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We tested five chemically and metabolically stable prostaglandin (PG) receptor agonists in a mouse model of dexamethasone-induced ocular hypertension (OHT). Whilst all compounds significantly (p < 0.05, ANOVA) lowered intraocular pressure (IOP) after twice-daily bilateral topical ocular dosing (5 µg/dose) over three weeks, the time course and magnitude of the responses varied. The onset of action of NS-304 (IP-PG receptor agonist) and rivenprost (EP4-PG receptor agonist) was slower than that of misoprostol (mixed EP2/EP3/EP4-PG receptor agonist), PF-04217329 (EP2-PG receptor agonist), and butaprost (EP2-PG receptor agonist). The rank order of IOP-lowering efficacies aligned with the onset of actions of these compounds. Peak IOP reductions relative to vehicle controls were as follows: misoprostol (74.52%) = PF-04217329 (74.32%) > butaprost (65.2%) > rivenprost (58.4%) > NS-304 (55.3%). A literature survey indicated that few previously evaluated compounds (e.g., latanoprost, timolol, pilocarpine, brimonidine, dorzolamide, cromakalim analog (CKLP1), losartan, tissue plasminogen activator, trans-resveratrol, sodium 4-phenyl acetic acid, etc.) in various animal models of steroid-induced OHT were able to match the effectiveness of misoprostol, PF-04217329 or butaprost. Since a common feature of the latter compounds is their relatively high affinity and potency at the EP2-PG receptor sub-type, which activates the production of intracellular cAMP in target cells, our studies suggest that drugs selective for the EP2-PG receptor may be suited to treat corticosteroid-induced OHT.

Background/aim: Our recent study revealed that the expression of lipoxygenase (LOX) and cyclooxygenase (COX) enzymes in the hypothalamus is activated by nesfatin-1, leading to the liberation of leukotrienes and prostaglandins (PG), respectively. Moreover, our prior report explained that intracerebroventricular (ICV) nesfatin-1 treatment triggers cardiovascular responses mediated by central LOX and COX enzymes. Building upon our prior reports, the present investigation sought to clarify the role of cardiovascularly active central COX products, such as thromboxane (TX) A2, PGF2α, PGE, and PGD, in orchestrating nesfatin-1-evoked reactions in mean arterial pressure (MAP) and heart rate (HR). Materials and methods: The Sprague Dawley rats, which had guide cannula in the lateral ventricle for intracerebroventricular (ICV) injections and catheter in arteria femoralis for monitoring MAP and HR, were underwent central pretreatment with furegrelate (the TXA2 synthase inhibitor), PGF2α-dimethylamine (PGF2α-DA, the PGF2α receptor antagonist), or AH6809 (the PGE and PGD receptor antagonist), 5 min prior to ICV nesfatin-1 administration. The cardiovascular parameters were observed and recorded for 60 min posttreatment Results: Nesfatin-1 induced cardiovascular responses in rats leading to pressor effect in MAP, and tachycardia following bradycardia in HR. Interestingly, ICV furegrelate, PGF2α-DA, or AH6809 pretreatment partially mitigated the cardiovascular effects revealed by nesfatin-1. Conclusion: The findings illuminate the role of nesfatin-1 in modulating MAP and HR through the central activation of specifically TXA2, PGF2α, PGE, and PGD from COX metabolites. Additionally, the study may also suggest the potential involvement of other central COX or LOX metabolites beyond these COX metabolites in mediating the cardiovascular effects produced by nesfatin-1. [ABSTRACT FROM AUTHOR]

The cellular mechanism by which epoxy fatty acids (EpFA) improves disease status is not well characterized. Previous studies suggest the involvement of cellular receptors and cyclic AMP (cAMP). Herein, the action of EpFAs derived from linoleic acid (LA), arachidonic acid (ARA), and docosahexaenoic acid on cAMP levels was studied in multiple cell types to elucidate relationships between EpFAs, receptors and cells' origin. cAMP levels were enhanced in HEK293 and LLC-PK1 cells by EpFAs from LA and ARA. Using selective antagonists, the EpFA effects on cAMP levels appear dependent on the prostaglandin E2 receptor 2 (EP2) but not 4 (EP4). Human coronary artery smooth muscle cells responded similarly to the EpFAs. However, we were not able to show the involvement of any of the receptors tested in this cell type. The results pinpointed distinct cell lines and receptor subtypes that natively respond to EpFA.

Cancer therapy reduces tumor burden via tumor cell death ("debris"), which can accelerate tumor progression via the failure of inflammation resolution. Thus, there is an urgent need to develop treatment modalities that stimulate the clearance or resolution of inflammation-associated debris. Here, we demonstrate that chemotherapy-generated debris stimulates metastasis by up-regulating soluble epoxide hydrolase (sEH) and the prostaglandin E2 receptor 4 (EP4). Therapy-induced tumor cell debris triggers a storm of proinflammatory and proangiogenic eicosanoid-driven cytokines. Thus, targeting a single eicosanoid or cytokine is unlikely to prevent chemotherapy-induced metastasis. Pharmacological abrogation of both sEH and EP4 eicosanoid pathways prevents hepato-pancreatic tumor growth and liver metastasis by promoting macrophage phagocytosis of debris and counterregulating a protumorigenic eicosanoid and cytokine storm. Therefore, stimulating the clearance of tumor cell debris via combined sEH and EP4 inhibition is an approach to prevent debris-stimulated metastasis and tumor growth.

