Enzyme In Prostaglandin Synthesis Research Articles

The usefulness of p16 and COX-2 expression on the prediction of progression to endometrial cancer.

Endometrial cancer (EC) is the most commonly diagnosed gynecological cancer. Endometrial hyperplasia (EH) is a more common diagnosis than EC. Endometrial hyperplasia is found in approximately 1.5% of all women presenting with abnormal bleeding. Endometrial hyperplasia progresses to EC, and especially, cancer risk increases in cases with atypical hyperplasia. p16, one of the tumor suppressor proteins involved in the cell cycle, and COX-2, one of the key enzymes of prostaglandin synthesis, are important markers for the diagnosis of both EH and EC. There is lack of consensus in the classification, diagnosis and treatment of EH. The subject of changes in the cell cycle in the progression of endometrial pathologies may help to identify and prevent these affected pathways in the treatment stage. The aim of this study is to investigate the expression of p16 and COX-2 during the development of EC from EH. We investigated COX-2 and P16 expressions in patients with proliferative endometrium, complex/simple endometrial hyperplasia and endometrioid adenocarcinoma. p16 expression increased in EH and EC (p<0.001). COX-2 expression was increased in endometrial cancer compared to other groups, but this increase was not found to be statistically significant. Although p16 and COX-2 expression were increased in patients with advanced grade/stage, lymphovascular invasion, and >50% of myometrial invasion, this increase was not statistically significant. More detailed studies are needed to investigate the prognostic significance of the COX-2 molecule. COX-2 might be a potential biomarker for the prognosis of endometrial cancer and a potential therapeutic target for EC treatment. Also, it might be used to prevent the progression of precursor lesions to invasive EC.

Abstract A089: Influence of pre-diagnosis aspirin use on epithelial ovarian cancer tumor immune microenvironment markers: results from the Nurses’ Health Study (NHS) and NHSII

Abstract Background: Daily aspirin use versus never use is associated with a 10-20% lower risk of developing epithelial ovarian cancer (EOC). Among women with EOC, aspirin use after diagnosis compared with never use is associated with a 30% improvement in ovarian cancer-specific survival. Inhibition of enzymes in prostaglandin synthesis is a key mechanism responsible for the anti-inflammatory and anti-neoplastic effects of aspirin. Prostaglandins influence immune inflammatory cells in the tumor microenvironment therefore our objective was to evaluate how aspirin use may influence the EOC tumor immune microenvironment. Methods: Tissue microarrays (TMAs) representing EOC tumor tissues from participants in the Nurses’ Health Study (NHS) and NHSII were assessed for total T cells, T cell activation and T cell exhaustion markers within the tumor (epithelium) area using multiplex immunofluorescence. Data on aspirin use and information on EOC risk factors and lifestyle variables were collected by questionnaire every two years. Beta-binomial models were used to estimate odds ratios (ORs) and 95% CIs; these models estimate the odds that a cell was positive for the marker(s) of interest comparing recent regular aspirin use (2+ times per week in the questionnaire cycle prior to diagnosis) versus never use, accounting for the total tumor cells in each core. Former users of aspirin were excluded. Multivariable models were adjusted for cohort, histotype (type 1 versus type 2), age and year of cancer diagnosis, number of CD3+ T cells (in tertiles), hysterectomy, tubal ligation, duration of oral contraceptive use, family history of breast or ovarian cancer, parity and body mass index (as fixed effects) and the participant (random effect) to account for multiple tissue cores per case. Results: We compared tumor tissues from 209 participants with recent pre-diagnosis use of aspirin with 88 participants who never used aspirin. Compared with cases who never used aspirin, recent aspirin users had higher odds of having tumors with recently activated cytotoxic T cells (CD3+CD8+CD69+, OR=1.69, 95% CI: 1.10, 2.59) and T cells expressing exhaustion markers (CD3+Lag-3+, OR=1.63, 95% CI: 1.09, 2.43; CD3+Tim-3+, OR= 1.62, 95% CI: 0.96, 2.72). In contrast, there was no association between recent aspirin use versus never use and odds of a tumor being positive for total T cells (CD3+, OR=1.20, 95% CI: 0.80, 1.79). Conclusions: Our data suggest that recent aspirin use before diagnosis was associated with higher odds of having EOC tumors expressing both recently activated cytotoxic T cells and T cell exhaustion markers. By improving our biological understanding of how aspirin use influences the ovarian tumor immune microenvironment, these results will assist to inform the optimal use of aspirin to improve EOC patient outcomes. Future work will focus on additional immune markers, assess non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use and evaluate associations between aspirin/NSAID use with EOC survival considering the context of tumor immune microenvironment biomarkers. Citation Format: Nicola S. Meagher, Cassandra Hathaway, Mary K. Townsend, Mollie E. Barnard, Jose R. Conejo-Garcia, Brooke L. Fridley, Daryoush Saeed-Vafa, Britton Trabert, Shelley S. Tworoger, Melissa A. Merritt. Influence of pre-diagnosis aspirin use on epithelial ovarian cancer tumor immune microenvironment markers: results from the Nurses’ Health Study (NHS) and NHSII [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A089.

