Upregulation of Cyclooxygenase-2 (COX-2) and Microsomal Prostaglandin E
            2
            Synthase-1 (mPGES-1) in Wall of Ruptured Human Cerebral Aneurysms

Background: A high expression of prostaglandin E2 (PGE2) is found in colorectal cancer. Therefore, blocking of PGE2 generation has been identified as a promising approach for anticancer therapy. Sulforaphane (SFN), an isothiocyanate derived from glucosinolate, is used as the antioxidant and anticancer agents. Methods: HT-29 cells were treated with various concentrations of SFN and compared to untreated cells for the expression of microsomal prostaglandin E synthase-1 (mPGES-1), cyclooxygenase 2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-2 and MMP-9 at the mRNA level. The PGE2 level was measured by ELISA assay. Apoptosis was evaluated by the proportion of sub-G1 cells. The activity of caspase-3 was determined using an enzymatic assay. HT-29 cell migration was assessed using a scratch test. Results: SFN preconditioning decreased the expression of COX-2, mPGES-1, HIF-1, VEGF, CXCR4, MMP-2, and MMP-9. An apoptotic effect of SFN was preceded by the activation of caspase-3 as well as accumulation of cells in the sub-G1 phase of the cell cycle. SFN decreased PGE2 generation and inhibited the in vitro motility/wound-healing activity of HT-29 cells. Conclusions: SFN anticancer effects are associated with antiproliferative, antiangiogenic, and antimetastatic activities arising from the downregulation of the COX-2/ mPGES-1 axis.

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Despite Transcriptional and Functional Coordination, Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 Largely Reside in Distinct Lipid Microdomains in WISH Epithelial Cells

Journal of Histochemistry & Cytochemistry ◽

10.1369/jhc.5a6710.2005 ◽

2005 ◽

Vol 53 (11) ◽

pp. 1391-1401 ◽

Cited By ~ 9

Author(s):

William E. Ackerman IV ◽

John M. Robinson ◽

Douglas A. Kniss

Keyword(s):

High Resolution ◽

Epithelial Cells ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Potential Mechanism ◽

Prostaglandin E Synthase ◽

Lipid Microdomains ◽

Cox 2 ◽

Cytokine Stimulation ◽

Soluble Fractions

Cytokine-induced prostaglandin (PG)E2 synthesis requires increased expression of cyclooxygenase-2 (COX-2) in human WISH epithelial cells. Recently, an inducible downstream PGE synthase (microsomal PGE synthase-1, mPGES-1) has been implicated in this inflammatory pathway. We evaluated cooperation between COX-2 and mPGES-1 as a potential mechanism for induced PGE2 production in WISH cells. Cytokine stimulation led to increased expression of both enzymes. Selective pharmacological inhibition of these enzymes demonstrated that induced PGE2 release occurred through a dominant COX-2/mPGES-1 pathway. Unexpectedly, immunofluorescent microscopy revealed that the expression of these enzymes was not tightly coordinated among cells after cytokine challenge. Within cells expressing high levels of both mPGES-1 and COX-2, immunolabeling of high-resolution semithin cryosections revealed that COX-2 and mPGES-1 were largely segregated to distinct regions within continuous intracellular membranes. Using biochemical means, it was further revealed that the majority of mPGES-1 resided within detergent-insoluble membrane fractions, whereas COX-2 was found only in detergent-soluble fractions. We conclude that although mPGES-1 and COX-2 show transcriptional and functional coordination in cytokine-induced PGE2 synthesis, complementary morphological and biochemical data suggest that a majority of intracellular mPGES-1 and COX-2 are segregated to discrete lipid microdomains in WISH epithelial cells.

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ApoL1 renal risk variants induce aberrant THP-1 monocyte differentiation and increase eicosanoid production via enhanced expression of cyclooxygenase-2

AJP Renal Physiology ◽

10.1152/ajprenal.00254.2017 ◽

2018 ◽

Vol 315 (1) ◽

pp. F140-F150 ◽

Cited By ~ 9

Author(s):

Hewang Lee ◽

Hila Roshanravan ◽

Ying Wang ◽

Koji Okamoto ◽

Junghwa Ryu ◽

...