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Regulatory subunits of protein kinase A (PKA) inhibit its kinase subunits. Intriguingly, their potential as cAMP-dependent signal transducers remains uncharacterized. We recently reported that type I PKA regulatory subunits (RIα) interact with phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchange factor 1 (P-REX1), a chemotactic Rac guanine exchange factor (RacGEF). Because P-REX1 is known to be phosphorylated and inhibited by PKA, its interaction with RIα suggests that PKA regulatory and catalytic subunits may fine-tune P-REX1 activity or those of its target pools. Here, we tested whether RIα acts as a cAMP-dependent factor promoting P-REX1-mediated Rac activation and cell migration. We observed that Gs-coupled EP2 receptors indeed promote endothelial cell migration via RIα-activated P-REX1. Expression of the P-REX1-PDZ1 domain prevented RIα/P-REX1 interaction, P-REX1 activation, and EP2-dependent cell migration, and P-REX1 silencing abrogated RIα-dependent Rac activation. RIα-specific cAMP analogs activated P-REX1, but lost this activity in RIα-knockdown cells, and cAMP pulldown assays revealed that P-REX1 preferentially interacts with free RIα. Moreover, purified RIα directly activated P-REX1 in vitro We also found that the RIα CNB-B domain is critical for the interaction with P-REX1, which was increased in RIα mutants, such as the acrodysostosis-associated mutant, that activate P-REX1 at basal cAMP levels. RIα and Cα PKA subunits targeted distinct P-REX1 molecules, indicated by an absence of phosphorylation in the active fraction of P-REX1. This was in contrast to the inactive fraction in which phosphorylated P-REX1 was present, suggesting co-existence of dual stimulatory and inhibitory effects. We conclude that PKAs regulatory subunits are cAMP-dependent signal transducers.

BackgroundThere is strong evidence linking inflammation and the development of pancreatic ductal adenocarcinoma. Cyclooxygenase-2 (COX-2) and COX-2-derived PGE2 are overexpressed in human and murine pancreatic ductal adenocarcinoma. Several studies have demonstrated an important role of COX-2-derived PGE2 in tumor-stroma interactions; however, the direct growth effects of prostaglandin E2 (PGE2) on pancreatic ductal adenocarcinoma cells is less well defined. Our aim was to investigate the effects of PGE2 on pancreatic ductal adenocarcinoma cell growth and to characterize the underlying mechanisms.MethodsHuman pancreatic ductal adenocarcinoma cell lines, Panc-1 and MIA PaCa-2, were treated with PGE2 in varying doses (0-10 μM). Effects on the phosphorylation of ERK1/2 were evaluated by Western blot. Colony formation was observed for cells treated with PGE2 for 11 days. DNA synthesis was determined by (3H)-thymidine incorporation assay. Gene expression of E-type prostaglandin (EP)2/EP4 receptors and their correlation with survival in patients with pancreatic ductal adenocarcinoma were assessed using the RNA-Seq data set from The Cancer Genome Atlas Research Network.ResultsPGE2 decreased the size and number of colonies in Panc-1 but not MIA PaCa-2 cells. In the Panc-1 cells, PGE2 activated PKA/CREB and decreased phosphorylation of ERK1/2, which was reversed by an EP4 receptor antagonist, while an EP2 receptor antagonist had no effect. In contrast, in MIA PaCa-2 cells, PGE2 had no effect on ERK1/2 phosphorylation. Treatment of both Panc-1 and MIA PaCa-2 cells with forskolin/IBMX decreased ERK1/2 phosphorylation. Finally, PGE2 decreased DNA synthesis only in Panc-1 cells, which was reversed by an EP4 receptor antagonist. In human pancreatic ductal adenocarcinoma, high EP2 and low EP4 gene expression was correlated to worse median overall survival (15.6 vs 20.8 months, log-rank P = .017).ConclusionOur study provides evidence that PGE2 can inhibit directly pancreatic ductal adenocarcinoma cell growth through an EP4-mediated mechanism. Together with our gene expression and survival analysis, this observation suggests a protective role of EP4 receptors in human pancreatic ductal adenocarcinoma that expresses E-type prostaglandin receptors.

Inflammation is frequently associated with initiation, progression, and metastasis of colorectal cancer (CRC). Here, we unveil a CRC-specific metastatic programme that is triggered via the transcriptional repressor, GFI1. Using data from a large cohort of clinical samples including inflammatory bowel disease and CRC, and a cellular model of CRC progression mediated by cross-talk between the cancer cell and the inflammatory microenvironment, we identified GFI1 as a gating regulator responsible for a constitutively activated signalling circuit that renders CRC cells competent for metastatic spread. Further analysis of mouse models with metastatic CRC and human clinical specimens reinforced the influence of GFI1 downregulation in promoting CRC metastatic spread. The novel role of GFI1 is uncovered for the first time in a human solid tumour such as CRC. Our results imply that GFI1 is a potential therapeutic target for interfering with inflammation-induced CRC progression and spread.