The role of CcPTGS2a in immune response against Aeromonas hydrophila infection in common carp (Cyprinus carpio)

Prostaglandin-endoperoxide synthase 2 (PTGS2), a crucial enzyme in prostaglandin synthesis, catalyzes the conversion of arachidonic acid to prostaglandins and plays a significant role in the inflammatory response. This investigation aimed to determine the regulatory role of PTGS2a in the innate immune response to bacterial infection in fish. To achieve this objective, the CcPTGS2a gene was identified and characterized in common carp (Cyprinus carpio), and its function in immune defense was investigated. According to the sequence and structural analysis results, CcPTGS2a had an open reading frame of 1806 bp that encoded 602 amino acids. It was estimated that the protein's theoretical molecular weight was 69.0 kDa, and its isoelectric point was 8.10. The structure of CcPTGS2a was observed to be conserved, with an epidermal growth factor domain and a peroxidase domain present. Moreover, the amino acid sequence of CcPTGS2a exhibited significant homology with the amino acid sequences of several fish species. CcPTGS2a mRNA was detected in the healthy tissues of common carp, with higher expression in the head kidney, spleen, gills, and liver. Following the challenges with Aeromonas hydrophila and lipopolysaccharide, CcPTGS2a mRNA showed unique geographic and temporal expression patterns, with significant increases detected in the head kidney, gills, spleen, and liver. Additionally, the recombinant CcPTGS2a protein exhibited detectable bacterial binding to various bacteria. As determined by subcellular localization analysis, CcPTGS2a was predominantly localized in the nucleus and cytoplasm. Furthermore, it was discovered that the overexpression of CcPTGS2a stimulated the up-regulation of ferroptosis-related genes and inflammatory cytokine mRNA expression in fish and EPC (Epithelioma papulosum cyprinid) cells while concurrently reducing the bacterial load of A. hydrophila. In contrast, the interference of CcPTGS2a decreased the mRNA expression of ferroptosis-related genes and inflammatory cytokines in fish and EPC cells and increased the bacterial load of A. hydrophila. Notably, A. hydrophila stimulation resulted in the up-regulation of CcPTGS2a protein expression in EPC cells. These results suggested that CcPTGS2a was involved in the immune response to bacterial infections in common carp.

The Sequence of Prostaglandin-Endoperoxide Synthase 2 Gene in Women with Cervicitis

Cervicitis is a clinical syndrome characterized by inflammation of primarily the columnar epithelium of the uterine endocervix. It can be acute or chronic. Prostaglandin endo peroxide synthase2 (Cyclooxygenase-2) is a key enzyme in prostaglandin synthesis, which is coded by the PTGS2 gene, and recognized as the master switch that activates the inflammatory response; its induction leads to the biosynthesis of prostaglandins. The current study aims to determine the CA125, CA 19.9, and, CA 15.3 markers level and their relationship with the COX-2 gene. Venous blood samples were obtained from 100 women with cervicitis whose ages ranged from 18 to 60 years, and 100 healthy women as a control group. Detection of CA19-9, CA- 125 and CA 15-3 markers was performed by using Cobas E411 analyzer while the CRP test was detected by using Afias CRP instrument. The conventional PCR was used for gene detection and DNA sequencing. The mean± SD of Ca125, CA15.3 and CRP showed a highly significant differences between patient (30.33±1.09), (22.82±1.07), (88.06±5.88) respectively and the healthy control (19.40±0.68), (18.34±0.77), (6.73±0.12) respectively-value &gt;0.001. The mutation in PTGS2 gene with highly CA125 marker 100(100%) and CRP levels 20(80%), while in CA15.3 marker 3(15%) and CA19.9 marker 1(5%). The mutation occurrence in analysis of rs20417 NSP of PTGS2 gene with wild CC GG and the variation C&gt;G G&gt;C.

