with median QTc values of 420 ms, all exhibiting hypokalemia and hypomagnesemia. The majority (14/23, 61%) were in group 3, with a median QTc of 399.2 ms and 79% displaying hypokalemia and hypomagnesemia. All 9 patients who experienced cardiac-related symptoms were adults, with 8 presenting these symptoms during intercurrent episodes. The study also compared clinical differences between BS and GS patients, noting a higher frequency of hypokalemia and hypomagnesemia in GS, whereas BS patients had more electrocardiographic alterations, although not statistically significant. No echocardiographic abnormalities were detected from the available data, and there were no recorded incidents of malignant arrhythmias or sudden death. Conclusion Electrocardiographic abnormalities in BS and GS patients fluctuate, often related to episodic events, with QT prolongation in one-third of cases but no severe cardiac complications, indicating a generally positive prognosis.

Deciphering the Pharmacological Mechanisms of Wen-Jing-Zhi-Tong Decoction in Treating Primary Dysmenorrhea by UPLC-Q-ExactiveOrbitrap-MS/MS with GC-MS and Network Pharmacology.

Primary dysmenorrhea (PDM) is a prevalent menstrual disorder among women, often underreported and undertreated. Wen-Jing-Zhi-Tong Decoction (WJZTD), a patented Traditional Chinese Medicine (TCM) herbal decoction, has shown efficacy in treating PDM. However, the underlying therapeutic mechanism of WJZTD in PDM treatment remains to be elucidated. This study aimed to employ integrative pharmacology and experimental validation to investigate the potential therapeutic mechanisms of WJZTD in treating PDM. The bioactive compounds of WJZTD were identified by UPLC-Q-Exactive-Orbitrap MS/MS and GC-MS. Putative targets of WJZTD were obtained from Swiss Target Prediction, STITCH, and BATMAN-TCM databases. Known targets of PDM were retrieved from Gene Cards and Drug Bank databases. Protein-to-protein interactions were constructed to screen key targets using the STRING database. Subsequently, GO and KEGG pathway enrichment analyses were performed based on Metascape. Finally, a PDM rat model was established to validate the potential therapeutic mechanisms of WJZTD using Western Blot, PCR, and ELISA. 390 bioactive compounds in WJZTD were identified through UPLC-Q-ExactiveOrbitrap MS/MS and GC-MS. Network pharmacology revealed 7 key compounds with 20 targets and pathways that are crucial for WJZTD in treating PDM. Behavioral tests confirmed that WJZTD can effectively ameliorate menstrual pain in PDM. WJZTD also inhibited prostaglandin production, thereby relieving uterine smooth muscle contraction. The downregulation of the BDNF/TrkB/ERK/CREB signaling pathway, identified as the key target and pathway through network pharmacology, may be crucial to the anti-nociceptive and anti-inflammatory effects of WJZTD in treating PDM. This study provides the first comprehensive analysis of the key compounds, targets, and pathways of WJZTD, laying a solid foundation for future pharmacological studies on PDM. The anti-nociceptive and anti-inflammatory effect may be attributed to the downregulation of the BDNF/TrkB/ERK/CREB signaling pathway.

Exploring in vitro and in vivo anti-inflammatory activities of the Thai traditional remedy Kheaw-Hom and its bioactive compound, ethyl p-methoxycinnamate, and ethnopharmacological analysis

