Cyclooxygenase-2 Expression Research Articles

A Patent-Pending Ointment Containing Extracts of Five Different Plants Showed Antinociceptive and Anti-Inflammatory Mechanisms in Preclinical Studies.

Background/Objectives: The antinociceptive and anti-inflammatory effects of a patent-pending ointment containing plant extracts from Eucalyptus globulus, Curcuma longa, Hamamelis virginiana, Echinacea purpurea, and Zingiber officinale were evaluated. Methods: Plant extracts were chemically characterized by gas chromatography-mass spectroscopy. The antinociceptive activity of the ointment was assessed using the hot plate, tail flick, and formalin tests, whereas the anti-inflammatory activity was measured using the acute and chronic TPA-induced ear edema tests. Mechanisms of action were evaluated using inhibitors from signaling pathways related to pain response and by using histological analysis and assessing the expression and activity of pro-inflammatory mediators. Results: The ointment showed antinociceptive and anti-inflammatory effects like those observed with diclofenac gel (1.16% v/v) and ketoprofen gel (2.5% v/v). The antinociceptive actions of the ointment are mediated by the possible participation of the opiodergic system and the nitric oxide pathway. The anti-inflammatory response was characterized by a decrease in myeloperoxidase (MPO) activity and by a reduction in ear swelling and monocyte infiltration in the acute inflammation model. In the chronic model, the mechanism of action relied on a decrease in pro-inflammatory mediators such as COX-2, IL-1β, TNF-α, and MPO. An in-silico study with myristic acid, one of the compounds identified in the ointment's plant mixture, corroborated the in vivo results. Conclusions: The ointment showed antinociceptive activities mediated by the decrease in COX-2 and NO levels, and anti-inflammatory activity due to the reduction in IL-1β and TNFα levels, a reduction in MPO activity, and a decrease in NF-κB and COX-2 expression.

The m6A modification of ACSL4 mRNA sensitized esophageal squamous cell carcinoma to irradiation via accelerating ferroptosis.

Radioresistance is a major obstacle for the therapy of esophageal squamous cell carcinoma (ESCC) and lead to a poor prognosis. Ferroptosis is supposed to be responsible for radioresistance. However, the ferroptosis-induced radioresistance in ESCC and its related regulatory mechanisms are not yet fully understood. In this study, human ESCC cell line and the corresponding radioresistance cells were irradiated with 6 megavolts (MV) X-ray. It was showed that irradiation led to less ferroptosis in radioresistant ESCC cells as compared to the parental cells, as depicted by transmission electron microscopy, intracellular Fe2+ iron contents, lipid peroxidation, and expression of COX2. The increase of ASCL4 expression levels in radioresistant cells after radiotherapy was smaller than that in the parental cells. ACSL4 overexpression significantly enhanced ferroptosis. The fold increase in ACSL4 m6A modification in the radioresistant cells was significantly smaller than that in the parental cells as detected by methylated RNA immunoprecipitation with qRT-PCR. METTL14 overexpression accelerated ferroptosis induced by irradiation via upregulating m6A modification of ACSL4 mRNA. In conclusions, ferroptosis ablation was responsible for the radioresistant of ESCC. The METTL14-mediated m6A modification of ACSL4 mRNA sensitized ESCC to irradiation via accelerating ferroptosis. This study sheds new light on our understanding of radioresistant in ESCC, and provides potential strategies for ESCC radiotherapy.

Disruption of the PGE2 synthesis / response pathway restrains atherogenesis in programmed cell death-1 (Pd-1) deficient hyperlipidemic mice.