The Bradykinin System Contributes to the Regulation of Prostaglandin-Endoperoxide Synthase 2 Expression in Human Amnion Fibroblasts: Implications for Term and Preterm Birth.

BackgroundBradykinin (BK) and its biologically active metabolite des-Arg9 bradykinin (DABK) play a pivotal role in inflammation. Since chorioamnionitis is the leading cause of preterm birth and prostaglandin E2 (PGE2) derived from the amnion is key to labor initiation, we investigated if bradykinin peptides are part of the regulatory network of PGE2 synthesis in human amnion at parturition.MethodsHuman amnion tissue was obtained from term and preterm birth for the study of the changes of the bradykinin system at parturition. Cultured primary human amnion fibroblasts, the major source of PGE2, were used to study the effects of bradykinin peptides on PTGS2 expression and PGE2 production as well as the effects of infection mediators on bradykinin receptors.ResultsBradykinin peptides and their receptors BDKRB1 and BDKRB2 were present in human amnion, and their abundance increased in term and preterm labor. However, transcripts of the genes encoding the bradykinin precursor and its proteolytic cleavage enzymes were hardly detectable in human amnion despite the increased abundance of bradykinin peptides in term and preterm labor, suggesting that there is an alternative source of bradykinin peptides for human amnion and their actions are enhanced in human amnion at parturition. In-vitro studies in cultured human amnion fibroblasts showed that both BK and DABK increased the expression of prostaglandin-endoperoxide synthase 2 (PTGS2), the rate-limiting enzyme in prostaglandin synthesis, and subsequent PGE2 production. These effects of BK and DABK were mediated through BDKRB2 and BDKRB1 receptors, respectively, with subsequent activation of the p38 and ERK1/2 pathways. Moreover, lipopolysaccharide (LPS) and serum amyloid A1 (SAA1), the important mediators of infectious inflammation, induced the expression of both BDKRB1 and BDKRB2 through toll-like receptor 4 (TLR4). Induction of BDKRB1 and BDKRB2 expression by LPS and SAA1 enhanced BK- or DABK-induced PTGS2 expression and PGE2 production in human amnion fibroblasts.ConclusionsThis study demonstrated for the first time that the human amnion is a target tissue of bradykinin peptides and the bradykinin system may be part of the regulatory network of PTGS2 expression and PGE2 production in human amnion fibroblasts at both term and preterm birth, which may be enhanced by infection.

Nuclear progesterone receptor regulates ptger4b and PLA2G4A expression in zebrafish (Danio rerio) ovulation

Previous studies have implicated the nuclear progesterone receptor (Pgr or nPR) as being critical to ovulation in fishes. This study investigated the expression of Pgr in zebrafish ovarian follicles throughout development as well as putative downstream targets of Pgr by searching the promoter regions of selected genes for specific DNA sequences to which Pgr binds and acts as a transcription factor. Expression of Pgr mRNA increases dramatically as follicles grow and mature. In silico analysis of selected genes linked to ovulation showed that the prostaglandin receptors ptger4a and ptger4b contained the progesterone responsive element (PRE) GRCCGGA in their promoter regions. Studies using full-grown follicles incubated in vitro revealed that ptger4b was upregulated in response to 17,20β-P. Our studies also showed that the expression of phospholipase A2 (PLA2G4A) mRNA and protein, a key enzyme in prostaglandin synthesis, was upregulated in response to 17,20β-P treatment. pla2g4a was not found to contain a PRE, indicating that it is regulated indirectly by 17,20β-P or that it may contain an as-of-yet unidentified PRE in its promoter region. Collectively, these studies provide further evidence of the importance of Pgr during the periovulatory periods through its involvement in prostaglandin production and function by controlling expression of PLA2G4A and the receptor EP4b and that these genes appear to be regulated through the actions of 17,20β-P.

Regulation of smooth muscle contractility by the epithelium in rat tracheas: role of prostaglandin E2 induced by the neurotransmitter acetylcholine.