BACKGROUND & AIMS: The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohns disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. METHODS: We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P

Objective: To evaluate the safety in the first 12 h, efficacy and maternal satisfaction of a double balloon catheter (DBC) with vaginal prostaglandin (PGE) for induction of labour (IOL). Methods: We conducted a multicentre randomised controlled study of 420 patients from 1st January 2016 to 31st December 2017 to evaluate the use of DBC in IOL in an Asian population looking at the adverse effects in the first 12 h after insertion. Women were assigned randomly to cervical ripening with either a DBC or a prostaglandin pessary. The adverse events in the 12 h after DBC or first prostaglandin inserted, the efficacy of a DBC to a prostaglandin in labour induction and maternal satisfaction were evaluated. Results: There were significantly less women with uterine hyperstimulation in the DBC (2 vs 24, p ≤ 0.0001) compared to the prostaglandin group. There were no women with uterine hyperstimulation and non-reassuring foetal status in the DBC while there were 5 women with uterine hyperstimulation and foetal distress in the prostaglandin group. Use of entonox was significantly less in the DBC group (p = 0.009). There were no significant differences in both groups in caesarean section, vaginal deliveries and time to delivery, although significant less time was needed to achieve cervical os dilation more than 4 cm in the DBC group (p ≤ 0.0001). Neonatal birth outcomes were similar. Women's pain scores were similar for both methods. 80.1% of women allocated the DBC and 76.8% of women allocated the PGE were keen to recommend their method of induction. Conclusion: Double balloon catheter remains a good alternative method for inducing women in view of a good safety profile with low risk of hyperstimulation and high maternal satisfaction. Clinical trial registration: ClinicalTrials.gov Identifier: NCT02620215. [ABSTRACT FROM AUTHOR]

Acid-sensing pathways, which trigger mucosal defense mechanisms in response to luminal acid, involve the rapid afferent-mediated "capsaicin pathway" and the sustained "prostaglandin (PG) pathway." Luminal acid quickly increases protective PG synthesis and release from epithelia, although the mechanism by which luminal acid induces PG synthesis is still mostly unknown. Acid exposure augments purinergic ATP-P2Y signaling by inhibition of intestinal alkaline phosphatase activity. Since P2Y activation increases intracellular Ca2+, we further hypothesized that ATP-P2Y signals increase the generation of H2O2 derived from dual oxidase, a member of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family activated by Ca2+. Our recent studies suggest that acid exposure increases H2O2 output, followed by phospholipase A2 and cyclooxygenase activation, increasing PG synthesis. Released prostaglandin E2 augments protective HCO3- and mucus secretion via EP4 receptor activation. Thus, the PG pathway as a component of duodenal acid sensing consists of acid-related intestinal alkaline phosphatase inhibition, ATP-P2Y signals, dual oxidase 2-derived H2O2 production, phospholipase A2 activation, prostaglandin E2 synthesis, and EP4 receptor activation. The PG pathway is also involved in luminal bacterial sensing in the duodenum via activation of pattern recognition receptors, including Toll-like receptors and nucleotide-binding oligomerization domain 2. The presence of acute mucosal responses to luminal bacteria suggests that the duodenum is important for host defenses and may reduce bacterial loading to the hindgut using H2O2, complementing gastric acidity and anti-bacterial bile acids.

Prostaglandin E2 (PGE2) promotes Th17 expansion while otherwise inhibiting other CD4+ T cell subsets. Here, we identified a PGE2-dependent pathway that induces pathogenic Th17 cells in autoimmune disease and is regulated by the transcription factor RORC. Compared with other CD4+ cell types from healthy subjects, there is a surprising lack of the prostaglandin receptor EP2 on Th17 cells; therefore, we examined the hypothesis that RORγt, which is highly expressed in Th17 cells, mediates EP2 downregulation. Chromatin immunoprecipitation followed by DNA sequencing revealed that RORγt binds directly to Ptger2 (the gene encoding EP2 receptor) in Th17 cells isolated from WT mice. In Th17 cells isolated from humans, RORC repressed EP2 by directly silencing PTGER2 transcription, and knock down of RORC restored EP2 expression in Th17 cells. Compared with Th17 cells from healthy individuals, Th17 cells from patients with MS exhibited reduced RORC binding to the PTGER2 promoter region, resulting in higher EP2 levels and increased expression of IFN-γ and GM-CSF. Finally, overexpression of EP2 in Th17 cells from healthy individuals induced a specific program of inflammatory gene transcription that produced a pathogenic Th17 cell phenotype. These findings reveal that RORC directly regulates the effects of PGE2 on Th17 cells, and dysfunction of this pathway induces a pathogenic Th17 cell phenotype.