Immune checkpoint inhibitors (ICIs) that target programmed cell death 1 (PD-1) have revolutionized cancer treatment by enabling the restoration of suppressed T-cell cytotoxic responses. However, resistance to single-agent ICIs still limits their clinical utility. Combinatorial strategies enhance the antitumor effects, but may also enhance the risk of immune related adverse effects of ICIs. Prostaglandin (PG) E2, formed by the sequential action of the cyclooxygenase (COX) and microsomal PGE synthase (mPGES-1) enzymes, acting via its E prostanoid (EP) receptors, EPr2 and EPr4, promotes lymphocyte exhaustion, revealing an additional target for ICIs. Thus, COX inhibitors and EPr4 antagonists are currently being combined with ICIs potentially to enhance antitumor efficacy in clinical trials. However, given the cardiovascular (CV) toxicity of COX inhibitors, such combinations may increase the risk particularly of CV AEs. Here, we compared the impact of distinct approaches to disruption of the PGE2 synthesis /response pathway- global or myeloid cell specific depletion of mPges-1 or global depletion of Epr4- on the accelerated atherogenesis in Pd-1 deficient hyperlipidemic (Ldlr KO) mice. All strategies restrained the atherogenesis. While depletion of mPGES-1 suppresses PGE2 biosynthesis, reflected by its major urinary metabolite, PGE2 biosynthesis was increased in mice lacking EPr4, consistent with enhanced expression of aortic Cox-1 and mPges-1. Deletions of mPges-1 and Epr4 differed in their effects on immune cell populations in atherosclerotic plaques; the former reduced neutrophil infiltration, while the latter restrained macrophages and increased the infiltration of T-cells. Consistent with these findings, chemotaxis by bone-marrow derived macrophages from Epr4 KO mice as impaired. in Epr4 depletion also resulted in extramedullary lymphoid hematopoiesis and inhibition of lipoprotein lipase activity (LPL) with coincident spelenomegaly, leukocytosis and dyslipidemia. Targeting either mPGES-1 or EPr4 may restrain lymphocyte exhaustion while mitigating CV irAEs consequent to PD-1 blockade.

Eudesmane-like sesquiterpenoids from the roots of Anisodus tanguticus and their anti-inflammatory effects

Eleven eudesmane-like sesquiterpenoids including eight novel compounds (1–4 and 6–9) were isolated from the roots of Anisodus tanguticus. Interestingly, compound 1 belongs to an unprecedented sesquiterpenoid type which was named isoeudesmane-type. Compounds 6–10 were unusual 15-nor-eudesmanes. Their structures were elucidated by comprehensive spectroscopic techniques, including NMR, HR-ESI-MS, ECD, and NMR calculations. Compounds 1, 5, and 7–10 exhibited inhibitory effects against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages with IC50 values of 20.92, 21.98, 34.45, 10.56, 14.39, and 5.20 μM, respectively. Compound 9 showed a significant anti-inflammatory effect by reducing the secretion of TNF-α and IL-6, as well as the protein expression of iNOS and COX-2.

Erythropoietin Reduces Inflammation, Oxidative Stress, and Apoptosis in a Rat Model of Bleomycin-Induced Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a lethal interstitial disease with unknown etiology and no effective cure, posing a great health burden to society. Erythropoietin (EPO) has been demonstrated to have protective roles in various tissues such as brain, spinal cord, heart, kidney and lung tissues. In this study, we investigate the specific anti-inflammatory, antioxidant and antiapoptotic effects of erythropoietin on lung tissue in a bleomycin-induced rat model of idiopathic pulmonary fibrosis. Recombinant human EPO or saline was injected, and the animals were monitored for 14 days after bleomycin instillation. Their hematocrit and serum EPO levels were determined. Histological and immunohistochemical analyses were performed. The extent of tissue injury, determined through morphometric analysis, was significantly decreased in size in animals treated with erythropoietin. An immunohistochemical analysis of the expression of cyclooxygenase-2 (COX-2), inducible synthase of nitric oxide (i-NOS), metalloproteinase-9 (MMP-9), erythropoietin receptor (EPO-R), and cytochrome-C (cyt-C) found these enzymes to be decreased in a statistically significant manner in animals treated with erythropoietin when compared to a non-treated group. The reduced expression of COX-2, i-NOS, MMP-9, EPO-R, and i-NOS in the lung tissues of animals treated with EPO indicates the anti-inflammatory, antioxidant and antiapoptotic action of erythropoietin, suggesting its potential therapeutic role in pulmonary fibrosis.