Ethnopharmacological relevanceKheaw-Hom (KH) remedy, a Thai traditional medicine (TTM) on the National List of Essential Medicines, has long been clinically used to treat fever and inflammation in children. However, no in vitro or in vivo anti-inflammatory or bioactive compound studies are published in the literature. Aims of the studyTo explore the in vitro and in vivo anti-inflammatory activities of KH remedy and its bioactive compound and analyze relationships between flavor and ethnopharmacological activities of plant components in KH remedy according to TTM theory. Materials and methodsEthyl p-methoxycinnamate (EPMC), a bioactive compound of KH remedy was analyzed using high performance liquid chromatography (HPLC). In vitro anti-inflammatory activities of ethanolic extract (KHE), aqueous extract (KHA), acid-hydrolysis of KHA (KHA-h), acid-hydrolysis of KH powder (KHP-h), and EPMC were investigated using lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-alpha (TNF-α) production in murine macrophage RAW 264.7 cells. In vivo anti-inflammatory activities of KH powder (KHP) and KHE were determined using carrageenan-induced paw edema and ethyl phenylpropiolate (EPP)-induced ear edema in rats and PGE2 production in tissue samples was examined. ResultsKHP-h showed the highest EPMC content (21.33 ± 1.08 mg/g of extract) and inhibited PGE2, NO, and TNF-α production with IC50 values of 11.92 ± 0.21, 30.61 ± 3.12, and 56.71 ± 2.91 μg/mL, respectively, followed by KHE and KHA-h while KHA did not. EPMC, a bioactive compound of KH remedy showed high anti-inflammatory activities through three pathways. KHP oral administration (100 mg/kg) significantly minimized rat paw inflammation at 1, 2, and 3 h while KHE (100 mg/kg) noticeably reduced at 2 and 3 h. KHP (100, 200, and 400 mg/kg) and KHE (100 mg/kg) significantly inhibited PGE2 production. KHP (1% w/v) notably reduced rat ear edema at 30, 60, and 120 min whereas KHE at all concentrations decreased swelling at 120 min. KHP and KHE at all doses significantly inhibited PGE2 production. Cool flavor was the main KH remedy flavor. Spicy plant components and some fragrant components showed high anti-inflammatory activity. ConclusionsResults from the in vivo study strongly paralleled the in vitro study. These findings support the rational use of KH remedy according to TTM theory for fever treatment and inflammation in children.

MPGES-1 Inhibitor Discovery Based on Computer-Aided Screening: Pharmacophore Models, Molecular Docking, ADMET, and MD Simulations.

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.

Bioequivalence of Celecoxib Capsules in Chinese Healthy Volunteers.

Celecoxib is a sulfanilamide nonsteroidal anti-inflammatory drug that can selectively inhibit cyclooxygenase-2 to inhibit prostaglandin production, achieving anti-inflammatory and analgesic effects. This study investigated the pharmacokinetics, safety, and bioequivalence of a single oral dose of celecoxib capsule (the test or reference preparation) in healthy volunteers under fasting and fed conditions. A single-center, randomized, open, single-dose, double-cycle crossover self-control design was conducted: 40 healthy volunteers were enrolled in the fasting and fed groups, respectively. A completely randomized method was used, with one group taking the test celecoxib preparation (T) and the other taking the reference celecoxib preparation (R). During the administration period, the safety of the drug was evaluated simultaneously, and venous blood was collected at the corresponding time points. The concentration of celecoxib in plasma was measured by liquid chromatography-tandem mass spectrometry. The main pharmacokinetic parameters were logarithmically converted and analyzed for variance. The 90% confidence interval for the bioavailability of the T compared to the R was calculated using maximum drug plasma concentration, area under the plasma concentration-time curve from time zero to the last quantifiable concentration point, and area under the plasma concentration-time curve from time zero to infinity for a single oral dose in volunteers, and the data obtained were all between 80% and 125%, indicating that the T and R have bioequivalence and good safety during fasting and fed administration.

Celecoxib alleviates nociceptor sensitization mediated by interleukin-1beta-primed annulus fibrosus cells

