scholarly journals Prostaglandin E and prostacyclin receptor expression in tumor and host tissues from MCG 101‐bearing mice: A model with prostanoid‐related cachexia

2005 ◽  
Vol 115 (4) ◽  
pp. 582-590 ◽  
Author(s):  
Wenhua Wang ◽  
Marianne Andersson ◽  
Christina Lõnnroth ◽  
Elisabeth Svanberg ◽  
Kent Lundholm
Keyword(s):  
Receptor Expression ◽  
Prostaglandin E ◽  
Prostacyclin Receptor ◽  
Host Tissues

p38 MAP kinase mediates mechanically induced COX-2 and PG EP4 receptor expression in podocytes: implications for the actin cytoskeleton

2004 ◽  
Vol 286 (4) ◽  
pp. F693-F701 ◽  
Author(s):  
Louis C. Martineau ◽  
Lyne I. McVeigh ◽  
Bernard J. Jasmin ◽  
Chris R. J. Kennedy
Keyword(s):  
Actin Cytoskeleton ◽  
Map Kinase ◽  
Mechanical Stress ◽  
P38 Map Kinase ◽  
Receptor Expression ◽  
Prostaglandin E ◽  
Glomerular Permeability ◽  
Ep4 Receptor ◽  
Filtration Barrier ◽  
Cox 2

A dynamic cytoskeleton allows podocytes to withstand significant mechanical stress on elevation of intraglomerular capillary pressure (Pgc). However, vasoactive hormones, such as prostaglandin E2 (PGE2), may challenge the integrity of the actin cytoskeleton, alter podocyte morphology, and compromise glomerular permeability. PGE2 synthesis correlates with the onset of proteinuria and increased Pgc following reduced nephron mass. We investigated the interplay among mechanical stress, cyclooxygenase (COX), E-prostanoid (EP) receptor expression, and the actin cytoskeleton, using an in vitro model of cell stretch. Immortalized mouse podocytes grown on flexible silicone membranes were cyclically stretched (5% elongation, 0.5 Hz) for 2 h. EP4 and COX-2 mRNA increased three- and sevenfold above nonstretched controls, whereas EP1 and COX-1 levels were unchanged. Six hours of stretch resulted in a threefold increase in PGE2-stimulated cAMP accumulation, a measure of EP4 receptor function, and an increase in COX-2 protein. The stretch-induced effects on COX-2/EP4 expression and EP4-induced cAMP production were attributable to p38 MAP kinase, as blockade of this pathway, but not of ERK or JNK, abrogated the response. These stretch-induced changes in expression were transcriptionally dependent as they were actinomycin D sensitive. Finally, we investigated the influence of enhanced EP4 signaling on the actin cytoskeleton. Addition of PGE2 resulted in actin filament depolymerization observable only in stretched cells. Our results indicate that key components of the eicosanoid pathway are upregulated by mechanically stimulated p38 MAP kinase in podocytes. Enhanced EP4 receptor signaling may undermine podocyte cytoskeletal dynamics and thereby compromise filtration barrier function under conditions of increased Pgc.

scholarly journals Renal prostaglandin E2 receptor (EP) expression profile is altered in streptozotocin and B6-Ins2Akita type I diabetic mice

2007 ◽  
Vol 292 (1) ◽  
pp. F278-F284 ◽  
Author(s):  
Rania Nasrallah ◽  
Huaqi Xiong ◽  
Richard L. Hébert
Keyword(s):  
Expression Profile ◽  
Receptor Expression ◽  
Prostaglandin E ◽  
Receptor Subtypes ◽  
Type I ◽  
Diabetic Mice ◽  
Diabetic Kidney ◽  
Urine Albumin ◽  
Ep Receptor ◽  
Prostaglandin E2 Receptor