Restoration of ARA metabolic disorders in vascular smooth muscle cells alleviates intimal hyperplasia

Intimal hyperplasia (IH) is an innegligible issue for patients undergoing interventional therapy. The proliferation and migration of vascular smooth muscle cells (VSMCs) induced by platelet-derived growth factor-BB (PDGF-BB) are critical events in the development of IH. While the exact mechanism and effective target for IH needs further investigation. Metabolic disorders of arachidonic acid (ARA) are involved in the occurrence and progression of various diseases. In this study, we found that the expressions of soluble epoxide hydrolase (sEH) and cyclooxygenase-2 (COX-2) were significantly increased in the VSMCs during balloon injury-induced IH. Then, we employed a COX-2/sEH dual inhibitor PTUPB to increase the concentration of epoxyeicosatrienoic acids (EETs) while prevent the release of pro-inflammatory prostaglandins. Results showed that PTUPB treatment significantly reduced neointimal thickening induced by balloon injury in rats in vivo and inhibited PDGF-BB-induced proliferation and migration of VSMCs in vitro. Our results showed that PTUPB may reverse the phenotypic transition of VSMCs by inhibiting Pttg1 expression. In conclusion, we found that the dysfunction of ARA metabolism in VSMCs contributes to IH, and the COX-2/sEH dual inhibitor PTUPB attenuates IH progression by reversing the phenotypic switch in VSMC through the Sirt1/Pttg1 pathway.

Novel Therapeutic Effects of Euphorbia heterophylla L. Methanol Extracts in Macular Degeneration Caused by Blue Light in A2E-Laden ARPE-19 Cells and Retina of BALB/c Mice.

Natural products with high antioxidant activity are considered as innovative prevention strategies to effectively prevent age-related macular degeneration (AMD) in the early stage because the generation of reactive oxygen species (ROS) leading to the development of drusen is reported as an important cause of this disease. To investigate the prevention effects of the methanol extracts of Euphorbia heterophylla L. (MEE) on AMD, its effects on the antioxidant activity, inflammatory response, apoptosis pathway, neovascularization, and retinal tissue degeneration were analyzed in N-retinylidene-N-retinylethanolamine (A2E)-landed spontaneously arising retinal pigment epithelia (ARPE)-19 cells and BALB/c mice after exposure to blue light (BL). The MEE contained 10 active components and showed high free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitric oxide (NO) radicals. The pretreatments of high-dose MEE remarkably suppressed the production of intracellular ROS (88.2%) and NO (25.2%) and enhanced (SOD) activity (84%) and the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) in A2E + BL-treated ARPE-19 cells compared to Vehicle-treated group. The activation of the inducible nitric oxide synthase (iNOS)-induced cyclooxygenase-2 (COX-2) mediated pathway, inflammasome activation, and expression of inflammatory cytokines was significantly inhibited in A2E + BL-treated ARPE-19 cells after the MEE pretreatment. The activation of the apoptosis pathway and increased expression of neovascular proteins (36% for matrix metalloproteinase (MMP)-9) were inhibited in the MEE pretreated groups compared to the Vehicle-treated group. Furthermore, the thickness of the whole retina (31%), outer nuclear layer (ONL), inner nuclear layer (INL), and photoreceptor layer (PL) were significantly increased by the MEE pretreatment of BALB/c mice with BL-induced retinal degeneration. Therefore, these results suggest that the MEE, with its high antioxidative activity, protects against BL-induced retinal degeneration through the regulation of the antioxidative system, inflammatory response, apoptosis, and neovascularization in the AMD mouse model.

Immunohistochemical Expression of Cyclooxygenase-2 in endometrioid carcinoma

Background and objectives: Cyclooxygenase-2 functions as an enzyme which synthesize prostaglandins from Arachidonic acid Cyclooxygenase -2 is one of the important factors in maintaining the endometrium during menstrual cycle. The Aim of this study was to assess expression of Cyclooxygenase-2 in endometrioid carcinoma by immunohistochemistry to explore association between Cyclooxygenase-2 expression and a certain number of clinicopathologic variables. Methods: A retrospective study was carried out for seventy-eight blocks that were preseved in formalin and embedded in paraffin of endometrioid carcinoma were obtained and randomly selected from a private laboratory in Erbil city during October 2020 to October 2022. COX-2 rabbit monoclonal antibody was used to satin slides obtained from endometrioid carcinoma blocks and the expression was scored by multiplying the number of stained cells by the intensity of staining. Results: Cyclooxygenase-2 expressed in 15.4% of cases of study cases. It is down-expressed in high grade endometrioid carcinoma while over-expressed in cases with myometrial invasion ?50%. Regarding other clinicopathological parameters like, lymphovascular invasion, tumor stage and lymphnode status, Cyclooxygenase-2 showing down-expression, there is no existence of notable link between the expression of Cyclooxygenase-2 and clinicopathological parameters, including: Age(p=0.197), Tumor grade(p=0.069), Myometrial invasion(p=0.261), Lympho vascular invasion(p=0.516), Lymph node status(p=1000) and Tumor stage(p=0.872). Conclusion: Cyclooxygenase-2 is expressed in a limited number of endometrioid carcinoma and there is lack of significant association between Cyclooxygenase-2 expression and clinicopathological parameters

Establishment of an Apical-Out Organoid Model for Directly Assessing the Function of Postbiotics.