BackgroundPrevious studies have suggested the involvement of epithelium in modulating the contractility of neighboring smooth muscle cells. However, the mechanism underlying epithelium-derived relaxation in airways remains largely unclear. This study aimed to investigate the mechanism underlying epithelium-dependent smooth muscle relaxation mediated by neurotransmitters.MethodsThe contractile tension of Sprague-Dawley (SD) rat tracheal rings were measured using a mechanical recording system. Intracellular Ca2+ level was measured using a Ca2+ fluorescent probe Fluo-3 AM, and the fluorescence signal was recorded by a laser scanning confocal imaging system. The prostaglandin E2 (PGE2) content was measured using an enzyme-linked immunosorbent assay kit.ResultsWe observed that the neurotransmitter acetylcholine (ACh) restrained the electric field stimulation (EFS)-induced contraction in the intact but not epithelium-denuded rat tracheal rings. After inhibiting the muscarinic ACh receptor (mAChR) or cyclooxygenase (COX), a critical enzyme in prostaglandin synthesis, the relaxant effect of ACh was attenuated. Exogenous PGE2 showed a similar inhibitory effect on the EFS-evoked contraction of tracheal rings. Moreover, ACh triggered phospholipase C (PLC)-coupled Ca2+ release from intracellular Ca2+ stores and stimulated COX-dependent PGE2 production in primary cultured rat tracheal epithelial cells.ConclusionsCollectively, this study demonstrated that ACh induced rat tracheal smooth muscle relaxation by promoting PGE2 release from tracheal epithelium, which might provide valuable insights into the cross-talk among neurons, epithelial cells and neighboring smooth muscle cells in airways.

&lt;p&gt;Human Secretary Phospholipase A2 Mutations and Their Clinical Implications&lt;/p&gt;

Phospholipases A2 (PLA2s) belong to a superfamily of enzymes responsible for hydrolysis of the sn-2 fatty acids of membrane phospholipids to release arachidonic acid. PLA2s are the rate limiting enzyme for the downstream synthesis of prostaglandins and leukotrienes that are the main mediators of inflammation. The extracellular forms of this enzyme are also called the secretary phospholipase A2 (sPLA2) and are distributed extensively in most of the tissues in the human body. Their integral role in inflammatory pathways has been the primary reason for the extensive research on this molecule. The catalytic mechanism of sPLA2 is initiated by a histidine/aspartic acid/calcium complex within the active site. Though they are known to have certain housekeeping functions, certain mutations of sPLA2 are known to be implicated in causation of certain pathologies leading to diseases such as atherosclerosis, cardiovascular diseases, benign fleck retina, neurodegeneration, and asthma. We present an overview of human sPLA2 and a comprehensive compilation of the mutations that result in various disease phenotypes. The study not only helps to have a holistic understanding of human sPLA2 mutations and their clinical implications, but is also a useful platform to initiate research pertaining to structure–function relationship of the mutations to develop effective therapies for management of these diseases.

ВПЛИВ ЕНДОГЕННИХ ПРОСТАНОЇДІВ НА ЖОВЧОСЕКРЕТОРНУ ФУНКЦІЮ У ЩУРІВ РІЗНИХ ВІКОВИХ ГРУП

In acute experiments on different age group of 30 white wild-type rats: juvenile (weight 130–175 g), mature (weight 200–250 g) and old (weight 300 g and more) we were investigated the changes in the volume rate of bile secretion with cyclooxygenase inhibition by acetylsalicylic acid (100 mkg/kg weight of animal) which is a blocker of the prostaglandin synthesis enzyme. We explored the changes of the level of choleresis and bile biochemical components by thin-layer chromatography In vivo. The relative abundances of cholecycle, henodeoxycholic, taurocholic and glycocholic bile acids in the liver of rats were determined by chromatography, with the subsequent densitometry. The biliary acid flow rate was calculated as the sum of the bile acid concentration multiplied by the volume of secreted biliary in one relevant thirty-minute sample. The conjugation coefficients were calculated for each thirty minute sample. Reduction of bile secretion by endogenous prostanoids was shown, because inhibition of prostaglandins synthesis caused the hypercholeresis on 42–112,5 % in different rat age groups, compared to control. Endogenous prostaglandins suppressed the processes of conjugation in old and juvenile age group on 117–189,1 %, in contrast these regulators have no significant effect on bile acids association with glycine and taurine in mature rats. The binding of endogenous prostanoids probably increased the conjugation processes in juvenile rats, whereas in the old experimental group acetylsalicylic acid was significantly reduced by 123 % on average. Analysis of changes in free and conjugated bile acids in the rats of different age groups showed that the ratio of qualitative changes in structure of the liver bile in rats with the cyclooxygenase blockade is mainly due to enhanced synthesis of free bile acids de novo. Therefore, endogenous prostanoids affect in the opposite way. There are have multi-directional impact on bile secretion in different age groups of rat that means ambiguous role of these drugs in liver function regulation at different stages of ontogenesis.