Keyword(s):

Gene Expression ◽

Specific Inhibitor ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Monocyte Differentiation ◽

Eicosanoid Production ◽

Gene And Protein Expression ◽

Cox 2 ◽

Tgf Β1

Apolipoprotein L1 ( ApoL1) genetic variants are strongly associated with kidney diseases. We investigated the role of ApoL1 variants in monocyte differentiation and eicosanoid production in macrophages, as activated tissue macrophages in kidney might contribute to kidney injury. In human monocyte THP-1 cells, transient overexpression of ApoL1 (G0, G1, G2) by transfection resulted in a 5- to 11-fold increase in CD14 and CD68 gene expression, similar to that seen with phorbol-12-myristate acetate treatment. All ApoL1 variants caused monocytes to differentiate into atypical M1 macrophages with marked increase in M1 markers CD80, TNF, IL1B, and IL6 and modest increase in the M2 marker CD163 compared with control cells. ApoL1-G1 transfection induced additional CD206 and TGFB1 expression, and ApoL1-G2 transfection induced additional CD204 and TGFB1 expression. Gene expression of prostaglandin E2 (PGE2) synthase and thromboxane synthase and both gene and protein expression of cyclooxygenase-2 (COX-2) were increased by ApoL1-G1 and -G2 variants compared with -G0 transfection. Higher levels of PGE2 and thromboxane B2, a stable metabolite of thromboxane A2, and transforming growth factor (TGF)-β1 were released into the supernatant of cultured THP-1 cells transfected with ApoL1-G1 and -G2, but not -G0. The increase in PGE2, thromboxane B2, and TGF-β1 was inhibited by COX-2-specific inhibitor CAY10404 but not by COX-1-specific inhibitor SC-560. These results demonstrate a novel role of ApoL1 variants in the regulation of monocyte differentiation and eicosanoid metabolism, which could modify the immune response and promote inflammatory signaling within the local targeted organs and tissues including the kidney.

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Defective Histone Acetylation Is Responsible for the Diminished Expression of Cyclooxygenase 2 in Idiopathic Pulmonary Fibrosis

Molecular and Cellular Biology ◽

10.1128/mcb.01776-08 ◽

2009 ◽

Vol 29 (15) ◽

pp. 4325-4339 ◽

Cited By ~ 122

Author(s):

William R. Coward ◽

Keiria Watts ◽

Carol A. Feghali-Bostwick ◽

Alan Knox ◽

Linhua Pang

Keyword(s):

Transcription Factor ◽

Idiopathic Pulmonary Fibrosis ◽

Pulmonary Fibrosis ◽

Hdac Inhibitors ◽

Histone H3 ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Mrna Levels ◽

Gene Assay ◽

Cox 2

ABSTRACT Diminished cyclooxygenase 2 (COX-2) expression in fibroblasts, with a resultant defect in the production of the antifibrotic mediator prostaglandin E2, plays a key role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Here, we have characterized the molecular mechanism. We found that COX-2 mRNA levels in fibroblasts from patients with IPF (F-IPF) were significantly lower than those in fibroblasts from nonfibrotic lungs (F-NL) after transforming growth factor β1 and interleukin-1β treatment but that COX-2 mRNA degradation rates were similar, suggesting defective transcription. A reporter gene assay showed that there were no clear differences between F-IPF and F-NL in transcription factor involvement and activation in COX-2 gene transcription. However, a chromatin immunoprecipitation assay revealed that transcription factor binding to the COX-2 promoter in F-IPF was reduced compared to that in F-NL, an effect that was dynamically linked to reduced histone H3 and H4 acetylation due to decreased recruitment of histone acetyltransferases (HATs) and increased recruitment of transcriptional corepressor complexes to the COX-2 promoter. The treatment of F-IPF with histone deacetylase (HDAC) inhibitors together with cytokines increased histone H3 and H4 acetylation. Both HDAC inhibitors and the overexpression of HATs restored cytokine-induced COX-2 mRNA and protein expression in F-IPF. The results demonstrate that epigenetic abnormality in the form of histone hypoacetylation is responsible for diminished COX-2 expression in IPF.

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Salmonella enterica Serovar Typhimurium Infection Induces Cyclooxygenase 2 Expression in Macrophages: Involvement of Salmonella Pathogenicity Island 2

Infection and Immunity ◽

10.1128/iai.72.12.6860-6869.2004 ◽

2004 ◽

Vol 72 (12) ◽

pp. 6860-6869 ◽

Cited By ~ 37

Author(s):

Kei-ichi Uchiya ◽

Toshiaki Nikai

Keyword(s):