In vitro organoids that mimic the physiological properties of in vivo organs based on threedimensional cell cultures overcome the limitations of two-dimensional culture systems. However, because the lumen of a typical intestinal organoid is internal, we used an apical-out intestinal organoid model in which the lumen that absorbs nutrients is outside to directly assess the function of postbiotics. A composite culture supernatant of Lactiplantibacillus plantarum KM2 and Bacillus velezensis KMU01 was used as a postbiotic treatment. Expression of COX-2 decreased in apical-out organoids co-treated with a lipopolysaccharide (LPS) and postbiotics. Expression of tight-junction markers such as ZO-1, claudin, and Occludin increased, and expression of mitochondrial homeostasis factors such as PINK1, parkin, and PGC1a also increased. As a result, small and large intestine organoids treated with postbiotics protected tight junctions from LPS-induced damage and maintained mitochondrial homeostasis through mitophagy and mitochondrial biogenesis. This suggests that an apical-out intestinal organoid model can confirm the function of food ingredients.

Integrated metabolomics and lipidomics investigation of the mechanism of Danggui Sini Decoction on improving lipid homeostasis in primary dysmenorrhea

BackgroundDanggui Sini Decoction (DGSND) is a classic prescription for treating primary dysmenorrhea (PD), while, the ameliorating effects of DGSND on PD and its mechanisms are not yet fully understood. PurposeThe present study is devoted to investigate the protective effect of DGSND against PD and the possible mechanism from the perspective of metabolomics as well as lipidomics. MethodsDGSND was characterized by UPLC-Q-TOF/MS. The PD rat model was induced by estradiol benzoate and oxytocin, and traditional pharmacology, including writhing times, latency time, biochemical index, organ index, and histopathology were performed to evaluated the efficacy of DGSND on PD. Urine metabolomics strategy combined with functional analysis was adopted to delineate the therapeutic effect of DGSND on PD rats and anchor the crucial pathway, and lipidomics analysis was further performed with the uterine tissue as the research object to elucidate the protective mechanism of DGSND from the perspective of lipid homeostasis. Finally, western blot analysis was used to validate the expression of key metabolic enzymes in lipid metabolism. ResultsDGSND was effective in ameliorating writhing times, latency time, the value of prostaglandin F2α (PGF2α)/PGE2, uterus index, and morphological changes of PD rats. Metabolic signature of PD rats was primarily characterized by the disturbance of steroid hormone metabolism, amino acid metabolism, and lipid metabolism. Functional analysis revealed the urine biomarkers of PD were most related with lipid abnormality. Further lipidomics analysis indicated DGSND exerted anti-PD effects by remodeling lipid homeostasis, which might be due to the significant correlations between different kinds of lipids, especially the extremely high correlation of phosphatidylethanolamine, phosphatidylcholine, and fatty acids. Moreover, the key metabolic enzymes expression of CK, PLA2, LPCAT3, COX-2, and 5-LOX can be greatly downregulated by DGSND. ConclusionOur findings demonstrated a novel protective mechanism of DGSND against PD by regulating lipid homeostasis.

Neuroprotection of isoorientin against microglia activation induced by lipopolysaccharide via regulating GSK3β, NF-κb and Nrf2/HO-1 pathways