Experimental sepsis-associated encephalopathy is accompanied by altered cerebral blood perfusion and water diffusion and related to changes in cyclooxygenase-2 expression and glial cell morphology but not to blood-brain barrier breakdown

Sepsis-associated encephalopathy (SAE) refers to brain dysfunction, including delirium, occurs during severe infection and is associated with development of post-traumatic stress disorder. SAE has been proposed to be related to reduced cerebral blood flow (CBF), blood–brain barrier breakdown (BBB), white matter edema and disruption and glia cell activation, but their exact relationships remain to be determined. In the present work, we set out to study CBF using Arterial Spin Labeling (ASL) and grey and white matter structure with T2- and diffusion magnetic resonance imaging (dMRI) in rats with cecal ligation and puncture (CLP)-induced encephalopathy. Using immunohistochemistry, the distribution of the vasoactive prostaglandin-synthesizing enzyme cyclooxygenase-2 (COX-2), perivascular immunoglobulins G (IgG), aquaporin-4 (AQP4) and the morphology of glial cell were subsequently assessed in brains of the same animals. CLP induced deficits in the righting reflex and resulted in higher T2-weighted contrast intensities in the cortex, striatum and at the base of the brain, decreased blood perfusion distribution to the cortex and increased water diffusion parallel to the fibers of the corpus callosum compared to sham surgery. In addition, CLP reduced staining for microglia- and astrocytic-specific proteins in the corpus callosum, decreased neuronal COX-2 and AQP4 expression in the cortex while inducing perivascular COX-2 expression, but did not induce widespread perivascular IgG diffusion. In conclusion, our findings indicate that experimental SAE can occur in the absence of BBB breakdown and is accompanied by increased water diffusion anisotropy and altered glia cell morphology in brain white matter.

Pyrogenic and neuroinflammatory properties of zymosan and its potential as an alternative to live yeast in antipyretic drug testing

Zymosan, an immunogenic cell wall extract of Saccharomyces cerevisiae has potential for use as an experimental pyrogen. However, the short-lived sickness responses noted with intraperitoneal and intra-articular administration of zymosan limits investigations on the long-term effectiveness of antipyretic drugs. Thus, there remains a need to establish an alternative route of zymosan administration that could induce long-lived fevers and inflammation. We injected male Sprague Dawley rats (250–300 g) subcutaneously with zymosan (30 or 300 mg/kg) or saline; n = 7–8. We measured core body temperature, cage activity, food intake and body mass for 24 h after injection. Blood and brain samples were collected at 2, 8, and 18 h after injection. Zymosan (300 mg/kg) induced fever, lethargy, and anorexia, which lasted for 24 h. Zymosan-induced sickness responses were accompanied by increased blood plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α; activation of inflammatory transcription factors (nuclear factor (NF) for IL-6, signal transducer and activator of transcription (STAT)-3, and NF-κB) in the hypothalamus and circumventricular organs; and increased hypothalamic mRNA expression of TNF-α, IL-1β, and IL-6 and rate-limiting enzymes for prostaglandin synthesis. Our results confirm the suitability of subcutaneous administration of zymosan for screening antipyretic and anti-inflammatory drugs in rats.

Essential role of prostaglandin E2 and the EP3 receptor in lymphatic vessel development during zebrafish embryogenesis

Lymphatic endothelial cells arise from the venous endothelial cells in embryonic lymphatic development. However, the molecular mechanisms remain to be elucidated. We here report that prostaglandin (PG) E2 plays essential roles in the embryonic lymphatic development through the EP3 receptor, one of the PGE2 receptors. Knockdown of the EP3 receptor or inhibition of cyclooxygenases (COX; rate-limiting enzymes for PG synthesis) impaired lymphatic development by perturbing lymphatic specification during zebrafish development. These impairments by COX inhibition were recovered by treatment with sulprostone (EP1/3 agonist). Knockdown of the EP3 receptor further demonstrated its requirement in the expression of sex determining region Y-box 18 (sox18) and nuclear receptor subfamily 2, group F, member 2 (nr2f2), essential factors of the lymphatic specification. The EP3 receptor was expressed in the posterior cardinal vein (region of embryonic lymphatic development) and the adjacent intermediate cell mass (ICM) during the lymphatic specification. COX1 was expressed in the region more upstream of the posterior cardinal vein relative to the EP3 receptor, and the COX1-selective inhibitor impaired the lymphatic specification. On the other hand, two COX2 subtypes did not show distinct sites of expression around the region of expression of the EP3 receptor. Finally, we generated EP3-deficient zebrafish, which also showed defect in lymphatic specification and development. Thus, we demonstrated that COX1-derived PGE2-EP3 pathway is required for embryonic lymphatic development by upregulating the expression of key factors for the lymphatic specification.