The homeostatic function of prostaglandin E2 (PGE2) is dependent on a balance of EP receptor-mediated events. A disruption in this balance may contribute to the progression of renal injury. Although PGE2 excretion is elevated in diabetes, the expression of specific EP receptor subtypes has not been studied in the diabetic kidney. Therefore, the purpose of this study was to characterize the expression profile of four EP receptor subtypes (EP1-4) in 16-wk streptozotocin (STZ) and B6-Ins2Akita type I diabetic mice. In diabetic mice, the ratio of kidney weight to body weight was increased twofold compared with controls, blood glucose was elevated, but urine albumin was only increased in B6-Ins2Akita mice. The excretion of PGE2 and its metabolite was augmented two- to fourfold as determined by enzyme immunoassay. Accordingly, renal cyclooxygenases were also increased in diabetic mice, with isoform-specific and regional differences in each model. Finally, there was altered EP1-4 receptor expression in diabetic kidneys, with significant differences between STZ and B6-Ins2Akita mice (fold-control). In STZ mice, cortical EP1 increased by 1.6, EP3 increased by 2.3, and EP4 decreased by 0.63; yet in B6-Ins2Akita mice, cortical EP1 increased by 2.4, but there was a general decrease in the remaining subtypes. Similarly, in the STZ medulla EP3 increased by 3.6, but both EP1 and EP3 increased by 5.5 and 1.95, respectively, in B6-Ins2Akita mice. Therefore, knowing the pattern of change in relative EP receptor expression in the kidney could be useful in identifying specific EP targets for the prevention of various components of diabetic kidney disease.

Induction of prostacyclin receptor expression in human erythroleukemia cells

FEBS Letters ◽  
1989 ◽  
Vol 255 (1) ◽  
pp. 172-174 ◽  
Author(s):  
Rosemary Murray ◽  
Lucinda Furci ◽  
Garret A. FitzGerald
Keyword(s):  
Receptor Expression ◽  
Prostacyclin Receptor ◽  
Erythroleukemia Cells

scholarly journals Prostaglandin E and F Receptor Expression and Myometrial Sensitivity at Labor Onset in the Sheep1

2005 ◽  
Vol 72 (4) ◽  
pp. 937-943 ◽  
Author(s):  
Hannah K. Palliser ◽  
Jonathan J. Hirst ◽  
Guck T. Ooi ◽  
Gregory E. Rice ◽  
Nicole L. Dellios ◽  
...  
Keyword(s):  
Receptor Expression ◽  
Prostaglandin E ◽  
Labor Onset

scholarly journals Rhinovirus exposure impairs immune responses to bacterial products in human alveolar macrophages

Thorax ◽  
2008 ◽  
Vol 63 (6) ◽  
pp. 519-525 ◽  
Author(s):  
B G G Oliver ◽  
S Lim ◽  
P Wark ◽  
V Laza-Stanca ◽  
N King ◽  
...  
Keyword(s):  
Immune Responses ◽  
Alveolar Macrophages ◽  
Bacterial Infections ◽  
Lipoteichoic Acid ◽  
Receptor Expression ◽  
Chronic Obstructive ◽  
Prostaglandin E ◽  
Obstructive Pulmonary Disease ◽  
Human Alveolar Macrophages ◽  
Bacterial Products

Background:Rhinovirus infection is responsible for considerable morbidity and mortality as the major cause of exacerbations of asthma, and is also known to induce exacerbations of cystic fibrosis and chronic obstructive pulmonary disease. Exacerbations of these diseases are also frequently associated with bacterial and atypical bacterial infection. Alveolar macrophages are the major immune cells in the airways and are important in defence against bacterial infections.Methods:The authors investigated whether rhinovirus modifies cytokine release, the pattern recognition receptor expression and phagocytosis by human alveolar macrophages in response to bacterial products.Results:Viable rhinovirus was detected in macrophages up to 3 days after exposure and viral RNA expression persisted for 10 days. Infectious but not UV inactivated rhinovirus increased tumour necrosis factor α (TNFα) and interleukin (IL)8 release by macrophages. In contrast, infectious rhinovirus impaired lipopolysaccharide and lipoteichoic acid induced TNFα and IL8 secretion by macrophages. Rhinovirus induced impairment of macrophage antibacterial immune responses did not involve IL10, prostaglandin E2 or downregulation of Toll-like receptor 2. Furthermore, the macrophage phagocytic response to labelled bacterial particles, but not to latex beads, was impaired.Conclusion:The authors have identified impairment of cytokine responses to bacterial lipopolysaccharide and lipoteichoic acid by alveolar macrophages in response to infectious rhinovirus. Virus induced impairment of antibacterial host defence has important implications in the pathogenesis of exacerbations of respiratory diseases.