Background: Isoorientin (ISO), a flavone C-glycoside, is a glycogen synthase kinase 3β (GSK3β) substrate-competitive inhibitor. ISO has potential in treatment of Alzheimer’s disease (AD). An excessive activation of GSK3β can lead to neuroinflammation causing neuronal damage. Microglia cells, as resident immune cells of the central nervous system, mediate neuroinflammation. Here, we studied the effects of ISO on microglial activation to alleviate neuroinflammation. Methods: Effects of ISO were observed upon the stimulation of mouse microglia BV2 or SIM-A9 cells by lipopolysaccharide (LPS). Lithium chloride (LiCl) was the positive control as a GSK3β inhibitor. The release of TNF-α and NO were analyzed by ELISA and Griess assays, while expressions of COX-2, Iba-1, BDNF, GSK3β, NF-κB p65, IκB, Nrf2 and HO-1 were detected by Western blotting. In the co-culture model of SIM-A9 cells and differentiated SH-SY5Y human neuroblastoma cells, effects of ISO on microglia-mediated neuronal damage were evaluated with the MTS assay. Results: ISO significantly inhibited the production of TNF-α (p < 0.01), NO (p < 0.001) and the expression of COX-2 (p < 0.01) and Iba-1 (p < 0.05) induced by LPS, and increased BDNF. The cell viability of SH-SY5Y was inhibited by LPS in the co-culture, which was prevented by ISO pretreatment. ISO increased the expression of p-GSK3β (Ser9), IκB and HO-1 in the cytoplasm, decreased NF-κB p65 and increased Nrf2 in the nucleus compared with the LPS group. Conclusion: ISO attenuated the activation of microglia through regulating the GSK3β, NF-κB and Nrf2/HO-1 signaling pathways to exert neuroprotection.

Tryptophan regulates the expression of IGFBP1 in bovine endometrial epithelial cells in vitro via the TDO2-AHR pathway

BackgroundThis study aimed to identify the roles of L-tryptophan (Trp) and its rate-limiting enzymes on the receptivity of bovine endometrial epithelial cells. Real-time PCR was conducted to analyze the differential expression of genes between different groups of bovine endometrial epithelial cells. Western blot was performed to detect Cyclooxygenase-2 (COX2) expression after treatment with Trp or kynurenine (the main metabolites of Trp). The kynurenine assay was used to examine if Trp or prostaglandin E2 (PGE2) can increase the production of kynurenine in the bovine endometrial epithelial cells.ResultsTrp significantly stimulates insulin growth factor binding protein 1 (IGFBP1) expression, a common endometrial marker of conceptus elongation and uterus receptivity for ruminants. When bovine endometrial epithelial cells are treated with Trp, tryptophan hydroxylase-1 remains unchanged, but tryptophan 2,3-dioxygenase 2 (TDO2) is significantly increased, suggesting tryptophan is mainly metabolized through the kynurenine pathway. Kynurenine significantly stimulates IGFBP1 expression. Furthermore, Trp and kynurenine significantly increase the expression of aryl hydrocarbon receptor (AHR). CH223191, an AHR inhibitor, abrogates the induction of Trp and kynurenine on IGFBP1. PGE2 significantly induces the expression of TDO2, AHR, and IGFBP1.ConclusionsThe regulation between Trp / kynurenine and PGE2 may be crucial for the receptivity of the bovine uterus.

Di(2-ethylhexyl) phthalate exposure aggravates hypoxia/reoxygenation injury in cerebral endothelial cells by downregulating epithelial cadherin expression.

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer that has adverse health effects. Most phthalates exhibit reproductive toxicity and are associated with diseases such as cardiovascular disorders. However, the effect of DEHP exposure on acute hypoxia/reperfusion injury remains unknown. Therefore, we assessed whether hypoxia/reperfusion injury is aggravated by exposure to DEHP and investigated plausible underlying mechanisms, including oxidative stress and expression of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and endothelial junctional proteins. bEnd.3 cells were exposed to DEHP and subsequently subjected to oxygen-glucose deprivation (OGD). Cell viability was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) proliferation assay. The effect of DEHP/OGD/reoxygenation (R) was evaluated by assessing the levels of NO, reactive oxygen species (ROS), and PGE2. The expression of COX-2, cleaved caspase-3, cleaved PARP, inducible nitric oxide synthase (iNOS), and the endothelial tight junction proteins claudin-5 and ZO-1 was evaluated using quantitative polymerase chain reaction and western blotting. OGD/R decreased cell viability, and DEHP exposure before OGD/R further aggravated cell viability. DEHP/OGD/R significantly increased NO, PGE2, and ROS production following OGD/R. In the DEHP/OGD/R group, iNOS, COX-2, cleaved caspase-3, and cleaved PARP expression increased, and claudin-5 and ZO-1 levels decreased compared with those in the OGD/R group. E-Cadherin expression decreased significantly after DEHP/OGD/R exposure compared with that after OGD/R; this decrease in expression was recovered by treatment with the COX-2 inhibitor indomethacin and antioxidant N-acetylcysteine. Exposure to DEHP exacerbated hypoxia-reoxygenation injury. The enhanced damage upon DEHP exposure was associated with increased oxidative stress and COX-2 expression, leading to E-cadherin downregulation and increased apoptosis.