PurposeThis study aims to analyze the effect of pro-inflammatory cytokine-stimulated human annulus fibrosus cells (hAFCs) on the sensitization of dorsal root ganglion (DRG) cells. We further hypothesized that celecoxib (cxb) could inhibit hAFCs-induced DRG sensitization.MethodshAFCs from spinal trauma patients were stimulated with TNF-α or IL-1β. Cxb was added on day 2. On day 4, the expression of pro-inflammatory and neurotrophic genes was evaluated using RT-qPCR. Levels of prostaglandin E2 (PGE-2), IL-8, and IL-6 were measured in the conditioned medium (CM) using ELISA. hAFCs CM was then applied to stimulate the DRG cell line (ND7/23) for 6 days. Then, calcium imaging (Fluo4) was performed to evaluate DRG cell sensitization. Both spontaneous and bradykinin-stimulated (0.5 μM) calcium responses were analyzed. The effects on primary bovine DRG cell culture were performed in parallel to the DRG cell line model.ResultsIL-1ß stimulation significantly enhanced the release of PGE-2 in hAFCs CM, while this increase was completely suppressed by 10 µM cxb. hAFCs revealed elevated IL-6 and IL-8 release following TNF-α and IL-1β treatment, though cxb did not alter this. The effect of hAFCs CM on DRG cell sensitization was influenced by adding cxb to hAFCs; both the DRG cell line and primary bovine DRG nociceptors showed a lower sensitivity to bradykinin stimulation.ConclusionCxb can inhibit PGE-2 production in hAFCs in an IL-1β-induced pro-inflammatory in vitro environment. The cxb applied to the hAFCs also reduces the sensitization of DRG nociceptors that are stimulated by the hAFCs CM.

Novel, Brain-Permeable, Cross-Species Benzothiazole Inhibitors of Microsomal Prostaglandin E Synthase-1 (mPGES-1) Dampen Neuroinflammation In Vitro and In Vivo.

Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible enzyme of the cyclooxygenase (COX) cascade that generates prostaglandin E2 (PGE2) during inflammatory conditions. PGE2 is known to be a potent immune signaling molecule that mediates both peripheral and central inflammations. Inhibition of mPGES-1, rather than COX, may overcome the cardiovascular side effects associated with long-term COX inhibition by providing a more specific strategy to target inflammation. However, mPGES-1 inhibitor development is hampered by the large differences in cross-species activity due to the structural differences between the human and murine mPGES-1. Here, we report that our thiazole-based mPGES-1 inhibitors, compounds 11 (UT-11) and 19 derived from two novel scaffolds, were able to suppress PGE2 production in human (SK-N-AS) and murine (BV2) cells. The IC50 values of inhibiting PGE2 production in human and murine cells were 0.10 and 2.00 μM for UT-11 and 0.43 and 1.55 μM for compound 19, respectively. Based on in vitro and in vivo pharmacokinetic data, we selected UT-11 for evaluation in a lipopolysaccharide (LPS)-induced inflammation model. We found that our compound significantly suppressed proinflammatory cytokines and chemokines in the hippocampus but not in the kidney. Taken together, we demonstrated the potential of UT-11 in treating neuroinflammatory conditions, including epilepsy and stroke, and warrant further optimization.

Combination pharmacotherapy for patent ductus arteriosus: Rationale and evidence

While cyclooxygenase inhibitors have been the most common medications used to facilitate earlier closure of patent ductus arteriosus in preterm infants, adverse effects and low efficacy in extremely low gestational age neonates (ELGANs) have highlighted a need for alternative options. Combination therapy with acetaminophen and ibuprofen is a novel strategy for PDA treatment in ELGANs, as it may facilitate higher ductal closure rates via additive action on two separate pathways inhibiting prostaglandin production. Initial small observational studies and pilot randomized clinical trials indicate potentially higher efficacy of the combination regime to induce ductal closure in comparison to treatment with ibuprofen alone. In this review, we examine the potential clinical impact of treatment failure in ELGANs with significant PDA, highlight the biological rationale in support of studying combination therapy, and review the randomized and non-randomized studies to date. With the rising number of ELGANs receiving neonatal intensive care, who are vulnerable to PDA-related morbidities, there is an urgent need for adequately powered clinical trials to systematically investigate the efficacy and safety of combination therapy for PDA treatment.

Renal interstitial cells promote nephron regeneration by secreting prostaglandin E2.

In organ regeneration, progenitor and stem cells reside in their native microenvironment, which provides dynamic physical and chemical cues essential to their survival, proliferation, and differentiation. However, the types of cells that form the native microenvironment for renal progenitor cells (RPCs) have not been clarified. Here, single-cell sequencing of zebrafish kidney reveals fabp10a as a principal marker of renal interstitial cells (RICs), which can be specifically labeled by GFP under the control of fabp10a promoter in the fabp10a:GFP transgenic zebrafish. During nephron regeneration, the formation of nephrons is supported by RICs that form a network to wrap the RPC aggregates. RICs that are in close contact with RPC aggregates express cyclooxygenase 2 (Cox2) and secrete prostaglandin E2 (PGE2). Inhibiting PGE2 production prevents nephrogenesis by reducing the proliferation of RPCs. PGE2 cooperates with Wnt4a to promote nephron maturation by regulating β-catenin stability of RPC aggregates. Overall, these findings indicate that RICs provide a necessary microenvironment for rapid nephrogenesis during nephron regeneration.