Signaling Pathway ◽

Salmonella Enterica ◽

Signal Transduction Pathway ◽

Specific Inhibitor ◽

Pathogenicity Island ◽

Interleukin 10 ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Wild Type ◽

Cox 2

ABSTRACT Salmonella pathogenicity island 2 (SPI-2) is required for intramacrophage survival and systemic infection in mice. We have recently reported that Salmonella enterica causes activation of the protein kinase A (PKA) signaling pathway in a manner dependent on SPI-2, resulting in the upregulation of interleukin-10 expression in macrophages (K. Uchiya et al., Infect. Immun. 72:1964-1973, 2004). We show in the present study the involvement of SPI-2 in a signal transduction pathway that induces the expression of cyclooxygenase 2 (COX-2), an inducible enzyme involved in the synthesis of prostanoids. High levels of prostaglandin E2 (PGE2) and prostacyclin (PGI2), which are known to activate the PKA signaling pathway via their receptors, were induced in J774 macrophages infected with wild-type Salmonella compared to a strain carrying a mutation in the spiC gene, located within SPI-2. The increased production of both prostanoids was dependent on COX-2. COX-2 expression was dose dependently blocked by treatment with a specific inhibitor of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway, and the phosphorylation level of ERK1/2 was higher in macrophages infected with wild-type Salmonella compared to the spiC mutant. Taken together, these results indicate that Salmonella causes an SPI-2-dependent ERK1/2 activation that leads to increased COX-2 expression, resulting in the upregulation of PGE2 and PGI2 production in macrophages. A COX-2 inhibitor inhibited not only Salmonella-induced activation of the PKA signaling pathway but also growth of wild-type Salmonella within macrophages, suggesting that Salmonella utilizes the COX-2 pathway to survive within macrophages and that the mechanism involves activation of the PKA signaling pathway.

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Cigarette smoke induces cyclooxygenase-2 and microsomal prostaglandin E2 synthase in human lung fibroblasts: implications for lung inflammation and cancer

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00239.2003 ◽

2004 ◽

Vol 287 (5) ◽

pp. L981-L991 ◽

Cited By ~ 122

Author(s):

Christine A. Martey ◽

Stephen J. Pollock ◽

Chantal K. Turner ◽

Katherine M. A. O'Reilly ◽

Carolyn J. Baglole ◽

...

Keyword(s):

Cigarette Smoke ◽

Human Lung ◽

Cyclooxygenase 2 ◽

Lung Fibroblasts ◽

Normal Lung ◽

Prostaglandin E ◽

Human Lung Fibroblasts ◽

Eicosanoid Production ◽

Normal Human ◽

Cox 2

Cigarette smoking can lead to many human pathologies including cardiovascular and respiratory disease. Recent studies have defined a role for fibroblasts in the development of colon cancer. Moreover, fibroblasts are now thought of as key “sentinel” cells that initiate inflammation by releasing proinflammatory mediators including prostaglandins (PGs). Pathological overexpression of cyclooxygenase-2 (COX-2) and excess eicosanoid production are found in the early stages of carcinogenesis. By promoting chronic inflammation, COX-2 and eicosanoid production may actually cause a predisposition to malignancy. Furthermore, the associated inflammation induced by production of these mediators is central to the pathogenesis of chronic obstructive pulmonary disease. Little is known of the responses of normal lung fibroblasts to cigarette smoke, despite their abundance. We report herein that normal human lung fibroblasts, when exposed to cigarette smoke extract, induce COX-2 with concurrent synthesis of prostaglandin E2 (PGE2). The mechanisms by which cigarette-derived toxicants lead to increased COX-2 levels and PGE2 synthesis include increases in steady-state COX-2 mRNA levels (approximately four- to fivefold), phosphorylation of ERK1/2, and nuclear translocation of the p50 and p65 subunits of the transcription factor NF-κB, which are important elements in COX-2 expression. Furthermore, there was a dramatic 25-fold increase in microsomal prostaglandin E synthase, the key enzyme involved in the production of PGE2. We propose that normal human lung fibroblasts, when exposed to cigarette smoke constituents, elicit COX-2 expression with consequent prostaglandin synthesis, thus creating a proinflammatory environment. This chronic inflammatory state may act as one of the first steps towards epithelial transformation.

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Expressions of cyclooxygenase-2 (COX-2) and prostaglandin E receptors (EPs) in gallbladder carcinoma (GBca)-association with tumor progression

Gastroenterology ◽

10.1016/s0016-5085(08)82848-x ◽

2001 ◽

Vol 120 (5) ◽

pp. A573

Author(s):

Junichi Shoda ◽

Toru Asano ◽

Toru Kawamoto ◽

Yasushi Matsuzaki ◽

Naomi Tanaka ◽

...