Combination of network pharmacology, in vitro experiments and molecular dynamic simulations revealed anti-inflammatory molecular mechanism of the shrub Metapanax delavayi

The leaves of Metapanax delavayi shrub have been widely used in Chinese traditional diet to prepare tea-like beverages for alleviating inflammation. This study aimed to identify phytochemical components of M. delavayi leaf extract (MDE), and assess their anti-inflammation effects. The results showed that of the 101 compounds identified in the MDE, 96 were assessed as potentially anti-inflammatory based on network pharmacology analysis. The MAPK signaling pathway was surmised as the major anti-inflammatory pathway of action. The MDE enhanced the viability of the RAW264.7 cells, significantly inhibiting the overproduction of inflammatory factors (NO, IL-6, TNF-α, and PGE2), relative mRNA expression of TNF-α, iNOS, and COX-2, as well as several proteins (p-P38, p-ERK, p-JNK, iNOS, and COX-2) in lipopolysaccharide-induced RAW264.7 cells, meanwhile TGF-β1 production was increased. The key residues involved in binding to the top 10 leaf metabolites were Lys53, Thr179, Asp177, Glu147, and Pro174, in p-P38, p-ERK, p-JNK proteins. Molecular dynamic simulations demonstrated that predominantly three phosphorylated proteins formed stable and tightly bound complexes with certain metabolites of MDE.

Immune-mediated impairment of tonic immobility defensive behavior in an experimental model of colonic inflammation.

Ulcerative colitis has been associated with psychological distress and an aberrant immune response. The immunomodulatory role of systemic cytokines produced during experimental intestinal inflammation in tonic immobility (TI) defensive behavior remains unknown. The present study characterized the TI defensive behavior of guinea pigs subjected to colitis induction at the acute stage and after recovery from intestinal mucosa injury. Moreover, we investigated whether inflammatory mediators (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-10, and prostaglandins) act on the mesencephalic nucleus, periaqueductal gray matter (PAG). Colitis was induced in guinea pigs by intrarectal administration of acetic acid. The TI defensive behavior, histology, cytokine production, and expression of c-FOS, IBA-1, and cyclooxygenase (COX)-2 in PAG were evaluated. Colitis reduced the duration of TI episodes from the first day, persisting throughout the 7-day experimental period. Neuronal c-FOS immunoreactivity was augmented in both columns of the PAG (ventrolateral (vlPAG) and dorsal), but there were no changes in IBA-1 expression. Dexamethasone, infliximab, and parecoxib treatments increased the duration of TI episodes, suggesting a modulatory role of peripheral inflammatory mediators in this behavior. Immunoneutralization of TNF-α, IL-1β, and IL-8 in the vlPAG reversed all effects produced by colitis. In contrast, IL-10 neutralization further reduced the duration of TI episodes. Our results reveal that peripherally produced inflammatory mediators during colitis may modulate neuronal functioning in mesencephalic structures such as vlPAG.