Interleukin-1β and prostaglandin-synthesizing enzymes as modulators of human omental and subcutaneous adipose tissue function

IL-1β stimulates expression of prostaglandin (PG)-synthesizing enzymes cyclooxygenase (COX)-2 and aldo-keto reductase (AKR)1B1 in human preadipocytes. We aimed to examine the impact of IL-1β, COX-2 and AKR1B1 on markers of human visceral and subcutaneous adipose tissue function, and to assess whether PG synthesis by these enzymes mediates IL-1β effects. Omental and subcutaneous fat samples were obtained from bariatric surgery patients. PG release and expression of inflammatory and adipogenic markers were assessed in explants treated with COX-2 inhibitor NS-398 or AKR1B1 inhibitor Statil, with or without IL-1β. Preadipocyte differentiation experiments were also performed. IL-1β decreased expression of PPARγ in both fat depots compared to control and increased expression of NF-κB1, IL-6, CCL-5, ICAM-1 and VEGFA, especially in visceral fat for IL-6, CCL-5 and VEGFA. Adding Statil or NS-398 to IL-1β blunted PGF2α and PGE2 release, but did not alter IL-1β effects on adipose tissue function markers. IL-1β down-regulated adipocyte differentiation whereas NS-398 alone increased this process. However, NS-398 did not prevent IL-1β inhibition of adipogenesis. We conclude that IL-1β induces a pro-inflammatory response in human adipose tissues, particularly in visceral fat, and acts independently of concomitant PG release. IL-1β and COX-2 appear to be critical determinants of adipose tissue pathophysiologic remodeling in obesity.

Transgenic expression of cyclooxygenase-2 in pancreatic acinar cells induces chronic pancreatitis.

Replacement of the exocrine parenchyma by fibrous tissue is a main characteristic of chronic pancreatitis. Understanding the mechanisms of pancreatic fibrogenesis is critical for the development of preventive and therapeutic interventions. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin synthesis, is expressed in patients with chronic pancreatitis. However, it is unknown whether COX-2 can cause chronic pancreatitis. To investigate the roles of pancreatic acinar COX-2 in fibrogenesis and the development of chronic pancreatitis, COX-2 was ectopically expressed specifically in pancreatic acinar cells in transgenic mice. Histopathological changes and expression levels of several profibrogenic factors related to chronic pancreatitis were evaluated. COX-2 was expressed in the pancreas of the transgenic mice, as detected by Western blot analysis. Immunohistochemical staining showed COX-2 was specifically expressed in pancreatic acinar cells. COX-2 expression led to progressive changes in the pancreas, including pancreas megaly, persistent inflammation, collagen deposition, and acinar-to-ductal metaplasia. Quantitative RT-PCR and immunostaining showed that profibrogenic factors were upregulated and pancreatic stellate cells were activated in the COX-2 transgenic mice. Expression of COX-2 in pancreatic acinar cells is sufficient to induce chronic pancreatitis. Targeting this pathway may be valuable in the prevention of chronic pancreatitis. NEW & NOTEWORTHY COX-2 expression is observed in pancreatic tissues of human chronic pancreatitis. In this study, we showed that COX-2 expression caused the development of chronic pancreatitis in transgenic mice, supporting the idea that COX-2 inhibition may be an effective preventive and therapeutic strategy.

Endometrial transcripts of proinflammatory cytokine and enzymes in prostaglandin synthesis are upregulated in the bitches with atrophic pyometra