CRISPR screen finds Prostaglandin E receptor 2 modulates activation of dendritic cells and cross-presentation of cell-associated antigens from fibroblasts

The sensing of pathogenic stimuli by dendritic cells (DCs) promotes antigen processing for cross-presentation, whereby the activation of DCs is followed by their migration to lymph nodes and spleen, where the cross-presented antigens can prime naïve T-cells for an adaptive immune response. DCs can also cross-present antigens in the absence of infection, but endogenous signals that promote antigen processing and presentation remain poorly understood. We observed that DCs efficiently cross-present cell-associated antigens from fibroblasts (3T3), even in the absence of pathogenic stimulus. We hypothesized that signals that promote DC activation might also promote processing of cell-associated antigens for presentation. In order to determine the molecular components responsible for DC activation, we performed a CRISPR knockout screen targeting a total of 704 known or predicted regulators involved in sensing of pathogens/danger signals. DCs were co-cultured with 3T3 and sorted into two populations for high and low expression of activation markers on DCs and the guides enriched were determined by sequencing. Prostaglandin E receptor 2 (PTGER2) was found to be the major hit. The results were validated in cDC1-like cell line, MutuDC, where direct activation of PTGER2 using its ligand prostaglandin E2 (PGE2) resulted in increased expression of activation markers (CD83 and CD86). Inhibition of the PGE2 production or of its receptor using small molecule inhibitors, resulted in significantly reduced activation of dendritic cells when co-cultured with 3T3 cells. The DC activation via PTGER2 was found to be mediated via cAMP production upon adenylyl cyclase activation. In addition, the inhibition of PTGER2 and PGE2 production via COX1/COX2 also resulted in reduced cross-presentation of cell-associated antigens. CRISPR screen found PTGER2 as the molecular component in dendritic cells that can regulate both DC activation and cross-presentation of cell-associated antigens in the absence of infection.

Obesity-associated renal alterations are mediated by Microsomal Prostaglandin E Synthase-1 (mPGES-1) in a sex-dependent manner.

Introduction: Obesity is characterized by a chronic-low grade inflammation that causes pathophysiological alterations in different target organs, contributing, among others, to the development of renal damage. Microsomal Prostaglandin E Synthase 1 (mPGES-1) is an inducible isomerase responsible for the overexpression of prostaglandin E2 (PGE2) under inflammatory conditions, including obesity. Inhibition of PGE2 production by non-steroidal anti-inflammatory drugs, that block cyclooxygenase-2 (COX-2) cascade, limits inflammatory processes. However, it can be associated with side- effects as nephrotoxicity due to the inhibition of other prostaglandins production. New drugs targeting mPGES-1 have shown promising results in different experimental models. Nevertheless, to our knowledge, efficacy of inhibition downstream COXs in the renal impact of obesity remains unexplored. Objective: To elucidate whether mPGES-1 depletion could prevent the development of renal alterations in an experimental model of obesity. Methods: We have developed a model of HFD-induced obesity (60% fat, 13 weeks) in males and females mPGES-1-/- and their control littermates mPGES-1+/+ mice. Renal structural alterations and changes in mRNA expression were studied by histological analysis and q-RT-PCR, respectively. Results: IHFD decreased renal mPGES-1 gene expression in females but not in males. On the contrary, mPGES-1 expression was upregulated in perirenal adipose tissue (PRAT) of both sexes. In females, HFD induced kidney and PRAT hypertrophy that was prevented by the absence of mPGES-1; whereas in males, HFD did not modify kidney weight, while increasing PRAT weight significantly more in mPGES-1+/+ than in mPGES-1-/- mice. Rt-qPCR studies revealed that HFD induced renal damage, inflammation and fibrosis in mPGES-1+/+ male mice, which was not observed in mPGES-1 deficient mice. In agreement, histological studies showed that HFD induced glomerular hypertrophy and renal fibrosis only in mPGES-1+/+ HFD males. These alterations were not likely mediated by oxidative stress. Of note, females were protected against renal inflammatory and fibrotic alterations induced by HFD. Additionally, mPGES-1 deficiency prevented HFD- induced PRAT inflammation, fibrosis and hypoxia in both males and females. HFD did not modify serum proteinuria in any sex. Conclusion: mPGES-1 participates in the renal alterations associated with obesity in a s ex-dependent manner.