RationaleBiologic pathways with significant genetic conservation across human populations have been implicated in the pathogenesis of primary graft dysfunction (PGD). The evaluation of the role of recipient genetic variation in PGD has thus far been limited to single, candidate gene analyses.ObjectivesWe sought to identify genetic variants in lung transplant recipients that are responsible for increased risk of PGD using a two-phase large-scale genotyping approach.MethodsPhase 1 was a large-scale candidate gene association study of the multicenter, prospective Lung Transplant Outcomes Group cohort. Phase 2 included functional evaluation of selected variants and a bioinformatics screening of variants identified in phase 1.Measurements and main resultsAfter genetic data quality control, 680 lung transplant recipients were included in the analysis. In phase 1, a total of 17 variants were significantly associated with PGD, four of which were in the prostaglandin E2 family of genes. Among these were a coding variant in the gene encoding prostaglandin E2 synthase (PTGES2; P = 9.3 × 10(-5)) resulting in an arginine to histidine substitution at amino acid position 298, and three variants in a block containing the 5' promoter and first intron of the PTGER4 gene (encoding prostaglandin E2 receptor subtype 4; all P < 5 × 10(-5)). Functional evaluation in regulatory T cells identified that rs4434423A in the PTGER4 gene was associated with differential suppressive function of regulatory T cells.ConclusionsFurther research aimed at replication and additional functional insight into the role played by genetic variation in prostaglandin E2 synthetic and signaling pathways in PGD is warranted.

Objective: To explore the application method and effect of ultrasound-guided epidural block in elderly hip replacement surgery. Methods: From June 2017 to May 2020, 112 cases of elderly patients who underwent hip replacement surgery in our hospital were selected as the research object, and the patients were divided into study group and control group of 56 cases in each groups accorded to the random number table method. The study group was given ultrasound-guided epidural block, and the control group was given traditional intravenous continuous analgesia. The two groups were given general anesthesia induction and maintenance, and the analgesic effects and patient's postoperative recovery were recorded. Results: There were no significant difference in gender, age, anesthesia time, operation time and intraoperative bleeding compared between the two groups (P>0.05). The postoperative hospital stay in the study group were significantly shorter than that in the control group (P<0.05). The visual analogue scale/score (VAS) scores of pain in the two groups at 1 d, 3 d and 7 d after surgery were significantly lower than those at 1d before operation, and the study groups were lower than the control group(P<0.05). The hip joint mobility of the study group at 1 d, 3 d and 7 d after surgery were significantly higher than that of the control group (P<0.05). The contents of Substance P (SP) and Prostaglandin E2 (Prostaglandin E2, PGE2) in the two groups at 1 d, 3 d and 7 d after surgery were significantly higher than those at 1 d before operation, and the study groups were lower than the control group(P<0.05). Conclusion: The application of ultrasound-guided epidural block in elderly hip replacement surgery can inhibit the release of serum SP and PGE2, can relieve postoperative pain, promote the recovery of hip function, and shorten the recovery time of patient [ABSTRACT FROM AUTHOR]

Epithelial injury and airway hyperresponsiveness are prominent features of asthma. We have previously demonstrated that laser ablation of single epithelial cells immediately induces global airway constriction through Ca(2+)-dependent smooth muscle shortening. The response is mediated by soluble mediators released from wounded single epithelial cells; however, the soluble mediators and signaling mechanisms have not been identified. In this study, we investigated the nature of the epithelial-derived soluble mediators and the associated signaling pathways that lead to the L-type voltage-dependent Ca(2+) channel (VGCC)-mediated Ca(2+) influx. We found that inhibition of adenosine A1 receptors (or removal of adenosine with adenosine deaminase), cyclooxygenase (COX)-2 or prostaglandin E receptor 3 (EP3) receptors, epidermal growth factor receptor (EGFR), or platelet-derived growth factor receptor (PDGFR) all significantly blocked Ca(2+) oscillations in smooth muscle cells and airway contraction induced by local epithelial injury. Using selective agonists to activate the receptors in the presence and absence of selective receptor antagonists, we found that adenosine activated the signaling pathway A1R→EGFR/PDGFR→COX-2→EP3→VGCCs→calcium-induced calcium release, leading to intracellular Ca(2+) oscillations in airway smooth muscle cells and airway constriction.