Inflammatory markers of endometrial origin are valuable in order to differentiate the pyometra from cystic endometrial hyperplasia in the bitch. In the present study, we hypothesized that histological categorization would distinguish the differential regulation of the proinflammatory genes in the endometrium of bitches with pyometra. Ovariohysterectomy was done on bitches with confirmatory diagnosis of pyometra (n = 18). Using endometrium to myometrium ratio of 0.79 as threshold, the uteri (n = 8/group) were categorized into hyperplastic pyometra (HP) and atrophic pyometra (AP). Two samples were excluded as the diagnosis was inconclusive. In parallel, endometrial tissue was collected for total RNA extraction to study the differential expression of TLR4, IL-6, IL-8, COX-2 and PGFS through real time PCR. Diestrus uterus of non-pyometra bitches (n = 6) served as control. The mean fold change (2−ΔΔCt) for the target genes was determined using β-actin as endogenous control and non-pyometra uterus as calibrator group. Except TLR4, other inflammatory genes were upregulated significantly by 1.82 to 3.74 times in the AP as compared to HP with maximum upregulation of COX-2 and PGFS. Further, correlation matrix with Spearman’s rho revealed that IL-8 had strong positive correlation with COX-2 and PGFS in the AP group (P < 0.05). It is concluded that histological grading of pyometra into HP and AP revealed differential regulation of inflammatory cytokines and enzymes in the PG synthetic pathway in the canine endometrium that has diagnostic potential under clinical settings.

Brewer’s yeast is a potent inducer of fever, sickness behavior and inflammation within the brain

Brewer’s yeast, derived from the yeast species Saccharomyces cerevisiae (S. cerevisiae), is commonly used for inducing pyrexia in pharmacological studies screening antipyretics in rats. Despite its widespread use, the peripheral and central inflammatory response associated with Brewer’s yeast-induced fever and sickness behavior in rats has not been investigated. Thus, we injected male Sprague-Dawley rats (150–200 g) subcutaneously with a high (4 g/kg, n = 9), medium (2 g/kg, n = 5) or low (0.4 g/kg, n = 6) dose of Brewer’s yeast solution or saline (0.9%, n = 6) and measured core body temperature, cage activity, food intake and body mass for six days after injection. Blood and brain samples were collected at 2, 8, 18 and 72 h after injection; n = 5–7 per time point. Brewer’s yeast administration dose-dependently induced fever, lethargy, anorexia and body mass stunting that was accompanied by increased blood plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α and activation of inflammatory transcription factors (nuclear factor (NF) for interleukin-6, signal transducer and activator of transcription (STAT)-3, and NF-κB)) in the hypothalamus and circumventricular organs. The increased activation of transcription factors following Brewer’s yeast administration was accompanied by increased hypothalamic mRNA expression of TNF-α, IL-1β and IL-6 and rate-limiting enzymes for prostaglandin synthesis. Our results show that subcutaneous administration of S. cerevisae induces prolonged fever, anorexia and lethargy that is accompanied by a pronounced increase in the synthesis of pro-inflammatory cytokines, key prostaglandin synthesizing enzymes and transcription factors, in the periphery and brain.

Autotaxin-lysophosphatidic acid-LPA3 signaling at the embryo-epithelial boundary controls decidualization pathways.

During pregnancy, up‐regulation of heparin‐binding (HB‐) EGF and cyclooxygenase‐2 (COX‐2) in the uterine epithelium contributes to decidualization, a series of uterine morphological changes required for placental formation and fetal development. Here, we report a key role for the lipid mediator lysophosphatidic acid (LPA) in decidualization, acting through its G‐protein‐coupled receptor LPA 3 in the uterine epithelium. Knockout of Lpar3 or inhibition of the LPA‐producing enzyme autotaxin (ATX) in pregnant mice leads to HB‐EGF and COX‐2 down‐regulation near embryos and attenuates decidual reactions. Conversely, selective pharmacological activation of LPA 3 induces decidualization via up‐regulation of HB‐EGF and COX‐2. ATX and its substrate lysophosphatidylcholine can be detected in the uterine epithelium and in pre‐implantation‐stage embryos, respectively. Our results indicate that ATX–LPA–LPA 3 signaling at the embryo‐epithelial boundary induces decidualization via the canonical HB‐EGF and COX‐2 pathways.

Prostaglandin synthesis enzymes' gene transcription in bitches with endometritis.