scholarly journals Prostacyclin signaling regulates circulating ghrelin during acute inflammation

2007 ◽  
Vol 196 (2) ◽  
pp. 263-273 ◽  
Author(s):  
Lisa D Madison ◽  
Jarrad M Scarlett ◽  
Peter Levasseur ◽  
XinXia Zhu ◽  
Kenneth Newcomb ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Acute Inflammation ◽  
Inflammatory Diseases ◽  
Second Messenger ◽  
Prostaglandin E ◽  
Amino Acid Peptide ◽  
Prostacyclin Receptor ◽  
Ghrelin Gene ◽  
Ghrelin Secretion

Ghrelin is an octanoylated 28 amino acid peptide predominantly secreted by the stomach, and has potent stimulatory effects on appetite. Several laboratories, including our own, have demonstrated that ghrelin levels fall in states of acute inflammation brought about by injection of bacterial lipopolysaccharide (LPS). We now demonstrate that the decrease in circulating ghrelin is not due to a decrease in ghrelin gene expression, but is instead likely to be due to an acute decrease in ghrelin secretion. Furthermore, we have found that the change in circulating ghrelin during acute inflammation required a prostaglandin second messenger, but did not require the synthesis of nitric oxide. Interestingly, i.v. injection of prostaglandin E2 failed to decrease circulating ghrelin levels, whereas prostacyclin decreased circulating ghrelin to a similar extent as did LPS. We also provide anatomical evidence for the mechanism of the regulation of ghrelin by inflammation. We demonstrate that the type 1 interleukin-1β (IL-1β) receptor is expressed within the gastric mucosa, but is not expressed by ghrelin cells. The prostacyclin receptor was also expressed in the gastric mucosa, and the majority of ghrelin-producing cells were found to co-express this receptor. Mice with genetic deletion of the type 1 IL-1 receptor do not suppress circulating ghrelin levels with LPS administration. Collectively, these data support a model in which the mechanism of inflammation induced decreases in ghrelin are due to the action of IL-1β on cells within the gastric mucosa that in turn produce prostacyclin as a second messenger. These data provide further support for the potential role of ghrelin as a therapeutic agent in acute and chronic inflammatory diseases.

scholarly journals Prostaglandin E-Prostanoid 4 Receptor Mediates Angiotensin II–Induced (Pro)Renin Receptor Expression in the Rat Renal Medulla

Hypertension ◽  
2014 ◽  
Vol 64 (2) ◽  
pp. 369-377 ◽  
Author(s):  
Fei Wang ◽  
Xiaohan Lu ◽  
Kexin Peng ◽  
Yaomin Du ◽  
Shu-Feng Zhou ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Renal Medulla ◽  
Receptor Expression ◽  
Prostaglandin E

Effect of COX-2 inhibitor NS-398 on expression of PGE2 receptor subtypes in M-1 mouse CCD cells

2001 ◽  
Vol 281 (1) ◽  
pp. F123-F132 ◽  
Author(s):  
Rania Nasrallah ◽  
Odette Laneuville ◽  
Shawn Ferguson ◽  
Richard L. Hébert
Keyword(s):  
Collecting Duct ◽  
Specific Inhibitor ◽  
Receptor Expression ◽  
Receptor Protein ◽  
Prostaglandin E ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
Camp Production ◽  
Protein Levels ◽  
Cox 2