Anti-Inflammatory and Antioxidant Activity of Syzygium polyanthum (Wight) Walp.

Syzygium polyanthum has been used as folk medicine to treat ailments related to oxidative stress and inflammation. In this study, the anti-inflammatory and antioxidant activity of stem bark and root bark of the plant were investigated. The experiments that have been carried out were estimation of total phenolic and total flavonoid in the methanol extracts and fractions of both parts, isolation and structure elucidation of chemical compounds, anti-inflammatory activity evaluation based on inhibition of prostaglandin E2 production in the LPS-induced human whole blood using radioimmunoassay technique as well as antioxidant activity based on assays by using free radical scavenging DPPH and FRAP. Results showed high amounts of phenolics and flavonoids in both parts of S. polyanthum. Seven compounds were succesfully isolated from the stem bark and identified as stigmasterol (1), 8-hydroxy-6-methoxy-3-pentylisocoumarin (2), 3,3’-di-O-methylellagic acid (3), methylgallate (4), asiatic acid (5), arjunolic acid (6), and daucosterol (7). The ethyl acetate fraction of the root bark showed potent inhibitory activity on the production of PGE2 (IC50 3.03 ± 0.83 μg/mL). The methanol extract of the stem bark displaying promising DPPH scavenging activity (SC50= 2.82 ± 0.1 μg/mL) and FRAP activity (7.02 ± 0.1 μg/μg of equivalent trolox amount). Compounds 1, 5, 6 and 7 showed pronounced inhibitory activity on the PGE2 production with IC50ranging from 0.052 to 1.25 μM. Meanwhile, compound 4 exhibited antioxidant activity toward DPPH (SC5010.60 μM) and FRAP (20.5 ± 1.0 μg/μg). The study concluded that S. polyanthum as a potential source for therapeutic agents with anti-inflammatory and antioxidant activities.

Sinomenine increases the methylation level at specific GCG site in mPGES-1 promoter to facilitate its specific inhibitory effect on mPGES-1

Prostaglandin E2 (PGE2) in cancer and inflammatory diseases is a key mediator of disease progression. Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to inhibit the expression of PGE2 by depressing cyclooxygenase (COX) in inflammatory treatments. However, the inhibition to COXs may cause serious side effects. Thus, it is urgent to develop new anti-inflammatory drugs aiming new targets to inhibit PGE2 production. Microsomal prostaglandin E synthase 1 (mPGES-1) catalyzes the final step of PGE2 biosynthesis. Therefore, the selective inhibition of mPGES-1 has become a promising strategy in the treatments of cancer and inflammatory diseases. Our previous studies confirmed that sinomenine (SIN) is a specific mPGES-1 inhibitor. However, the exact mechanism by which SIN inhibits mPGES-1 remains unknown. This study aimed to explain the regulation effect of SIN to mPGES-1 gene expression by its DNA methylation induction effect. We found that the demethylating agent 5-azacytidine (5-AzaC) reversed the inhibitory effect of SIN to mPGES-1. Besides, SIN selectively increased the methylation level of the promoter region in the mPGES-1 gene while the pretreatment of 5-AzaC suppressed this effect. The results also shows that pretreatment with SIN increased the methylation level of specific GCG sites in the promoter region of mPGES-1. This specific methylation site may become a new biomarker for predicting and diagnosing RA and cancer with high expression of mPGES-1. Also, our research provides new ideas and solutions for clinical diagnosis and treatment of diseases related to mPGES-1 and for targeted methylation strategy in drug development.