739. SIGNIFICANCE OF COX2 INHIBITOR FOR ESOPHAGEAL CANCER FROM THE CLINICAL AND EXPERIMENTAL ESTIMATE

Abstract (Aims) We report experimental and clinical evidence that COX2 represent a potential molecular target for the treatment and prevention of esophageal cancer. (Methods) (A)Experiment: Thirty 8-week male wistar rats were exposed to duodenal content esophageal reflux. All animal underwent an esophagoduodenal anastomosis (EDA) with total gastrectomy in order to produce chronic esophagitis. In ten rats the sham (Control). They were sacrified at 40th week. Their esophagi were examined for HE, COX2,PGE2, PCNA and total bile acids in the esophageal lumen was measured. (B)Clinical: The expression of COX2 was examined for 68 specimens of esophageal squamous cell carcinoma (SCC) and the correlation of COX2 expression with clinicopatholigic features was examined. (Results) (A) After 40 weeks of reflux, columnar dysplasia, squamous cell carcinoma and adenocarcinoma were found. Total bile acid in the esophageal lumen was significantly increased in the EDA group compared with the sham operated rats. PCNA LI and esophageal tissue PGE2 were higher in dysplastic and cancer tissue than that of control. Overexpression of COX2 was shown in dysplastic and cancer tissue. COX2 may play an important role in esophageal cancer by duodenal content reflux.(B) COX2 immunoreactivity was weak in 27(40%) and strong in 41(60%) of the carcinomas. The proportion of poorly differentiated SCC among tumors with a strong expression of COX2 (34%) was significantly higher than among tumors with a weak expression of COX2 (19%, p=0.02). The depth of tumors (p=0.004), lymph node metastasis (p=0.0009) and the stage of the tumors (p=0.001) were advanced significantly more progressively in ECCS with a strong COX2 expression. Moreover, survival was significantly reduced (p=0.02) among patients with strong COX2 expression when compared with the COX2 weak group. This study showed that strong expression of COX2 was correlated with tumor progression and poor differentiation in ESCC. (Conclusion) In this experimental study, we demonstrate that bile reflux of duodenal contents induce COX2 and increase prostaglandin synthesis in dysplastic and cancer tissue. Our study suggests that COX2 may play a role in esophageal carcinoma development and progression, COX2 inhibitors may be potential targets for the prevention or treatment of esophageal carcinoma.

740. RABEPRAZOLE PROTECTS REFLUX ESOPHAGITIS DUE TO BILE IN RAT MODEL

Abstract Aims we studied the effect of proton pump inhibitor(PPI)(Rabeprazole) therapy on esophageal bile reflux in esophagitis after total gastrectomy. (Methodology) Sixteen 8-week old male Wistar rats were underwent total gastrectomy and esophagoduodenostomy to induce esophageal reflux of biliary and pancreatic juice. In 5 rats the sham operation induced a midline laparatomy alone (Sham). One week following surgery, they were treated with saline (Control) (n=8) PPI (Rabeprazole)(n=8)(30mg/kg/day) ip for 2 weeks. 3 weeks after operation, all rats were killed and the esophagus was evaluated histologically. Esophageal injury was evaluated by macroscopic, microscopic findings and expression of COX2 and PGE2. We performed the measurement of bile acid in the esophageal lumen and common bile duct. Results At 3 weeks after surgery, duodenal reflux induced esophageal erosions and ulcer formation. The macroscopic ulcer score and microscopic ulcer length were significantly reduced by PPI. The enhanced expression of COX2 and PGE2 in the control group was also markedly inhibited in the PPI group. Really, there is no difference between control group and PPI group in bile acid concentration from the common bile duct. PPI does not inhibit the secretion of bile acid from the common bile duct. But, the bile acid activity in the esophageal lumen was significantly increased in the control group, and this increase was significantly inhibited in the PPI group. Conclusion These results indicate that bile acid, which is inhibited by Rabeprazole, plays an important role in the mucosal damage induced by duodenal reflux.

741. EXPRESSION OF COX2 AND P53 IN RAT ESOPHAGEAL CANCER INDUCED BY REFLUX OF DUODENAL CONTENTS

Abstract Aim. Reflux of duodenal contents can induce mucosal injury, stimulate cell proliferation, and promote tumorigenesis. We examined the expression of COX2 and p53 in rat esophageal lesions induced by duodenal content reflux. Methods. Thirty 8-week-old male Wistar rats were exposed to duodenal content esophageal reflux. All animals underwent an esophagoduodenal anastomosis (EDA) with total gastrectomy in order to produce chronic esophagitis. Ten rats were the sham. Control. They were sacrificed at the 40th week. Their esophagi were examined for HE, COX2, p53, and proliferating cell nuclear antigen (PCNA). Results. After 40 weeks of reflux, dysplasia, squamous cell carcinoma (SCC), and adenocarcinoma (ADC) were found. PCNA labeling index was higher in dysplastic and cancer tissue than that in normal. Overexpression of COX2 was shown in ADC and SCC. Wild-type p53 accumulation was found in ADC, and not in SCC. Conclusion. Reflux of duodenal contents into the esophagus led to ADC and SCC in rats. COX2 may play an important role in esophageal cancer by duodenal content reflux. Our present results suggest an association between wild-type p53 accumulation and COX2 expression in ADC, with no such relation seen in SCC.