While searching for a counterpart to cyclic AMP, a new compound was found to inhibit adenylate cyclase. It was identified as prostaglandyl‐(15‐4′)‐myo‐inositol (1′:2′‐cyclic)‐phosphate (cyclic PIP). The substrates for its biosynthesis are prostaglandin E (PGE) and the novel inositol phosphate, guanosine diphospho‐4‐myo‐inositol 1:2‐cyclic phosphate (n‐IP). The basic regulatory properties of cyclic PIP are to inhibit dose‐dependently protein kinase A (PKA) and to seven‐fold activate protein ser/thr phosphatase holoenzyme. These regulations occur as rapidly as the activation of PKA by cyclic AMP. Such regulatory properties are essential for the meticulous regulation of the equilibrium between the phospho‐ and de‐phospho‐form of interconvertible enzymes. The synthesis of cyclic PIP is stimulated by insulin and noradrenaline (α‐receptor action). The insulin‐stimulated cyclic PIP synthase is active in a tyrosine‐phosphorylated state. A comparable characterization of the adrenaline‐stimulated cyclic PIP synthase is still incomplete. In streptozotocin‐diabetic rats, the hormonal stimulation of cyclic PIP synthesis decreases with time. Cyclic PIP synthesis is activated by biguanides as metformin two to four‐fold and by antihypertensive drugs two‐fold. Inhibition of cyclic PIP synthesis leads to a metabolic state as observed in early‐stage type‐2 diabetes. In summary, all living cells synthesize cyclic PIP, which switches on anabolism, whereas cyclic AMP triggers catabolism. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) results in permanent loss of motor functions. A significant aspect of the tissue damage and functional loss may be preventable as it occurs, secondary to the trauma. We show that the phospholipase A(2) (PLA(2)) superfamily plays important roles in SCI. PLA(2) enzymes hydrolyze membrane glycerophospholipids to yield a free fatty acid and lysophospholipid. Some free fatty acids (arachidonic acid) give rise to eicosanoids that promote inflammation, while some lysophospholipids (lysophosphatidylcholine) cause demyelination. We show in a mouse model of SCI that two cytosolic forms [calcium-dependent PLA(2) group IVA (cPLA(2) GIVA) and calcium-independent PLA(2) group VIA (iPLA(2) GVIA)], and a secreted form [secreted PLA(2) group IIA (sPLA(2) GIIA)] are up-regulated. Using selective inhibitors and null mice, we show that these PLA(2)s play differing roles. cPLA(2) GIVA mediates protection, whereas sPLA(2) GIIA and, to a lesser extent, iPLA(2) GVIA are detrimental. Furthermore, completely blocking all three PLA(2)s worsens outcome, while the most beneficial effects are seen by partial inhibition of all three. The partial inhibitor enhances expression of cPLA(2) and mediates its beneficial effects via the prostaglandin EP1 receptor. These findings indicate that drugs that inhibit detrimental forms of PLA(2) (sPLA(2) and iPLA2) and up-regulate the protective form (cPLA2) may be useful for the treatment of SCI.

The Wnt signaling pathway is a robust regulator of skeletal homeostasis. Gain-of-function mutations promote high bone mass, whereas loss of Lrp5 or Lrp6 co-receptors decrease bone mass. Similarly, mutations in antagonists of Wnt signaling influence skeletal integrity, in an inverse relation to Lrp receptor mutations. Loss of the Wnt antagonist Sclerostin (Sost) produces the generalized skeletal hyperostotic condition of sclerosteosis, which is characterized by increased bone mass and density due to hyperactive osteoblast function. Here we demonstrate that prostaglandin E(2) (PGE(2)), a paracrine factor with pleiotropic effects on osteoblasts and osteoclasts, decreases Sclerostin expression in osteoblastic UMR106.01 cells. Decreased Sost expression correlates with increased expression of Wnt/TCF target genes Axin2 and Tcf3. We also show that the suppressive effect of PGE(2) is mediated through a cyclic AMP/PKA pathway. Furthermore, selective agonists for the PGE(2) receptor EP2 mimic the effect of PGE(2) upon Sost, and siRNA reduction in Ptger2 prevents PGE(2)-induced Sost repression. These results indicate a functional relationship between prostaglandins and the Wnt/β-catenin signaling pathway in bone.

Aims: To further explore the effects of a novel EP2 and EP3 dual agonist, ONO‐8055, on detrusor contractility, we investigated the responses of bladder strips from sham and lumbar canal stenosis (LCS) rats to this agonist, its effects on lower urinary tract function in normal rats, and mRNA expression of EP2 and EP3 receptors in the sham and LCS rats. Methods: The responses of bladder strips from sham and LCS rats to ONO‐8055 were measured. The effects of ONO‐8055 on LUT function of normal rats were investigated with awake cystometry and intraurethral perfusion pressure (Pura) measurements. The relative mRNA of bladder and urethral tissue of the sham and LCS rats was quantified using specific probes for EP1, EP2, EP3, and EP4 genes. Results: Compared with the vehicle, the muscle tensions of both the sham and LCS rats were significantly increased after adding this agonist. On awake cystometry of normal rats, bladder capacity and Pura were decreased in the ONO‐8055 groups, but a statistically significant difference in mean changes was demonstrated only between the vehicle group and the group receiving the highest dose. Compared with the sham rats, mRNA expressions of the four EP receptors in the lower urinary tract of the LCS rats did not show a statistically significant difference. Conclusions: This agonist did not augment bladder contractility or urethral relaxation in normal rats. [ABSTRACT FROM AUTHOR]

The inhibitory effects of Mitrella kentii leaf and stem extracts on the production prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) and antagonist effect on platelet-activating factor (PAF) receptor binding were evaluated. The inhibition of PGE2 and TXB2 productions were determined using the radioimmunoassay technique, and the inhibitory effect of PAF receptor binding to rabbit platelet was determined using the 3H-PAF as a ligand. Among the extracts tested, ethyl acetate, methanol and hexane leaf extracts, and methanol stems extract showed inhibitory effects on PGE2 and TXB2 productions and antagonistic effect on PAF receptor binding. M. kentii extracts may have the potential of being developed as supplements for inflammatory conditions. [ABSTRACT FROM AUTHOR]

B cell receptor (BCR) signaling contributes to the pathogenesis of B cell malignancies, and most B cell lymphomas depend on BCR signals for survival. Identification of genes that restrain BCR-mediated proliferation is therefore an important goal toward improving the therapy of B cell lymphoma. Here, we identify Ptger4 as a negative feedback regulator of proliferation in response to BCR signals and show that its encoded EP4 receptor is a principal molecule conveying the growth-suppressive effect of prostaglandin E2 (PGE2). Stable knockdown of Ptger4 in B cell lymphoma markedly accelerated tumor spread in mice, whereas Ptger4 overexpression yielded significant protection. Mechanistically, we show that the intrinsic activity of Ptger4 and PGE2-EP4 signaling target a similar set of activating genes, and find Ptger4 to be significantly down-regulated in human B cell lymphoma. We postulate that Ptger4 functions in B cells as a candidate tumor suppressor whose activity is regulated by PGE2 in the microenvironment. These findings suggest that targeting EP4 receptor for prostaglandin may present a novel strategy for treatment of B cell malignancies.