MiR-26a Reduces Inflammatory Responses via Inhibition of PGE2 Production by Targeting COX-2.

MicroRNAs are small non-coding RNA regulatory molecules that play an important role in the development and function of immune cells. MicroRNA-26a (miR-26a) exhibits anti-inflammatory immune effects on immune cells. However, the exact mechanism by which miR-26a plays an anti-inflammatory role remains unclear. Here, we report that miR-26a reduces inflammatory response via inhibition of prostaglandin E2 (PGE2) production by targeting cyclooxygenase-2 (COX-2). We found that miR-26a was downregulated in vitro and in vivo. The miR-26a mimic significantly decreased COX-2 protein levels, further inhibiting pro-inflammatory cytokine production in LPS-stimulated macrophages. We predicted that miR-26a could potentially target COX-2 in LPS-stimulated macrophages. Computational algorithms showed that the 3′-UTR of COX-2 mRNA contains a binding site for miR-26a. This putative targeting relationship between miR-26a and COX-2 was further confirmed by a dual-reporter gene assay. The anti-inflammatory effects of the miR-26a mimic were diminished by PGE2 supplementation. Importantly, miR-26a mimics protected mice from lethal endotoxic shock and attenuated pro-inflammatory cytokine production. Collectively, these results suggest that miR-26a may function as a novel feedback negative regulator of the hyperinflammatory response and as a drug target for the progression of inflammation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10753-022-01631-2.

The Trypanosome-Derived Metabolite Indole-3-Pyruvate Inhibits Prostaglandin Production in Macrophages by Targeting COX2.

The protozoan parasite Trypanosoma brucei is the causative agent of the neglected tropical disease human African trypanosomiasis, otherwise known as sleeping sickness. Trypanosomes have evolved many immune-evasion mechanisms to facilitate their own survival, as well as prolonging host survival to ensure completion of the parasitic life cycle. A key feature of the bloodstream form of T. brucei is the secretion of aromatic keto acids, which are metabolized from tryptophan. In this study, we describe an immunomodulatory role for one of these keto acids, indole-3-pyruvate (I3P). We demonstrate that I3P inhibits the production of PGs in activated macrophages. We also show that, despite the reduction in downstream PGs, I3P augments the expression of cyclooxygenase (COX2). This increase in COX2 expression is mediated in part via inhibition of PGs relieving a negative-feedback loop on COX2. Activation of the aryl hydrocarbon receptor also participates in this effect. However, the increase in COX2 expression is of little functionality, as we also provide evidence to suggest that I3P targets COX activity. This study therefore details an evasion strategy by which a trypanosome-secreted metabolite potently inhibits macrophage-derived PGs, which might promote host and trypanosome survival.

Salicinoyl Quinic Acids and Their Prostaglandin E2 Production Inhibitory Activities from the Fruits of Casearia grewiifolia.

Phytochemical investigation on the dried fruits of Casearia grewiifolia led to the identification of 10 new salicinoyl quinic acid derivatives (1-10), a new benzoyl quinic acid (11), and two known compounds (12 and 13). The structures of the new compounds were elucidated by interpreting 1D and 2D NMR spectroscopic data including HMBC and EXSIDE along with a chemical method for sugar unit analysis. All isolates were evaluated for their inhibitory activities against prostaglandin E2 (PGE2) production in ultraviolet B (UVB)-irradiated HaCat keratinocytes. Of the isolates tested, compounds 6 and 12 were found to inhibit PGE2 production with IC50 values of 20.5 and 28.8 μM, respectively.