Our present study has investigated the effect of cyclooxygenase-2 (COX-2) inhibition on prostaglandin E2 (PGE2) receptor expression in M-1 cortical collecting duct cells and measured their response to PGE2. Using a semiquantitative titration analysis method, we show that following the addition of the COX-2-specific inhibitor NS-398, E-prostanoid receptor subtype (EP3 and EP4) mRNA expression was found to increase threefold each vs. the vehicle-treated control. We also observed that EP1but not EP2 is expressed in M-1 cells and EP2levels are not induced by NS-398. To determine the status of the PGE2 response on exposure to NS-398, we measured cAMP levels in cells after stimulation with varying concentrations of PGE2, then pretreated the cells with 10 μM NS-398 before PGE2 exposure and found a significant rise in the stimulatory effect of PGE2 on cAMP production. Finally, Western blot analysis of the levels of the EP4 receptor protein in control vs. NS-398-treated cells revealed an induction in protein levels in these cells, correlating with the induction in EP4 mRNA. We conclude that NS-398 upregulates the expression of EP3 and EP4 mRNA in M-1 cells. Also, EP4 protein levels are increased, resulting in an increased stimulation of cAMP production by PGE2.

scholarly journals Prostaglandin E2 inhibits profibrotic function of human pulmonary fibroblasts by disrupting Ca2+ signaling

2019 ◽  
Vol 316 (5) ◽  
pp. L810-L821 ◽  
Author(s):  
Subhendu Mukherjee ◽  
Wei Sheng ◽  
Alexander Michkov ◽  
Krishna Sriarm ◽  
Rui Sun ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Phosphodiesterase Inhibitor ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Receptor Expression ◽  
Prostaglandin E ◽  
Receptor Subtypes ◽  
Pulmonary Fibroblasts ◽  
Stress Fiber Formation

We have shown that calcium (Ca2+) oscillations in human pulmonary fibroblasts (HPFs) contribute to profibrotic effects of transforming growth factor-β (TGF-β) and that disruption of these oscillations blunts features of pulmonary fibrosis. Prostaglandin E2 (PGE2) exerts antifibrotic effects in the lung, but the mechanisms for this action are not well defined. We thus sought to explore interactions between PGE2 and the profibrotic agent TGF-β in pulmonary fibroblasts (PFs) isolated from patients with or without idiopathic pulmonary fibrosis (IPF). PGE2 inhibited TGF-β-promoted [Ca2+] oscillations and prevented the activation of Akt and Ca2+/calmodulin-dependent protein kinase-II (CaMK-II) but did not prevent activation of Smad-2 or ERK. PGE2 also eliminated TGF-β-stimulated expression of collagen A1, fibronectin, and α-smooth muscle actin and reduced stress fiber formation in the HPFs. RNA sequencing revealed that HPFs preferentially express EP2 receptors relative to other prostanoid receptor subtypes: EP2 expression is ~10-fold higher than that of EP4 receptors; EP1 and EP3 receptors are barely detectable; and EP2-receptor expression is ~3.5-fold lower in PFs from IPF patients than in normal HPFs. The inhibitory effects of PGE2 on synthetic function and stress fiber formation were blocked by selective EP2 or EP4 antagonists and mimicked by selective EP2 or EP4 agonists, the phosphodiesterase inhibitor isobutylmethylxanthine and forskolin, all of which elevate cellular cAMP concentrations. We conclude that PGE2, likely predominantly via EP2 receptors, interferes with Ca2+ signaling, CaMK-II activation, and Akt activation in IPF-HPFs and HPFs treated with TGF-β. Moreover, a decreased expression of EP2 receptors in pulmonary fibroblasts from IPF patients may contribute to the pathophysiology of this disease.

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