Purpose Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. Methods For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E2 immunoassay were conducted. Results Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E2 synthesis in CPAE cells. Conclusions Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement.

Early definitive diagnosis of necrotizing enterocolitis (NEC) based on Bell's staging criteria is difficult because there are few observable changes on abdominal imaging and blood chemistry tests at the onset of the disease. To investigate whether prostaglandin E-2 major urinary metabolite (PGE-MUM) can be a useful surrogate marker reflecting the disease state and severity of NEC in infants. Infants were enrolled in this study between January 2014 and December 2016. NEC diagnosis was based on Bell's staging criteria > Stage II or necrotic bowel observed at surgery. After diagnosis, PGE-MUM level was measured and compared with that of the other disease and healthy infant groups. Median PGE-MUM value was highest in the NEC group (576 [65–3672] μg/g•Cre/BSA × 1000), followed by the other disease group (94 [57–296] μg/g•Cre/BSA × 1000) and the healthy infant group (19 [10–44] μg/g•Cre/BSA × 1000) (sensitivity: 92.3%, specificity: 81.5%, accuracy: 85.0%; p < 0.01). PGE-MUM level correlated with improved status of NEC, length of necrotic intestine, and Bell's staging criteria. PGE-MUM level may be a useful surrogate biomarker reflecting the disease state of NEC. The method of urine sample collection is also advantageous, being noninvasive for infants. This is the first study reporting PGE-MUM level in NEC. Study of diagnostic test. LEVEL II. [ABSTRACT FROM AUTHOR]

Abstract Aims To examine the effects of RQ-00434739, a novel selective TRPM8 antagonist, on deep body temperature (DBT) and normal bladder sensory function and overactivity and its associated facilitation of mechanosensitive primary bladder single-unit afferent activities (SAAs) induced by intravesical l -menthol or prostaglandin E2 (PGE2) instillation in rats. Main methods The effect of RQ-00434739 on DBT was evaluated using intravenous administration of RQ-00434739 (1 mg/kg) or its vehicle under urethane anaesthesia. Cystometry (CMG) was performed on conscious and freely moving rats. SAAs were measured from the left L6 dorsal root under urethane anaesthesia, and the fibers were grouped as Aδ- or C-fiber based on their conduction velocity. For both CMG and SAA measurements, after baseline recording with saline instillation, further recording was performed with intravesical l -menthol (6 mM) or PGE2 (60 μM) instillation after pretreatment with intravenous RQ-00434739 (1 mg/kg) or its vehicle. Key findings RQ-00434739 did not significantly affect DBT. In CMG measurements, RQ-00434739 administration increased mean voided volume. Both l -menthol and PGE2 instillation decreased mean voided volume following vehicle pretreatment, whereas such effects were not observed following RQ-00434739 pretreatment. In SAA measurements, either l -menthol or PGE2 instillations increased SAAs of C-fibers, but not SAAs of Aδ-fibers, in the presence of vehicle. RQ-00434739 pretreatment significantly inhibited the l -menthol- and PGE2-induced activation of C-fiber SAAs. Significance The present results demonstrate that blockade of TRPM8 channels can inhibit the pathological activation of mechanosensitive C-fibers and suggest that RQ-00434739 may be a promising therapeutic drug candidate for bladder hypersensitive disorders without affecting DBT. [ABSTRACT FROM AUTHOR]

Gastric cancer (GC) represents the third leading cause of cancer-related deaths worldwide. The levels of prostaglandin E2, a key player in the hallmarks of cancer, are mainly regulated by prostaglandin-endoperoxide synthase 2 (PTGS2) and ATP-binding cassette subfamily C member 4 (ABCC4), involved in its synthesis and exportation, respectively, and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and solute carrier organic anion transporter family member 2A1 (SLCO2A1), responsible for its inactivation. Even though there are distinct molecular signatures across ethnic populations, most published studies focus on Asian populations. Our main aim was to explore the genetic expression of the aforementioned molecules in a Caucasian population. 94 “Normal” and 89 tumoral formalin-fixed paraffin-embedded (FFPE) samples from GC patients were used to assess the mRNA expression of PTGS2, ABCC4, hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD), SLCO2A1 by Real-Time PCR. We found an upregulation for the PTGS2 gene mean factor of 2.51 and a downregulation for the HPGD and SLCO2A1 genes (mean factor of 0.10 and 0.37, respectively) in tumorous mucosa in a gender-independent manner. In females, we observed an ABCC4 downregulation and a PTGS2 mRNA upregulation compared to males in tumoral mucosa (mean factor of 0.61 and 1.64, respectively). We reported dysregulation of the inflammation triggered PGE2 pathway in a Caucasian population with an intermediate risk for GC, which might highlight the applicability of aspirin in the treatment of GC patients.