Endometritis is a major cause of infertility in many domestic species. However, until now the pathogenesis of the endometritis in the bitch is unclear. The aim of this study was to evaluate the gene transcription pattern of prostaglandin (PG) synthesis enzymes (cyclooxygenase [COX2], PTGES-1 and PGFS) in the endometrium of bitches with or without endometritis. Thirty mixed breed bitches in dioestrus, aged between 1 and 5years, and weighing between 10 and 30kg were used. After ovariohysterectomy (OVX), uterine biopsy samples were collected from the middle part of both horns. Then, endometrial epithelium was collected using the cytobrush method and mRNA analysis was performed by real-time RT-PCR. Data were analysed with Kruskal-Wallis anova using the sas® software. Uterine condition was identified by endometrial biopsies (normal endometria [n=11; NE], acute endometritis [n=10; AE] and chronic endometritis [n=9; CE]). The COX2, PTGES-1 and PGFS/AKR1C3 mRNA expression in bitches with and without endometritis was similar. Except for PGFS/AKR1C3, gene transcription of COX2 and PTGES-1 was significantly increased in AE compared with CE. In addition, COX2 gene transcription was significantly increased in AE compared with NE. In contrast, no differences were found for COX2, PTGES-1 and PGFS/AKR1C3 mRNA expression in the samples of NE compared with CE.

Immunohistochemical Expression of Cyclo-oxygenase 2 and Liver X Receptor-α in Acne Vulgaris.

Acne Vulgaris (AV) is a common inflammatory disease of pilosebaceous units. Liver X Receptor-α (LXR-α) is a ligand activated transcription factor. It controls transcription of genes involved in lipid and fatty acid synthesis. Cyclo-oxygenase 2 (COX2) is a rate limiting enzyme in prostaglandin synthesis. It plays important role in inflammation. To evaluate the immunohistochemical expression of LXR-α and COX2 in acne vulgaris skin biopsies to explore their possible pathogenic role in this disease. Sixty five subjects were included (45 cases with AV and 20 age and gender-matched healthy controls). Skin biopsies were taken from lesional and perilesional skin of cases and from site-matched areas of control subjects. The evaluation of LXR-α and COX2 was done using immunohistochemical technique. Data were collected, tabulated and statistically analysed using a personal computer with "(SPSS) version 11" program. Chi-square test was used to study the association between qualitative variables. Mann-Whitney test was used for comparison between quantitative variables. Student's t-test was used for comparison between two groups having quantitative variables. Spearman's coefficient was used to study the correlation between two different variables. Differences were considered statistically significant with p<0.05. COX2 was upregulated in lesional skin compared with peilesional and control skin both in epidermis and pilosebaceous units (p<0.001 for all). Higher epidermal COX2% was significantly associated with papulopustular acne (p=0.009) and higher acne score (p=0.018). Higher pilosebaceous units COX2% was significantly associated with papulopustular acne (p=0.04). LXR-α was upregulated in lesional skin compared with peilesional and control skin both in epidermis and pilosebaceous units (p<0.001 for all). Higher LXR-α % in epidermis and pilosebaceous units was significantly associated with papulopustular acne (p=0.01 for both) and higher acne score (p=0.03 for both). Significant positive correlation was detected between COX2% and LXR-α % in epidermis (p=0.001, r=0.87) and pilosebaceous units (p=0.001, r=0.65). Both LXR-α and COX-2 play a role in the pathogenesis of acne vulgaris through their effects on cellular proliferation, inflammation and lipid synthesis. Research for new therapeutic modalities based on their inhibition is needed. More understanding of the interaction between LXR-α, COX2 and acne lesions may lead to effective interference, possibly directed toward specific cell types or steps within inflammatory pathways.

Prostaglandin D2 signaling mediated by the CRTH2 receptor is involved in MK-801-induced cognitive dysfunction

Chemoattractant receptor-homologous molecule expressed on T helper type 2 cells (CRTH2), which is a second receptor for prostaglandin (PG) D2, is involved in inflammatory responses in peripheral tissue; however, its role in cognitive function remains unclear. Here, we demonstrate that CRTH2 is involved in cognitive function using a well-established animal model of cognitive dysfunction induced by MK-801, an N-methyl-d-aspartate receptor antagonist. Genetic deletion and pharmacological inhibition of CRTH2 suppressed MK-801-induced cognitive dysfunction. Pharmacological inhibition of cyclooxygenase-1, a rate-limiting enzyme in PG synthesis, also suppressed MK-801-induced cognitive dysfunction. Moreover, an MK-801-induced increase in c-Fos expression in the paraventricular nucleus (PVN) was abolished in the CRTH2-deficient mice. Together, these results suggest that PGD2-CRTH2 signaling is involved in both MK-801-induced cognitive dysfunction and neuronal activity regulation in the PVN. Furthermore, genetic association studies suggest that CRTH2 is weakly associated with cognitive function in humans. Our study provides evidence that PGD2-CRTH2 signaling is involved in cognitive function and may represent a potential therapeutic target for cognitive dysfunction in patients with psychiatric disorders.