The inhibitory effects of Orengedokuto on inducible PGE2 production in BV-2 microglial cells

Background and aimReactive microglia has been associated with neuroinflammation caused by the production of proinflammatory molecules such as cytokines, nitric oxide, and prostaglandins. The overexpression of these molecules may provoke neuronal damage that can cause neurodegenerative diseases. A traditional herbal medicine, Orengedokuto (OGT), has been widely used for treating inflammation-related diseases. However, how it influences neuroinflammation remains poorly understood. Experimental procedureThis study investigated the effects of OGT on inflammatory molecule induction in BV-2 microglial cells using real-time RT-PCR and ELISA. An in vivo confirmation of these effects was then performed in mice. Results and conclusionOGT showed dose-dependent inhibition of prostaglandin E2 (PGE2) production in BV-2 cells stimulated with lipopolysaccharide (LPS). To elucidate the mechanism of PGE2 inhibition, we examined cyclooxygenases (COXs) and found that OGT did not suppress COX-1 expression or inhibit LPS-induced COX-2 upregulation at either the transcriptional or translational levels. In addition, OGT did not inhibit COX enzyme activities within the concentration that inhibited PGE2 production, suggesting that the effect of OGT is COX-independent. The inhibitory effects of OGT on PGE2 production in BV-2 cells were experimentally replicated in primary cultured astrocytes and mice brains. OGT can be useful in the treatment of neuroinflammatory diseases by modulating PGE2 expression.

Polysubstituted Pyrimidines as Potent Inhibitors of Prostaglandin E2 Production: Increasing Aqueous Solubility.

Water solubility is one of the key features of potential therapeutic agents. In order to enhance the low water solubility of the parent 5-butyl-4-(4-methoxyphenyl)-6-phenylpyrimidin-2-amine, a potent inhibitor of prostaglandin E2 (PGE2 ) production, we synthesized and evaluated a new series of derivatives in which the butyl group at the C5 position of the pyrimidine ring was replaced with a less lipophilic substituent, preferably with a hydrophilic aliphatic moiety. Except for the 5-cyanopyrimidine derivative, all target compounds exhibited increased (2.7-87-fold) water solubility relative to the parent compound. Although nontoxic in mouse peritoneal cells, the prepared compounds were either equipotent or weaker inhibitors of PGE2 production than the parent compound. The most promising compound from the series was found to be the 5-(2,5,8,11-tetraoxadodecyl)pyrimidine derivative (with three polyethylene glycol units at the C5 position), which exhibited 32-fold higher water solubility and only slightly weaker inhibitory activity (22 % of remaining PGE2 production) compared with the parent compound (15 % of remaining PGE2 production).

COMPARISON OF NONSTEROIDAL ANTI-INFLAMMATORY OF COX-1 AND COX-2 REGARDING SIDE EFFECTS IN THE ASTROINTESTINAL TRACT

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat symptoms caused by rheumatoid arthritis due to their ability to inhibit prostaglandin synthesis by inhibiting cyclooxygenase (COX). The side effects of NSAIDs are also associated with inhibiting prostaglandin production. Consequently, their application is problematic. NSAID selective COX-2 inhibitors give minor gastrointestinal complications. Our study aims to compare nonsteroidal anti-inflammatory inhibitors of COX-1 and COX-2 regarding side effects in the gastrointestinal tract of patients with rheumatoid arthritis. Keywords: Nonsteroidal anti-infammatory drugs, rheumatoid arthtritis, COX-2, gastrointestinal tract, PPIs .

The impact of damage-associated molecules released from canine tumor cells on gene expression in macrophages

Dying or damaged cells that are not completely eradicated by the immune system release their intracellular components in the extracellular space. Aberrant exposure of the damage-associated molecules to the immune system is often associated with inflammation and cancer pathogenesis. Thus, elucidating the role of damage-associated molecules in inducing sterile immune responses is crucial. In this study, we show that prostaglandin E2 (PGE2) is produced in the supernatants from several types of canine necrotic tumor cell lines. Inhibition of PGE2 production by indomethacin, a potent inhibitor of cyclooxygenase (COX) enzymes, induces the expression of tumor necrosis factor (Tnf) mRNA in the necrotic tumor cell supernatants. These results comply with the previous observations reported in mouse cell lines. Furthermore, comprehensive ribonucleic acid-sequencing (RNA-seq) analysis revealed that three categories of genes were induced by the damage-associated molecules: (i) a group of PGE2-inducible genes, (ii) genes that promote inflammation and are suppressed by PGE2, and (iii) a group of genes not suppressed by PGE2. Collectively, our findings reveal the hitherto unknown immune regulatory system by PGE2 and damage-associated molecules, which may have clinical implications in inflammation and cancer.