Epigallocatechin gallate (EGCG), a major polyphenol in green tea, possesses antioxidant properties and regulates various cell functions. Here, we examined the function of EGCG in inflammatory bone resorption. In calvarial organ cultures, lipopolysaccharide (LPS)‐induced bone resorption was clearly suppressed by EGCG. In osteoblasts, EGCG suppressed the LPS‐induced expression of COX‐2 and mPGES‐1 mRNAs, as well as prostaglandin E2 production, and also suppressed RANKL expression, which is essential for osteoclast differentiation. LPS‐induced bone resorption of mandibular alveolar bones was attenuated by EGCGin vitro, and the loss of mouse alveolar bone mass was inhibited by the catechinin vivo.

Abstract The ductus arteriosus (DA), an essential fetal shunt between the pulmonary trunk and the descending aorta, changes its structure during development. Our previous studies have demonstrated that prostaglandin E 2 (PGE 2 )-EP4 signaling promotes intimal cushion formation (ICF) by activating the migration of DA smooth muscle cells via the secretion of hyaluronan. We hypothesized that, in addition to hyaluronan, PGE 2 may secrete other proteins that also regulate vascular remodeling in the DA. In order to detect PGE 2 stimulation-secreted proteins, we found that CCN3 protein was increased in the culture supernatant in the presence of PGE 2 in a dose-dependent manner by nano-flow liquid chromatography coupled with tandem mass spectrometry analysis and enzyme-linked immunosorbent assay. Quantitative RT-PCR analysis revealed that PGE 2 stimulation tended to increase the expression levels of CCN3 mRNA in DA smooth muscle cells. Immunohistochemical analysis revealed that CCN3 was highly localized in the entire smooth muscle layers and the endothelium of the DA. Furthermore, exogenous CCN3 inhibited PGE 2 -induced ICF in the ex vivo DA tissues. These results suggest that CCN3 is a secreted protein of the DA smooth muscle cells induced by PGE 2 to suppress ICF of the DA. The present study indicates that CCN3 could be a novel negative regulator of ICF in the DA to fine-tune the PGE 2 -mediated DA remodeling. Highlights • CCN3 is secreted from smooth muscle cells of the ductus arteriosus by prostaglandin E 2. • Nano-flow LC-MS/MS analysis is a powerful tool for detecting a novel secreted protein. • CCN3 inhibits intimal cushion formation in the ductus arteriosus. [ABSTRACT FROM AUTHOR]

Abstract: Abdominal aortic aneurysm (AAA) is a progressive disease that has an increasing prevalence with aging, but no effective pharmacological therapy to attenuate AAA progression is currently available. We reported that the prostaglandin E receptor EP4 plays roles in AAA progression. Here, we show the effect of CJ‐42794, a selective EP4 antagonist, on AAA using two mouse models (angiotensin II‐ and CaCl2‐induced AAAs) and human aortic smooth muscle cells isolated from AAA tissue. Oral administration of CJ‐42794 (0.2 mg/kg per day) for 4 weeks significantly decreased AAA formation in ApoE−/− mice infused with angiotensin II (1 μg/kg per min), in which elastic fiber degradation and activations of matrix metalloproteinase (MMP)‐2 and MMP‐9 were attenuated. Interleukin‐6 (IL‐6) proteins were highly expressed in the medial layer of angiotensin II‐induced mouse AAA tissues, whereas this expression was significantly decreased in mice treated with CJ‐42794. AAA formation induced by periaortic CaCl2 application in wild‐type mice was also reduced by oral administration of CJ‐42794 for 4 weeks. After oral administration of CJ‐42794 beginning 2 weeks after periaortic CaCl2 application and continuing for an additional 4 weeks, the aortic diameter and elastic fiber degradation grade were significantly smaller in CJ‐42794‐treated mice than in untreated mice. Additionally, in smooth muscle cells isolated from human AAA tissues, stimulation of CJ‐42794 inhibited PGE2‐induced IL‐6 secretion in a dose‐dependent manner and decreased PGE2‐induced MMP‐2 activity. These data suggest that inhibition of EP4 has the potential to be a pharmacological strategy for attenuation of AAA progression. [ABSTRACT FROM AUTHOR]

Prostaglandin E2 (PGE2) has been introduced as an important factor for embryo implantation. So the present study was carried out to evaluate the effect of seminal fluid (SF) on PGE2 pathway in uterus tissues of mice during window of preimplantation. The messenger RNA (mRNA) expressions of microsomal PGE synthase (mPGES) and cytosolic PGE synthase (cPGES) as well as protein expression of PGE receptor 2 and 4 (EP2 and EP4) were determined in uterine tissue of control and seminal vesicle–excised (SVX)–mated female mice during days 1 to 5 of pregnancy using real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively. We found that mRNA expression of mPGES at day 1 and 2 of pregnancy was significantly higher in the control group than the SVX-mated group (P < .05), but such result was not obtained for cPGES expression. The protein levels of EP2 at day 1 to 4 of pregnancy were significantly higher in the control group compared with the SVX-mated group (P < .05), also the EP4 levels were significantly different between the control and SVX-mated groups at the first day of pregnancy (P < .05). Implantation rate was higher in the control group and also there were positive correlations between mPGES and EP2 expressions in the fifth day of pregnancy with implantation rate. Our results demonstrated significant effect of SF on uterine expressions of the evaluated factors, especially mPGES and EP2. Regarding the correlations between levels of these factors and implantation rate, we suggest that possibly one of the important mechanisms of SF in affecting female pregnancy is through mPGES and EP2. [ABSTRACT FROM AUTHOR]