Keyword(s):

Tumor Progression ◽

Gallbladder Carcinoma ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Cox 2

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Hepatitis C Virus Stimulates the Expression of Cyclooxygenase-2 via Oxidative Stress: Role of Prostaglandin E2 in RNA Replication

Journal of Virology ◽

10.1128/jvi.79.15.9725-9734.2005 ◽

2005 ◽

Vol 79 (15) ◽

pp. 9725-9734 ◽

Cited By ~ 107

Author(s):

Gulam Waris ◽

Aleem Siddiqui

Keyword(s):

Hepatocellular Carcinoma ◽

Hepatitis C Virus ◽

Hepatitis C ◽

Glycogen Synthase ◽

Rna Replication ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Pyrrolidine Dithiocarbamate ◽

Cox 2

ABSTRACT Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, which can lead to the development of liver cirrhosis and hepatocellular carcinoma. Recently, the activation of cyclooxygenase-2 (Cox-2) has been implicated in the HCV-associated hepatocellular carcinoma. In this study, we focus on the signaling pathway leading to Cox-2 activation induced by HCV gene expression. Here, we demonstrate that the HCV-induced reactive oxygen species and subsequent activation of NF-κB mediate the activation of Cox-2. The HCV-induced Cox-2 was sensitive to antioxidant (pyrrolidine dithiocarbamate), Ca2+ chelator (BAPTA-AM), and calpain inhibitor (N-acetyl-Leu-Leu-Met-H). The levels of prostaglandin E2 (PGE2), the product of Cox-2 activity, are increased in HCV-expressing cells. Furthermore, HCV-expressing cells treated with the inhibitors of Cox-2 (celecoxib and NS-398) showed significant reduction in PGE2 levels. We also observed the enhanced phosphorylation of Akt and its downstream substrates glycogen synthase kinase-3β and proapoptotic Bad in the HCV replicon-expressing cells. These phosphorylation events were sensitive to inhibitors of Cox-2 (celecoxib and NS-398) and phosphatidylinositol 3-kinase (LY294002). Our results also suggest a potential role of Cox-2 and PGE2 in HCV RNA replication. These studies provide insight into the mechanisms by which HCV induces intracellular events relevant to liver pathogenesis associated with viral infection.

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Fluid Secretion Caused by Aerolysin-Like Hemolysin of Aeromonas sobria in the Intestines Is Due to Stimulation of Production of Prostaglandin E2 via Cyclooxygenase 2 by Intestinal Cells

Infection and Immunity ◽

10.1128/iai.01098-07 ◽

2007 ◽

Vol 76 (3) ◽

pp. 1076-1082 ◽

Cited By ~ 2

Author(s):

Yoshio Fujii ◽

Ken Tsurumi ◽

Masaaki Sato ◽

Eizo Takahashi ◽

Keinosuke Okamoto

Keyword(s):

Intestinal Mucosa ◽

Fluid Secretion ◽

Cyclooxygenase 2 ◽

Prostaglandin E ◽

Camp Production ◽

Fluid Accumulation ◽

Protein Levels ◽

Aeromonas Sobria ◽

Cox 2 ◽

Cox 1

ABSTRACT To clarify the mechanisms of diarrheal disease induced by Aeromonas sobria, we examined whether prostaglandin E2 (PGE2) was involved in the intestinal secretory action of A. sobria hemolysin by use of a mouse intestinal loop model. The amount of PGE2 in jejunal fluid and the fluid accumulation ratio were directly related to the dose of hemolysin. The increase over time in the level of PGE2 was similar to that of the accumulated fluid. In addition, hemolysin-induced fluid secretion and PGE2 synthesis were inhibited by the selective cyclooxygenase 2 (COX-2) inhibitor NS-398 but not the COX-1 inhibitor SC-560. Western blot analysis revealed that hemolysin increased the COX-2 protein levels but reduced the COX-1 protein levels in mouse intestinal mucosa in vivo. These results suggest that PGE2 functions as an important mediator of diarrhea caused by hemolysin and that PGE2 is produced primarily through a COX-2-dependent mechanism. Subsequently, we examined the relationship between PGE2, cyclic AMP (cAMP), and cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channels in mouse intestinal mucosa exposed to hemolysin. Hemolysin increased the levels of cAMP in the intestinal mucosa. NS-398 inhibited the increase in cAMP production, but SC-560 did not. In addition, H-89, a cAMP-dependent protein kinase A (PKA) inhibitor, and glibenclamide, a CFTR inhibitor, inhibited fluid accumulation. Taken together, these results indicate that hemolysin activates PGE2 production via COX-2 and that PGE2 stimulates cAMP production. cAMP then activates PKA, which in turn stimulates CFTR Cl− channels and finally leads to fluid accumulation in the intestines.

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