Abstract P430: Angiotensin-(1-7) Induces A Decrease In Proinflammatory Genes Expression Through A Mas Receptor-Mediated Translocation To Brainstem Nuclei Of Spontaneously Hypertensive Rats

Mas receptor (MasR) displays differential trafficking in brainstem neurons from spontaneously hypertensive rats (SHRs): the fraction of dynamin-mediated internalized MasRs into early endosomes was larger and the fraction of MasRs recycled back to the plasma membrane was smaller in SHR than in Wistar neurons. Surprisingly, in SHR neurons but not in Wistar neurons, Ang-(1-7) induced MasR translocation to the nucleus. Our aim was to investigate the biological response elicited by MasR in the nucleus and whether MasR translocation was due to interaction with other receptors. We evaluated: 1) nitric oxide (NO) generation by DAF (diaminofluorescein) fluorescence; 2) interleukin (IL) 6, IL-1β, cyclooxygenase 2 (COX2) and NFkB expression by real time PCR; and 3) MasR interaction with AT1R and the dopamine type 2 receptor (D2R) by proximity ligation assay in brainstem neuronal primary cultures from Wistar and SHR rats incubated in the presence or absence of Ang-(1-7) or Ang-(1-7) + dynasore (DYN) (dynamin inhibitor) or Ang-(1-7) + A779 (MasR antagonist) during 30 min. Ang-(1-7) (100 nM) induced a decrease in the pro-inflammatory factors IL-6, IL-1β, COX2 and NFkB expression in brainstem neurons from Wistar and SHR rats which was blocked by A779, suggesting a MasR-mediated response. The effect of Ang-(1-7) was prevented when MasR internalization was prevented by DYN only in SHRs neurons but not in Wistar neurons, suggesting that the effect of Ang-(1-7) in SHR neurons is mediated by MasR translocation to the nucleus. Treatment of neurons with Ang-(1-7) induced an increase in NO in the nucleus of SHR but not of Wistar neurons and this effect was prevented by DYN and A779, suggesting that the Ang-(1-7)-induced NO production in the nucleus was due to MasR translocation to this compartment. MasR stimulation with Ang-(1-7) induced an increase in MasR-D2R heteromerization in SHR but not in Wistar neurons, and no change in MasR-AT1R heteromerization. Ou study showed that MasR translocation to the nucleus resulted in a reduction in pro-inflammatory genes expression and an increase in NO generation in SHR neurons. A fraction of MasR was translocated through the interaction with D2Rs, suggesting that this heteomer may be involved in the anti-inflammatory responses elicited by Mas translocation to the nucleus.

Indomethacin inhibits human seasonal coronaviruses at late stages of viral replication in lung cells: Impact on virus-induced COX-2 expression

Coronaviruses (CoV), zoonotic viruses periodically emerging worldwide, represent a constant potential threat to humans. To date, seven human coronaviruses (HCoV) have been identified: HCoV-229E, HCoV-NL63, HCoV-OC43 and HCoV-HKU1, globally circulating in the human population (seasonal coronaviruses, sHCoV), and three highly-pathogenic coronaviruses, SARS-CoV, MERS-CoV and SARS-CoV-2. Although sHCoV generally cause only mild respiratory diseases, severe complications may occur in specific populations, highlighting the need for broad-spectrum anti-coronavirus drugs. Herein we show that indomethacin (INDO), a non-steroidal anti-inflammatory drug widely used in the clinic for its potent anti-inflammatory and analgesic properties, effectively inhibits the replication of Alpha-coronavirus HCoV-229E and Beta-coronavirus HCoV-OC43 in human lung-derived cells. Indomethacin does not interfere with HCoV binding or entry into target cells, but acts at late stages of the virus life cycle, inhibiting viral RNA synthesis and infectious viral particles production. Although INDO anti-inflammatory action is mediated by blocking cyclooxygenase-1 and -2 (COX-1/2) enzymatic activity, the antiviral effect appears to be cyclooxygenase-independent and is not mimicked by the potent COX-1/2 inhibitor aspirin. Interestingly we found that both seasonal HCoVs markedly (>100 fold) induce the expression of the pro-inflammatory mediator COX-2 in lung cells; notably, INDO-treatment was found to effectively inhibit virus-induced COX-2 expression at the transcriptional level, revealing an additional mechanism to prevent COX-2-mediated inflammatory reactions in HCoV-infected lung cells, besides COX activity inhibition. Altogether the results indicate that indomethacin, possessing both potent anti-inflammatory properties and a direct antiviral activity against HCoV, could be effective in the treatment of Alpha- and Beta-coronavirus infections.