Scutellaria root, the root of Scutellaria baicalensis Georgi, is a crude drug used for inflammatory diseases. In our previous report, the combination of flavonoids contained in Scutellaria root have been found to inhibit PGE production more strongly than individual flavonoids. Here, to investigate the mechanism of the synergistic effect, we examined the effects of an equimolar mixture (F-mix) of baicalein ( 1), wogonin ( 2) and oroxylin A ( 3) on the production of PGE in LPS-treated J774.1 cells. Although 1 and 3 inhibited COX-2 activity, the F-mix showed no synergistic effect on COX-2 inhibition. Therefore, we investigated the steps leading to the activation of COX-2 protein. Compounds 1- 3 and F-mix inhibited the expression of COX-2 protein. However, only 2 inhibited the expression of COX-2 mRNA among the flavonoids, and the F-mix showed no synergistic effect. Only 1 inhibited NF-κB translocation into the nucleus, and the F-mix showed no synergistic effect. Although 2 did not affect NF-κB translocation, it strongly inhibited NF-κB-dependent transcriptional activity, and the F-mix inhibited the activity slightly more than 2. Compounds 1- 3 also inhibited NO production, and the F-mix showed a synergistic effect. However, the effects of each flavonoid on the expression of iNOS mRNA were not consistent with those on COX-2 mRNA. Because the flavonoids inhibit different steps in the production of PGE and NO, and their mixture did not show apparent synergistic effects in each step, we conclude that the synergistic effect of the flavonoid mixture reflects the total effect of the flavonoids inhibiting different steps in the NF-κB signalling pathway. [ABSTRACT FROM AUTHOR]

Curcumin is an important molecule found in turmeric plants and has been reported to exhibit some profound anti-inflammatory activities by interacting with several important molecular targets found in the mitogen-activated protein kinase and NF-κβ pathways. As part of our continuing effort to search for new anti-inflammatory agents with better in vitro and in vivo efficacies, we have synthesized a series of new unsymmetrical dicarbonyl curcumin derivatives and tested their effects on prostaglandin E secretion level in interferon-γ/lipopolysaccharide-activated macrophage cells. Among those, five compounds exhibited remarkable suppression on prostaglandin E production with IC values ranging from 0.87 to 18.41 µM. The most potent compound 17f was found to down-regulate the expression of cyclooxygenase-2 mRNA suggesting that this series of compounds could possibly target the mitogen-activated protein kinase signal transduction pathway. Whilst the compound did not affect the expression of the conventional mitogen-activated protein kinases, the results suggest that it could disrupt the phosphorylation and activation of the proteins particularly the c-Jun N-terminal kinases. Finally, the binding interactions were examined using the molecular docking and dynamics simulation approaches. [ABSTRACT FROM AUTHOR]

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Platelets are anucleated cells that circulate in the blood as sentinels of tissue integrity. In fact, they are rich in a plethora of proteins and other factors stored in different granules which they selectively release upon stimulation. Moreover, platelets synthesize a vast number of lipids and release various types of vesicles, including exosomes which are rich in genetic material. Platelets possess a central function to interact with other cell types, including inflammatory cells and cancer cells. Recent findings have enlightened the capacity of platelets to induce changes in the phenotype of cancer cells which acquire invasiveness thus enhancing their metastatic potential. Thus, it has been hypothesized that targeting the platelet may represent a novel strategy to prevent the development and progression of cancer. This is supported by the efficacy of the antiplatelet agent low-dose aspirin. Studies are ongoing to verify whether other antiplatelet agents share the anticancer effectiveness of aspirin. [ABSTRACT FROM AUTHOR]

Objective: To find an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) that rapidly metabolises Prostaglandin E (PGE) as a mediator of wound healing, we examined seven flavonoids for this role. Results: 7,3′,4′-Trimethoxyflavone (TMF) had the lowest IC value of 0.34 µM for 15-PGDH inhibition but >400 µM for cytotoxicity, indicating a high therapeutic index. TMF elevated PGE levels in a concentration-dependent manner in both A549 lung cancer and HaCaT cells. It also significantly increased mRNA expression of multidrug resistance-associated protein 4 (MRP4) and of prostaglandin transporter (PGT) slightly in HaCaT cells. In addition, TMF facilitated in vitro wound healing in a HaCaT scratch model, which was completely inhibited by adding both 15-PGDH and NAD as cofactor, confirming the involvement of PGE in its wound healing effect. Conclusion: TMF with a high therapeutic index can facilitate wound healing through PGE elevation by 15-PGDH inhibition. [ABSTRACT FROM AUTHOR]